Low Transvalvular Gradient Research Articles

Transapical aortic valve implantation after previous heart surgery

Objective: Transcatheter aortic valve implantation is a new method for the treatment of very-high-risk patients with aortic valve stenosis. Particularly in patients who have had previous cardiac surgery, the operative risk can be reduced. Nevertheless, this new procedure has some potential risks in these patients, due to the increased danger of endocarditis and in view of potential graft damage after previous bypass grafting or prosthesis damage after previous valve replacement, caused by wire manipulation or valve liberation. Methods: Between April 2008 and January 2010, 198 consecutive patients underwent transapical aortic valve implantation. Group A consisted of 158 patients without previous heart surgeryand groupB had 40 patientswith previousheart operation (23coronary arterybypass grafting, threeaorticvalve replacements, two mitral valve repairs, one replacement, and 11 combined operations). Although patients in group B (75 11) were significantly younger than the ones in group A (80 8) (p = 0.003), the preoperative risk score was significantly higher in group B (group A — the European System for Cardiac Operative Risk Evaluation (EuroSCORE): 37 18%; the Society of Thoracic Surgeons (STS) mortality score: 21 16; group B — EuroSCORE: 53 21%; STS mortality score: 29 18) (p < 0.001, p = 0.006). Results:The technical success rate was 99.5% (157/158) in group A and 100% (40/ 40) in group B. One patient in group A developed an annulus rupture. The postoperative echocardiographic examinations showed low transvalvular gradient due to the special design of the valve, without differences between the two groups. The 30-day mortality was 6.9% in group A and 5.0% in group B, and the 1-year survival was 77% and 74% in group A and group B, respectively (nonsignificant). Conclusions: Transcatheter valve implantation can be performed successfully after previous heart surgery. Particular care should be taken to achieve optimal valve position and not to damage grafts or prosthetic valves during manipulation with guide wires or valve positioning. # 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Non-Invasive Determination of Left Ventricular Workload in Patients with Aortic Stenosis Using Magnetic Resonance Imaging and Doppler Echocardiography

Early detection and accurate estimation of aortic stenosis (AS) severity are the most important predictors of successful long-term outcomes in patients. Current clinical parameters used for evaluation of the AS severity have several limitations including flow dependency. Estimation of AS severity is specifically challenging in patients with low-flow and low transvalvular pressure gradient conditions. A proper diagnosis in these patients needs a comprehensive evaluation of the left ventricle (LV) hemodynamic loads. This study has two objectives: (1) developing a lumped-parameter model to describe the ventricular-valvular-arterial interaction and to estimate the LV stroke work (SW); (2) introducing and validating a new index, the normalized stroke work (N-SW), to assess the global hemodynamic load imposed on the LV. N-SW represents the global hemodynamic load that the LV faces for each unit volume of blood ejected. The model uses a limited number of parameters which all can be measured non-invasively using current clinical imaging modalities. The model was first validated by comparing its calculated flow waveforms with the ones measured using Cardiovascular Magnetic Resonance (CMR) in 49 patients and 8 controls. A very good correlation and concordance were found throughout the cycle (median root mean square: 12.21 mL/s) and between the peak values (r = 0.98; SEE = 0.001, p<0.001). The model was then used to determine SW using the parameters measured with transthoracic Doppler-echocardiography (TTE) and CMR. N-SW showed very good correlations with a previously-validated index of global hemodynamic load, the valvular arterial impedance (), using data from both imaging modalities (TTE: r = 0.82, SEE = 0.01, p<0.001; CMR: r = 0.74, SEE = 0.01, p<0.001). Furthermore, unlike , N-SW was almost independent from variations in the flow rate. This study suggests that considering N-SW may provide incremental diagnostic and prognostic information, beyond what standard indices of stenosis severity and provide, particularly in patients with low LV outflow.

