Degenerative Mitral Regurgitation Outcomes in Asian Compared With European-American Institutions

Nadira Hamid; Francesca Bursi; Giovanni Benfari; Jean-Louis Vanoverschelde; Christophe Tribouilloy; Elena Biagini; Jean-Francois Avierinos; Andrea Barbieri; Yiting Fan; Federico Guerra; Chua Yeow Leng; Benjamin Essayagh; Agnés Pasquet; Catherine Szymansky; Alexis Théron; Hector I Michelena; Vuyisile T Nkomo; David Vancraeynest; Dan Rusinaru; Francesco Grigioni; Maurice L Enriquez-Sarano; Ding Zee Pin; Alex Pui-Wai Lee; MIDA Investigators

doi:10.1016/j.jacasi.2024.03.003

Degenerative Mitral Regurgitation Outcomes in Asian Compared With European-American Institutions

JACC Asia. 2024 May 21;4(6):468-480. doi: 10.1016/j.jacasi.2024.03.003. eCollection 2024 Jun.

Authors

Nadira Hamid^{1

2}, Francesca Bursi³, Giovanni Benfari^{4

5}, Jean-Louis Vanoverschelde⁶, Christophe Tribouilloy⁷, Elena Biagini⁸, Jean-Francois Avierinos⁹, Andrea Barbieri¹⁰, Yiting Fan¹¹, Federico Guerra¹², Chua Yeow Leng¹, Benjamin Essayagh⁴, Agnés Pasquet⁶, Catherine Szymansky⁷, Alexis Théron⁹, Hector I Michelena⁴, Vuyisile T Nkomo⁴, David Vancraeynest⁶, Dan Rusinaru⁷, Francesco Grigioni¹³, Maurice L Enriquez-Sarano^{4

14}, Ding Zee Pin¹, Alex Pui-Wai Lee¹⁵; MIDA Investigators

Affiliations

¹ National Heart Centre Singapore, Singapore.
² New York Presbyterian Hospital, Columbia University Medical Center, New York, New York.
³ University of Milan, Department of Health Sciences, Division of Cardiology, San Paolo Hospital, ASST Santi Paolo e Carlo, Milan, Italy.
⁴ Department of Cardiovascular Medicine, Mayo Clinic, Rochester Minnesota, USA.
⁵ University of Verona, Department of Medicine, Section of cardiology, Verona, Italy.
⁶ Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain and Divisions of Cardiology and Cardiothoracic Surgery, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
⁷ Department of Cardiology, Amiens University Hospital, Amiens, France, and EA 7517 MP3CV Université de Picardie Jules Verne University Hospital, Amiens, France.
⁸ Cardiovascular Department, University Hospital S. Orsola-Malpighi, Bologna, Italy.
⁹ Cardiovascular Division, Aix-Marseille Université, INSERM MMG U1251, Marseille, France.
¹⁰ Divison of Cardiology, Department of Diagnostics, Clinical and Health Public, University of Modena, University of Modena and Reggio Emilia, Modena, Italy.
¹¹ Shanghai Chest Hospital, Shanghai, P.R. China.
¹² Cardiology and Arrhythmology Clinic, Marche Polytechnic University, University Hospital "Umberto I - Lancisi - Salesi", Ancona, Italy.
¹³ Cardiovascular Department, University Campus Bio-Medico, Rome, Italy.
¹⁴ Minneapolis Heart Institute, Minneapolis, Minnesota, USA.
¹⁵ Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong, P.R. China.

Abstract

Background: Clinical outcome and interventional thresholds for degenerative mitral regurgitation (DMR) were developed in studies of patients at European and American institutions (EAIs), but little is known about patients at Asian institutions (AsIs).

Objectives: This study sought to contrast DMR presentation/management/outcomes of AsI patients vs EAI patients.

Methods: Patients with DMR due to flail leaflet from Hong Kong and Singapore (AsI cohort, n = 737) were compared with EAI patients (n = 682) enrolled in the MIDA (Mitral regurgitation International Database) registry with similar eligibility criteria.

Results: AsI patients presented similar DMR lesion/consequences vs EAI patients, but they were younger, with fewer symptoms (74% vs 44% Class I), more sinus rhythm (83% vs 69%), and lower EuroSCORE II (European System for Cardiac Operative Risk Evaluation II) (0.9 ± 0.5 vs 1.4 ± 1.5; all P < 0.0001). Imaging showed smaller absolute left atrial/ventricular dimensions in AsI patients, belying cardiac dilatation with larger body surface area-indexed diameters (all P < 0.01). Surgical/interventional mitral repair was similarly predominant (90% vs 91%; P = 0.47), and early repair was similarly beneficial (for AsI patients, adjusted HR: 0.28; 95% CI: 0.16-0.49; for EAI patients, HR: 0.32; 95% CI: 0.20-0.49; both P < 0.0001). However, AsI patients underwent fewer interventions (55% ± 2% vs 77% ± 2% at 1 year; P < 0.0001) and incurred excess mortality (adjusted HR: 1.60 [95% CI: 1.13-2.27] vs EAI patients; P = 0.008) at long-term postdiagnosis. Propensity score matching (434 patient pairs), which balanced all clinical characteristics, confirmed that there was undertreatment and excess mortality in the long term in AsI patients with DMR (P < 0.0001).

Conclusions: Imaging may underestimate volume overload in AsI patients due to smaller cardiac cavities related to smaller body size compared with EAI patients with similar mitral lesions and DMR severity. AsI patients enjoy similar mitral repair predominance and early intervention benefits but undergo fewer mitral interventions than EAI patients and incur subsequent excess mortality, suggesting the need to account for imaging and cultural specificity to improve DMR outcomes worldwide.

Keywords: degenerative mitral regurgitation; ethnicity; mitral surgery; outcome.