Evaluation Of Prosthetic Valve Function Research Articles

Abstract 12934: Valve, Ventricle, Vessel or Virus: Who is the Shocking Culprit?

Introduction: Determining the etiology of dyspnea in patients with structural heart disease can be challenging, especially in the current era with high prevalence of COVID-19. Our case highlights the importance of evaluating bioprosthetic valve function in the setting of a change in clinical status. Case: An 82 year old female with surgical coronary revascularization and bioprosthetic aortic valve replacement in 2003 presented with dyspnea. Her evaluation revealed hypoxemia, leukocytosis and a chest x-ray supportive of viral infection when the local prevalence of both COVID-19 and influenza were at their peak. She was admitted to the intensive care unit with impending respiratory failure most likely from an infectious etiology. Echocardiogram revealed an ejection fraction (EF) of 25% and severe prosthetic aortic regurgitation with a pressure half time of 117ms ( Figure ). Six months prior, she had normal EF and normal prosthetic valve function. Interestingly, she lacked a wide pulse pressure, murmur of aortic insufficiency, and other characteristic exam findings of valvular dysfunction. The patient rapidly deteriorated into cardiogenic shock. Following urgent evaluation for transcatheter aortic valve replacement, she had successful valve-in-valve deployment of a 23mm Edwards S3 Ultra valve. Her hemodynamic parameters improved immediately and she was weaned from inotropic support 1 day following valve replacement. Conclusions: Evaluation of prosthetic valve function is integral when a patient’s clinical condition changes. In our patient, depressed EF resulting in an elevated left ventricular end-diastolic pressure likely diminished the regurgitant fraction and the expected aortic insufficiency murmur. Periodic evaluation of prosthetic heart valve function is necessary, particularly when the patient’s clinical condition changes. Acute severe aortic regurgitation with cardiogenic shock is fatal without rapid evaluation and valve replacement.

Cine-Computed Tomography for the Evaluation of Prosthetic Heart Valve Function

Background: After aortic valve replacement (AVR), suspected prosthetic valve dysfunction (mechanical or biological) may arise based on echocardiographic transvalvular velocities and gradients, leading to reoperative surgical intervention being considered. Our experience has found that 4-dimensional (space and time) image reconstruction of ECG-gated computed tomography, termed cine-CT, may be helpful in such cases. We review and illustrate our experience. Methods: Twenty-seven AVR patients operated previously by a single surgeon (who performs >100 AVRs/year) were referred for repeat evaluation of suspected aortic stenosis (AS) based on elevated transvalvular velocities and gradients. The patients were fully evaluated by cine-CT. Results: In all but 2 cases, the cine-CT strikingly and visually confirmed normal leaflet function and excursion, with no valve thrombosis, restriction by pannus, or obstruction by clot. In only 2 cases did cine-CT reveal decreased mechanical valve leaflet excursion. Repeat surgery was required in only 1 case while all other patients continued clinically without cardiac events. Conclusions: Echocardiography is an extraordinarily useful tool for the evaluation of prosthetic valve function. Increased pressure recovery beyond the valve and other factors may occasionally lead to exaggerated gradients. Cine-CT is emerging as an extremely valuable tool for further evaluation of suspected prosthetic valve AS. Our experience has been extremely helpful, as is shown in the dramatically reassuring images.

Inverted Aortic Prosthesis in the Mitral Position: Is Upside Down Always the Right Side Up?

Evaluation of prosthetic valve function is a challenging task. The clinician has to employ multiple parameters to quantify dysfunction (if present), the results of which can be mutually discrepant. This results from heterogeneity in the design of the valves themselves, implantation techniques, and both intra- and interpatient hemodynamic variability. Specifically, the location and angle of valve implantation can have a profound impact on its flow characteristics that can lead to symptoms despite satisfactory mechanical function. The authors present the case of inverted implantation of a prosthesis designed for the aortic position in the mitral annulus and resultant mitral stenosis. What follows is an examination of how the flow characteristics, such as pressure recovery, energy loss, and vortex formation, create a gradient that could not be explained by valve size alone.

Multi-institutional evaluation of the indications and radiation dose of functional cardiovascular computed tomography (CCT) imaging in congenital heart disease.

Ventricular volumes and ejection fraction are often used in clinical decision making in patients with congenital heart disease (CHD). The referral diagnosis, radiation exposure and image quality of functional cardiac computed tomography (CT) in a relatively large cohort of patients of CHD has not been reported. This is a retrospective evaluation of functional CT studies performed in CHD patients from three institutions (1/2007–3/2013). Patient and scanner characteristics, radiation dose estimates and image quality were compared. Two hundred ninety-eight functional CT studies were evaluated. The most common referral diagnosis were tetralogy of Fallot (33 %), transposition complexes(24 %) single ventricle heart disease (15 %), and left sided obstruction (15 %). The reason for cardiac CT was presence of pacemaker (60 %), need for detailed coronary artery imaging (18 %), metallic artifact inC MR(12 %), evaluation of prosthetic valve function (4 %), and claustrophobia or BMI too large for the available MR scanner (6 %). 266(89.3 %) scans allowed quantification of ventricular function,25 (8.4 %) scans allowed qualitative assessment of function, and 7 (2.3 %) of the scans were non-diagnostic for functional analysis. Median DLP was 399 mGy cm (186,614), and median effective dose was 5.5 mSv (2.6, 8.5).Radiation dose and image quality varied across institutions.Cardiac CT function imaging can be performed in patients with congenital heart disease when CMR is contraindicated or has poor image quality. Radiation dose and image quality varies across institutions.

Multi-institutional evaluation of the indications and radiation dose of functional cardiovascular computed tomography (CCT) imaging in congenital heart disease.

