Comparison of Cardiac Resynchronization Therapy Outcomes in Patients With New York Heart Association Functional Class I/II Versus III/IV Heart Failure

Background: Several randomized trials have shown that cardiac resynchronization therapy (CRT) benefits New York Heart Association (NYHA) functional class I/II heart failure (HF) patients, but it is unknown if similar outcomes occur in the real-world. Methods and Results: All patients receiving CRT between 2003 and 2008 with ejection fraction (EF) <= 35% and QRS duration >= 120 ms were included. Outcomes assessed were subjective clinical response, echocardiographic response, and survival free of cardiovascular (CV) hospitalization. Baseline demographics in functional class I/II (n = 155) and functional class III/IV (n = 512) were similar, except for differences in age and several comorbidities. Clinical response was similar in both groups. The functional class I/II group had a greater decrease in left ventricular (LV) end-diastolic dimension (P = .031), and trended toward greater improvements in LV end-systolic dimension (P = .056) and EF (P = .059). The functional class I/II group had a better 5-year survival rate (79 vs 54%; P < .0001) and survival free of CV hospitalization (45% vs 26%; P < .0001). Conclusions: In this real-world clinical scenario, NYHA functional class I/II CRT patients improved clinical status, and LV function and size as good as or better than those in NYHA functional class III/IV patients. These observations provide further support for the use of CRT in patients with mild symptoms of HF. (J Cardiac Fail 2012;18:373-378)