Abstract Aims Infective endocarditis (IE) is a serious and potentially fatal complication of mitral valve (MV) intervention. There are limited data comparing the incidence of IE after MV repair compared with bioprosthetic MV replacement. The aim of this study was to analyse the incidence and timing of IE after MV repair compared with bioprosthetic valve replacement, in both surgical and transcatheter patient populations. Methods and results A literature search of Medline, Embase, and Cochrane Library (January 2000—September 2025) was conducted. Pooled IE incidence rates were derived using random-effects models. Eighty-two studies (80 939 patients, total follow-up 350 252 patient-years) were included. The overall incidence rate of IE was 0.97 per 100-patient-years (95% confidence interval [CI] 0.71–1.34). IE was more common after surgical MV replacement (SMVR) than surgical MV repair (SMVr): incidence rate 0.93 (95% CI 0.41–1.81) vs 0.39 (95% CI 0.25–0.62) per 100-patient-years, incidence rate ratio (IRR) 2.34 (95% CI 1.06–5.18), P = .035. The incidence of IE after transcatheter MV replacement (TMVR) was comparable to transcatheter MV repair (TMVr) (2.88 [95% CI 1.91–4.33] vs 1.70 [95% CI 0.84–3.43] per 100-patient-years), IRR 1.56 (95% CI 0.73–3.34), P = .250. The cumulative incidence of IE following SMVR was significantly higher than following SMVr at 1- and 2-years post-procedure, but not at 6 months. Conclusions IE is an infrequent complication of mitral valve intervention. The incidence of IE following SMVR is significantly higher than following SMVr, while the incidence of IE following TMVR is numerically but not significantly higher than following TMVr. Reducing IE risk after mitral intervention is a clinical and research priority.
Hemodynamic and Clinical Outcomes of Transcatheter Valve Expansion in Degenerated Mitral Bioprostheses
BACKGROUND: Transcatheter mitral valve-in-valve replacement is an established therapy for intermediate and high-risk patients with degenerated bioprostheses, but restricted transcatheter valve (THV) expansion within rigid surgical frames and elevated gradients have raised durability concerns. This study aimed to evaluate midterm outcomes of mitral valve-in-valve patients according to THV expansion and sizing strategy. METHODS: Patients who underwent mitral valve-in-valve with balloon-expandable valves at Mayo Clinic Rochester between 2014 and 2023 were retrospectively analyzed. THV expansion (inflow, waist, outflow) was measured from procedural fluoroscopy and indexed to nominal size, with zero indicating expansion to nominal dimensions. Median index values were used as subgroup cutoffs to compare the incidence of the primary composite outcome of all-cause mortality, heart failure readmission, and valve reintervention. RESULTS: The analysis included 80 patients with a median follow-up of 2.5 years. A total of 53 (66%) valves were underexpanded across all 3 sizes, with median inflow, waist, and outflow expansion indices of −10.2, −16.2, and −3.2, respectively. Across all indices, THV expansion closer to nominal size was associated with lower rates of the primary outcome ( P <0.05). Greater expansion correlated with a larger mitral valve area and lower transvalvular mean gradient. Oversized THVs were significantly less expanded and had a higher incidence of the primary composite outcome compared with recommended-size THVs ( P =0.02). CONCLUSIONS: THV underexpansion in degenerated mitral bioprostheses is common and associated with elevated gradients and worse midterm outcomes. Further research is warranted to define THV expansion targets and improve outcomes following mitral valve-in-valve intervention.
Valve thrombosis and antithrombotic therapy after bioprosthetic mitral valve replacement: a systematic review and meta-analysis
Abstract Aims Transcatheter mitral valve replacement (TMVR) has become a feasible alternative to surgical mitral valve replacement (SMVR) in selected patients at high surgical risk. The risk of valve thrombosis following SMVR and TMVR, and the optimal antithrombotic therapy following these procedures, remains uncertain. We aimed to compare the incidence of bioprosthetic mitral valve thrombosis (bMVT) after SMVR and TMVR, and the incidence of bMVT between patients on different antithrombotic regimens. Methods and results A literature search of Medline, Embase, and Cochrane Library was performed between January 2000 and August 2024. Random-effects models were used to derive pooled estimates of the incidence of bMVT in the absence of prior or active endocarditis and valve thrombosis. A total of 47 studies (6170 patients, total follow-up 9541.8 patient-years) were eligible for inclusion. The overall incidence of bMVT was 5.05 [95% confidence interval (CI) 3.18–8.01, I2 = 82%] per 100-patient-years. Subclinical bMVT was more common than clinically significant bMVT: incidence 19.11 vs. 7.91 per 100-patient-years, adjusted incidence rate ratio (aIRR) 4.62 (95% CI 1.39–15.36), P = 0.012. bMVT was numerically more common after TMVR than SMVR, but the comparison was not statistically significant: incidence 7.03 vs. 0.58 per 100-patient-years, aIRR 2.19 (95% CI 0.72–6.72), P = 0.170. Patients on vitamin-K antagonists (VKA) had a lower incidence of bMVT than patients on direct oral anticoagulants (DOAC; incidence 5.72 vs. 17.08, aIRR 0.31, 95% CI 0.13–0.73, P = 0.007). Conclusions bMVT is not uncommon, with numerically higher incidence in transcatheter compared to surgical valves, but the comparison was not statistically significant. VKAs are associated with a lower incidence of bMVT compared to DOACs.