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).