New York Heart Association functional class, QRS duration, and survival in heart failure with reduced ejection fraction: implications for cardiac resychronization therapy

Aims Symptom severity assessed by NYHA functional class and QRS duration are essential criteria for selection of heart failure (HF) patients for CRT. This study assessed the relationship between NYHA class, QRS duration, and survival in a nationwide HF registry. Methods and results We studied 13 423 patients with HF in NYHA class II–IV and LVEF