Predictive value of exercise stress echocardiography in asymptomatic patients with severe aortic regurgitation and preserved left ventricular systolic function without LV dilatation.

The management of asymptomatic patients with severe aortic regurgitation (AR) and preserved left ventricular (LV) systolic function remains controversial. We evaluated the predictive value of exercise stress echocardiography (ESE) in asymptomatic severe AR with preserved LV systolic function for identifying high risk patients who might benefit from early referral for surgery. Symptom-limited treadmill ESE was performed in 67 asymptomatic patients with severe AR (effective regurgitant orifice area > 30 mm2, regurgitant volume > 60 ml) and preserved LV systolic function without LV dilatation [ejection fraction (EF) ≥ 50% and LV end-systolic diameter ≤ 50 mm]. A post-exercise EF increase of > 4% was defined as presence of contractile reserve (CR). The primary outcome was defined as the composite of symptoms development, deterioration in LV function (EF < 50% in echocardiography) and aortic valve replacement (AVR) at follow-up. Operations performed within 60 days of ESE were excluded. Twenty-eight patients were CR (+) and 39 patients were CR (-). Compared with the CR (+) group, the CR (-) group was older (52.0 ± 14.0 years vs. 43.8 ± 10.6 years, p = 0.011) and had higher Ln N-terminal natriuretic peptide (NT-proBNP) [5.2 (4.5-5.7) vs. 4.1 (3.7-5.1), p = 0.001]. The CR (-) group showed lower exercise time than the CR (+) group (576 ± 159 s vs. 671 ± 108 s, p = 0.008). Otherwise, there were no differences in demographics and imaging data between the two groups. During a follow-up duration of 46 ± 23 months, the primary outcome occurred in 17 patients (25%) including development of symptoms (n = 9), new-onset LV systolic dysfunction (n = 1) and AVR (n = 7). Fourteen of 17 were CR (-) group patients. The survival rate during follow-up was significantly lower in the CR (-) group than in the CR (+) group of asymptomatic severe AR patients (log-rank p = 0.035). The absence of CR in ESE is independently associated with deterioration of symptoms or LV systolic function in asymptomatic patients with severe AR and preserved LV systolic function. It can further risk stratify asymptomatic patients with severe AR and preserved LV systolic function and may influence the optimal timing of AVR.