Heart failure medical therapy and outcomes in patients undergoing transcatheter mitral valve repair for secondary mitral regurgitation: a TVT Registry analysis across 449 US centers
Authors: Varshney A S , Shah M , Vemulapalli S , Kosinski A , Bhatt A S , Sandhu A T , Hirji S , Defilippis E M , Shah P B , Fiuzat M , Ogara P T , Bhatt D L , Kaneko T , Givertz M M , Vaduganathan M 
Published: November 2023

Abstract

Background
Guidelines recommend medical therapy optimization prior to transcatheter mitral valve repair (TMVr) in patients with heart failure (HF), left ventricular ejection fraction (LVEF) &lt;50%, and severe secondary mitral regurgitation (SMR). Whether TMVr is being performed on the background of optimal guideline directed medical therapy (GDMT) in clinical practice is unknown.

Purpose
To assess pre-procedure GDMT (B-blockers, ACEI [angiotensin converting enzyme inhibitor]/ARB [angiotensin receptor blocker], ARNI [angiotensin receptor neprilysin inhibitor], MRA [mineralocorticoid receptor antagonist]) use and association with outcomes in patients with HF and LVEF &lt;50% undergoing TMVr.

Methods
Patients with LVEF &lt;50% who underwent TMVr for SMR from July 2019 – March 2022 in the Transcatheter Valve Therapy Registry were identified. Patients on inotropes or in shock pre-TMVr were excluded. Cox proportional hazards models were constructed to evaluate adjusted associations between pre-TMVr medical therapy (no, single, double, or triple therapy) and risk of the one-year composite outcome of mortality or HF hospitalization. Sensitivity analyses excluded patients with HF with mildly reduced ejection fraction (HFmrEF) (LVEF &gt;40%) or New York Heart Association (NYHA) class I (asymptomatic) prior to TMVr.

Results
A total of 4,199 patients across 449 sites were identified. Prior to TMVr, B-blockers (85.1%) were prescribed most frequently, followed by ACEI/ARB (44.4%), MRA (28.6%), and ARNI (19.9%). Triple therapy was prescribed for 19.2% of patients, while 38.2% were on double therapy, 36.0% were on single therapy, and 6.5% were on no medical therapy. Triple therapy use varied from 0 - 61% across sites with an adjusted median odds ratio of 1.48 (95% confidence interval [CI] 1.25-3.88, P&lt;0.001), suggesting a 1.5-fold variation in the likelihood that similar risk patients at 2 random US sites received triple therapy pre-TMVr (Figure 1). In patients with one-year follow-up available (n=2,014, 341 sites), the composite rate of one-year mortality or HF hospitalization was lowest in patients on triple therapy (23.1%) compared with double (24.8%), single (35.7%), and no (41.1%) therapy (P≤0.01). Associations persisted after accounting for clinically relevant covariates, with lower risk in patients on triple therapy (adjusted hazard ratio [aHR] 0.73, 95% CI 0.55-0.97) and double therapy (aHR 0.60, 95% CI 0.50-0.74) prior to TMVr compared with no/single therapy. Results were similar when only patients with symptomatic HFrEF were considered (i.e., those with HFmrEF or NYHA class I pre-TMVr were excluded) (Figure 2).

Conclusions
Under one-fifth of patients who underwent TMVr for SMR were prescribed comprehensive GDMT, with substantial variation across clinical sites. Compared with no or single therapy, triple and double therapy use prior to TMVr was independently associated with reduced risk of mortality or HF hospitalization one-year after intervention.Figure 1Figure 2