Prosthetic Aortic Stenosis Research Articles

Clinical Outcome of Reoperation for Mechanical Prosthesis at Aortic Position

Redo aortic valve surgery is usually associated with a high risk of mortality and complications. The aim of this study was to investigate the perioperative and long-term outcomes of reoperation after prior mechanical prosthesis implantation at the aortic position. The clinical data of 146 consecutive patients who underwent reoperation at the aortic position between 2003 and 2019 were analysed. Mean age was 51.5±12.7 years and 69 (47.3%) were female. The median interval from prior surgery to redo aortic valve surgery was 6 years. The aetiologies were pannus formation with prosthetic aortic stenosis in 62 cases (42.5%), prosthetic valve endocarditis (PVE) in five (3.4%), PVE with perivalvular leakage (PVL) in 16 (11.0%), PVL in 45 (30.8%), thrombosis in seven (4.8%), and aortic disease in 11 (7.5%). As for surgical procedure, aortic valve replacement was performed in 81 cases (55.5%), Bentall in 34 (23.3%), PVL repair in six (4.1%), and pannus debridement in 25 (17.1%). Fourteen (14) (9.6%) patients expired perioperatively. Prolonged ventilation time and postoperative renal failure were proved to be significant independent predictors of mortality according to multivariate analysis. Overall survival was 87.8%±7.4% and 76.4%±15.1% at 5 and 10 years, respectively. Survival was 87.7%±13.7% and 84.2%±15.6% in the pannus group, and 84.5%±12.6% and 74.6%±19.4% in the non-pannus group at 5 and 10 years, respectively (p=0.951). Survival was 87.5%±14.2% and 75.8%±22.7% in the PVL group and 84.7%±11.9% and 81.6%±13.5% in the non-PVL group at 5 and 10 years, respectively (p=0.365). Pannus formation and PVL are two major indications for reoperation of mechanical prosthesis at the aortic position. Redo aortic valve surgery has a satisfactory outcome but with a high risk of complications. Long-term survival of patients seems not to be related to the aetiology. Final decision-making of redo aortic valve surgery should be based on aetiology.

Impact of valve size, predicted effective and indexed effective orifice area after aortic valve replacement.

The impact of manufacturer labeled prosthesis size and predicted effective orifice area (EOA) on long-term survival after aortic valve replacement is not clear although indexed effective orifice area (iEOA) has been associated with worse survival. Data was retrospectively collected from Jan 2000-Dec 2019 for prosthesis type, model, and size for isolated aortic valve replacements. Stratified survival was compared between groups and subgroups for labeled valve size, EOA and predicted patient prosthesis mismatch (PPM). A total of 3444 patients were included. Moderate and severe PPM was 15.6% and 1.6%, respectively. Cumulative lifetime hazard was worse for biological valves (mortality: biological 77.7% vs. mechanical 64.8%, p = .001). Moderate prosthetic aortic stenosis (AS), (EOA = 1-1.5 cm2 ) was 12.1% and severe prosthetic AS (EOA ≤ 1 cm2 ) was 0.8%, respectively. Survival was 10.5 ± 0.4 years with moderate to severe prosthetic AS (EOA≤1.5 cm2 ) versus 12.6 ± 0.2 years with mild to no prosthetic AS (EOA>1.5 cm2 ), p = .001. Worse survival in the presence of moderate-severe prosthetic AS was seen with biological valves (9.7 ± 0.4 years vs. 11.2 ± 0.2 years, p = .001 for EOA≤1.5, >1.5 cm2 , respectively). Moderate to severe PPM was associated with worse survival (11.1 ± 0.4 years for iEOA ≤ 0.85 cm2 /m2 vs. 12.5 ± 0.2 years with iEOA > 0.85 cm2 /m2 , p = .001). Moderate to severe PPM predicted worse long term survival (hazard ratio: 3.56; 95% confidence interval: 1.37-9.25; p = .009). Predicted prosthetic moderate to severe AS and moderate to severe PPM adversely affect long term survival. Smaller valves are associated with reduced survival.

