Prevalence and prognostic impact of dynamic atrial functional mitral regurgitation assessed by isometric handgrip exercise.

Aims: In atrial functional mitral regurgitation (aFMR), a considerable proportion of patients displays a discrepancy between symptoms and echocardiographic findings at rest. Exercise testing plays a substantial role in assessing the haemodynamic relevance of mitral regurgitation (MR) and is recommended by current guidelines. Here, we aimed to assess the prevalence, extent, and prognostic impact of exercise-induced changes in patients with aFMR.

Methods And Results: Patients with at least mild MR who underwent handgrip exercise echocardiography at the University Hospital Duesseldorf between January 2019 and September 2021 were enrolled. Patients were followed up for 1 year to assess clinical outcomes. Eighty patients with aFMR were included [median age: 80 (77-83) years; 53.8% female]. The median N-terminal pro-brain natriuretic peptide level was 1756 (1034-3340) ng/L. At rest, half of the patients (53.8%) had mild MR, 20 patients (25.0%) had moderate MR, and 17 patients (21.2%) had severe MR. In approximately every fifth patient (17.5%) with non-severe MR at rest, the MR became severe during exercise. Handgrip exercise led to a reclassification of MR severity in 28 patients (35.0%). At 1-year follow-up, adverse events occurred more often in patients with severe MR at rest (76.5%) and exercise-induced dynamic severe MR (66.7%) than in those with non-severe MR (28.6%; P < 0.001).

Conclusion: Handgrip exercise during echocardiography revealed exercise-induced changes in aFMR in every third patient. These data may have implications for therapeutic decision-making in symptomatic patients with non-severe aFMR at rest.