Isometric Handgrip Stress Test during Right Heart Catheterization in Patients with Mitral Regurgitation -A Case Series Study.

Objective The severity of mitral regurgitation (MR) dynamically changes during a stress test. Isometric handgrip is a readily-available stress test in daily practice; however, little is known regarding the response to isometric handgrip in MR patients during right heart catheterization. We aimed to evaluate this issue from our case-series study. Methods We retrospectively investigated consecutive MR patients using the isometric handgrip stress test during right heart catheterization at our institution between October 2019 and April 2021. After resting measurements were obtained, sustained maximum-effort hand dynamometer grasping was maintained for about 2-3 minutes. We investigated the differences in right heart catheterization data between at rest and during handgrip, and evaluated the individual response to the isometric handgrip stress test. Results We investigated a total of 15 patients (mean age: 75±6 years, moderate/severe MR: 7/8, primary/secondary MR: 8/7, mean left ventricular ejection fraction: 56±16%, exertional dyspnea: 10). During the handgrip test, the pulmonary capillary wedge pressure (PCWP) significantly increased [9 (8, 13) mmHg at rest to 20 (15, 27) mmHg during handgrip; p<0.001]. PCWP changes varied among individuals (range 2-22 mmHg) and were not correlated with patients' backgrounds including age, the natriuretic peptide levels, left ventricular ejection fraction, left atrial diameter or E/e' (all p>0.05). Patients with PCWP ≥25 mmHg during handgrip had a higher prevalence of exertional dyspnea than those without [6 (100%) vs. 4 (44%); p=0.04]. Conclusion We observed dynamic and varied hemodynamic changes during isometric handgrip in MR patients, suggesting that further research is needed to evaluate the clinical value of this maneuver.