Aortic root replacement with stentless xenografts in patients with aortic stenosis

ObjectiveStentless bioprosthetic valves such as the Freestyle conduit have been widely used as an option for aortic root replacement in the setting of aortic root aneurysms with acceptable long-term outcomes. However, there is a paucity of data regarding the use of the Freestyle prosthesis in patients with aortic stenosis. MethodsAll patients with a primary diagnosis of severe aortic stenosis who underwent complete aortic root replacement with Freestyle conduits were included. Primary outcomes included survival and readmissions for heart failure. Secondary outcomes included immediate postoperative complications. ResultsIn total, 2529 patients with severe aortic stenosis who needed an open aortic valve replacement with a biological prosthesis were operated on between 2011 and 2017. Of these, 294 patients underwent aortic root replacements using the Freestyle conduit with a primary diagnosis of native or prosthetic aortic stenosis. Eighty-four (28.6%) of the patients underwent reoperative sternotomy. The majority (53.7%) of the cohort were men. The mean age was 67.5 ± 13.0 years. Mean Society of Thoracic Surgeons Predicted Risk of Mortality when calculated with the assumption of aortic valve replacement ± coronary artery bypass grafting was 8.10% ± 10.8. The median follow-up time for the entire group was 2.7 years (interquartile range 0.9-4.5 years). Operative (30-day) mortality was 7.1% (n = 21). Kaplan–Meier mortality estimates at 1 and 5 years are 16.6% and 27.6%, respectively. Mean gradients were 7.15 ± 4.47 mm Hg at 1 month and 6.32 ± 4.76 mm Hg at 1 year. Readmissions for heart failure at 30 days, 1 year, and 5 years were 5.6%, 11.8%, and 17.4%, respectively. ConclusionsAortic root replacement using Freestyle bioprostheses is a viable option for patients with severe aortic stenosis with low risk of hospital readmission for heart failure.

Clinical Outcomes of Repeat Aortic Valve Replacement for Subaortic Pannus in Mechanical Aortic Valve.

This study aimed to evaluate the early and late clinical outcomes after repeat aortic valve replacement (AVR) for subaortic pannus in patients with mechanical valves. Methods and Results: Between 2001 and 2017, 51 patients (median age, 59 years; 42 women) with prosthetic aortic stenosis (AS) caused by pannus ingrowth underwent repeat AVR because of acute malfunction of monoleaflet valve (3 patients), severe prosthetic AS (30 patients), and moderate prosthetic AS at the time of tricuspid or mitral valve surgery (18 patients). The median follow-up duration was 100 (interquartile range, 64-138) months. Double valve replacement was performed in 45 (88%) patients. Median time interval from previous operation was 161 (interquartile range, 121-194) months. The explanted mechanical AV was monoleaflet and bileaflet in 16 (31%) and 34 (67%) patients, respectively. Concomitant procedures included 16 mitral valve replacements (14 repeat) and 36 tricuspid valve surgeries (15 replacements, 21 repairs). No hospital deaths or cases of heart block occurred. Overall survival and event-free survival rates at 10 years were 88% and 51%, respectively. Late complications included recurrent prosthetic AS (4 patients), new paravalvular leakage of the mitral valve (5 patients), and severe tricuspid regurgitation (2 patients). Although repeat AVR for subaortic pannus had acceptable early and late survival, recurrent prosthetic AS was frequently observed during late follow-up.

Incremental Prognostic Use of Left Ventricular Global Longitudinal Strain in Asymptomatic/Minimally Symptomatic Patients With Severe Bioprosthetic Aortic Stenosis Undergoing Redo Aortic Valve Replacement.

