The natural history of asymptomatic patients with aortic regurgitation and normal left ventricular function.

In asymptomatic patients with severe aortic regurgitation and normal left ventricular function, aortic valve replacement has been recommended to preserve left ventricular function. In such patients, however, the natural history without operation is unknown. We therefore performed serial studies in 77 asymptomatic patients with normal left ventricular ejection fraction at rest as determined by radionuclide angiography and normal left ventricular fractional shortening as determined by echocardiography; 63 patients had 3 + to 4 + aortic regurgitation visualized by aortic root cineangiography, and the other 14 patients had pulse pressures >70 mm Hg. During mean follow-up of 49 months (range 6 to 114) no patient died and 12 patients underwent aortic valve replacement because of the onset of symptoms (11 patients) or the onset of left ventricular dysfunction without symptoms (one patient). By life table analysis, the percent of patients who did not require operation was 90 ± 3% (+ SE) at 3 years, 81 + 6% at 5 years, and 75 ± 7% at 7 years. In the 12 who did have surgery there were no operative or late deaths (postoperative follow-up 8 to 75 months, mean 38), left ventricular ejection fraction increased (45 ± 5% [ + SD] preoperatively, 58 + 11 postoperatively; p < .001), and left ventricular diastolic dimension determined echocardiographically decreased (74 4 mm preoperatively, 52 + 5 mm postoperatively; p < .001). Thus, in asymptomatic patients with normal left ventricular function, death is rare, and less than 4% per year require aortic valve replacement because symptoms or left ventricular dysfunction develop. When aortic valve replacement is delayed until symptoms or left ventricular dysfunction develop, postoperative survival is excellent, and left ventricular size and function improve postoperatively. Hence, "prophylactic" aortic valve replacement to preserve left ventricular function should not be performed in asymptomatic patients with severe aortic regurgitation and normal left ventricular function. Circulation 68, No. 3, 509-517, 1983. LEFT VENTRICULAR systolic function is an important determinant of long-term prognosis in patients with chronic aortic regurgitation. Numerous studies indicate that symptomatic patients with impaired preoperative left ventricular function are at risk for irreversible myocardial dysfunction and death from congestive heart failure after aortic valve replacement.'-7 Hence, many investigators recommend that asymptomatic or mildly symptomatic patients with left ventricular dysfunction should undergo operation before the development of severe symptoms.4' 8-13 The fear of a patient developing irreversible left ventricular failure From the Cardiology Branch, National Heart, Lung and Blood Institute, Bethesda, MD. Address for correspondence: Robert 0. Bonow, M.D., Bldg. 10, Rm. 7B-15, National Institutes of Health, Bethesda, MD 20205. Received March 8, 1983; revision accepted April 28, 1983. has also led to the recommendation that operation be performed in all patients with significant aortic regurgitation, even if left ventricular function is normal.3' 14-16 However, the natural history of asymptomatic patients with aortic regurgitation and normal left ventricular function is unknown. We therefore performed serial studies in 77 patients with asymptomatic aortic regurgitation and normal left ventricular systolic function to determine the time course of development of either symptoms or left ventricular dysfunction and to identify echocardiographic and radionuclide angiographic variables predictive of these events. We also studied the postoperative survival and functional results when operation is delayed until the onset of symptoms or of left ventricular dysfunction. Vol. 68, No. 3, September 1983 509 by gest on O cber 5, 2017 http://ciajournals.org/ D ow nladed from