Timing of operation for chronic aortic regurgitation: influence of left ventricular function on clinical management.

Since symptomatic patients with aortic regurgitation and normal ventricular function (ejection fraction greater than or equal to 50%, fractional shortening greater than or equal to 29%, end-systolic diameter less than or equal to 55 mm) have a significantly higher three year survival postoperatively than patients with impaired left ventricular function (ejection fraction less than 50%, fractional shortening less than 29%, end-systolic diameter greater than 55 mm), the indication for surgery should be established prior to the onset of left ventricular functional impairment. In two-thirds or more of asymptomatic patients with left ventricular dysfunction, symptoms are incurred within two to three years. Additionally, in patients with impaired left ventricular function but with only slight or no symptoms or a normal exercise capacity, respectively, postoperatively there is a higher three year survival rate than in patients with marked symptoms or compromised exercise capacity. In patients in whom preoperative left ventricular dysfunction is present for only a relatively short duration (less than 14 months), the probability of postoperative regression of ventricular dilation and dysfunction is higher than in those whose left ventricular functional impairment is of longer duration (greater than 18 months). Thus, in asymptomatic patients with left ventricular dysfunction, the indication for surgery should be established before the onset of symptoms or compromise of exercise capacity. In asymptomatic patients with normal left ventricular function, symptoms or left ventricular dysfunction develop at a low incidence of 4% per year. Accordingly, with conservative, nonsurgical management, these patients have an excellent prognosis. Patients in whom the onset of symptoms or left ventricular dysfunction can be anticipated to develop, may be identified on the basis of an end-systolic diameter greater than 50 mm, a decrease in left ventricular ejection fraction during exercise, a progressive increase in the end-systolic as well as end-diastolic diameter or a rapid decrease in fractional shortening or ejection fraction seen during follow-up observation. The indication for surgery, however, should be established only at the onset of symptoms or left ventricular dysfunction since in all of these patients, regression of ventricular dilatation and normalization of left ventricular function can be expected postoperatively. The preoperative left ventricular function is a primary determinant of postoperative results even on employment of myocardial protection and a hemodynamically-favorable prosthesis.(ABSTRACT TRUNCATED AT 400 WORDS)