Exercise right heart catheterization predicts outcome in asymptomatic degenerative aortic stenosis

Degenerative aortic stenosis (DAS) is the most frequent valvular heart disease. It remains unclear how to identify asymptomatic DAS patients with normal left ventricular ejection fraction who have a high probability of event occurrence and would thus benefit from early intervention. Here, we describe a protocol for exercise hemodynamics in true asymptomatic patients with moderate or severe DAS and assess the prognostic value of the data obtained in this population.

This study involved a prospective single-centre registry of consecutive asymptomatic patients with moderate or severe DAS. Patients underwent cardiopulmonary exercise testing to confirm symptom absence during exercise and then right heart catheterization (RHC) at rest and during exercise. Events were defined as death, surgical aortic valve replacement, or transcatheter aortic valve implantation according to clinical guidelines.

Thirty-three patients underwent baseline and exercise RHC. The mean aortic valve area was 1.08 cm² and the aortic gradient was 39mmHg. The mean pulmonary artery pressure was 21mmHg with a pulmonary artery occlusion pressure of 14mmHg and cardiac output of 5.6 L/min. The mean pulmonary artery pressure at peak exercise was 34mmHg. After a mean follow-up of 27 months, 8 patients experienced an event (24%). There were no differences in baseline variables, aortic valve area, or cardiopulmonary exercise testing parameters between the event and event-free groups. Patients with an event did not have higher pulmonary or filling pressures after peak exercise but had lower pulmonary artery oxygen saturation on effort (median, 48% vs 57%, P=.03).

Exercise RHC is feasible and safe in this population. Peak pulmonary artery oxygen saturation might identify patients with increased risk of serious adverse events.