Abstract 19213: Long-Term Prognostic Value of and Serial Changes in Plasma N-terminal Pro B-type Natriuretic Peptide in Patients Undergoing Transcatheter Aortic Valve Implantation

Background: Little is known about the usefulness of evaluating cardiac neurohormones in patients undergoing transcatheter aortic valve implantation (TAVI). The objectives of this study were to evaluate the baseline values and serial changes of NT-proBNP following TAVI, its related factors and prognostic value. Methods and Results: A total of 333 consecutive patients undergoing TAVI were included. Baseline, procedural and follow-up (median: 20 [8 to 35] months) data were prospectively collected. Systematic NT-proBNP measurements were performed at baseline, hospital discharge, 1-month, 6- to12 months, and yearly thereafter. Baseline NT-proBNP values were elevated in 86% of the patients (median: 1692 [667-3910] pg/mL); lower left ventricular ejection fraction and stroke volume index, higher LV mass, and renal dysfunction were associated with greater baseline values (p&lt;0.01 for all). Higher NT-proBNP levels were independently associated with increased long-term overall and cardiovascular mortality (P&lt;0.001 for both), with a baseline cut-off level of ~2,000 pg/mL best determining poorer outcomes (P&lt;0.001). At 6- to 12-month follow-up, NT-proBNP levels had decreased (P&lt;0.001) by 23 (IQR: -62 to +32)% and remained stable up to 4-year follow-up. In 39% of the patients, however, NT-proBNP values increased to some degree. Pre-procedural chronic atrial fibrillation, lower mean transaortic gradient and moderate/severe mitral regurgitation were the predictors of the lack of NT-proBNP improvement after TAVI (P&lt;0.01 for all). Conclusions: Very high NT-proBNP levels were observed in most TAVI candidates, which in turn predicted a higher overall and cardiac mortality after a median follow-up of approximately 2 years. TAVI was associated with a significant decrease in NT-proBNP levels over time, but a lack of improvement was observed in more than one third of the patients, mainly due to the presence of chronic atrial fibrillation, a lower transvalvular gradient and moderate-to-severe mitral regurgitation. These results strongly suggest the usefulness of implementing NT-proBNP measurements for the clinical decision-making process and follow-up of TAVI patients.

Abstract 9883: Impact of Low Transvalvular Gradient on Early and Late Outcomes After Aortic Valve Replacement for Aortic Stenosis

Background: Few data are available concerning the results of aortic valve replacement (AVR) for low-gradient severe aortic stenosis (AS). Aim of this study was to assess the hypothesis that low-gradient is an independent predictor of early and late results after AVR. Methods: We retrospectively analyzed a series of 340 consecutive AS patients (area≦1.0cm 2 ) who underwent AVR from 2002 to 2012. Low-gradient AS was defined by the mean transvalvular gradient &lt;40mmHg (n=68, 20%). The outcome measures included hospital mortality, major postoperative complication, prolonged length of hospital stay, and late survival. Results: Hospital mortality was 3.2% (n=11) (low-gradient 8.8%; high-gradient 1.8%; p=0.01). Low-gradient AS was an independent predictor for hospital mortality (odds ratio [OR] 6.0, 95% confidence interval [CI]: 1.6 to 21.2, p=0.006), but did not predict any postoperative major complication. NYHA class III/IV was another independent predictor of hospital mortality (OR 19.3, 95%CI: 2.4 to 155.1, p=0.005). In the patients with low-gradient AS who were in NYHA class III/IV (n=25), hospital mortality was significantly higher (24%) compared to those in NYHA class II (n=43, hospital mortality 0%). Multivariable predictors of late mortality (excluding hospital death) included NYHA class III/IV (OR 9.6, 95%CI: 1.2 to 76.7, p=0.03) and creatinine &gt;2mg/dl (OR 6.9, 95%CI: 2.1 to 22.8, p=0.002). Low-gradient was no longer a risk of late mortality in operative survivors. The survival rate at 7 years after AVR was 84±10% in low-gradient and 95±2% in high-gradient patients (p=0.42). We also calculated propensity score for low-gradient status (C-statistic: 0.71), and 37 low-gradient were matched to 41 high-gradient patients. No statistically significance was observed in late survival between propensity matched low and high-gradient patients (83% vs 95% at 7 years, p=0.86). Conclusions: Low-gradient AS was an independent predictor of increased hospital mortality, but did not predict late mortality in operative survivors. Surgical risk was very high in low-gradient patients with advanced NYHA class. However, AVR could be performed safely if low-gradient AS patients were in NYHA class II, and good long-term survival was seen in operative survivors.

