Asymptomatic Aortic Regurgitation: Indications for Operation

Left ventricular(LV) systolic function is an important determinant of long-term prognosis in patients with chronic aortic regurgitation. In patients undergoing aortic valve replacement (AVR), those with preoperative LV dysfunction have a greater risk of postoperative congestive heart failure and death than do those in whom preoperative LV systolic function Is normal. Patients with preoperative LV dysfunction are not a homogeneous group, however, but may be further stratified according to risk on the basis of the severity of symptoms, exercise intolerance, and temporal duration of LV dysfunction. Hence, asymptomatic patients with reproducible and definite evidence of impaired LV function should undergo operation without waiting for the development of symptoms or more severe LV dysfunction. Among asymptomatic patients with normal LV systolic function (normal ejection fraction and fractional shortening), the prognosis is excellent with only a gradual rate of deterioration during conservative, nonoperative management. The long-term follow-up experience of such patients indicates that the annual mortality rate is less than 0.5% and that less than 4% per year require AVR because symptoms or LV dysfunction at rest develop. Patients likely to require operation over a 10-year period because symptoms or LV dysfunction develop can be identified on the basis of age, severity of LV dilatation by echocardiography, and progressive change in LV dimensions or resting ejection fraction during the course of serial follow-up studies. Patients at risk of sudden death before surgery Is performed may be Identified by extreme LV dilatation (diastolic dimension > 80 mm, systolic dimension > 55 mm). If asymptomatic patients are followed carefully and undergo operation only after the onset of symptoms, depressed ejection fraction at rest, or extreme LV dilatation, the operative mortality is low, long-term postoperative survival is excellent, and LV function after operation improves in virtually every patient. Hence, although asymptomatic patients with depressed LV contractile function at rest or extreme LV dilatation should undergo AVR before the onset of symptoms, the great majority of asymptomatic patients with normal LV contractile function at rest do not require “prophylactic” valve replacement to preserve LV function. AVR is justifiable in asymptomatic patients who manifest consistent and reproducible evidence of either LV contractile dysfunction at rest or extreme LV dilatation on noninvasive studies. (J Card Surg 1994;9[Suppl]:170–173)