Ventricular volumes and ejection fraction are often used in clinical decision making in patients with congenital heart disease (CHD). The referral diagnosis, radiation exposure and image quality of functional cardiac computed tomography (CT) in a relatively large cohort of patients of CHD has not been reported. This is a retrospective evaluation of functional CT studies performed in CHD patients from three institutions (1/2007-3/2013). Patient and scanner characteristics, radiation dose estimates and image quality were compared. Two hundred ninety-eight functional CT studies were evaluated. The most common referral diagnosis were tetralogy of Fallot (33%), transposition complexes (24%) single ventricle heart disease (15%), and left sided obstruction (15%). The reason for cardiac CT was presence of pacemaker (60%), need for detailed coronary artery imaging (18%), metallic artifact in CMR (12%), evaluation of prosthetic valve function (4%), and claustrophobia or BMI too large for the available MR scanner (6%). 266 (89.3%) scans allowed quantification of ventricular function, 25 (8.4%) scans allowed qualitative assessment of function, and 7 (2.3%) of the scans were non-diagnostic for functional analysis. Median DLP was 399mGycm (186, 614), and median effective dose was 5.5mSv (2.6, 8.5). Radiation dose and image quality varied across institutions. Cardiac CT function imaging can be performed in patients with congenital heart disease when CMR is contraindicated or has poor image quality. Radiation dose and image quality varies across institutions.

Increased prosthetic valve gradients: Abnormal prosthetic function or pressure recovery?

The non-invasive evaluation of prosthetic valve function is challenging. The effects of flow rate, valvular geometry, leaflet motion, and pressure recovery all impact the Doppler assessment of prosthetic performance. Differentiating prosthesis obstruction from pressure recovery in patients who are found to have high Doppler velocities across an aortic valve prosthesis is critical in order to direct appropriate management. In this manuscript, we present two cases of patients with aortic valve prosthesis with high Doppler velocities and review the pathophysiology and evaluation of prosthesis function.

Evaluation of Prosthetic Valve Function by Platelet Function Analysis and Von Willebrand Factor Indices

AbstractAbstract 1128 BackgroundDysfunctional or mismatched prosthetic heart valves can results in high shear stress related von Willebrand factor (VWF) impairment, and clinical bleeding. This mechanism is similar to that seen in aortic stenosis patients, where gastrointestinal bleeding related to VWF multimer loss is well described (Heyde syndrome). In this study, we compared the results of VWF testing of patients with normally functioning cardiac valve prostheses, dysfunctional prosthetic valves, severe native aortic stenosis, and normal controls. MethodsA total of 75 patients, 31 female and 44 male with a median age of 79.5 years were recruited to this study. Thirty patients had severe aortic stenosis (mean gradient > 40 mm Hg); 39 patients had normally functioning prosthetic valves, 21 aortic (AVR) and 18 mitral valves (MVR); and 6 patients had with dysfunctional valves (4 aortic and 2 mitral). Whole blood and plasma samples were drawn from patients and tested for platelet function analyzer-100 collagen ADP closure time (PFA-CADP), VWF antigen (VWF:Ag), VWF activity by latex immunoassay (VWF:Ltx), VWF multimer analysis and VWF multimer densitometry ratio of large vs medium to low molecular weight multimers (>15 mers/2–15 mers). ResultsThe 6 dysfunctional prosthetic valve patients included patient-prosthesis mismatch (2) and (one each), thrombosed mechanical aortic prosthesis, torn biological aortic prosthesis, severe tissue mitral prosthetic regurgitation, and post-mitral valve repair severe mitral regurgitation. Four of six patients had clinically significant bleeding. Most aortic stenosis and all 6 prosthetic dysfunction patients had abnormal VWF multimers which is rare in normally functioning prostheses and completely absent in normal donors. VWF:Ltx/Ag was lower in AS and MVR than normal. VWF:Ltx/Ag ratio, VWF:multimer ratio and PFA-CADP were all significantly abnormal in patients with dysfunctional prosthetic valve. VWF:multimer ratios in normally functioning prostheses tended to be intermediate between normals and than those of patients with severe AS or prosthetic valve dysfunction (Table).TableNormalsProsthetic DysfunctionAVRMVRSevere ASAbnormal VWF multimers0/216/62/211/1826/30Multimer ratio >15/2–15 mers0.24 ± 0.050.13 ± 0.01*,†0.17 ± 0.02*0.19 ± 0.04*0.13 ± 0.03*,†PFA-100 CADP89 ± 16141 ± 36*,†98 ± 2993 ± 31181 ± 69*,†Ltx/Ag0.96 ± 0.110.71 ± 0.06*,†0.93 ± 0.09‡0.87 ± 0.05*0.87 ± 0.16*,†*p<0.001 vs normals. † p<0.001 vs AVR+MVR. cm=NS vs normal, but p<0.02 vs mitral valve replacement. ConclusionsVWF testing including quantitative von Willebrand multimer analysis and PFA-CADP reliably separate dysfunctional from normally functioning cardiac prostheses, and should be considered in the evaluation of patients with cardiac prostheses, especially those who have clinically significant bleeding. Disclosures:No relevant conflicts of interest to declare.

Usefulness of Live/Real Time Three‐Dimensional Transthoracic Echocardiography in Evaluation of Prosthetic Valve Function

We studied 31 patients with prosthetic valves (PVs) using two-dimensional and three-dimensional transthorathic echocardiography (2DTTE and 3DTTE, respectively) in order to determine whether 3DTTE provides an incremental value on top of 2DTTE in the evaluation of these patients. With 3DTTE both leaflets of the St. Jude mechanical PV can be visualized simultaneously, thereby increasing the diagnostic confidence in excluding valvular abnormalities and overcoming the well-known limitations of 2DTTE in the examination of PVs, which heavily relies on Doppler. Three-dimensional transthorathic echocardiography provides a more comprehensive evaluation of PV regurgitation than 2DTTE with its ability to more precisely quantify PV regurgitation, in determining the mechanism causing regurgitation, and in localizing the regurgitant defect. Furthermore, 3DTTE is superior in identifying, quantifying, and localizing PV thrombi and vegetations, in addition to the unique feature of providing a look inside mass lesions by serial sectioning. These preliminary results suggest the superiority of 3DTTE over 2DTTE in the evaluation of PVs and that it provides incremental knowledge to the echocardiographer.

