Abstract 3268: Natural History of Mild and Moderate Aortic Regurgitation: Worsening Severity is the Exception not the Rule
Background: Prior studies have documented the rate of progression of valvular aortic stenosis and form the basis for “prophylactic” aortic valve replacement in patients with moderate aortic stenosis undergoing other cardiac procedures. In contrast, studies of aortic regurgitation have either focused exclusively on severe regurgitation or have provided only short-term follow-up on a small number of patients.
Methods: To provide longer term natural history data, we studied 600 consecutive pts with an echocardiographic diagnosis of isolated mild or moderate aortic regurgitation for whom at least one-year echocardiographic follow-up was available. Mean ± SD follow-up was 5.0 ± 3.4 yrs. There were 311 females, with a mean age at initial study of 67 ± 15 yrs. 6 patients had a bicuspid aortic valve. Each patient had an average of 4.5 ± 2.8 follow-up studies. The latest follow-up point was considered for analysis.
Results: (see table⇓) For 527 of the 600 patients (87.8%)with mild or moderate aortic regurgitation at entry, the severity of regurgitation was unchanged during follow-up. Of the 5 (0.8%) pts who progressed to severe AR, 1 patient had endocarditis (mild to severe) while 4 had aneurysmal dilatation of the ascending aorta or annular ectasia (1 with bicuspid AV). The average time from initial echo to documentation of severe regurgitation was 6.9 (mild to severe) or 5.5 yrs (moderate to severe).
Conclusion: Over a mean follow-up of 5.0 years, approximately 9 of 10 patients with mild or moderate aortic regurgitation did not develop worsening regurgitation and less than 1% progressed to severe regurgitation. In this series, progression to severe regurgitation was associated with endocarditis or significant dilation of the aortic root or annulus. These data may be useful in guiding surgical decision regarding “prophylactic” aortic valve replacement in patients with aortic regurgitation undergoing other cardiac surgery.