With improved survival of patients undergoing primary bioprosthetic aortic valve replacement (AVR), reoperation to relieve severe prosthetic aortic stenosis (PAS) is increasing. Timing of redo surgery in asymptomatic/minimally symptomatic patients remains controversial. Left ventricular (LV) global longitudinal strain (GLS) is a marker of subclinical LV dysfunction. In asymptomatic/minimally symptomatic patients with severe PAS undergoing redo AVR, we sought to determine whether LV-GLS provides incremental prognostic use. We studied 191 patients with severe bioprosthetic PAS (63±16 years, 58% men) who underwent redo AVR between 2000 and 2012 (excluding mechanical PAS, severe other valve disease transcatheter AVR, and LV ejection fraction <50%). Society of Thoracic Surgeons score was calculated. Standard echocardiography data were obtained. LV-GLS was measured on 2-, 3-, and 4-chamber views using velocity vector imaging. Severe PAS was defined as aortic valve area <0.8 cm2, mean aortic valve gradient ≥40 mm Hg, and dimensionless index <0.25. A composite outcome of death and congestive heart failure admission was recorded. At baseline, mean Society of Thoracic Surgeons score, LV ejection fraction, mean aortic valve gradients, and right ventricular systolic pressure were 7±6, 58±6%, 54±10 mm Hg and 40±14 mm Hg, whereas 50% had >2+ aortic regurgitation. Median LV-GLS was -14.2% (-11.4, -17.1%). At 4.2±3 years, 41 (22%) patients met the composite end point (2.5% deaths and 1% strokes at 30 days postoperatively). On multivariable Cox survival analysis, LV-GLS was independently associated with longer-term composite events (hazard ratio, 1.21; 95% confidence interval, 1.10-1.33), P<0.01. The C statistic for the clinical model (Society of Thoracic Surgeons score, degree of aortic regurgitation, and right ventricular systolic pressure) was 0.64 (95% confidence interval 0.54-0.79), P<0.001. Addition of LV-GLS to the clinical model increased the C statistic significantly to 0.71 (95% confidence interval 0.58-0.81), P<0.001. In asymptomatic/minimally symptomatic patients with severe bioprosthetic PAS undergoing redo AVR, baseline LV-GLS provides incremental prognostic use over established predictors and could potentially aid in surgical timing and risk stratification.

Abstract 13161: Incremental Prognostic Utility of Left Ventricular Global Longitudinal Strain in Asymptomatic/minimally Symptomatic Patients With Severe Bioprosthetic Aortic Stenosis Undergoing Redo Aortic Valve Replacement

Introduction: With improved survival of patients undergoing primary bioprosthetic aortic valve replacement (AVR), reoperation to relieve severe prosthetic aortic stenosis (PAS) is increasing. Timing of redo surgery in asymptomatic/minimally symptomatic patients remains controversial. Left ventricular global longitudinal strain (LV-GLS) is a marker of subclinical LV dysfunction. In asymptomatic/minimally symptomatic patients with severe PAS undergoing redo AVR, we sought to determine if LV-GLS provides incremental prognostic utility. Methods: We studied 191 patients with severe bioprosthetic PAS (63±16 years, 58% men) who underwent redo-AVR between 2000-12 (excluding mechanical PAS, severe other valve disease transcatheter AVR, LV ejection fraction &lt;50%). Society of Thoracic Surgeons (STS) score was calculated. Standard echocardiography data was obtained. LV-GLS was measured on 2, 3 and 4-chamber views using Velocity Vector Imaging. Severe PAS was defined as AV area &lt;0.8 cm 2 , mean AV gradient ≥40 mm Hg and/or dimensionless index &lt;0.25. A composite outcome of death and congestive heart failure (CHF) admission was recorded. Results: At baseline, mean STS score, LV ejection fraction, mean AV gradients, right ventricular systolic pressure (RVSP) were 7±6, 58±6%, 54±10 mm Hg and 40±14 mm Hg, while 50% had &gt;II+ aortic regurgitation (AR). Median LV-GLS was -14.2% [-11.4, -17.1%]. At 4.2±3 years, 41 (22%) patients met the composite endpoint. The results of the multivariable Cox analysis are shown in Table 1. Kaplan-Meier survival curves separated based on median LV-GLS are shown in Figure 1. Incremental prognostic utility of LV-GLS over established predictors is shown in Figure 2. Conclusions: In asymptomatic/minimally symptomatic patients with severe bioprosthetic PAS undergoing redo AVR, baseline LV-GLS provides incremental prognostic utility over established predictors; and could potentially aid in surgical timing and risk stratification.