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound: A Report From the American Society of Echocardiography's Guidelines and Standards Committee and the Task Force on Prosthetic Valves, Developed in Conjunction With the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association, the European Association of Echocardiography, a registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography and the Canadian Society of Echocardiography, Endorsed by the American College of Cardiology Foundation, American Heart Association, European Association of Echocardiography, a registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography, and Canadian Society of Echocardiography

Accreditation Statement:The American Society of Echocardiography is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The ASE designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit™. Physicians should only claim credit commensurate with the extent of their participation in the activity.The American Registry of Diagnostic Medical Sonographers and Cardiovascular Credentialing International recognize the ASE's certificates and have agreed to honor the credit hours toward their registry requirements for sonographers.The ASE is committed to ensuring that its educational mission and all sponsored educational programs are not influenced by the special interests of any corporation or individual, and its mandate is to retain only those authors whose financial interests can be effectively resolved to maintain the goals and educational integrity of the activity. Although a monetary or professional affiliation with a corporation does not necessarily influence an author's presentation, the essential areas and policies of the ACCME require that any relationships that could possibly conflict with the educational value of an activity be resolved prior to publication and disclosed to the audience. Disclosures of faculty and commercial support relationships, if any, have been indicated.Target Audience:This activity is designed for all cardiovascular physicians and cardiac sonographers with a primary interest and knowledge base in the field of echocardiography. In addition, residents, researchers, clinicians, intensivists, and other medical professionals with specific interest in cardiac ultrasound will find this activity beneficial.Objectives:Upon completing this article, participants will be better able to:1.Name the components of a complete imaging and Doppler evaluation for prosthetic valve function.2.Identify the components of an integrative approach to assessing prosthetic aortic and mitral valve stenosis and regurgitation.3.Identify the components of an integrative approach to assessing prosthetic pulmonary and tricuspid valve stenosis and regurgitation.4.Describe the pitfalls and limitations of the evaluation of prosthetic valve function.5.Recognize the special aspects of the pediatric population that add complexity to the evaluation of prosthetic valve function.Author Disclosures:Elyse Foster receives research and grant support from Evalve (Menlo Park, CA), Boston Scientific Corporation (Natick, MA), and Evidence Based Research, Inc (Vienna, VA). Paul A. Grayburn is the Associate Editor of the American Journal of Cardiology and receives research support from the National Institutes of Health (Bethesda, MD), Evalve (Menlo Park, CA), GE (Milwaukee, WI), and Amersham (Amersham, UK). Harry Rakowski chairs the Data Safety Monitoring Board for Medtronic, Inc (Minneapolis, MN). Neil J. Weissman receives research/grant support from ATS Medical, Inc (Minneapolis, MN), Sorin/Carbomedics (Milan, Italy), Edwards Lifesciences (Irvine, CA), St Jude Medical (St Paul, MN), MitralSolutions, Inc (Fort Lauderdale, FL), Arbor Surgical Technologies (Sunnyvale, CA), Evalve (Menlo Park, CA) Mitralign, Inc (Tewksbury, MA), Medispec (Germantown, MD), and Direct Flow Medical, Inc (Santa Rosa, CA).William A. Zoghbi, John B. Chambers, Jean G. Dumesnil, John S. Gottdiener, Bijoy K. Khandheria, Robert A. Levine, Gerald Ross Marx, Fletcher A. Miller, Jr, Satoshi Nakatani, Miguel A. Quiñones, L. Leonardo Rodriguez, Madhav Swaminathan, Alan D. Waggoner, and Miguel Zabalgoitia all reported that they have no actual or potential conflicts of interest in relation to this program.Conflict of Interest:This activity has been peer reviewed by a nonbiased member of the ASE ACCME/CME committee. No indication of an actual or potential bias in relation to the author disclosures was determined.Estimated Time to Complete This Activity: 1hour The American Society of Echocardiography is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The ASE designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit™. Physicians should only claim credit commensurate with the extent of their participation in the activity. The American Registry of Diagnostic Medical Sonographers and Cardiovascular Credentialing International recognize the ASE's certificates and have agreed to honor the credit hours toward their registry requirements for sonographers. The ASE is committed to ensuring that its educational mission and all sponsored educational programs are not influenced by the special interests of any corporation or individual, and its mandate is to retain only those authors whose financial interests can be effectively resolved to maintain the goals and educational integrity of the activity. Although a monetary or professional affiliation with a corporation does not necessarily influence an author's presentation, the essential areas and policies of the ACCME require that any relationships that could possibly conflict with the educational value of an activity be resolved prior to publication and disclosed to the audience. Disclosures of faculty and commercial support relationships, if any, have been indicated. This activity is designed for all cardiovascular physicians and cardiac sonographers with a primary interest and knowledge base in the field of echocardiography. In addition, residents, researchers, clinicians, intensivists, and other medical professionals with specific interest in cardiac ultrasound will find this activity beneficial. Upon completing this article, participants will be better able to:1.Name the components of a complete imaging and Doppler evaluation for prosthetic valve function.2.Identify the components of an integrative approach to assessing prosthetic aortic and mitral valve stenosis and regurgitation.3.Identify the components of an integrative approach to assessing prosthetic pulmonary and tricuspid valve stenosis and regurgitation.4.Describe the pitfalls and limitations of the evaluation of prosthetic valve function.5.Recognize the special aspects of the pediatric population that add complexity to the evaluation of prosthetic valve function. Elyse Foster receives research and grant support from Evalve (Menlo Park, CA), Boston Scientific Corporation (Natick, MA), and Evidence Based Research, Inc (Vienna, VA). Paul A. Grayburn is the Associate Editor of the American Journal of Cardiology and receives research support from the National Institutes of Health (Bethesda, MD), Evalve (Menlo Park, CA), GE (Milwaukee, WI), and Amersham (Amersham, UK). Harry Rakowski chairs the Data Safety Monitoring Board for Medtronic, Inc (Minneapolis, MN). Neil J. Weissman receives research/grant support from ATS Medical, Inc (Minneapolis, MN), Sorin/Carbomedics (Milan, Italy), Edwards Lifesciences (Irvine, CA), St Jude Medical (St Paul, MN), MitralSolutions, Inc (Fort Lauderdale, FL), Arbor Surgical Technologies (Sunnyvale, CA), Evalve (Menlo Park, CA) Mitralign, Inc (Tewksbury, MA), Medispec (Germantown, MD), and Direct Flow Medical, Inc (Santa Rosa, CA). William A. Zoghbi, John B. Chambers, Jean G. Dumesnil, John S. Gottdiener, Bijoy K. Khandheria, Robert A. Levine, Gerald Ross Marx, Fletcher A. Miller, Jr, Satoshi Nakatani, Miguel A. Quiñones, L. Leonardo Rodriguez, Madhav Swaminathan, Alan D. Waggoner, and Miguel Zabalgoitia all reported that they have no actual or potential conflicts of interest in relation to this program. This activity has been peer reviewed by a nonbiased member of the ASE ACCME/CME committee. No indication of an actual or potential bias in relation to the author disclosures was determined. Estimated Time to Complete This Activity: 1hour I.Introduction 976II.General Considerations With Prosthetic Valves 977A.Types of Prosthetic Valves 977B.Evaluation of Prosthetic Valves With Echocardiography and Doppler: General Recommendations 9771.Clinical Data 9782.Echocardiographic Imaging 9783.Doppler Echocardiography 979a.Determination of Gradients Across Prosthetic Valves 979b.EOA 980c.Pressure Recovery: Hemodynamic Conditions and Clinical Implications 980d.PPM 981e.Doppler Recordings and Measurements Based on Prosthetic Valve Position 981f.Physiologic Regurgitation 982g.Pathologic Prosthetic Regurgitation 982C.Considerations for Intraoperative Patients 982D.Complications of Prosthetic Valves 9831.General Considerations: Early Versus Late Complications 983a.Early Complications 983b.Late Complications 9832.Endocarditis 9833.Prosthetic Valve Thrombosis Versus Pannus 984E.Stress Echocardiography in Evaluating Prosthetic Valve Function 9841.Prosthetic Aortic Valves 9842.Prosthetic Mitral Valves 985F.Other Techniques for Assessing Replacement Heart Valves 9861.Cinefluoroscopy 9862.CT 9863.Cardiac Catheterization 986G.Postoperative Evaluation and Follow-Up Studies 986III.Evaluation of Prosthetic Aortic Valves 986A.Prosthetic Aortic Valve Function and Stenosis 9861.Imaging Considerations 9862.Doppler Parameters of Prosthetic Aortic Valve Function 986a.Velocity and Gradients 986b.EOA 987c.DVI 9873.Diagnosis of Prosthetic Aortic Valve Stenosis 987B.Prosthetic Aortic Valve Regurgitation 9891.Imaging Considerations 9892.Doppler Evaluation of Severity of Prosthetic AR 989a.Color Doppler 989b.Spectral