NYHA Functional Classification and Outcomes After Transcatheter Mitral Valve Repair in Heart Failure: The COAPT Trial

Objectives: The aim of this study was to evaluate the outcomes of MitraClip implantation versus guideline-directed medical therapy (GDMT) in patients with secondary mitral regurgitation (SMR) according to baseline functional status as assessed by the widely used New York Heart Association (NYHA) functional classification.

Background: Patients with heart failure (HF) and impaired functional status at baseline have poor prognosis. Whether the effects of transcatheter repair of secondary SMR in patients with HF are influenced by baseline functional status is unknown.

Methods: In the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial, patients with HF with moderate to severe or severe SMR who remained symptomatic despite maximally tolerated GDMT were randomized to MitraClip implantation versus GDMT alone. Outcomes were evaluated according to baseline functional status as assessed using the NYHA functional classification. The primary endpoint of interest was the rate of death or HF-related hospitalization (HFH) at 2 years in time-to-first-event analyses.

Results: Among 613 randomized patients, 240 were in NYHA functional class II (39.2%), 322 were in NYHA functional class III (52.5%), and 51 were in ambulatory NYHA functional class IV (8.3%). Rates of death or HFH were progressively higher with increasing NYHA functional class. Compared with GDMT alone, MitraClip implantation resulted in lower 2-year rates of death or HFH consistently in patients in NYHA functional class II (39.7% vs. 63.7%; hazard ratio [HR]: 0.54; 95% confidence interval [CI]: 0.37 to 0.77), NYHA functional class III (46.6% vs. 65.5%; HR: 0.60; 95% CI: 0.45 to 0.82), and NYHA functional class IV (66.7% vs. 85.2%; HR: 0.55; 95% CI: 0.28 to 1.10; p_interaction = 0.86). Greater improvements in quality of life at 2 years were observed in patients treated with the MitraClip compared with GDMT irrespective of baseline functional status.

Conclusions: The NYHA functional classification provides prognostic utility in patients with HF and moderate to severe or severe SMR. In the COAPT trial, the benefits of MitraClip implantation were consistent in patients with better or worse functional status as assessed by NYHA functional class. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] [COAPT]; NCT01626079).