Predictors of persistence of functional mitral regurgitation after cardiac resynchronization therapy

Elnagar, Amr E.; Elrabbat, Khaled E.; Katta, Azza A.; Elfeshawy, Yasmeen M.; Elsayed, Amr A

doi:10.21608/bmfj.2025.397762.2498

Predictors of persistence of functional mitral regurgitation after cardiac resynchronization therapy

Articles in Press

Document Type : Original Article

Authors

¹ Assistant Professor of Cardiology Faculty of Medicine - Benha University

² Professor of Cardiology Faculty of Medicine - Benha University

³ Consultant of Cardiology Cardiac Institute

⁴ (M.B.B.S) Cardiology resident at Elsheik Zayed Specialized Hospital

⁵ Lecturer of Cardiology Faculty of Medicine-Benha University

10.21608/bmfj.2025.397762.2498

Abstract

Background: Functional mitral regurgitation (FMR) commonly occurs in dilated cardiomyopathy. Cardiac resynchronization therapy (CRT) is an effective approach; however, some cases continue to experience persistent or worsening mitral regurgitation (MR), underscoring the need to identify predictive factors. Methods: This prospective study followed 100 adults with non-ischemic dilated cardiomyopathy indicated for CRT. Baseline evaluations included demographics, comorbidities, laboratory tests, ECG, and detailed echocardiography with multiparametric MR grading. Follow-up at 3 and 6 months included repeat assessments, NYHA class, 6-minute walk test, and imaging. Logistic regression was employed to recognize variables associated with MR improvement or persistence post-CRT. Results: CRT improved functional status and exercise capacity, evidenced by reduced NYHA class and increased 6-minute walk distance. Echocardiography showed enhanced ejection fraction and fractional shortening, with reductions in left atrial size and ventricular dimensions (EDD, EDV, ESD, ESV). Tenting height and area also decreased. Most cases exhibited reduced MR severity. No significant predictors were identified pre-CRT. Post-CRT, MR improvement was associated with smaller end-systolic volume, higher fractional shortening, larger mid-diastolic mitral annular area, increased regurgitation, and wider vena contracta. Persistent MR was more common in older cases and those with larger baseline MR jet area, higher EDV, elevated heart rate, enlarged left atrium, prolonged PR interval, and wider QRS duration. Conclusion: In non-ischemic dilated cardiomyopathy, FMR improvement after CRT is mainly linked to reverse remodeling and residual MR severity. Baseline clinical and echocardiographic variables can help identify cases at risk for persistent MR, enabling personalized management strategies.

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