Meta-analysis of the outcome of patients with low gradient severe aortic stenosis and preserved left ventricular ejection fraction

A number of patients with severe aortic valve stenosis (AS) as defined on the basis of aortic valve area (AVA) have low transvalvular gradient. When associated with a reduced left ventricular ejection fraction (LVEF), this condition is called low flow-low gradient AS [1]. Since gradient measurement is flow dependent, decreased LVEF may explain the low gradient. Nevertheless, low gradient severe AS can be associated also with preserved LVEF. Management of this subgroup of patients is controversial because of the limited amount of data on its prevalence, natural history and outcome after aortic valve replacement (AVR) [2,3].

Transfemoral and Transseptal Valve-in-Valve Implantation Into a Failing Mitral Xenograft With a Balloon-Expandable Biological Valve

Valve-in-valve implantation for degenerated surgical bioprosthetic valves is becoming an increasingly accepted approach in selected high-risk patients. In the past, valve-in-valve implantations have been mainly performed in aortic position and only rarely in mitral position. We describe the case of an 81-year-old female patient with severe mitral regurgitation of a degenerated Carpentier-Edwards biological prosthesis treated by transfemoral and transseptal implantation of a SAPIEN-XT valve.

Transcatheter Aortic Valve Implantation in Very High-Risk Patients With EuroSCORE of More Than 40%

Transcatheter aortic valve implantation (TAVI) is a new method for the treatment of high-risk patients with aortic valve stenosis. Although a logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) of more than 40% has been considered a contraindication for this new procedure, we routinely perform this procedure in this very high-risk patient group. We analyzed the results of TAVI patients with a EuroSCORE of over 40%. Between April 2008 and January 2012, 514 consecutive patients underwent TAVI. In the study group (group I, EuroSCORE > 40%) of 186 patients the EuroSCORE was 63% ± 16% (range 40 to 98) and the Society of Thoracic Surgeons predicted risk of mortality score was 23% ±14% (range 4 to 90); there were 26 (14%) patients in cardiogenic shock. The mean age was 81 ± 8 (range 36 to 99) years and there were 122 women and 64 men. Group II (the control group, EuroSCORE < 40%) consisted of 328 patients. In this group the EuroSCORE was significantly lower (23% ± 9%, range 2% to 40%). The STS mortality score was 11% ± 8% (1% to 48%). In this group were 196 men and 132 women with a mean age of 78 ± 8 (range 29 to 97) years. Technically, in group I the valve was successfully implanted in 99.5% (185 of 186). In 25 (13%) patients the procedure was performed on the heart-lung machine and in 25 (13%) patients an elective percutaneous coronary intervention was performed in the same session. Postoperative echocardiography showed a low transvalvular gradient (mean 4.5% ± 2.5%, range 2 to 15) and a low rate of paravalvular regurgitation (grade 0 in 97, less than grade I in 49, less than grade II in 38 patients, and grade II in 2 patients). The overall 30-day mortality in patients with EuroSCORE of over 40% (group I), including that in patients in cardiogenic shock, was 6.5%, and in patients with EuroSCORE of over 40% (group I) and without cardiogenic shock it was 5.7%; the 1-year survival was 67% and 71%, respectively, and the 2-year survival was 54% and 56%, respectively. Patients with comorbidities, as mirrored by a EuroSCORE of more than 40% should not be refused for TAVI. On the contrary, this is a supreme indication for the TAVI procedure.

Silent cerebral infarcts after cardiac catheterization: A randomized comparison of radial and femoral approaches

Single center studies using serial cerebral diffusion-weighted magnetic resonance imaging in patients having cardiac catheterization have suggested that cerebral microembolism might be responsible for silent cerebral infarct (SCI) as high as 15% to 22%. We evaluated in a multicenter trial the incidence of SCIs after cardiac catheterization and whether or not the choice of the arterial access site might impact this phenomenon. Patients were randomized to have cardiac catheterization either by Radial (n = 83) or Femoral (n = 77) arterial approaches by experimented operators. The main outcome measure was the occurrence of new cerebral infarct on serial diffusion-weighted magnetic resonance imaging. Patient and catheterization characteristics, including duration of catheterization, were similar in both groups. The risk of SCI did not differ significantly between the Femoral and Radial groups (incidence of 11.7% versus 17.5%; OR, 0.85; 95% CI, 0.62-1.16; P = .31). At multivariable analysis, the independent predictors of SCI were the patient's higher height and lower transvalvular gradient. The high rate of SCI after cardiac catheterization of patients with aortic stenosis was confirmed, but its occurrence was not affected by the selection of Radial and Femoral access.

