Prosthesis-Patient Mismatch in Bovine Pericardial Aortic Valves

Impact of Prosthesis-Patient Mismatch After Surgical Aortic Valve Replacement: Systematic Review and Meta-Analysis of Reconstructed Time-to-Event Data of 122 989 Patients With 592 952 Patient-Years

BACKGROUND

It remains controversial whether prosthesis-patient mismatch (PPM) impacts long-term outcomes after surgical aortic valve replacement. We aimed to evaluate the association of PPM with mortality, rehospitalizations, and aortic valve reinterventions.

METHODS AND RESULTS

We performed a systematic review with meta-analysis of reconstructed time-to-event data of studies published by March 2023 (according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Sixty-five studies met our eligibility criteria and included 122 989 patients (any PPM: 68 332 patients, 55.6%). At 25 years of follow-up, the survival rates were 11.8% and 20.6% in patients with and without any PPM, respectively (hazard ratio [HR], 1.16 [95% CI, 1.13-1.18], P<0.001). At 20 years of follow-up, the survival rates were 19.5%, 12.1%, and 8.8% in patients with no, moderate, and severe PPM, respectively (moderate versus no PPM: HR, 1.09 [95% CI, 1.06-1.11], P<0.001; severe versus no PPM: HR, 1.29 [95% CI, 1.24-1.35], P<0.001). PPM was associated with higher risk of cardiac death, heart failure-related hospitalizations, and aortic valve reinterventions over time (P<0.001). Statistically significant associations between PPM and worse survival were observed regardless of valve type (bioprosthetic versus mechanical valves), contemporary PPM definitions unadjusted and adjusted for body mass index, and PPM quantification method (in vitro, in vivo, Doppler echocardiography). Our meta-regression analysis revealed that populations with more women tend to have higher HRs for all-cause death associated with PPM.

CONCLUSIONS

The results of the present study suggest that any degree of PPM is associated with poorer long-term outcomes following surgical aortic valve replacement and provide support for implementation of preventive strategies to avoid PPM after surgical aortic valve replacement.

Impact of Flow on Prosthesis-Patient Mismatch Following Transcatheter and Surgical Aortic Valve Replacement

BACKGROUND

Severe prosthesis-patient mismatch (PPM) is diagnosed by an indexed effective orifice area <0.65 cm²/m², which is derived from stroke volume index. We examined the impact of flow, determined by stroke volume index, on severe PPM following transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR).

METHODS

We included SAVR patients from the PARTNER 2A trial (Placement of Aortic Transcatheter Valve 2A) and TAVR patients from the PARTNER 2 S3i (Placement of Aortic Transcatheter Valve 2 S3i) registry. The primary end point was the separate analysis of all-cause death, cardiac death, and rehospitalization at 5 years. Following TAVR and SAVR, we compared the primary end points between severe versus no-severe PPM in all patients, in low flow (LF), and in normal flow. Multivariable analysis was performed to determine variables associated with the end points.

RESULTS

Nine hundred fifty-four TAVR and 726 SAVR patients with PPM and flow data were included. Severe PPM following TAVR was significantly lower compared with SAVR in all patients (9% versus 28%, P<0.0001), in normal flow (5% versus 8%, P=0.04), and in LF (20% versus 42%, P<0.0001). Severe PPM was associated with rehospitalization following TAVR (odds ratio, 1.52 [95% CI, 1.01-2.29], P=0.0456) and SAVR (odds ratio, 1.51 [95% CI, 1.06-2.16], P=0.0237). Severe PPM in LF was independently associated with cardiac death following TAVR (odds ratio, 1.85 [95% CI, 1.06-3.23], P=0.0308). Following SAVR, severe PPM in LF and low ejection fraction was associated with increased cardiac death (35.26% versus 12.51%, P=0.01) and rehospitalization (37.59% versus 15.46%, P=0.006) compared with severe PPM in LF and preserved ejection fraction, respectively. Severe PPM in normal flow was not associated with clinical outcomes despite higher gradients and smaller valves compared with severe PPM in LF.

CONCLUSIONS

Severe PPM is more common following SAVR compared with TAVR. Regardless of the implanted valve size or gradient, severe PPM impacts mortality only in patients with LF following TAVR and LF and low ejection fraction following SAVR. Severe PPM in normal flow is not associated with poor outcomes. Registration: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01314313 and NCT02687035.