Doppler 9903.Role of TEE in Prosthetic AR 9914.An Integrative Approach in Evaluating Prosthetic AR 991IV.Evaluation of Prosthetic Mitral Valves 991A.Prosthetic Mitral Valve Function and Stenosis 9911.Imaging Considerations 991a.Parasternal Views 991b.Apical Views 9922.Doppler Parameters of Prosthetic Mitral Valve Function 992a.Peak Early Mitral Velocity 992b.Mean Gradient 993c.Pressure Half-Time 993d.EOA 994e.DVI 9953.Diagnosis of Prosthetic Mitral Valve Stenosis 995B.Prosthetic Mitral Valve Regurgitation 9961.Imaging Considerations 9962.Role of TEE 9963.Assessment of Severity of Prosthetic MR 996V.Evaluation of Prosthetic Pulmonary Valves 996A.Prosthetic Pulmonary Valve Function 9961.Imaging Considerations 9962.Evaluation of Pulmonary Valve Function 998B.Prosthetic Pulmonary Valve Regurgitation 998VI.Evaluation of Prosthetic Tricuspid Valves 998A.Prosthetic Tricuspid Valve Function 9981.Imaging Considerations 9982.Doppler Parameters of Tricuspid Prosthetic Valve Function 9993.Diagnosis of Prosthetic Tricuspid Valve Stenosis 999B.Prosthetic TR 10001.Imaging Considerations 10002.Doppler Parameters of Tricuspid Prosthetic Valve Regurgitation 10003.TEE for Prosthetic Tricuspid Valves 1001VII.Echocardiographic Evaluation of Prosthetic Valves in the Pediatric Population 1002A.Prosthetic Valves Are Uncommon in Pediatrics 1002B.Aspects of Pediatric Congenital Heart Disease Alter the Standard Approach to Echocardiographic Prosthetic Valve Evaluation 1002C.Importance of PPM in Pediatrics 1003D.Potential Pitfalls in the Measurement of Prosthetic Valve EOA in Pediatrics 1004E.Evaluation of Corresponding Atrial and Ventricular Size and Function 1004F.The Need for More Research in the Pediatric Population 1004VIII.Conclusions and Future Directions 1004Appendix A: Normal Doppler Echocardiographic Values for Prosthetic Aortic Valves 1010Appendix B: Normal Doppler Echocardiographic Values for Prosthetic Mitral Valves 1013 In patients with significant valvular stenosis or regurgitation, an intervention on the valve with repair, valvuloplasty, or valve replacement is ultimately inevitable. Although valve repair is now frequently performed, especially for mitral regurgitation (MR) and tricuspid regurgitation (TR), valve replacement remains common, particularly in adults. This enlarging cohort may be difficult to assess. Symptoms may be nonspecific, making it difficult to differentiate the effects of prosthetic valve dysfunction from ventricular dysfunction, pulmonary hypertension, the pathology of the remaining native valves, or noncardiac conditions. Although physical examination can alert clinicians to the presence of significant prosthetic valve dysfunction, diagnostic methods are often needed to assess the function of the prosthesis. Echocardiography with Doppler is the method of choice for the noninvasive evaluation of prosthetic valve function. This document offers a review of echocardiographic and Doppler techniques used in the assessment of prosthetic valves and provides recommendations and general guidelines for the evaluation of prosthetic valve function on the basis of the scientific literature and the consensus of an international panel of experts. Issues of medical management and considerations for reoperation on valvular complications are beyond the scope of the current recommendations and have been recently addressed.1Bonow R.O. Carabello B.A. Kanu C. et al.ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): developed in collaboration with the Society of Cardiovascular Anesthesiologists: endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons.Circulation. 2006; 114: e84-e231Crossref PubMed Scopus (1159) Google Scholar Echocardiography of prosthetic heart valves is more demanding, both to perform and to interpret, compared with the assessment of native valves. By their design, almost all replacement valves are obstructive compared with normal native valves. The degree of obstruction varies with the type and size of the valve. Thus, it may be difficult to differentiate obstructive hemodynamics due to valve design from those of mild obstruction observed with pathologic changes and from prosthesis-patient mismatch (PPM). Most mechanical valves and many biologic valves are associated with trivial or mild transprosthetic regurgitation. The pattern of this “physiologic” regurgitation varies with the design of the replacement valve. Last, because of shielding and artifacts, insonation of the valve and particularly of regurgitant jets associated with the valve may be difficult. A full transthoracic echocardiographic study requires multiple angulations of the probe and the use of off-axis views. On rare occasions, intermittent obstruction may be suspected, and prolonged Doppler examination may then be required for diagnosis. Transesophageal echocardiography (TEE) is more likely to be needed than for native valves for the evaluation of prosthetic valvular structure and associated complications, including regurgitation, especially in the mitral position. Over the past 40 years, a large variety of prosthetic valves have been developed with the aim of improving hemodynamic function, increasing durability, and reducing complications. Nevertheless, there is no ideal valve, and all prosthetic valves are prone to dysfunction. The valve types now implanted include bileaflet and tilting disc mechanical valves, stented porcine and pericardial xenografts, stentless porcine xenografts, cadaveric homografts, and autografts (Ross procedure). Various types of currently used prosthetic valves in the aortic and mitral positions are listed in Appendices A and B, Appendices A and B. Figure 1, Figure 2 depict examples of mechanical and bioprosthetic valves and their echocardiographic images, respectively. In patients with aortic root disease, composite grafts may be required to replace the aortic valve and root, usually necessitating coronary reimplantation. Recently, successful percutaneous aortic and pulmonary valve replacements have been accomplished.Figure 2Examples of stented, stentless, and percutaneous biologic valves and their echocardiographic features in diastole (middle) and in systole (right) as seen by TEE. The stentless valve is inserted by the root inclusion technique. Mild perivalvular AR in the percutaneous valve is shown by arrow. The percutaneous biologic valve is currently for investigational use only. Videos 7 to 10, Videos 7 to 10, Videos 7 to 10, Videos 7 to 10 show the valve motion and color Doppler flow pattern of these valves. View video clips online.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Prosthetic valves are broadly grouped as biologic or mechanical (Table 1).2Jamieson W.R. Current and advanced prostheses for cardiac valvular replacement and reconstruction surgery.Surg Technol Int. 2002; 10: 121-149PubMed Google Scholar The most frequently implanted biologic valve is a stented xenograft. These are composed of fabric-covered polymer or wire stents. The valve may be an entire porcine valve or a composite from 2 or 3 individual pigs. The cusps of stented pericardial xenografts are made from pericardium using a template and sewn inside or outside of the stent posts. Usually, the pericardium is bovine, but pericardium of other species has also been used. Xenografts also differ in the method of preservation of the valve cusps, the use of anticalcification regimens, and the composition and design of the stents and sewing rings.Table 1Types of prosthetic heart valvesBiologic StentedPorcine xenograftPericardial xenograft StentlessPorcine xenograftPericardial xenograftHomograft (allograft)Autograft PercutaneousMechanical Bileaflet Single tilting disc Caged-ball Open table in a new tab Stentless xenograft graft valves usually consist of a preparation of porcine aorta. The aorta may be relatively long (Medtronic Freestyle; Medtronic, Inc, Minneapolis, MN) or may be sculpted to fit under the coronary arteries (St Jude Medical Toronto; St Jude Medical, St Paul Minnesota). Some are tricomposite (CryoLife O'Brien, CryoLife, Inc, Kennesaw, GA; BioCor, LLC, Yardley, PA) or made from bovine pericardium (Sorin Freedom; Sorin Group, Milan, Italy). Homograft valves consist of cryopreserved human aortic or, less commonly, pulmonary valves. Most are prepared in tissue banks, although a small number are produced by commercial companies (eg, CryoLife). Stentless valves were introduced to increase the effective orifice area (EOA). It was also hoped that stresses on the cusps might be lessened, leading to better durability and less thrombosis. Currently, the most frequently implanted mechanical valves are the bileaflet valves. The various designs differ in the composition and purity of the pyrolytic carbon, the shape and opening angle of the leaflets, the design of the pivots, the size and shape of the housing, and the design of the sewing ring. Single tilting disc valves are also frequently used, whereas the Starr-Edwards caged-ball valve is rarely used nowadays but, because of its durability, will continue to be encountered. Usually, the reported size of a prosthesis refers to the outer diameter of the valve ring, in millimeters. Comparison of the different valve types is difficult, however, because of major variations in sizing convention.3Christakis G.T. Buth K.J. Goldman B.S. et al.Inaccurate and misleading valve sizing: a proposed standard for valve size nomenclature.Ann Thorac Surg. 1998; 66: 1198-1203Abstract Full Text Full Text PDF PubMed Scopus (61) Google Scholar, 4Chambers J.B. Oo L. Narracott A. Lawford P.M. Blauth C.I. Nominal size in six bileaflet mechanical aortic valves: a comparison of orifice size and biologic equivalence.J Thorac Cardiovasc Surg. 2003; 125: 1388-1393Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar This means that for a given patient's tissue annulus, there may be major differences in the labeled size. In a study comparing valve size as stated by the manufacturer against a modeled patient tissue annulus provided by machined polypropylene blocks, the patient “tissue annulus” diameter ranged from 3.5 mm smaller to 3.0 mm larger than the labeled size.4Chambers J.B. Oo L. Narracott A. Lawford P.M. Blauth C.I. Nominal size in six bileaflet mechanical aortic valves: a comparison of orifice size and biologic equivalence.J Thorac Cardiovasc Surg. 2003; 125: 1388-1393Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar The various valve types can differ also by their implantation position relative to the valve annulus. This is mainly in the aortic site. Valve implantation can be intra-annular, partially supra-annular, or wholly supra-annular. The supra-annular position is designed to lift as much of the replacement valve above the annulus to maximize the orifice area available for flow. The maximum label size implantable may then be limited by the diameter of the aortic root or the position of the coronary ostia. Percutaneous valve implantation is an emerging technique whose feasibility has already been demonstrated.5Grube E. Schuler G. Buellesfeld L. et al.Percutaneous aortic valve replacement for severe aortic stenosis in high-risk patients using the second- and current third-generation self-expanding CoreValve prosthesis: device success and 30-day clinical outcome.J Am Coll Cardiol. 