A Bjork-Shiley Valve 40 Years in Action

The Bjork–Shiley mechanical heart valve (Shiley Corp, Irvine, CA) was one of the earliest tilting disc valve prosthesis used for the replacement of diseased cardiac valves. This valve was implanted in a large number of patients in the 1970s and early 1980s. A change in the valve design in the early 1980s led to a high rate of fracture and disc escape and a high patient mortality. As a result, the manufacturer of this valve stopped the production of the valve. We recently treated a patient with a Bjork–Shiley mitral valve prosthesis implanted more than 40 years ago. An 83-year-old man with cardiomyopathy, permanent atrial fibrillation, and a biventricular pacemaker with threatened skin erosion of the pacemaker pocket underwent revision of the pacemaker pocket with transfer of the pacemaker generator to a sub-pectoral position. He had undergone a mitral valve replacement with a Bjork– Shiley tilting disc valve in 1970 (Fig 1). In preparation for surgery, an intravenous heparin infusion was started and warfarin was withheld until international normalized ratio level reached 2. The Bjork–Shiley tilting disc valve was a low profile mechanical valve with a Delrin disc held in a tantalum housing by two metal struts. The valve was introduced in clinical practice in 1969 [1]. The initial Delrin disc was subsequently replaced with a pyrolytic carbon disc. This valve provided significant advantage over the bulky Starr–Edwards cage ball valve with a lower transvalvular gradient [2]. A change in the design of the valve led to a high failure rate of this valve and its disappearance from

Valve with exchangeable biologic leaflets

There has long been a need for a biologic valve that is easy to insert, safe, and durable, with low transvalvular pressure gradients and no anticoagulation requirement. Despite recent advances in biologic valve leaflet treatments with glutaraldehyde, alcohol, ethylene, and surfactant, biologic valves are not routinely recommended—particularly for younger patients—because of the risk of valve leaflet failure with time. This report describes a valve with an easy-toinsert base and exchangeable biologic leaflet set with low pressure gradients to allow the easier replacement of leaflets.

Comparison of Outcome of Higher Versus Lower Transvalvular Gradients in Patients With Severe Aortic Stenosis and Low (

Left ventricular systolic dysfunction in patients with severe aortic stenosis (AS) is associated with poor outcome. This analysis was designed primarily to describe the clinical course of a large series of consecutive patients with severe AS and low ejection fraction (EF) (<40%) who, because of high surgical risk, were referred for transcatheter aortic valve implantation consideration. A cohort of 270 patients with severe AS and low EF (<40%) who were referred to participate in a clinical trial of transcatheter aortic valve implantation was studied. Clinical, hemodynamic, and periprocedural complications and follow-up mortality data were collected and compared between patients with low mean transvalvular gradients (≤40 mm Hg, n = 170 [63%]) and high transvalvular gradients (>40 mm Hg, n = 100 [37%]). Patients with low gradients were younger (mean age 79.8 ± 9.1 vs 83.8 ± 7.7 years, p <0.001) and had higher incidences of coronary artery disease and renal failure. Mean aortic valve area was larger (0.73 ± 0.23 vs 0.53 ± 0.18 cm(2), p <0.001), while mean EF (26.4 ± 6.9% vs 30.5% ± 6.6%, p <0.001), cardiac output (3.7 ± 1.1 vs 4.1 ± 1.3 L/min, p = 0.04), and cardiac index (1.9 ± 0.5 vs 2.1 ± 0.6 L/min/m(2), p = 0.04) were lower in patients with lower gradients compared to those with higher gradients, respectively. Mortality was higher in patients with low gradients (53.8%) at a mean follow-up of 151 days compared to those with high gradients (41%) at a mean follow-up of 256 days (p = 0.01). In conclusion, patients with severe AS and low EF with low transvalvular gradients are at higher risk for worse outcomes compared to patients with high transvalvular gradients. Surgery or transcatheter aortic valve implantation treatment and high baseline transvalvular gradient are associated with EF improvement.

