SERIAL LONG-TERM ASSESSMENT OF THE NATURAL-HISTORY OF ASYMPTOMATIC PATIENTS WITH CHRONIC AORTIC REGURGITATION AND NORMAL LEFT-VENTRICULAR SYSTOLIC FUNCTION

Background. Many asymptomatic patients with aortic regurgitation and normal left ventricular systolic function remain clinically stable for many years, but others ultimately develop symptoms or left ventricular dysfunction and require operation. To identify indexes of left ventricular function predictive of symptomatic and functional deterioration during the long-term course of asymptomatic patients, we studied 104 asymptomatic patients with chronic severe aortic regurgitation and normal left ventricular ejection fraction at rest. Methods and Results. Serial echocardiographic (average, 7.8 per patient) and radionuclide angiographic (average, 5.0 per patient) studies were obtained over a mean follow-up period of 8 years (range, 2-16 years). By Kaplan-Meier life table analysis, 58 +/- 9% of patients remained asymptomatic with normal ejection fraction at 11 years, an average attrition rate of less than 5% per year; two patients died suddenly, four developed asymptomatic left ventricular dysfunction, and 19 underwent operation because symptoms developed. By univariate Cox regression analysis, many variables on initial study were associated with death, ventricular dysfunction, or symptoms, including age, left ventricular end-systolic dimension and end-diastolic dimension, fractional shortening, and both rest and exercise ejection fraction (all p < 0.001). The average rates of change of rest ejection fraction, fractional shortening, and end-systolic dimension were also associated with death or symptoms by univariate Cox analysis (all p < 0.01). However, when all variables were included in a multivariate Cox analysis, only age (p < 0.05), initial end-systolic dimension (p < 0.001), and rate of change in end-systolic dimension and rest ejection fraction during serial studies (both p < 0.05) predicted outcome. Conclusions. Thus, in addition to indexes of left ventricular function determined on initial evaluation, serial long-term changes in systolic function identify patients likely to develop symptoms and require operation. Patients have a higher risk of symptomatic deterioration if there is progressive change in end-systolic dimension or resting ejection fraction during the course of serial studies.