Dilated cardiomyopathy: long-term follow-up and predictors of survival

Abstract To determine long-term survival and the prognostic factors of dilated cardiomyopathy, we retrospectively studied a consecutive series of 111 patients (95 men, 16 women, mean age: 45.5 ± 8.1 years) undergoing cardiac catheterization and diagnostic coronary angiography from January 1970 to December 1979. The inclusion criteria were: normal coronary angiography, diffuse hypokinesia of the left ventricle and left ventricular ejection fraction less than 50%. Base-line clinical data were collected from the hospital records and follow-up data were obtained from the general practitioners and cardiologists. A questionnaire was sent to all living patients. The length of follow-up ranged from 6 to 16 years. Six patients (5%) were lost to follow-up. At the time of catheterization, a majority of the patients had dyspnea and were in New York Heart Association (NYHA) classes II (41%) and III (31%). Clinical history revealed an excessive alcohol consumption in 56% of the patients. During follow-up, 66 patients (63%) died (heart failure: 37%; sudden death: 19%; non-cardiac death: 15%; unknown cause: 27%). Actuarial survival was 90, 50, and 33% at 1, 5, and 10 years, respectively. Univariate analysis revealed that 10-year mortality was related to: left ventricular ejection fraction less than 30%; left ventricular end-diastolic pressure greater than 10 mm Hg; cardiothoracic ratio greater than 54%; episodes of heart failure; left ventricular end-diastolic volume greater than 200 m;/m 2 , dyspnea of NYHA class III or IV; absence of smoking; absence of moderate systemic hypertension; electrocardiographic evidence of left ventricular hypertrophy and mean systemic arterial pressure greater than 95 mm Hg. Cox multivariate analysis showed that left ventricular ejection fraction was the main prognostic indicator and that mean systemic arterial pressure was an independent predictor of secondary importance. In the subgroup of patients with an ejection fraction equal to or greater than 30%, left ventricular ejection fraction remained the only predictor of survival. It lost its prognostic value in the subgroup with an ejection fraction of less than 30%. In the latter subgroup, history of smoking and NYHA classification became independent prognostic factors.