Observations on the Optimum Time for Operative Intervention for Aortic Regurgitation: II. Serial Echocardiographic Evaluation of Asymptomatic Patients

A recent echocardiographic study of symptomatic patients who had aortic valve replacement for isolated aortic regurgitation indicated that patients in whom preoperative left ventricular end–systolic dimension (LVD[SYS]) exceeded 55 mm or fractional shortening (%FS) was less than 25% were at high risk of developing congestive heart failure and dying after an otherwise successful operation. Because indices of left ventricular systolic function might identify asymptomatic patients with aortic regurgitation who might benefit from earlier operation, 37 such patients were evaluated with serial echocardiograms (mean follow–up 34 months). Fourteen patients (38%) subsequently developed symptoms and were recommended for operation (SUBSQ OP). Twenty–three patients (62%) remain asymptomatic during follow–up (NON OP). LVD(SYS) and %FS were the most sensitive measurements for distinguishing on initial examination the patients who subsequently required operation from those who have not (LVD[SYS] 53.0 mm SUBSQ OP vs 44.3 mm NON OP, p = 0.001; %FS 28.8% SUBSQ OP vs 33.9% NON OP,p = 0.002). During serial studies, the maximum rate of change in end–systolic dimension exceeded 7 mm per year in only one patient. Four of five patients (80%) with end–systolic dimension greater than 55 mm developed symptoms and came to operation during a mean follow–up of 39 months. Of the 20 patients whose initial end–systolic dimension was 50 mm or less, only four patients (20%) developed symptoms and required operation, and none died during follow–up. Thus, an asymptomatic patient with aortic regurgitation whose end–systolic dimension is less than 50 mm appears to be at low risk and can be safely followed with echocardiograms at yearly intervals. Asymptomatic patients with end–systolic dimension of 50–54 mm are being followed with serial echocardiograms every 4–6 months. Operation is now being recommended to patients with end–systolic dimensions of 55 mm or greater, even in the absence of symptom.