Predictors of Clinical Response to Transcatheter Reduction of Secondary Mitral Regurgitation: The COAPT Trial.

BACKGROUND

Transcatheter mitral valve repair with the MitraClip results in marked clinical improvement in some but not all patients with secondary mitral regurgitation (MR) and heart failure (HF).

OBJECTIVES

This study sought to evaluate the clinical predictors of a major response to treatment in the COAPT trial.

METHODS

Patients with HF and severe MR who were symptomatic on maximally tolerated guideline-directed medical therapy (GDMT) were randomly assigned to MitraClip plus GDMT or GDMT alone. Super-responders were defined as those alive without HF hospitalization and with ≥20-point improvement in the Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS) score at 12 months. Responders were defined as those alive without HF hospitalization and with a 5 to <20-point KCCQ-OS improvement at 12 months. Nonresponders were those who either died, were hospitalized for HF, or had <5-point improvement in KCCQ-OS at 12 months.

RESULTS

Among 614 enrolled patients, 41 (6.7%) had missing KCCQ-OS data and could not be classified. At 12 months, there were 79 super-responders (27.2%), 55 responders (19.0%), and 156 nonresponders (53.8%) in the MitraClip arm compared with 29 super-responders (10.2%), 46 responders (16.3%), and 208 nonresponders (73.5%) in the GDMT-alone arm (overall p < 0.0001). Independent baseline predictors of clinical responder status were lower serum creatinine and KCCQ-OS scores and treatment assignment to MitraClip. MR grade and estimated right ventricular systolic pressure at 30 days were improved to a greater degree in super-responders and responders but not in nonresponders.

CONCLUSIONS

Baseline predictors of clinical super-responders in patients with HF and severe secondary MR in the COAPT trial were lower serum creatinine, KCCQ-OS score and MitraClip treatment. Improved MR severity and reduced right ventricular systolic pressure at 30 days are associated with a long-term favorable clinical response after transcatheter mitral valve repair. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [COAPT]; NCT01626079).