Predictors of Progression in Patients With Stage B Aortic Regurgitation

Background: The natural history of stage B aortic regurgitation (AR) is unknown.

Objectives: This study sought to examine determinants, rate, and consequences of progression of AR.

Methods: Consecutive patients with ≤moderate chronic AR quantified by effective regurgitant orifice area (EROA) and regurgitant volume (RVol) from 2004 to 2017 who had ≥1 subsequent echocardiogram with quantitation were included.

Results: Of 1,077 patients (66 ± 15 years of age), baseline trivial/mild AR was noted in 196 (18%), mild-to-moderate AR in 465 (43%), and moderate AR in 416 (39%); 10-year incidence of progression to ≥moderate-severe AR (stage C/D; progressors) was 12%, 30%, and 53%, respectively. At 4.1-year follow-up (interquartile range: 2.1 to 7.2 years), there were 228 progressors (21%), whose annualized progression rates within 3 years before diagnosis of ≥moderate-severe AR were 4.2 mm²/year for EROA and 9.9 ml/year for RVol. Baseline AR severity and dimensions of sinotubular junction and annulus were associated with progression (all p ≤ 0.007); hypertension and systolic blood pressure were not. Progressors had faster chamber remodeling, functional class decline, and more aortic valve/aortic surgery. At medium-term follow-up, 242 patients (22%) died; poor survival was linked to age, comorbidities, functional class, resting heart rate, and left ventricular (LV) ejection fraction (p ≤ 0.003), not LV end-systolic dimension index. Survival after progression to stage C/D AR was associated with LV end-systolic dimension index (adjusted p = 0.02).

Conclusions: Progression from stage B to stage C/D AR was observed in 21% patients. Repeat echocardiography for trivial/mild, mild-to-moderate, and moderate AR at every 5, 3, and 1 years, respectively, was reasonable. EROA, RVol, annulus, and sinotubular junction should be routinely measured to estimate progression rates and identify patients at high risk of progression, which was associated with adverse consequences.