Objectives

The current study was designed to determine the effect of secular trend and referral bias on the natural history of idiopathic dilated cardiomyopathy.

Background

In a previous study of 104 patients with idiopathic dilated caraiomyopathy conducted in a referral population at the Mayo Clinic between 1960 and 1973, the 1- and 5-year mortality rates were 31% and 64%, respectively.

A recent study of 40 patients with idiopathic dilated cardiomyopathy conducted in a population-based cohort at the Mayo Clinic between 1975 and 1984 reported 1- and 5-year morality rates of 5% and 20%, respectively.

We hypothesized that improvements in diagnosis and therapy have occurred since the original referral cohort was described and that these improvements have altered the apparent natural history of the disease.