Does Heart-Failure Etiology Affect the Benefits of CRT?

Cardiac resynchronization therapy (CRT) improves NYHA class, quality of life, exercise capacity, and left-ventricular structure and function in patients with class III-IV heart failure, long QRS durations, and LV ejection fractions <35% who are receiving optimal medical therapy (Journal Watch Cardiology Jul 26 2002). Nevertheless, about 20% to 30% of trial subjects do not benefit from CRT, prompting investigators at a Dutch center to explore the potential role of heart-failure etiology.

Seventy-four consecutive patients (78% men) who met traditional selection criteria for CRT received CRT-capable biventricular pacemakers; cardiomyopathy was ischemic in 34 patients and nonischemic (dilated) in 40. Before and 6 months after pacemaker implantat…