2007; 50: 69-76Abstract Full Text Full Text PDF PubMed Scopus (619) Google Scholar, 6Khambadkone S. Coats L. Taylor A. et al.Percutaneous pulmonary valve implantation in humans: results in 59 consecutive patients.Circulation. 2005; 112: 1189-1197Crossref PubMed Scopus (235) Google Scholar, 7Webb J.G. Chandavimol M. Thompson C.R. et al.Percutaneous aortic valve implantation retrograde from the femoral artery.Circulation. 2006; 113: 842-850Crossref PubMed Scopus (553) Google Scholar Clinical trials evaluating safety and durability are currently in progress. Percutaneous valves have been implanted in the pulmonary and aortic positions.5Grube E. Schuler G. Buellesfeld L. et al.Percutaneous aortic valve replacement for severe aortic stenosis in high-risk patients using the second- and current third-generation self-expanding CoreValve prosthesis: device success and 30-day clinical outcome.J Am Coll Cardiol. 2007; 50: 69-76Abstract Full Text Full Text PDF PubMed Scopus (619) Google Scholar, 6Khambadkone S. Coats L. Taylor A. et al.Percutaneous pulmonary valve implantation in humans: results in 59 consecutive patients.Circulation. 2005; 112: 1189-1197Crossref PubMed Scopus (235) Google Scholar, 7Webb J.G. Chandavimol M. Thompson C.R. et al.Percutaneous aortic valve implantation retrograde from the femoral artery.Circulation. 2006; 113: 842-850Crossref PubMed Scopus (553) Google Scholar The basic concept is of a tissue valve mounted on a balloon or self-expandable stent. Preliminary experience suggests that echocardiography will be a valuable tool for guiding the procedure and for the evaluation of gradients and residual aortic regurgitation (AR).8Moss R. Ivens E. Pasupati S. et al.Role of echocardiography in percutaneous aortic valve implantation.J Am Coll Cardiol Cardiovasc Imaging. 2008; 1: 15-24Abstract Full Text Full Text PDF Scopus (160) Google Scholar Normal values for velocities and gradients are available in a small number of patients, but low gradients should be expected.7Webb J.G. Chandavimol M. Thompson C.R. et al.Percutaneous aortic valve implantation retrograde from the femoral artery.Circulation. 2006; 113: 842-850Crossref PubMed Scopus (553) Google Scholar, 8Moss R. Ivens E. Pasupati S. et al.Role of echocardiography in percutaneous aortic valve implantation.J Am Coll Cardiol Cardiovasc Imaging. 2008; 1: 15-24Abstract Full Text Full Text PDF Scopus (160) Google Scholar In select older high-risk patients, particularly those with prior coronary artery bypass grafting and severely calcific aortas in whom aortic cross-clamping would pose undue technical difficulty and risk, an aortic valve bypass (apicoaortic conduit) may be performed. This operation interposes a fabric conduit containing either a bioprosthetic or mechanical valve between the left ventricular (LV) apex and descending thoracic aorta.9Gammie J.S. Brown J.W. Brown J.M. et al.Aortic valve bypass for the high-risk patient with aortic stenosis.Ann Thorac Surg. 2006; 81: 1605-1610Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar Postoperative evaluation focuses on evaluation of the apical cannula for absence of thrombus and adequate flow. A comprehensive evaluation is needed for the optimal assessment of prosthetic valve function. This includes obtaining pertinent clinical information in addition to echocardiography and Doppler evaluation. A comparison with a baseline study or serial postoperative Doppler echocardiographic studies is often helpful, particularly when the function of the valve is in question (Table 2).Table 2Essential parameters in the comprehensive evaluation of prosthetic valve functionParameterClinical informationDate of valve replacementType and size of the prosthetic valveHeight, weight, body surface areaSymptoms and related clinical findingsBlood pressure and heart rateImaging of the valveMotion of leaflets or occluderPresence of calcification on the leaflets or abnormal echo densities on the various components of the prosthesisValve sewing ring integrity and motionDoppler echocardiography of the valveContour of the jet velocity signalPeak velocity and gradientMean pressure gradientVTI of the jetDVIPressure half-time in MV and TV.EOA∗EOA using the continuity equation; needs to be compared with normal Doppler values of the valve type and size.Presence, location, and severity of regurgitation†Transthoracic Doppler is less sensitive to detection of valvular regurgitation in mitral and tricuspid prosthesis; TEE is frequently needed for a more definitive assessment.Other echocardiographic dataLV and RV size, function, and hypertrophyLA and right atrial sizeConcomitant valvular diseaseEstimation of pulmonary artery pressurePrevious postoperative studies, when availableComparison of above parameters is particularly helpful in suspected prosthetic valvular dysfunctionMV, Mitral valve; TV, tricuspid valve.∗ EOA using the continuity equation; needs to be compared with normal Doppler values of the valve type and size.† Transthoracic Doppler is less sensitive to detection of valvular regurgitation in mitral and tricuspid prosthesis; TEE is frequently needed for a more definitive assessment. Open table in a new tab MV, Mitral valve; TV, tricuspid valve. The reason for the echocardiographic study and the patient's symptoms should be clearly documented. Furthermore, because Doppler findings and interpretation depend on the type and size of the replacement valve, this information and the date of surgery should be incorporated in the report when available, as this can be used in subsequent studies. Blood pressure and heart rate should be measured. The heart rate of the cardiac cycles used for Doppler measurements is particularly important in mitral and tricuspid prosthetic valves, because the mean gradient is dependent on the diastolic filling period. Finally, the patient's height, weight, and body surface area should be recorded to assess whether PPM is present and to interpret cardiac chamber size. The echocardiographic assessment of patients with prosthetic valves includes standardized measurement and evaluation of the size of cardiac chambers, LV wall thickness and mass, and indices of LV systolic and diastolic function per guidelines of the ASE.10Lang R.M. Bierig M. Devereux R.B. et al.Recommendations for chamber quantification: a report from the American Society of Echocardiography's Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology.J Am Soc Echocardiogr. 2005; 18: 1440-1463Abstract Full Text Full Text PDF PubMed Scopus (3836) Google Scholar In patients with aortic prostheses, measurements of the aortic root and ascending aorta are recommended. Valves should be imaged from multiple views, with particular attention to the following:•the opening and closing motion of the moving parts of the prosthesis (leaflets for bioprosthesis and occluders for mechanical prostheses);•the presence of leaflet calcifications or abnormal echo density attached to the sewing ring, occluder, leaflets, stents, or cage; and•the appearance of the sewing ring, including careful inspection for regions of separation from the native annulus and for abnormal rocking motion during the cardiac cycle. In general, magnification of real-time images is necessary for better visualization of the leaflets or occluder mechanism. Mild thickening is often the first sign of primary failure of a biologic valve and is a signal to follow the patient more carefully.11Alam M. Goldstein S. Lakier J.B. Echocardiographic changes in the thickness of porcine valves with time.Chest. 1981; 79: 663-668Crossref PubMed Google Scholar Occluder motion of a mechanical valve may not be well visualized by transthoracic echocardiography (TTE) because of artifact and reverberations. Nevertheless, optimal 2-dimensional (2D) echocardiographic visualization of occluder motion in tilting disc valves in the mitral or tricuspid position frequently necessitates incremental rotation of the imaging plane from apical views until the occluder motion is seen. Rocking motion of a replacement valve is almost invariably a sign of a large dehiscence in the aortic position.12Effron M.K. Popp R.L. Two-dimensional echocardiographic assessment of bioprosthetic valve dysfunction and infective endocarditis.J Am Coll Cardiol. 1983; 2: 597-606Abstract Full Text PDF PubMed Google Scholar For valves in the mitral position, however, retention of the posterior or both the anterior and posterior native leaflets can allow increased mo

