Dilated cardiomyopathy: functional status, hemodynamics, arrhythmias, and prognosis

The natural history of dilated cardiomyopathy is variable, and the prognosis difficult to predict. Several clinical and hemodynamic parameters have been proposed as prognostic indicators. Reports on the relationship between ventricular arrhythmias, degree of hemodynamic impairment, and sudden death are controversial. To define accurately the prognosis in dilated cardiomyopathy, 55 patients with this clinical syndrome underwent clinical evaluation, radionuclide ventriculography, echocardiography, 12-lead electrocardiography, and 24 hr ambulatory monitoring, and the data thus obtained were evaluated based on predictive value. Over a follow-up period of 14.1 +/- 7.9 months, 11 patients (20%) died, all suddenly. Univariate analysis revealed that patients with more severe functional impairment (P = 0.0449), lower cardiac index (P = 0.0226), lower ejection fraction (P = 0.0426), and higher pulmonary artery wedge pressure (P = 0.0314) had greater mortality risk. Age, duration of symptoms, 12-lead electrocardiographic abnormalities, and atrial arrhythmias were not predictive of higher mortality. The number of PVCs per hr, the occurrence of couplets, the degree of PVCs prematurity, and the presence, frequency, rate, and duration of ventricular tachycardia did not have prognostic significance. A stepwise discriminant analysis identified functional class, cardiac index, and presence or absence of multiform PVCs as the group of variables that together could more accurately predict outcome in our dilated cardiomyopathy patients. Using a formula derived from the results of this analysis, the outcomes of 36 of 49 patients (74%) was correctly predicted, with a specificity of 100% and a sensitivity of 70%.