Dynamic mitral regurgitation unmasked by handgrip exercise is linked with outcomes in (non-) dilated cardiomyopathy

Recent studies suggest that secondary mitral regurgitation (MR) is a dynamic condition influenced by global and regional left ventricular (LV) remodeling as well as by mitral valvular deformation. Exercise testing is crucial in assessing the hemodynamic relevance of MR and is recommended by current guidelines. However, data are still lacking on the prevalence and prognostic impact of dynamic MR in patients with non-ischemic cardiomyopathy.

We aimed to assess the prevalence, hemodynamic consequences, and prognostic impact of exercise-induced changes in patients with MR and hypokinetic non-dilated and dilated cardiomyopathy.

Patients with hypokinetic non-dilated and dilated cardiomyopathy and at least mild MR who underwent handgrip echocardiography at the University Hospital Duesseldorf between January 2018 and September 2021 were enrolled. Follow-up was performed at one year.

Fifty-eight patients were included (median age 73 [65;81] years; 41 % female; mean LVEF 37 ± 10 %). At rest, 28 patients (48 %) presented with mild MR and 30 patients with moderate MR (52 %). Fifteen patients (26 %) with non-severe MR at rest, developed severe MR during handgrip exercise. Patients with dynamic MR had larger left ventricular volumes, increased mitral annular diameter, and more advanced mitral valve tenting during exercise than those without dynamic MR. Patients with dynamic MR were more likely to undergo MV surgery/interventions (Chi² 23.19; log-rank test p < 0.001).

The hemodynamic changes provoked by isometric exercise unmasked dynamic MR in a significant number of patients without severe MR at rest. These data may have implications for therapeutic decision-making in symptomatic patients with non-severe MR at rest.