Characteristics and Outcomes of Patients With Severe Bioprosthetic Aortic Valve Stenosis Undergoing Redo Surgical Aortic Valve Replacement.

With improved event-free survival of patients undergoing primary bioprosthetic aortic valve replacement (AVR), reoperation to relieve severe prosthetic aortic stenosis (PAS) is increasing. We sought to (1) identify of the characteristics of patients with severe bioprosthetic PAS undergoing redo AVR, and (2) assess the outcomes of these patients, along with factors associated with adverse outcomes. We studied 276 patients with severe bioprosthetic PAS (64±16 years, 58% men) who underwent redo-AVR between 2000 and 2012 (excluding mechanical PAS, severe other valve disease, and transcatheter AVR). Society of Thoracic Surgeons score was calculated. Severe PAS was defined as AV area <0.8 cm(2), mean AV gradient ≥40 mm Hg, or dimensionless index <0.25. A composite outcome of death and congestive heart failure admission was recorded. Mean Society of Thoracic Surgeons score and mean AV gradients were 8±8 and 53±17 mm Hg, whereas 28% had >II+ aortic regurgitation. Only 39% had an isolated redo AVR, the rest were combination surgeries (coronary bypass and/or aortic surgeries). At 4.2±3 years, 64 (23%) patients met the composite end point (48 deaths and 19 congestive heart failure admissions, 2.5% 30-day deaths). On multivariable Cox survival analysis, higher Society of Thoracic Surgeons score (hazard ratio, 1.35), higher grades of aortic regurgitation (hazard ratio, 1.29), and higher right ventricular systolic pressure (hazard ratio, 1.3) were associated with worse longer-term outcomes (all P<0.01). At an experienced center, in patients with severe bioprosthetic PAS undergoing redo AVR, the majority undergo combination surgeries but have excellent outcomes.

Coronary artery fistulas: A case presentation and literature review

Coronary fistulas are rare anomalies that connect the coronary artery to either a cardiac chamber (coronary cameral fistula) or vein (arteriovenous fistula). They arise due to abnormalities in embryologic development and are often coincidental findings. The exact incidence is estimated to be between 0.1-0.2 percent of the general population. There are no consensus guidelines for management of these fistulas. We present a patient with a large fistula and will review the literature and management decisions for this clinical abnormality.A 66-year-old man with diabetes, hypertension and a prior bioprosthetic aortic valve presented to the Loma Linda VA Hospital with shortness of breath. An echocardiogram revealed moderate to severe prosthetic aortic stenosis, and an angiogram showed 80% mid left anterior descending (LAD) obstruction with a large arteriovenous fistula. The fistula extended from the circumflex artery to coronary sinus. He was referred for redo open heart surgery with aortic valve replacement, coronary bypass grafting and repair of the fistula. There are multiple case reports of these malformations causing symptoms of angina, coronary steal or heart failure based on various testing modalities. However, in 31 individuals with incidental findings of coronary fistulas from a small case series, no adverse effects on cardiac function were noted based on physical exam or functional testing. If treatment is deemed beneficial, surgery is the most available option and another study of 41 symptomatic patients reported low post-operative morbidity and mortality after nine-year follow-up. The authors believe that large fistulas found incidentally should be further evaluated for ischemia and monitored for symptoms. For individuals with small fistulas, conservative management is a viable strategy as there is a high incidence of spontaneous closure. If a fistula is determined to be symptomatic, operative repair is well tolerated.

Accelerated degeneration of a bovine pericardial bioprosthetic aortic valve in children and young adults.