Feasibility and Diagnostic Accuracy of Quantitative Assessment of Mechanical Prostheses Leaflet Motion by Transthoracic and Transesophageal Echocardiography in Suspected Prosthetic Valve Dysfunction

Transthoracic (TTE) and transesophageal echocardiography (TEE) are the standard techniques for the evaluation of prosthetic valve function. However, quantitative evaluation of leaflet(s) motion is not routinally carried out, although leaflet(s) opening and closing angle measurements are important information to recognize prosthetic dysfunction. For this purpose, cinefluoroscopy is considered the "gold standard" technique. The aim of this study was the evaluate the diagnostic accuracy of TTE and TEE in the quantitative assessment of leaflet motion in patients with mechanical protheses. One hundred-eleven patients with mitral (single disk 18; bileaflet 48) and aortic (single disk 22; bileaflet 23) prostheses, were referred to TTE, TEE, and cinefluoroscopy for electrical cardioversion of atrial fibrillation (n = 40) or suspected prosthesis dysfunction (n = 71). Echocardiographic evaluation included leaflet(s) opening and closing angle measurements; results were compared with cinefluoroscopy. For mitral prostheses, opening and closing angles were correctly identified by TTE in 85% and by TEE in 100% of patients, regardless of prosthetic valve type, with a good concordance with cinefluoroscopy. For aortic prostheses, opening angles were correctly identified by TTE and TEE, respectively, in 40% and 77% of patients with single-disk and in 13% and 35% of patients with bileaflet prostheses. Both TTE and TEE were rarely able to identify closing angles. In conclusion, quantitative evaluation of mitral leaflet(s) motion may be accurately achieved with TTE and TEE, leading to increased diagnostic efficacy of prosthetic valve dysfunction. In the aortic position, TTE and TEE allow a quantitative evaluation of leaflet(s) dynamics only in a minority of patients and cinefluoroscopy still remains the first-choice technique.

