Cardiopulmonary Exercise Testing in Percutaneous Mitral Valve Repair: A Single Centre’s Experience

Abstract

Chronic severe mitral regurgitation (MR) confers negative hemodynamic consequences and long-term morbidity and mortality1. The adverse remodeling processes result in the inability of mitral valve leaflets to co-apt optimally in functional MR (FMR)2. Even after optimal medical therapy, or revascularization, FMR may not necessarily be reduced adequately. In such patients who remain persistently symptomatic from residual MR, the next course of management may be the surgical or percutaneous intervention of the mitral valve apparatus. Subsequently, percutaneous repair via transcatheter delivered systems has emerged as the treatment of choice; especially, in patients assessed to be at a high operative risk with a suitable anatomy for minimally invasive approaches to re-appose the mitral leaflets3. This has also revolutionized the approach to the management of primary mitral regurgitation (PMR), such as from mitral valve prolapse. It was treated conventionally by the surgical intervention with mitral valve repair or replacement, allowing an alternative option for the high surgical risk patients 4. In our center, the transcatheter mitral valve repair procedure (MitraClip) has been introduced in the year 2012, providing an option of percutaneous intervention to the patients where MR is unsuitable for the surgical correction. However, persistent symptoms may occur due to the concomitant non-valvular or non-cardiac pathologies, particularly chronic pulmonary diseases. Also, assessment of functional class is subjective and may be confounded by other variables, such as sedentary lifestyle, self-imposed exercise restrictions, or orthopedic conditions. The cardiopulmonary exercise test (CPET) provides an objective assessment of the exercise capacity, obviating the subjective aspects of self-reported symptoms and functional status Besides, CPET is also useful to discern pulmonary and functional status. Besides, CPET is also useful to discern pulmonary and non-cardiac contributory components of the perceived decreased functional capacity, including motivational factors. Multiple CPET parameters, related to hemodynamic surrogates before and after the MitraClip procedure, also enable a more objective evaluation of the cardiovascular impact of the repair, allowing insights into the improvements in cardiac hemodynamics post intervention7-10.