Low-Flow Low-Gradient Aortic Stenosis

Aortic stenosis (AS) remains a common and important clinical entity and, when severe, is associated with significant morbidity and mortality. Fortunately, definitive surgical therapies have been developed that have significantly altered the natural history of this disease. The clinical challenge is to accurately assess AS severity and identify patients who are most likely to benefit from aortic valve replacement. Both the American and European cardiac societies define severe AS as that associated with an aortic valve area (AVA) of 40 mm Hg, and a peak transvalvular flow velocity of >4.0 m/s.1,2 Moderate AS is defined as an AVA of 1.0 to 1.5 cm2, a mean gradient of 25 to 40 mm Hg, and a peak velocity of 3.0 to 4.0 m/s, whereas mild AS is associated with less significant abnormalities in these parameters. The classification of stenotic severity, however, is not always so straightforward, and patients are frequently encountered for whom the clinical data are conflicting, including those with AVA in the severe range but with low transvalvular gradient (<40 mm Hg) and low transvalvular flow (<35 mL/m2). These patients with low-flow low-gradient AS (LFLG AS) account for a significant proportion of patients who present for evaluation of severe aortic stenosis. Article see p 27 The majority of patients with LFLG AS have reduced left ventricular ejection fraction (LVEF <50%) and have either severe AS and resultant LV failure (“true AS”) or lesser degrees of AS and an unrelated cardiomyopathy (“pseudo-AS”). These 2 entities can often be distinguished through the use of an inotropic challenge3; however, a significant minority of patients with LFLG AS have low transvalvular flow (<35 mL/m 2 ) despite preserved LVEF and have been referred to as having “paradoxical …

Letter by Daneshvar Regarding Article, “Outcome of Patients With Low-Gradient “Severe” Aortic Stenosis and Preserved Ejection Fraction”

HomeCirculationVol. 124, No. 13Letter by Daneshvar Regarding Article, “Outcome of Patients With Low-Gradient “Severe” Aortic Stenosis and Preserved Ejection Fraction” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Daneshvar Regarding Article, “Outcome of Patients With Low-Gradient “Severe” Aortic Stenosis and Preserved Ejection Fraction” Samuel A. Daneshvar, MD Samuel A. DaneshvarSamuel A. Daneshvar Fellow in Training, Cardiovascular Medicine USC Keck School of Medicine Los Angeles, CA (Daneshvar) Search for more papers by this author Originally published27 Sep 2011https://doi.org/10.1161/CIRCULATIONAHA.111.041012Circulation. 2011;124:e361To the Editor:I read with great interest the study by Jander et al,1 in which patients in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study with low-gradient severe aortic stenosis (AS) were compared with those with moderate AS and were found to have similar outcomes in terms of aortic valve events, cardiovascular events, and cardiovascular death. Earlier, Bahlmann et al2 showed in a separate analysis of the SEAS study that 45.7% of patients with severe AS by echocardiographic assessment would be reclassified as having lesser degrees of AS by energy loss index. Bahlmann et al2 demonstrated that women had higher degrees of pressure recovery, which was due to smaller aortic root size. Furthermore, patients with lower transvalvular gradients were more likely to have clinically significant pressure recovery.In the study by Jander et al,1 compared with patients with moderate AS, patients with severe AS were predominantly women (55.2% versus 27.2%; P<0.01) with lower mean transaortic gradients (44.8±11.9 versus 53.0±7.4 mm Hg; P<0.01) and peak transaortic gradients (26.2±7.3 versus 31.2 ±4.1 mm Hg; P<0.01). These patients would be more likely to have clinically significant pressure recovery. Thus, it is possible that a substantial number of patients classified as having severe AS by aortic valve area index obtained by echocardiography would have moderate AS by energy loss index. Of interest, the energy loss index, which takes into account pressure recovery, has excellent correlation with aortic valve area index calculated on the basis of cardiac catheterization.3 It would be of importance if future studies of low-gradient aortic stenosis would compare clinical outcomes of patients with moderate or severe aortic stenosis determined on the basis of energy loss index. This information may be available through further analysis of the SEAS study.Samuel A. Daneshvar, MD Fellow in Training, Cardiovascular Medicine USC Keck School of Medicine Los Angeles, CADisclosuresNone.

