Prognostic Value of Exercise-Stress Echocardiography in Asymptomatic Patients With Aortic Valve Stenosis

Abstract

Objectives: This study sought to evaluate the prognostic value of mean pressure gradient (MPG) increase and peak systolic pulmonary artery pressure (SPAP) measured during exercise stress echocardiography in asymptomatic patients with aortic stenosis (AS).

Background: Exercise testing is recommended in asymptomatic AS patients, but the additional value of exercise-stress echocardiography, especially the prognostic value of MPG increase and peak SPAP, is still debated.

Methods: We enrolled all consecutive patients with pure, isolated, asymptomatic AS and preserved ejection fraction ≥50% and normal SPAP (<50 mm Hg) who underwent symptom-limited exercise echocardiography at our institution. Occurrence of AS-related events (symptoms or congestive heart failure) or occurrence of aortic valve replacement was recorded.

Results: We enrolled 148 patients (66 ± 15 years of age; 74% males; MPG: 47 ± 13 mm Hg; SPAP: 34 ± 6 mm Hg). No complications were observed. Thirty-six patients (24%) had an abnormal exercise test result (occurrence of symptoms, fall in blood pressure, and/or ST-segment depression) and were referred for surgery. Among the 112 patients with a normal exercise test result, 38 patients (34%) had abnormal exercise echocardiography scores (MPG increase >20 mm Hg and/or SPAP at peak exercise >60 mm Hg). These 112 patients were managed conservatively. During a mean follow-up of 14 ± 8 months, an AS-related event occurred in 30 patients, and 25 patients underwent surgery. Neither MPG increase >20 mm Hg nor peak SPAP >60 mm Hg was predictive of occurrence of AS-related events or aortic valve replacement (all p > 0.20). In contrast, baseline AS severity was an important prognostic factor (all p < 0.01).

Conclusions: In this observational study including 148 patients with asymptomatic AS, we confirmed and extended the importance of exercise testing for unveiling functional limitation. More importantly, neither the increase in MPG nor in SPAP at peak exercise was predictive of outcome. Our results do not support the use of these parameters in risk-stratification and clinical management of asymptomatic AS patients.

Keywords: aortic valve stenosis; asymptomatic diseases; exercise-stress echocardiography; prognosis.