Reclassification of prosthesis-patient mismatch after transcatheter aortic valve replacement using predicted vs. measured indexed effective orifice area

AIMS

The objective was to compare the incidence and impact on outcomes of measured (PPMM) vs. predicted (PPMP) prosthesis-patient mismatch following transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

All consecutives patients who underwent TAVR between 2007 and 2018 were included. Effective orifice area (EOA) was measured by Doppler-echocardiography using the continuity equation and predicted according to the normal reference for each model and size of valve. PPM was defined using EOA indexed (EOAi) to body surface area as moderate if ≤0.85 cm2/m2 and severe if ≤ 0.65 cm2/m2 (respectively, ≤ 0.70 and ≤ 0.55 cm2/m2 if body mass index ≥ 30 kg/m2). The outcome endpoints were high residual gradient (≥20 mmHg) and the composite of cardiovascular mortality and hospital readmission for heart failure at 1 year. Overall, 1088 patients underwent a TAVR (55% male, age 79.1 ± 8.4 years, and STS score 6.6 ± 4.7%); balloon-expandable device was used in 83%. Incidence of moderate (10% vs. 27%) and severe (1% vs. 17%) PPM was markedly lower when defined by predicted vs. measured EOAi (P < 0.001). Balloon-expandable device implantation (OR: 1.90, P = 0.029) and valve-in-valve procedure (n = 118; OR: 3.21, P < 0.001) were the main factors associated with PPM occurrence. Compared with measured PPM, predicted PPM showed stronger association with high residual gradient. Severe measured or predicted PPM was not associated with clinical outcomes.

CONCLUSION

The utilization of the predicted EOAi reclassifies the majority of patients with PPM to no PPM following TAVR. Compared with measured PPM, predicted PPM had stronger association with haemodynamic outcomes, while both methods were not associated with clinical outcomes.

SAVR versus TAVI: What about the Hemodynamic Performance? An In Vivo and In Vitro Analysis

Background Surgical aortic valve replacement (SAVR) is nowadays discussed whether it remains the gold standard of treatment. In the last decade, there has been a tremendous increase in transcatheter aortic valve implantation (TAVI) due to the growing expertise and excellent results of the catheter-based approach. We, therefore, retrospectively compared the rapid deployment valve (RDV), the Edwards Intuity valve (IEV), with the Edwards Sapien 3 (S3V) with regard to post-procedural hemodynamics.

Methods A total of 246 patients treated with TAVI or SAVR between February 2009 and November 2015 were included. One-hundred twenty-five patients were analyzed in the SAVR group and compared with 121 patients undergoing TAVI. Transvalvular pressure gradients (PGs) and the incidence and extent of aortic regurgitation (AR) were compared post-procedurally by echocardiography for each valve size. In vitro hemodynamics were analyzed by placing both valves into an aortic silicone phantom connected to a pulsatile flow pump and measured using phase-contrast magnetic resonance imaging (4D flow MRI).

Results Post-procedurally, mean transvalvular PGs for the 23 mm valves were 9 (7;11.5) versus 13 (9;18) (p < 0.001), whereas maximum PGs were 16.5 (14;22) versus 25.5 mm Hg (17.5;34) (p < 0.001) in IEV and S3V patients, respectively. The 21 mm IEV showed significantly lower transvalvular PGs compared with the 23 mm S3V: mean PGs: 11 (8;13) versus 13 (9;18) (p < 0.05); maximum PG: 19.5 (13;24) versus 25.5 (18;34) mm Hg (p < 0.05). Analysis revealed significantly lower post-procedural transvalvular PGs for larger valves sizes. With respect to AR, the incidence of AR was significantly lower in IEV group (p < 0.05). In vitro velocities and turbulent kinetic energy values showed similar results between both valves.

Conclusion Implanted RDVs presented a lower incidence of paravalvular regurgitation and were associated with significantly lower post-procedural transvalvular PGs, especially for small valve sizes. Our data might support the application of rapid deployment aortic valves in patients with small aortic annulus in the TAVI era.

