Cardiac Resynchronization Induces Major Structural and Functional Reverse Remodeling in Patients With New York Heart Association Class I/II Heart Failure

Cardiac resynchronization therapy (CRT) improves LV structure, function, and clinical outcomes in New York Heart Association class III/IV heart failure with prolonged QRS. It is not known whether patients with New York Heart Association class I/II systolic heart failure exhibit left ventricular (LV) reverse remodeling with CRT or whether reverse remodeling is modified by the cause of heart failure. Six hundred ten patients with New York Heart Association class I/II heart failure, QRS duration > or =120 ms, LV end-diastolic dimension > or =55 mm, and LV ejection fraction < or =40% were randomized to active therapy (CRT on; n=419) or control (CRT off; n=191) for 12 months. Doppler echocardiograms were recorded at baseline, before hospital discharge, and at 6 and 12 months. When CRT was turned on initially, immediate changes occurred in LV volumes and ejection fraction; however, these changes did not correlate with the long-term changes (12 months) in LV end-systolic (r=0.11, P=0.31) or end-diastolic (r=0.10, P=0.38) volume indexes or LV ejection fraction (r=0.07, P=0.72). LV end-diastolic and end-systolic volume indexes decreased in patients with CRT turned on (both P