The natural history of myocardial disease in dialysis patients.

Among dialysis patients, only 23% have a normal echocardiogram, about 10% have recurrent or chronic congestive heart failure, and 17% have asymptomatic ischemic heart disease. The predisposing factors for congestive heart failure are dilated cardiomyopathy, hypertrophic hyperkinetic disease, and ischemic heart disease. Dilated cardiomyopathy, a disorder of systolic function, includes among its risk factors age, hyperparathyroidism, and smoking. Hypertrophic disease results in diastolic dysfunction, and its predictors include age, hypertension, aluminum accumulation, anemia, and, perhaps, hyperparathyroidism. Ischemic heart disease is due to the presence of coronary artery disease and also to nonatherosclerotic disease caused by the reduction in coronary vasodilator reserve and altered myocardial oxygen delivery and use. The clinical outcome of congestive heart failure is comparable to that of nonrenal patients with medically refractory heart failure. Left ventricular hypertrophy is an important independent determinant of survival. A subset have hyperkinetic disease with severe hypertrophy and have a bad survival, as low as 43% have a 2-yr survival after the first admission to hospital with cardiac failure. The prognosis for those with dilated cardiomyopathy is less severe but is worse than those with normal echocardiogram. The survival of patients with symptomatic ischemic heart disease was little different from that of patients without symptoms, suggesting that the underlying cardiomyopathies had an adverse impact on survival independent of ischemic disease. Much research needs to be undertaken on the risk factors, natural history, and therapy of the various types of cardiac disease prevalent in dialysis patients.