Invited Commentary

Traditionally, the severity of aortic stenosis has been determined by the magnitude of the transvalvular pressure gradient. It is undisputed, that in case of a severely reduced left ventricular function, even a moderate transvalvular pressure gradient may qualify a patient for valve replacement, as the impaired ventricle is no longer capable of building up a greater pressure differential. But how do we determine left ventricular function? It is common practice to use the left ventricular ejection fraction (LVEF) as a marker of left ventricular performance. In most, but not all patients, it reflects systolic function well enough to serve as an acceptable surrogate marker. In addition, diastolic dysfunction, which may affect left ventricular function just as severely as systolic dysfunction, is only poorly assessed by LVEF. In summary, a patient can suffer from severe left ventricular dysfunction, despite a normal LVEF. Driven by the advances of echocardiography, which allows a fairly accurate measurement of the aortic valve orifice area, more and more patients have been identified with severe aortic stenosis and a low transvalvular pressure gradient, in the presence of a normal LVEF. Although the issue has been discussed among cardiologists for some time, it has been addressed in a number of studies only recently. It is the great merit of this excellent article by Tarantini and coworkers, that it is among the first to report the outcome of these patients after aortic valve replacement [1Tarantini G. Covolo E. Razzolini R. et al.Valve replacement for severe aortic stenosis with low transvalvular gradient and left ventricular ejection fraction exceeding 0.50.Ann Thorac Surg. 2011; 91: 1808-1815Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar]. The study shows clearly the superior survival of patients who had undergone valve replacement in comparison to those who had not and gives a strong argument in favor of surgery for this particular group of patients. Furthermore, the article gives us a ball park figure how many patients with severe aortic stenosis may be affected. As it is the surgeon who takes ultimately responsibility for the operative indication, it is important to be aware of these facts and to advocate valve replacement where it is appropriate. Valve Replacement for Severe Aortic Stenosis With Low Transvalvular Gradient and Left Ventricular Ejection Fraction Exceeding 0.50The Annals of Thoracic SurgeryVol. 91Issue 6PreviewSevere aortic stenosis with a low transvalvular gradient and preserved left ventricular ejection fraction (LVEF) is often misdiagnosed, leading to undertreatment of such patients with no clear indication for surgical intervention. This study investigated the outcome of aortic valve replacement (AVR) in patients with severe aortic stenosis and a low transvalvular gradient despite normal LVEF. Full-Text PDF

Valve Replacement for Severe Aortic Stenosis With Low Transvalvular Gradient and Left Ventricular Ejection Fraction Exceeding 0.50

Severe aortic stenosis with a low transvalvular gradient and preserved left ventricular ejection fraction (LVEF) is often misdiagnosed, leading to undertreatment of such patients with no clear indication for surgical intervention. This study investigated the outcome of aortic valve replacement (AVR) in patients with severe aortic stenosis and a low transvalvular gradient despite normal LVEF. Between 1985 and 2008, we evaluated 73 patients who underwent AVR compared with 29 patients who did not. Overall, aortic valve area was 1.0 cm2 or smaller, LVEF was 0.50 or higher, and transvalvular gradient was 30 mm Hg or less. Multivariate and Cox analyses were used to compare these two groups according to AVR. Compared with controls, AVR patients were younger and with higher body mass index. Coronary artery bypass grafting was performed simultaneously in 38 AVR patients (52%). At follow-up (median, 42 months; interquartile range, 23 to 75 months), survival was longer in AVR patients. By Cox analysis, AVR remained a major predictor of lower mortality (hazard ratio, 0.237; 95% confidence interval, 0.119 to 0.470; p<0.0001). In patients with severe aortic stenosis and low transvalvular gradient despite a normal LVEF, AVR was associated with significant improvement in long-term survival and functional status and with a low operative mortality.

A second prosthesis as a procedural rescue option in trans-apical aortic valve implantation

Trans-apical aortic valve implantation (TA-AVI) using the Edwards SAPIEN™ prosthesis has evolved to a routine procedure for selected high-risk elderly patients. In rare cases, misplacement of the SAPIEN™ valve (too low a position), dysfunction of the leaflets or perforation of the interventricular septum (ventricular septal defect, VSD) occurs and requires immediate implantation of a second prosthesis within the first one. Results of this 'bailout' maneuver have not been reported yet. Of 305 TA-AVI procedures, 15 patients required a second prosthesis due to dysfunctional leaflets (n = 6), low position (n = 7), or VSD (n = 2). Mean age was 82.5 ± 1.3 years, mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 45.5 ± 5.4, and Society of Thoracic Surgeons (STS) Score was 13.5 ± 1.5. All second SAPIEN™ valves could be implanted successfully within the first one. The second prosthesis solved leaflet dysfunction, sealed the VSD (lower position of the second prosthesis), or corrected the initial misplacement (higher position of the second prosthesis) in all patients. Within 30 days, four patients died (low cardiac output n = 3, all with preoperative ejection fraction (EF) <35%; intestinal ischemia n = 1). Intra-operative echocardiogram and angiogram revealed mild paravalvular leak in three and none/trace in 12 patients. Transvalvular gradients were low despite the implantation of the second valve (P(max)/mean 13.7 ± 4.3/6.4 ± 2.0). Placement of a second SAPIEN™ valve is a valuable 'bailout' technique in case of VSD, dysfunctional leaflets, or too low placement of the first prosthesis. The technique leads to an excellent functional result with low transvalvular gradients. The simple, straight, tubular stent design of the SAPIEN™ prosthesis may be the ideal design for such valve-in-valve procedures.

