Mode of death in idiopathic dilated cardiomyopathy: a multivariate analysis of prognostic determinants.

A total of 110 patients with idiopathic dilated cardiomyopathy were followed prospectively for 53 +/- 8 (range 41 to 69) months to determine prognostic factors identifying patients at risk for sudden death or death from congestive heart failure. During the follow-up period 39 patients died, 14 of congestive heart failure and 25 suddenly. The incidence of cardiac death after 1 year was 18%, after 2 years 35%, and after 4 years 39%. Multivariate logistic regression analysis identified four independent prognostic factors: left ventricular ejection fraction, cardiac index, number of ventricular pairs/24 hours, and atrial rhythm (sinus rhythm or atrial fibrillation). With the final model of logistic regression 77 of 88 patients (88%) could be classified correctly as being at risk for death from chronic heart failure or sudden cardiac death. Patients who were likely to die of congestive heart failure were characterized by a markedly impaired left ventricular function (measured in terms of left ventricular ejection fraction, cardiac index, or both) and a low number of pairs/24 hours. The association between frequent complex ventricular arrhythmias and depressed left ventricular function identifies patients who are at risk for sudden death. The presence of atrial fibrillation significantly increases the risk of sudden death and death from congestive heart failure.