Physiological assessment of endoscopic mitral valve repair using cardiopulmonary exercise testing

Few physiological assessments are available for patients who undergo mitral valve repair for severe mitral regurgitation (symptomatic or asymptomatic). The aim of the study was to evaluate change in exercise tolerance as a means of physiological assessment following mitral valve repair.

We studied 41 consecutive patients who received elective isolated mitral valve repair for severe mitral regurgitation in a minimally invasive manner via a completely endoscopic platform and who underwent cardiopulmonary exercise testing in our institution between February 2018 and August 2019. There were 21 asymptomatic (group A) and 20 symptomatic (group S) patients. Physiological assessment was performed by cycle ergometer cardiopulmonary exercise testing pre-operatively and at approximately 6 months post-operatively.

Mean age was 59 ± 11.6 years and 24 patients were male (58.5%). Overall, there was no significant change in peak oxygen consumption or anaerobic threshold after surgical repair. There were no intergroup differences in terms of peak oxygen consumption, anaerobic threshold, ventilation/carbon dioxide production, or gas exchange ratio. There were no intergroup differences in any transthoracic echocardiographic variable except for post-operative left atrial dimension (group A: 35.2 ± 5.9 vs. group S: 39.8 ± 6.2, p = 0.01).

There was no statistically discernible change in functional capacity at 6-12 months after endoscopic mitral valve repair. The physiological assessment found no improvements in cardiopulmonary exercise testing values post-operatively despite improvement of the symptoms.