Effect of sutureless implantation of the Perceval S aortic valve bioprosthesis on intraoperative and early postoperative outcomes

Prolonged aortic crossclamping can increase mortality and morbidity after aortic valve replacement in elderly and high-risk patients. Sutureless implantation of the prosthesis has the potential to shorten aortic crossclamp time. The Perceval S valve (Sorin Biomedica Cardio Srl, Sallugia, Italy), a sutureless implantable aortic bioprosthesis, was used in 32 patients (median age, 78 years; median logistic euroSCORE, 9.99) requiring aortic valve replacement with or without concomitant coronary artery bypass grafting. Hemodynamic parameters and clinical outcome were obtained at discharge, at 6 months, and up to 1 year postoperatively. Aortic crossclamp time needed for aortic valve replacement was 18 ± 6 minutes. Hemodynamics at discharge showed good function of all Perceval S valves with low transvalvular pressure gradients (mean, 12 ± 5 mm Hg and peak, 23 ± 9 mm Hg) and low incidence of paravalvular or valvular leakage. Operative mortality was 0%. Follow-up at 1 year showed 3 non-valve-related deaths. Survivors showed good clinical outcome and stable hemodynamic function of the valve prosthesis, except for 1 patient in whom endocarditis developed. Despite a moderate decrease in platelet counts persisting up to 12 months, freedom of bleeding and thromboembolic events was 100%. It is possible to implant a well-functioning sutureless stent-mounted valve in the aortic position in less than 20 minutes of aortic crossclamping. This is associated with excellent early clinical and hemodynamic outcome in high-risk patients. Moderate changes in hematologic parameters persisted but were not related to clinical events.

Outcome of Patients With Low-Gradient “Severe” Aortic Stenosis and Preserved Ejection Fraction

Retrospective studies have suggested that patients with a low transvalvular gradient in the presence of an aortic valve area < 1.0 cm² and normal ejection fraction may represent a subgroup with an advanced stage of aortic valve disease, reduced stroke volume, and poor prognosis requiring early surgery. We therefore evaluated the outcome of patients with low-gradient "severe" stenosis (defined as aortic valve area < 1.0 cm² and mean gradient ≤ 40 mm Hg) in the prospective Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. Outcome in patients with low-gradient "severe" aortic stenosis was compared with outcome in patients with moderate stenosis (aortic valve area 1.0 to 1.5 cm²; mean gradient 25 to 40 mm Hg). The primary end point of aortic valve events included death from cardiovascular causes, aortic valve replacement, and heart failure due to aortic stenosis. Secondary end points were major cardiovascular events and cardiovascular death. In 1525 asymptomatic patients (mean age, 67 ± 10 years; ejection fraction, ≥ 55%), baseline echocardiography revealed low-gradient severe stenosis in 435 patients (29%) and moderate stenosis in 184 (12%). Left ventricular mass was lower in patients with low-gradient severe stenosis than in those with moderate stenosis (182 ± 64 versus 212 ± 68 g; P < 0.01). During 46 months of follow-up, aortic valve events occurred in 48.5% versus 44.6%, respectively (P = 0.37; major cardiovascular events, 50.9% versus 48.5%, P = 0.58; cardiovascular death, 7.8% versus 4.9%, P = 0.19). Low-gradient severe stenosis patients with reduced stroke volume index (≤ 35 mL/m²; n = 223) had aortic valve events comparable to those in patients with normal stroke volume index (46.2% versus 50.9%; P = 0.53). Patients with low-gradient "severe" aortic stenosis and normal ejection fraction have an outcome similar to that in patients with moderate stenosis.

