How many patients with dilated cardiomyopathy may potentially benefit from cardiac resynchronization therapy?

The clinical and electrocardiographic Marburg Cardiomyopathy database was analyzed to identify potential candidates for cardiac resynchronization therapy(CRT) with biventricular or left ventricular pacing among 566 patients with dilated cardiomyopathy (DCM). All of the following restrictive selection criteria were fulfilled by 38 patients (7%): NYHA functional class greater than or equal to 3 (n = 193, 34%), left ventricular ejection fraction (LVEF) <30% (n = 238, 42%), sinus rhythm (n = 437, 77%), left bundle branch block (LBBB, n = 142, 25%), and QRS duration greater than or equal to 150 ms (n = 136, 24%). In 78 of the 566 patients (14%) all of the following less restrictive selection criteria were fulfllled: NYHA functional class greater than or equal to3 (n = 193, 34%), LVEF < 35% in presence of any underlying rhythm (n = 326, 58%), QRS duration greater than or equal to 120 ms with right or left bundle branch block (n = 223,39%). Thus, between 7% and 14% of patients with DCM were candidates for CRT depending on the application of strict versus less restrictive selection criteria.