Cardiopulmonary exercise testing augments watchful waiting in asymptomatic severe primary mitral regurgitation

Abstract

Introduction Our aim is to describe the use of cardiopulmonary exercise testing in watchful waiting for asymptomatic severe primary mitral regurgitation. Methods Between October 2016 and October 2017, ten patients with asymptomatic severe primary mitral regurgitation underwent watchful waiting in a single centre. Baseline assessment included history, physical examination, transthoracic echocardiogram and cardiopulmonary exercise testing. Patients were re-evaluated every 6 months with history, physical examination and transthoracic echocardiogram; and at 12 months with cardiopulmonary exercise testing. Results At 1 year follow up, five patients remained asymptomatic with no significant change in left ventricular ejection fraction ( p = 0.18). This was associated with no significant change in cardiopulmonary exercise testing parameters. However, five patients developed early new symptoms or changes in echocardiographic parameters with a significant fall in left ventricular ejection fraction ( p < 0.01). This was associated with a significant fall in anaerobic threshold ( p = 0.04) and four of the five patients having an abnormal percentage predicted peak VO2 at 1 year follow up. Conclusions Changes in symptomatic status or echocardiographic parameters during a watchful waiting approach for asymptomatic severe primary mitral regurgitation is associated with a significant reduction in cardiopulmonary exercise testing parameters.