Early hemodynamic and neurohormonal response after transcatheter aortic valve implantation

The conventional surgical aortic bioprostheses used for treatment of aortic stenosis (AS) are inherently stenotic in nature. The more favorable mechanical profile of the Medtronic CoreValve bioprosthesis may translate into a better hemodynamic and neurohormonal response. The early hemodynamic and neurohormonal responses of 56 patients who underwent successful transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve bioprosthesis for severe symptomatic AS were compared with those of 36 patients who underwent surgical aortic valve replacement (SAVR) using tissue valves in the same period. At baseline, patients in the TAVI and SAVR group had comparable indexed aortic valve area (0.33 ± 0.1 vs 0.34 ± 0.1 cm² , respectively; P = .69) and mean transvalvular gradient (51.1 ± 16.5 vs 53.1 ± 14.3 mm Hg, respectively; P = .56). At 30-day follow-up, mean transvalvular gradient was lower in the TAVI group than in the SAVR group (10.3 ± 4 vs 13.1 ± 6.2 mm Hg, respectively; P = .015), and the indexed aortic valve area was larger in the TAVI group (1.0 ± 0.14 vs 0.93 ± 0.13 cm²/m²; P = .017). There was a trend toward a higher incidence of moderate patient-prosthesis mismatch in the surgical group compared with the TAVI group (30.5% vs 17.8%, respectively; P = .11). The overall incidence of prosthetic regurgitation (any degree) was higher in the TAVI group than in the SAVR group (85.7% vs 16.7%, respectively; P < .00001). The left ventricular mass index decreased after TAVI (175.1 ± 61.8 vs 165.6 ± 57.2 g/m²; P = .0003) and remained unchanged after SAVR (165.1 ± 50.6 vs 161 ± 64.8 g/m²; P = .81). Similarly, NT-ProBNP decreased after TAVI (3,479 ± 2,716 vs 2,533 ± 1,849 pg/mL; P = .033) and remained unchanged after SAVR (1,836 ± 2,779 vs 1,689 ± 1,533 pg/mL; P = .78). There was a modest correlation between natriuretic peptides and left ventricular mass index in the whole cohort (r = 0.4, P = .013). In patients with severe AS, TAVI resulted in lower transvalvular gradients and higher valve areas than SAVR. Such hemodynamic performance after TAVI may have contributed to early initiation of a reverse cardiac remodeling process and a decrease in natriuretic peptides.

Transapical aortic valve implantation after previous heart surgery

Transcatheter aortic valve implantation is a new method for the treatment of very-high-risk patients with aortic valve stenosis. Particularly in patients who have had previous cardiac surgery, the operative risk can be reduced. Nevertheless, this new procedure has some potential risks in these patients, due to the increased danger of endocarditis and in view of potential graft damage after previous bypass grafting or prosthesis damage after previous valve replacement, caused by wire manipulation or valve liberation. Between April 2008 and January 2010, 198 consecutive patients underwent transapical aortic valve implantation. Group A consisted of 158 patients without previous heart surgery and group B had 40 patients with previous heart operation (23 coronary artery bypass grafting, three aortic valve replacements, two mitral valve repairs, one replacement, and 11 combined operations). Although patients in group B (75 ± 11) were significantly younger than the ones in group A (80 ± 8) (p = 0.003), the preoperative risk score was significantly higher in group B (group A - the European System for Cardiac Operative Risk Evaluation (EuroSCORE): 37 ± 18%; the Society of Thoracic Surgeons (STS) mortality score: 21 ± 16; group B - EuroSCORE: 53 ± 21%; STS mortality score: 29 ± 18) (p < 0.001, p = 0.006). The technical success rate was 99.5% (157/158) in group A and 100% (40/40) in group B. One patient in group A developed an annulus rupture. The postoperative echocardiographic examinations showed low transvalvular gradient due to the special design of the valve, without differences between the two groups. The 30-day mortality was 6.9% in group A and 5.0% in group B, and the 1-year survival was 77% and 74% in group A and group B, respectively (nonsignificant). Transcatheter valve implantation can be performed successfully after previous heart surgery. Particular care should be taken to achieve optimal valve position and not to damage grafts or prosthetic valves during manipulation with guide wires or valve positioning.