Aortic valve cell seeding into decellularized animal pericardium by perfusion-assisted bioreactor

Animal-derived pericardium is the elective tissue employed in manufacturing heart valve prostheses. The preparation of this tissue for biological valve production consists of fixation with aldehydes, which reduces, but not eliminates, the xenoantigens and the donor cellular material. As a consequence, especially in patients below 65-70 years of age, the employment of valve substitutes contaning pericardium is not indicated due to progressive calcification that causes tissue degeneration and recurrence of valve insufficiency. Decellularization with ionic or nonionic detergents has been proposed as an alternative procedure to prepare aldehyde- or xenoantigen-free pericardium for biological valve manufacturing. In the present contribution, we optimized a decellularization procedure that is permissive for seeding and culturing valve competent cells able to colonize and reconstitute a valve-like tissue. A high-efficiency cellularization was achieved by forcing cell penetration inside the pericardium matrix using a perfusion bioreactor. Because the decellularization procedure was found not to alter the collagen composition of the pericardial matrix and cells seeded in the tissue constructs consistently grew and acquired the phenotype of "quiescent" valve interstitial cells, our investigation sets a novel standard in pericardium application for tissue engineering of "living" valve implants.

Surgical sutureless and transcatheter aortic valves: hemodynamic performance and clinical outcomes in propensity score-matched high-risk populations with severe aortic stenosis

OBJECTIVES

In propensity score-matched patients with severe aortic stenosis treated with surgical aortic valve replacement (AVR) with the 3f Enable sutureless prosthesis (Medtronic, Minneapolis, Minnesota) or transcatheter aortic valve replacement (TAVR), the hemodynamic performance of both valves and mid-term survival of patients were evaluated.

BACKGROUND

Data on hemodynamic performance of surgical sutureless bioprostheses in high operative risk patients with aortic stenosis are scarce.

METHODS

Of 258 patients undergoing TAVR or surgical aortic valve replacement with the 3f Enable valve, 80 (79 ± 5 years of age, 100% men) were included in the current analysis on the basis of propensity score 1:1 matching for baseline clinical and hemodynamic characteristics. All patients had hemodynamic echocardiographic evaluation at baseline and discharge. Mid-term survival was analyzed.

RESULTS

Compared with the 3f Enable valve, TAVR prostheses (Edwards SAPIEN XT [Edwards Lifesciences, Irvine, California] and CoreValve [Medtronic]) had larger effective orifice area index (1.00 ± 0.30 cm(2)/m(2) vs. 0.76 ± 0.22 cm(2)/m(2); p < 0.001), lower pressure gradient (8.14 ± 4.21 mm Hg vs. 10.72 ± 4.01 mm Hg; p = 0.006), less frequent prosthesis-patient mismatch (30.0% vs. 67.5%; p = 0.001), and low flow (46.2% vs. 72.5%; p = 0.02), but more frequent aortic regurgitation (87.5% vs. 20.0%; p < 0.001). The presence of prosthesis-patient mismatch was independently associated with a low-flow state at discharge (odds ratio: 4.70; p = 0.004) and independently associated with the use of the sutureless prosthesis (odds ratio: 3.90; p = 0.02). However, the survival of the 2 groups was comparable after 1.5-year (interquartile range: 0.79 to 2.01 years) follow-up (log-rank test, p = 0.95).

CONCLUSIONS

TAVR prostheses demonstrated better hemodynamics than the 3f Enable valve but a higher incidence of aortic regurgitation. However, these differences did not influence mid-term survival of patients.

Comparison of outcomes and presentation in men-versus-women with bicuspid aortic valves undergoing aortic valve replacement

Gender disparities in short- and long-term outcomes have been documented in cardiac and valvular heart surgery. However, there is a paucity of data regarding these differences in the bicuspid aortic valve (BAV) population. The aim of this study was to examine gender-specific differences in short- and long-term outcomes after surgical aortic valve (AV) replacement in patients with BAV. A retrospective analysis was performed in 628 consecutive patients with BAV who underwent AV surgery from April 2004 to December 2013. To reduce bias when comparing outcomes by gender, propensity score matching obtained on the basis of potential confounders was used. Women with BAV who underwent AV surgery presented with more advanced age (mean 60.7 ± 13.8 vs 56.3 ± 13.6 years, p <0.001) and less aortic regurgitation (29% vs 44%, p <0.001) and had a higher risk for in-hospital mortality (mean Ambler score 3.4 ± 4.4 vs 2.5 ± 4.0, p = 0.015). After propensity score matching, women received more blood products postoperatively (48% vs 34%, p = 0.028) and had more prolonged postoperative lengths of stay (median 5 days [interquartile range 5 to 7] vs 5 days [interquartile range 4 to 6], p = 0.027). Operative, discharge, and 30-day mortality and overall survival were not significantly different. In conclusion, women with BAV who underwent AV surgery were older, presented with less aortic regurgitation, and had increased co-morbidities, lending higher operative risk. Although women received more blood products and had significantly longer lengths of stay, short- and long-term outcomes were similar.