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

Abstract 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. Graphical Abstract Graphical Abstract (Top) Echocardiographic images of a patient with mild atrial functional mitral regurgitation at rest and a marked exercise-induced increase in mitral regurgitation severity during handgrip exercise. (Bottom) The leaflet-to-annulus index is determined by summing the length of the anterior and posterior mitral valve leaflet and dividing it through the mitral annulus diameter. AML, anterior mitral leaflet; AP diameter, anterior–posterior diameter; LAI, leaflet-to-annulus index; PML, posterior mitral leaflet.