Experience with aortic valve replacement (AVR) with current-generation pericardial bioprostheses in young patients is limited. The death of a child with accelerated bioprosthetic aortic stenosis prompted enhanced surveillance of all such patients at our institution. We reviewed records of 27 patients who had undergone AVR (median follow-up, 13.7 months) with a bovine pericardial bioprosthesis at ≤30 years of age. In the Mitroflow LXA valve group (n=15), freedom from valve failure was 100% at 1 year, 53% (95% confidence interval, 12-82) at 2 years, and 18% (95% confidence interval, 1-53) at 3 years. No Magna/Magna Ease valves (n=12) failed by 3 years. Among valve failure patients, median age at AVR was 12 years (range, 10-21 years). Life-threatening prosthetic aortic stenosis was detected at a median of 6 months after prior echocardiograms showing mild or less gradients. Patients with Mitroflow LXA compared with Magna/Magna Ease valves were smaller (median body surface area, 1.42 versus 1.93 m(2); P=0.002) and younger (median age, 13.0 versus 20.9 years; P=0.02) at AVR. Pathology demonstrated diffuse intrinsic leaflet calcification, not associated with inflammation or infection, and virtually immobile leaflets in closed position. Young patients undergoing AVR with Mitroflow LXA pericardial valves are at high risk for rapid progression from mild or less to severe aortic stenosis over months, highlighting their need for heightened echocardiographic surveillance and suggesting that this aortic bioprosthesis should not be implanted in the young. Current data are insufficient to assess the safety of AVR with other pericardial bioprostheses in children and the youngest adults.

Sometimes an ounce of extracorporeal membrane oxygenation prevention is worth a pound of extracorporeal membrane oxygenation cure

Emergency aortic valve replacement in the setting of severe aortic valve stenosis and cardiogenic shock carries increased risk of morbidity, including postcardiotomy cardiac failure. 1 Mechanical circulatory support with extracorporeal membrane oxygenation (ECMO) can be a lifesaving therapy for such patients. We report here the management of a patient with severe prosthetic aortic stenosis in cardiogenic shock whom we treated with ECMO therapy to achieve clinical stabilization before urgent aortic valve replacement. CLINICAL SUMMARY A 77-year old woman was admitted with a non–STsegment myocardial infarction, severe prosthetic aortic valve stenosis, and an ejection fraction of 37%. The patient had cardiogenic shock develop and underwent placement of an intra-aortic balloon pump. This resulted in stabilization of her systemic blood pressure; however, acute kidney injury developed, with low urinary output (67 mL over 6 hours) and elevated serum creatinine level (acute increase

Mitroflow Bioprosthesis Stent Deformation: A Rare Cause of Early Prosthetic Stenosis

We report the case of a severe prosthetic aortic stenosis in a 61-year-old male patient with an aortic Mitroflow LF bioprosthesis (Sorin Group) at early (6 months) postoperative echocardiographic follow-up. At reintervention, we found significant stent deformation, asymmetric orientation of the posts, and subsequent central kinking and prolapse of one leaflet. Maldistribution of pledgeted mattress sutures over the flexible stent was found to be the origin of its permanent deformation. Simple technical preventive strategies of this previously unreported complication are suggested.

Prosthetic aortic stenosis: a method to prevent its occurrence by measurement of aortic size from preoperative aortogram.

A cause of early death after aortic valve replacement with a caged-ball prosthesis is obstruction to left ventricular outflow because the prosthesis is too large for the aortic root. Of 68 patients dying within two months of aortic valve replacement, death in ten, each of whom had had intractable low cardiac output after operation, was attributed at necropsy to prosthetic aortic stenosis, despite the use of small sized (8A Starr-Edwards) prostheses in seven of them. The diameters of the aorta at the sinotubular junction, determined from the preoperative cineangiograms, in the seven patients with prosthetic stenosis were &lt; 30 mm in all. Poppet clearances, defined as the differences between poppet and aortic root diameters, ranged from 4 to 12 mm (avg. 9). In contrast, the diameters of the aortas at the sinotubular junctions in eight control patients (unobstructed prosthetic aortic valves and early death from other causes) were &gt; 30 in all but one, and the poppet clearances ranged from 12 to 19 mm (avg. 15). Thus, prosthetic aortic stenosis is likely to develop after aortic valve replacement with rigid-framed caged ball valves if the preoperative aortograms disclose aortic diameters at the sinotubular junctions to be &lt; 30 mm. In such patients, either the aorta must be widened for a caged-ball prosthesis or a central flow valve must be used.