Regurgitant Volume Informs Rate of Progressive Cardiac Dysfunction in Asymptomatic Patients With Chronic Aortic or Mitral Regurgitation

ObjectivesThis study hypothesized that regurgitation severity, as determined by using the regurgitant volume index, would better delineate differential cardiac dysfunction in asymptomatic patients with moderate to severe aortic regurgitation (AR) and mitral regurgitation (MR).BackgroundFrequent surveillance echocardiography is considered appropriate in asymptomatic patients with moderate to severe AR and MR. However, the evidence to support this practice and to define the appropriate frequency is limited.MethodsThis was an observational cohort study of consecutive patients with moderate to severe asymptomatic AR or MR who underwent exercise echocardiography. Our cohort included 130 patients with moderate to severe asymptomatic MR and 130 patients with moderate to severe asymptomatic AR who were matched according to age and regurgitant volume index. All patients underwent yearly echocardiographic follow-up studies. Regurgitation severity was determined according to regurgitant volume index, with a level ≥30 ml/m2 considered a marker of severe regurgitation.ResultsDuring follow-up, regardless of etiology, patients with severe regurgitation demonstrated increasing left ventricular volume indexes (4.2 ± 1.5 ml/m2 per year; p = 0.01) and decreasing left ventricular ejection fractions (1.3 ± 0.4% per year; p = 0.002). In patients with moderate regurgitation, left ventricular volumes and ejection fractions did not significantly change. In addition, patients with severe regurgitation experienced a similar drop in contractility (end-systolic pressure/end-systolic volume ratio and single-beat pre-load recruitable stroke work) during follow-up independent of regurgitation etiology. Contractility parameters did not change in patients with moderate regurgitation.ConclusionsThese asymptomatic patients with moderate AR or MR had stable cardiac function during 3 years of follow-up; thus, frequent echocardiography without a change in clinical status may not be necessary. In the setting of severe regurgitation, further cardiac deterioration occurred at a similar rate and manner irrespective of whether the dysfunction was related to AR or MR.