Prognostic Importance of Health Status Versus Functional Status in Heart Failure and Secondary Mitral Regurgitation.

OBJECTIVES: This study sought to understand the extent to which health status and exercise capacity are independently associated with long-term outcomes in patients with heart failure (HF) and secondary mitral regurgitation (MR). BACKGROUND: Secondary MR in patients with HF leads to impaired health status (Kansas City Cardiomyopathy Questionnaire Overall Summary Score [KCCQ-OS]) and exercise capacity (6-minute walk distance [6MWD]), both of which improve after transcatheter mitral valve repair (TMVr). METHODS: The study used data from the COAPT trial (N = 604) to examine the association of baseline KCCQ-OS and 6MWD with 2-year mortality and HF hospitalization, adjusting for treatment arm and patient factors. We also examined the association of change in KCCQ-OS and 6MWD from baseline to 1 month with risk of outcomes from 1 month to 2 years. Interactions of KCCQ-OS and 6MWD with treatment assignment were explored. RESULTS: Mean baseline KCCQ-OS was 53 ± 23 points, and 6MWD was 240 ± 125 meters. In models including both measures, greater baseline 6MWD (but not KCCQ-OS) was associated with reduced 2-year mortality (HR per 125 meters: 0.75, 95% CI: 0.61-0.92). When stratified by treatment group, both baseline KCCQ-OS and 6MWD were independently associated with HF hospitalization in patients treated with medical therapy, whereas only KCCQ-OS was associated with HF hospitalization in patients treated with TMVr. In separate analyses, 1-month improvements in KCCQ-OS and 6MWD were each associated with lower subsequent risk of mortality and HF hospitalization, independent of treatment group. CONCLUSIONS: Among patients with HF and severe secondary MR, assessment of both health status and exercise capacity provide complementary prognostic information for patients with HF and severe secondary MR-both before and after TMVr. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial]; NCT01626079).