ABSTRACT

BACKGROUND- In the COAPT trial among patients with heart failure (HF) and moderate-to-severe (3+) or severe (4+) secondary mitral regurgitation (SMR), patients treated with the transcatheter mitral valve replacement (TMVR) had reduced rates of HF hospitalization and mortality compared with guideline-directed medical therapy (GDMT) alone.

OBJECTIVES- To describe the echocardiographic patient qualification process for COAPT, baseline echocardiographic characteristics, changes over time, and the interaction between treatment group and echocardiographic parameters on clinical outcomes.

METHODS- A novel echocardiographic algorithm was implemented for grading MR severity during the screening process. Standardized echocardiograms were obtained at baseline and during regular follow-up intervals through 2 years, and analyzed by a core laboratory.

RESULTS- A total of 614 patients were randomized to TMVR plus maximally- tolerated GDMT or GDMT alone. Mean baseline left ventricular ejection fraction (LVEF) was 31.3±9.3%, LV end-diastolic volume was 192.7±71 ml, and effective regurgitant orifice area was 0.41±0.15 cm2. The beneficial effect of TMVR compared with GDMT alone was consistent in all echocardiographic subgroups, independent of the severity of LV dysfunction, LV dilatation, pulmonary hypertension, severity of tricuspid regurgitation or individual MR characteristics. The LVEF decreased and the LV volumes progressively increased in both groups during follow-up, although less after TMVR (P<0.05).

CONCLUSIONS- HF patients in the COAPT trial with 3+ or 4+ SMR, selected using strict echocardiographic criteria, benefitted from TMVR with reduced 2-year rates of death and HF hospitalization. Strict application of these echocardiographic criteria should enable the COAPT results to be translated to clinical practice.