Extent and predictors of exercise-induced changes in ischemic mitral regurgitation during handgrip exercise

Abstract

Abstract Background Mitral regurgitation (MR) is frequent in patients with ischemic heart disease and carries a dismal prognosis. Recent studies suggest that ischemic MR is a dynamic condition influenced by global and regional left ventricular (LV) remodeling as well as mitral valvular deformation. Handgrip exercise may serve as alternative exercise intervention to bicycle exercise. Purpose To assess degree and determinants of exercise-induced changes in ischemic MR during handgrip exercise. Methods We prospectively enrolled 205 patients with at least mild ischemic MR that underwent echocardiography at rest and during three minutes of handgrip exercise according to a standardized protocol. Results Mean age in our patient cohort was 75±10 years, 30% were female, and 58% suffer from atrial fibrillation. Median NT-proBNP was 2657 (1331–6599) ng/l. Mean left ventricular ejection fraction was 44±14%. At rest, MR severity was graded as mild in 57% of patients, moderate MR in 34% and severe in 9%. Mean effective regurgitant orifice area (EROA) at rest was 15±6 mm2 and regurgitation volume was 25±11 ml. During handgrip exercise, 58 patients (28%) showed an increase in MR severity in at least one grade; 30 patients (15%) with non-severe MR at rest, developed severe MR during handgrip exercise. The EROA decreased (>5 mm2) in 5% of patients, remained unchanged in 50% (between −5 mm2 and +5 mm2), and increased (>5 mm2) in 45% of patients (Fig. 1B). A small increase (5–10 mm2) was observed in 30%, while 15% of patients revealed a marked increase in EROA (>10 mm2) (Fig. 1B). The degree of MR at rest was not associated with exercise-induced increases in EROA (r=−0.03; p=0.641)(Fig. 1C). However, echocardiographic parameters of local (e.g. tenting height) and global (e.g. LVESVi) LV remodeling, as well as mitral valvular deformation correlated with exercise-induced changes in EROA (Table 1). Conclusion In patients with secondary MR due to ischemic heart disease, handgrip echocardiography unmasks exercise-induced increases of MR severity in a significant proportion of patients. Dynamic MR during handgrip exercise is associated with parameters of global and local LV remodeling as well with parameters of mitral valvular deformation. Future studies need to address the prognostic importance of exercise-induced changes in MR severity in patients with ischemic cardiomyopathy. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): This work was supported by the Forschungskommission of the Medical Faculty of the Heinrich Heine University Düsseldorf to Maximilian Spieker for a Clinician Scientist Track.