Cardiac resynchronization therapy in patients with systolic left ventricular dysfunction and symptoms of mild, heart failure secondary to ischemic or nonischemic cardiomyopathy

Cardiac resynchronization therapy (CRT) is beneficial in selected patients with moderate to severe heart failure (New York Heart Association [NYHA] classes III to IV). Patients with mildly symptomatic heart failure (NYHA class 11) are currently not eligible for CRT and the potential beneficial effects in these patients have not been well studied. Fifty consecutive patients in NYHA class 11 heart failure and 50 consecutive patients in NYHA classes III to IV (control group) were prospectively included. All patients had left ventricular (LV) ejection fraction <= 35% and QRS duration > 120 ms. The effects of CRT in NYHA class 11 patients were compared with the results obtained in both groups. The severity of baseline LV dyssynchrony (assessed with color-coded tissue Doppler imaging) was comparable between patients in NYHA class 11 versus those in NYHA classes III to IV (83 +/- 49 vs 96 +/- 51 ms, p = NS); resynchronization was achieved in all patients. NYHA class 11 patients showed a significant improvement in LV ejection fraction (from 25 +/- 7% to 33 +/- 10%, p < 0.001) and reduction in LV end-systolic volume (from 168 55 to 132 51 ml, p < 0.001) after CRT, similar to patients in NYHA classes III to IV. In addition, only 8% of NYHA class 11 patients had progression of heart failure symptoms. In conclusion, CRT had comparable effects in patients in NYHA class 11 and in NYHA classes III to IV heart failure in terms of LV resynchronization, improvement in LV ejection fraction, and LV reverse remodeling. (c) 2006 Elsevier Inc. All rights reserved.