Determinants of Increased Transmitral Gradients Under Dynamic Isometric Handgrip Exercise After Edge‐to‐Edge Repair With the Fourth‐Generation MitraClip

Aim: Mitral regurgitation (MR) is a prevalent cardiovascular condition, and its treatment remains challenging, especially in high‐risk patients. The fourth‐generation MitraClip system (NTW and XTW) offers enhanced capabilities for repairing mitral valves (MVs) with complex anatomies. This study evaluates the haemodynamic function of MVs after edge‐to‐edge with wide MitraClip under physical stress induced by handgrip exercise stress echocardiography. Methods: This prospective study included 27 patients with severe MR. All patients underwent successful MitraClip implantation, and handgrip stress echocardiography was performed predischarge. The primary endpoint was a postprocedure mean transmitral gradient (TMG) < 5 mmHg under stress. A machine learning (ML) model using logistic regression as the learner and advanced data augmentation techniques, including random splitting of data into training and testing subsets and repeating the process 50 times, were employed to ensure robustness. Results: MitraClip implantation reduced MR severity from 3.02 ± 0.22 to 0.98 ± 0.43 ( p < 0.0001). Stress‐induced increases in heart rate, blood pressure and TMG were significant (TMG: 3.04 ± 0.90 mmHg at rest vs. 4.11 ± 1.53 mmHg under stress, p < 0.0001). Thirty‐seven percent of patients exhibited TMG ≥ 5 mmHg during stress. Predictors of elevated TMG included secondary MR, BMI, and multiple clip implantation (AUC = 0.90; 95% CI: 0.79–0.96). Despite increased TMG, no patients experienced significant symptoms or pathological MR. Conclusion: Wide MitraClips effectively reduce MR with satisfactory haemodynamic performance. Handgrip stress echocardiography is a feasible and valuable tool for assessing postprocedure valve function. Larger cohorts are necessary to confirm the impact of secondary MR and use of multiple clips on increased TMG under stress.