Dilated (congestive) cardiomyopathy. Follow-up study of 137 patients.
The purpose of this study was to examine the clinical course of dilated (congestive) cardiomyopathy (DCM) and to identify the factors of prognostic significance. Between January 1969 and April 1982, 137 patients with a diagnosis of dilated cardiomyopathy were followed-up for a mean period of 48,7 +/- 40 months. Mean duration of illness before the first study was 15,5 months. A history of excessive alcohol intake was present in 22% of the patients and an influenza like syndrome in 9%. At diagnosis most of the patients were in NYHA functional class IV (43,5%) and III (35%). The 5-year survival rate was 45%, the mean annual mortality rate 10,2% and the highest mortality rate 14% in the second and third year. One hundred and seven patients (78%) progressed to major complications (worsening heart failure and death), while thirty patients (22%) showed stable or even improved conditions. Systemic or pulmonary emboli occurred in 18% of the patients, with a significant prevalence in patients with atrial fibrillation (p less than 0,05). Prognosis was unfavorably affected by the following factors: bi-ventricular heart failure as first clinical manifestation (p less than 0,01), intraventricular conduction delay (LBBB, LAHB) (p less than 0,05), significant cardiomegaly (cardiothoracic ratio greater than 0,53, p less than 0,001), left ventricular dysfunction (left ventricular fractional shortening less than 14%, p less than 0,005, left ventricular end-diastolic pressure greater than 17 mmHg, p less than 0,05, left ventricular end diastolic volume greater than 185 ml/m2, p less than 0,001, cardiac index less than 2,2/min/m2, p less than 0,001).