Echocardiographic doppler evaluation of prosthetic valve function and dysfunction.

Echocardiographic doppler evaluation of prosthetic valve function and dysfunction.

EVALUATION OF PROSTHETIC VALVE FUNCTION AND ASSOCIATED COMPLICATIONS

Significant advances in imaging modalities have occurred to evaluate prosthetic valve function and associated complications. These developments involve predominantly the introduction of Doppler technology for the non-invasive determination of gradients and valve areas and TEE for an improved assessment of valve structure, function, and associated complications. The current role of cinefluoroscopy is mostly to complement TEE in the evaluation of motion of mechanical prosthetic valves in the aortic position. Cardiac catheterization is now rarely needed to assess valve function. Diagnosis of prosthetic valve obstruction can be performed in the majority of cases with transthoracic Doppler echocardiography. Differentiation of valve obstruction from normal valve function in small valves with high flow conditions, however, may be difficult. Because of this and the variability in normal valves among different prostheses, knowledge of the type and size of the implanted valve is essential. Patients and ultrasound laboratories are encouraged to seek and provide this information on a routine basis. Although transthoracic echocardiography is the main diagnostic modality for the serial evaluation of prosthetic valve function, it is important to recognize its limitations in assessing prosthetic mitral regurgitation and evaluating structural abnormalities of prosthetic valves. These are the situations in which TEE has the most impact. A summary of general indications of TEE in prosthetic valves is provided in Table 6. Finally, a baseline transthoracic Doppler study is essential in the overall follow-up and serial evaluation of valve function. For future comparisons, the best indices of valve functions are those obtained for patients as their own control, from a baseline Doppler echocardiographic study performed early after the operation.

