Usefulness of exercise-stress echocardiography for risk-stratification of asymptomatic patients with aortic stenosis (AS) is still debated (Class IIb recommendation). The exercise-induced increase in transvalvular gradient has been proposed as a prognostic factor but data are scarce. We sought to evaluate the additional prognostic value of echocardiographic parameters during exercise-stress echocardiography.
In this observational prospective study, we enrolled all consecutive asymptomatic patients with moderate / severe AS and normal ejection fraction who underwent an exercise-stress echocardiography at our institution. Clinical and echocardiographic data at rest and at peak exercise were collected. The composite primary outcome variable was the occurrence of AS related events (symptoms or heart failure related to the AS or cardiovascular death during follow-up).
Among the 121 patients enrolled, 35 (29%) had an abnormal exercise test (occurrence of symptoms or abnormal blood pressure profile during exercise) and were operated on within the following weeks. Eighty-six patients (mean [quartiles]; age 67 [57-75] years, 68 male, mean gradient 46 [35-52]mm hg, aortic valve area 0,97 [0,82-1,11]) had a normal exercise test and 39 (48%) reached the clinical endpoint during follow-up (17.5 [10.9-36.4] months). The proposed threshold of 18 mm Hg mean gradient increase had no prognostic value. In multivariate analysis, rest mean gradient (p < 0.001; HR 1.07 [1.03-1.11]) but not exercise-induced increase mean gradient (p = 0.4; HR 0.69 [0.29-1.65]) were predictive of outcome.
Exercise-induced increase in mean gradient was not predictive of outcome in patients with normal exercise-test. Our results raise question regarding the additional value and therefore the use of exercise-stress echocardiography for risk-stratification of asymptomatic patients with AS.