Mid-term results of mitral valve repair for ischemic mitral regurgitation adjusted according to the degree of remodeling progression

Comparison of transcatheter edge-to-edge and surgical repair in patients with functional mitral regurgitation using a meta-analytic approach

Background

Evidence regarding favorable treatment of patients with functional mitral regurgitation (FMR) using transcatheter edge-to-edge repair (TEER) is constantly growing. However, there is only few data directly comparing TEER and surgical mitral valve repair (SMVr).

Aims

To compare baseline characteristics, short-term and 1-year outcomes in FMR patients undergoing mitral valve (MV) TEER or SMVr using a meta-analytic approach.

Methods

Systematic database search identified 1,703 studies reporting on TEER or SMVr for treatment of FMR between January 2010 and December 2020. A meta-analytic approach was used to compare outcomes from single-arm and randomized studies based on measures by means of their corresponding 95% confidence intervals (CI). Statistical significance was assumed if CIs did not overlap. A total of 21 TEER and 37 SMVr studies comprising 4,304 and 3,983 patients were included.

Results

Patients in the TEER cohort presented with higher age (72.0 ± 1.7 vs. 64.7 ± 4.7 years, p < 0.001), greater burden of comorbidities like hypertension (p < 0.001), atrial fibrillation (p < 0.001), lung disease (p < 0.001) and chronic renal disease (p = 0.005) as well as poorer left ventricular ejection fraction (30.9 ± 5.7 vs. 36.6 ± 5.3%, p < 0.001). In-hospital mortality was significantly lower with TEER [3% (95%-CI 0.02-0.03) vs. 5% (95%-CI 0.04-0.07)] and 1-year mortality did not differ significantly [18% (95%-CI 0.15-0.21) vs. 11% (0.07-0.18)]. NYHA [1.06 (95%-CI 0.87-1.26) vs. 1.15 (0.74-1.56)] and MR reduction [1.74 (95%-CI 1.52-1.97) vs. 2.08 (1.57-2.59)] were comparable between both cohorts.

Conclusion

Despite considerably higher age and comorbidity burden, in-hospital mortality was significantly lower in FMR patients treated with TEER, whereas a tendency toward increased 1-year mortality was observed in this high-risk population. In terms of functional status and MR grade reduction, comparable 1-year results were achieved.

Effect of early versus late onset mitral regurgitation on left ventricular remodeling in ischemic cardiomyopathy in an animal model

BACKGROUND

Patients who survive a myocardial infarction have progressive cardiac dysfunction and ventricular remodeling. Mitral regurgitation is often diagnosed in these patients, and is a risk factor that portends poor prognosis. Whether such postinfarction mitral regurgitation magnifies adverse left ventricular remodeling is unclear, which was studied in an animal model.

METHODS

Forty-one adult rats were induced with myocardial infarction using left coronary artery ligation and assigned to 3 groups: group 1, myocardial infarction only; group 2, myocardial infarction with severe mitral regurgitation introduced after 4 weeks; and group 3, myocardial infarction with severe mitral regurgitation introduced after 10 weeks. Valve regurgitation was introduced by advancing a transapical ultrasound-guided needle into the mitral valve anterior leaflet. Animals were survived to 20 weeks from the index procedure, with biweekly cardiac ultrasound, and invasive hemodynamics and histology at termination.

RESULTS

At 20 weeks, end diastolic volume was largest in the groups with mitral regurgitation, compared with the group without the valve lesion (group 1, 760.9 ± 124.6 μL; group 2, 958.0 ± 115.1 μL; group 3, 968.3 ± 214.9 μL). Similarly, end systolic volume was larger in groups with regurgitation (group 1, 431.2 ± 152.6 μL; group 2, 533.2 ± 130.8 μL; group 3, 533.1 ± 177.5 μL). In the infarction-only group, left ventricular remodeling was maximal until 6 weeks and plateaued thereafter. In groups with mitral regurgitation, left ventricular remodeling was significantly elevated at the onset of regurgitation and persisted.

CONCLUSIONS

Mitral regurgitation is a potent driver of adverse cardiac remodeling after a myocardial infarction, irrespective of the timing of its onset.

Influence of preoperative right ventricular function on left ventricular remodeling and survival after subvalvular repair for functional mitral regurgitation

OBJECTIVES

The objective of this study was to analyze our surgical experiences with mitral valve plasty (MVP) combined with subvalvular procedures (SVPs) for functional mitral regurgitation (FMR) and to determine which preoperative factors affected clinical outcomes.

METHODS

This study retrospectively analyzed 33 patients who underwent MVP combined with SVPs for FMR with a left ventricular ejection fraction lower than 40% and advanced remodeled left ventricles. The mean follow-up period was 49 ± 33 months.

RESULTS

The preoperative mean right ventricular fractional area change (RVFAC) used to quantify right ventricular (RV) systolic function was 26 ± 11%. Sixteen patients (48%) had an RVFAC < 26%. One patient died during hospital stay, and nine more patients died of cardiac causes during follow-up. The 3- and 5-year rates of freedom from cardiac-related mortality were 78% and 68%, respectively. RVFAC was the significant predictor of cardiac-related mortality in a univariate analysis (risk ratio [RR] = 0.92, 95% confidence interval [CI] 0.85-0.99, p = 0.03) and demonstrated a non-significant tendency to predict cardiac-related mortality in the Cox multivariate analysis (RR = 0.94, 95% CI 0.86-1.003, p = 0.08). Continued reverse left ventricular remodeling was associated with an RVFAC ≥ 26%. At 3 years, there was also a significant difference in survival rates of cardiac-related mortality between patients with an RVFAC ≥ 26% and < 26% (94% vs. 61%; p = 0.03).

CONCLUSIONS

Preoperative RV function affected left ventricular remodeling and cardiac-related mortality after MV surgery. MVP combined with SVPs for FMR provided promising results for patients without severe RV dysfunction.

Direct Percutaneous Mitral Annuloplasty in Patients With Functional Mitral Regurgitation: When and How

Mitral regurgitation (MR) is a frequent valvular disease among patients deemed too high risk for surgery. Echocardiography along with CT is the primary diagnostic tool for MR and offers a comprehensive 3D assessment in patient selection and screening for the optimal treatment method. The direct percutaneous mitral annuloplasty addresses the underlying mechanisms of functional MR with a less invasive, catheter-based approach. The here-described techniques proved a sufficient safety profile, delivered significant MR reduction in most of the cases, and were associated with a notable improvement of symptoms. Although long-term outcome assessment is needed to support these early reports, the percutaneous mitral annuloplasty is likely to set a new standard of treatment in the forthcoming future.