Impact of Mitral Regurgitation Severity and Cause on Effort Tolerance–Integrated Stress Myocardial Perfusion Imaging and Echocardiographic Assessment of Patients With Known or Suspected Coronary Artery Disease Undergoing Exercise Treadmill Testing

Abstract

Background Mitral regurgitation ( MR ) has the potential to impede exercise capacity; it is uncertain whether this is because of regurgitation itself or the underlying cause of valvular insufficiency. Methods and Results The population comprised 3267 patients who underwent exercise treadmill myocardial perfusion imaging and transthoracic echocardiography within 6±8 days. MR was present in 28%, including 176 patients (5%) with moderate or greater MR . Left ventricular systolic function significantly decreased and chamber size increased in relation to MR , paralleling increments in stress and rest myocardial perfusion deficits (all P <0.001). Exercise tolerance (metabolic equivalents of task) decreased stepwise in relation to graded MR severity ( P <0.05). Workload was significantly lower with mild versus no MR (mean±SD, 9.8±3.0 versus 10.1±3.0; P =0.02); magnitude of workload reduction significantly increased among patients with advanced versus those with mild MR (mean±SD, 8.6±3.0 versus 9.8±3.0; P <0.001). MR ‐associated exercise impairment was accompanied by lower heart rate and blood pressure augmentation and greater dyspnea (all P <0.05). Both functional and nonfunctional MR subgroups demonstrated significantly decreased effort tolerance in relation to MR severity ( P ≤0.01); impairment was greater with functional MR ( P =0.04) corresponding to more advanced left ventricular dysfunction and dilation (both P <0.001). Functional MR predicted reduced metabolic equivalent of task–based effort (B=−0.39 [95% CI, −0.62 to −0.17]; P =0.001) independent of MR severity. Among the overall cohort, advanced (moderate or greater) MR was associated with reduced effort tolerance (B=−1.36 [95% CI, −1.80 to −0.93]; P <0.001) and remained significant ( P =0.01) after controlling for age, clinical indexes, stress perfusion defects, and left ventricular dysfunction. Conclusions MR impairs exercise tolerance independent of left ventricular ischemia, dysfunction, and clinical indexes. Magnitude of exercise impairment parallels severity of MR .

Right ventricular function and its coupling to pulmonary circulation predicts exercise tolerance in systolic heart failure

“…13,14 Left-side parameters and exercise tolerance Left atrial volume index was the only left-side parameters associated with CPET (peak VO 2 in the overall population). The absence of relationship with LVEF has been previously described, 4 but recent reports have suggested the important role of LV diastolic dysfunction 35 and/or MR 36 on exercise capacity. While an association between MR and peak VO 2 was present in our univariate model, MR haemodynamic repercussion and subsequent RV dysfunction and/or PH were stronger predictors of CPET in our cohort.…”

Comparison of Cardiorespiratory Fitness between Patients with Mitral Valve Prolapse and Healthy Peers: Findings from Serial Cardiopulmonary Exercise Testing

“…Moreover, MVP symptoms are frequently disproportionate to objective findings through exhaustive clinical and laboratory investigation. Although several studies have observed that advanced MR impairs exercise tolerance independent of left ventricular ischemia and dysfunction [21,22], little is known regarding the influence of trivial or mild MR on exercise capacity.…”

Rest and exercise oxygen uptake and cardiac output changes 6 months after successful transcatheter mitral valve repair

“…Overall, these studies suggest that pMVR treatment is associated with an improvement in symptoms, quality of life, functional status and, in some but not all studies, exercise capacity. 8 , 9 , 10 , 11 , 12 Indeed, although MR directly impairs exercise performance, 13 both the COAPT and the MITRA‐FR trials reported a null effect of pMVR on the 6‐min walk test (6MWT). 6 , 7 , 14 Differently, several other studies suggested an improved exercise performance, 11 , 15 assessed in the great majority of reports by 6MWT.…”