Prognostic implications of mitral valve geometry in patients with secondary mitral regurgitation: the COAPT trial

The impact of mitral valve geometry on outcomes after MitraClip treatment in secondary mitral regurgitation (MR) has not been examined. We therefore sought to evaluate the association between mitral valve geometry and outcomes of patients with heart failure (HF) and secondary MR treated with guideline-directed medical therapy (GDMT) and MitraClip.

Mitral valve geometry was assessed from the baseline echocardiograms in 614 patients from the COAPT trial. The primary endpoint for the present study was the composite of all-cause mortality or HF hospitalization (HFH) within 2 years. Effect of treatment arm (MitraClip plus maximally tolerated GDMT vs. GDMT alone) on outcomes according to baseline variables was assessed. Among 29 baseline mitral valve echocardiographic parameters, increasing anteroposterior mitral annular diameter was the only independent predictor of the composite endpoint of all-cause mortality or HFH [adjusted hazard ratio (aHR) per cm 1.49; P = 0.04]. The effective regurgitant orifice area (EROA) was independently associated with all-cause mortality alone (aHR per cm² 2.97; P = 0.04) but not with HFH, whereas increasing anteroposterior mitral annular diameter was independently associated with HFH alone (aHR per cm 1.85; P = 0.005) but not all-cause mortality. Other mitral valve morphologic parameters were unrelated to outcomes. MitraClip reduced HFH and mortality independent of anteroposterior mitral annular diameter and EROA (P_interaction = 0.77 and 0.27, respectively).

In patients with HF and severe secondary MR, a large anteroposterior mitral annular diameter and greater EROA were the strongest echocardiographic predictors of HFH and death in patients treated with GDMT alone and with the MitraClip.