Echocardiographic assessment of prosthetic valve endocarditis.

Prosthetic valve endocarditis is still a very serious complication, carrying an incidence of death between 30 and 70% in some series. Therefore early and accurate diagnosis is crucial. Early (less than 60 days post surgery) endocarditis is usually a fulminant disease, where staphylococcal infection is most common. Late prosthetic endocarditis resembles more closely other forms of the disease. Conventional echocardiography is useful in the evaluation of prosthetic valve function, but it is very limited in the demonstration of infective lesions, primarily because of acoustic shadowing. Transoesophageal echocardiography (TE) enables high resolution imaging of the heart without chest wall interference, and viewing of the heart from the posterior (atrial, low pressure) side, where most of the vegetations are expected to be found in both mitral and tricuspid positions. It also enables better visualization of the left ventricular outflow tract, where aortic prosthetic vegetations tend to be present. Furthermore, transoesophageal echocardiography allows accurate diagnosis of some of the common complications of endocarditis: abscess/cavity formation; mycotic aneurysm; prosthetic valve dehiscence and regurgitation. In spite of these advantages, limitations should be recognized. Struts are commonly seen on transoesophageal echocardiography following surgery and should not be confused with vegetations. Similarly, normal prosthetic regurgitation should not be confused with paravalvar leakage. Nevertheless, transoesophageal echocardiography, when expertly used, changes the possibility for early and more accurate diagnosis of prosthetic valve endocarditis dramatically. Transoesophageal echocardiography should be included among the major criteria in the diagnosis and follow-up of prosthetic valve endocarditis.

Doppler echocardiographic assessment of the St. Jude Medical prosthetic valve in the aortic position using the continuity equation.

To test whether the continuity equation can be applied to the noninvasive assessment of prosthetic aortic valve function, Doppler echocardiography was performed in 67 patients (mean age, 58 +/- 14 years) within 10 +/- 6 days after valve replacement with St. Jude Medical valves. All patients were clinically stable and without evidence of valve dysfunction. Valve size ranged from 19 to 31 mm, and ejection fraction ranged from 30% to 75%. With the parasternal long-axis view, the left ventricular outflow diameter measured just proximal to the prosthetic valve correlated well with valve size (r = 0.92). Doppler-derived maximal gradients ranged from 9 to 71 mm Hg. Effective prosthetic aortic valve area by the continuity equation ranged between 0.73 cm2 for a 19-mm valve and 4.23 cm2 for a 31-mm valve. With analysis of variance, effective orifice area differentiated various valve sizes (p less than 10(-14)) better than did gradients alone (p = 0.003) and correlated better with actual valve orifice area (r = 0.83 versus - 0.40). A Doppler velocity index, the ratio of peak velocity in the left ventricular outflow to that of the aortic jet, averaged 0.41 +/- 0.09 and was less dependent on valve size (r = 0.43). Thus, the continuity equation can be applied to the assessment of prosthetic St. Jude valves in the aortic position. By accounting for flow through the valve, it provides an improved assessment over the sole use of gradients in the evaluation of prosthetic valve function.

Doppler echocardiography assessment of prosthetic heart valves.

Transthoracic Doppler echocardiography is an accurate noninvasive method for the evaluation of prosthetic valve function. The flow characteristics and pressure gradients of normally functioning mechanical and bioprosthetic valves have been, in general established. Normal functioning mitral valve prostheses have a valve area greater than 1.8 cm 2 with the St. Jude valve having the largest effective valve area and normally functioning aortic prosthetic valves have a peak instantaneous gradient of less than 45 mmHg, with the Starr-Edwards valves (Starr-Edwards, Irvine CA) showing the highest gradients. The incidence of minimal or mild regurgitation is approximately 15% to 30% in the mitral position and 25% to 50% in the aortic position, with the higher incidence of regurgitation seen with mechanical compared to bioprosthetic valves. Transthoracic Doppler echocardiography can accurately detect patients with prosthetic valvular stenosis. The presence of prosthetic aortic regurgitation can also generally be accurately assessed, except in the presence of both prosthetic aortic and mitral valves. Assessment of prosthetic mitral regurgitation remains limited due to significant attenuation of the ultrasound beam by the prosthesis and the frequent underestimation of severity of regurgitation. Other limitations of transthoracic studies include assessment of leaflet morphology, detection of vegetations and valve abscesses, and differentiation between valvular and paravalvular regurgitation.

Doppler assessment of prosthetic valves.

Doppler evaluation of prosthetic valves is a complex process involving assessment of both forward and regurgitant flow. It is important to consider the type of prosthesis, its size, its position, its relationship to the ultrasound beam, and the patient's cardiac output and afterload condition in any evaluation of prosthetic valve function.

Doppler evaluation of bioprosthetic and mechanical aortic valves: Data from four models in 107 stable, ambulatory patients

To test the applicability of Doppler ultrasound in the evaluation of prosthetic valve function, 107 patients with normal ejection fractions in whom Starr-Edwards, Bjo¨rk-Shiley, Carpentier-Edwards, and Hancock models had been implanted in the aortic position were examined. Maximal transvalvular velocity was recorded by non-imaging continuous wave Doppler ultrasound. Means of maximal velocities by model and size ranged from <2 to 4 m/sec. The Starr-Edwards valve showed the highest velocities, the Bjo¨rk-Shiley the lowest, and the bioprosthetic models showed velocities in between. A significant inverse relation between velocity and size, and standard deviations averaging ± 14% enabled the technique to measure differences between sizes of the same model. Aortic regurgitation was detected in 24% of the patients. This study, conducted in well and stable patients, established values for maximal velocity across normally functioning aortic mechanical and tissue prostheses of different models and sizes. The intersubject variability was relatively small which, together with a previously shown minimal intrasubject variability, was testimony to a methodology that should prove useful in longitudinal postoperative evaluations.