Background

A sizeable proportion of patients with secondary mitral regurgitation (SMR) do not receive guideline-directed medical therapy (GDMT) for heart failure (HF). This study aimed to assess the prognostic impact of GDMT in patients with SMR who underwent transcatheter edge-to-edge mitral valve repair (TEER).

Methods

We retrospectively analyzed patients with SMR and a left-ventricular ejection fraction (LVEF) of <50% who underwent TEER with the MitraClip system at three German centers. According to the 2021 European Society of Cardiology HF guidelines, GDMT was defined as the use of renin-angiotensin-aldosterone system inhibitors, beta-blockers, and mineralocorticoid receptor antagonists. Patients were divided into two groups: GDMT or non-GDMT groups.

To minimize confounding by patient factors for GDMT, we calculated the propensity scores and carried out inverse probability of treatment weighting (IPTW) analyses to compare two-year mortality between the two groups. The propensity score was built using multiple logistic regression model, consisting of baseline patient characteristics and echocardiographic parameters.

Also, post-procedural echocardiographic assessments were collected at one year after TEER, and LV reverse remodeling was defined as a reduction in the LV end-systolic volume of ≥10% from baseline to the one-year follow-up.

Results

Of 463 patients (mean age: 74 ± 9 years; male: 72.6%), 228 patients (49.2%) were treated with GDMT upon discharge. IPTW-adjusted Kaplan–Meier curve showed patients with GDMT had a lower incidence of mortality compared to those without GDMT (19.8% vs. 31.1%, p=0.011; Figure 1). In IPTW-adjusted Cox-proportional hazard analysis, GDMT was associated with a reduced risk of two-year mortality (weighted hazard ratio: 0.58; 95% confidence interval: 0.35–0.95; p=0.030). The prognostic impact of GDMT was consistent across the clinical subgroups, including age, renal function, LVEF, and residual MR. Moreover, patients with GDMT had a higher rate of the LV reverse remodeling at one year after TEER compared to those without GDMT (40.2% vs. 26.8%; p=0.038).

Conclusions

In patients with SMR, GDMT was associated with a reduced risk of all-cause mortality within two years after TEER. Our findings underline that there is a crucial need for using optimal GDMT to improve patient outcomes after undergoing TEER for SMR.