Factors influencing post-surgical survival in degenerative mitral regurgitation

• Published in: European heart journal Vol. 44; no. 10; pp. 871 - 881
• Main Authors: Butcher, Steele C, Essayagh, Benjamin, Steyerberg, Ewout W, Benfari, Giovanni, Antoine, Clemence, Grigioni, Francesco, Le Tourneau, Thierry, Roussel, Jean-Christian, van Wijngaarden, Aniek, Marsan, Nina Ajmone, Tribouilloy, Christophe, Rusinaru, Dan, Hochstadt, Aviram, Topilsky, Yan, Michelena, Hector I, Delgado, Victoria, Bax, Jeroen J, Enriquez-Sarano, Maurice
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 07-03-2023; Oxford University Press (OUP)
• Subjects: Atrial Fibrillation - complications; Cardiac Surgical Procedures; Female; Human health and pathology; Humans; Life Sciences; Male; Mitral Valve Insufficiency - complications; Stroke Volume; Ventricular Function, Left; Pulmonary artery systolic pressure; Tricuspid regurgitation; Left atrial volume index; Atrial fibrillation
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehad004

Abstract
Aims
Indications for surgery in patients with degenerative mitral regurgitation (DMR) are increasingly liberal in all clinical guidelines but the role of secondary outcome determinants (left atrial volume index ≥60 mL/m2, atrial fibrillation, pulmonary artery systolic pressure ≥50 mmHg and moderate to severe tricuspid regurgitation) and their impact on post-operative outcome remain disputed. Whether these secondary outcome markers are just reflective of the DMR severity or intrinsically affect survival after DMR surgery is uncertain and may have critical importance in the management of patients with DMR. To address these gaps of knowledge the present study gathered a large cohort of patients with quantified DMR, accounted for the number of secondary outcome markers and examined their independent impact on survival after surgical correction of the DMR.
Methods and results
The Mitral Regurgitation International DAtabase-Quantitative registry includes patients with isolated DMR from centres across North America, Europe, and the Middle East. Patient enrolment extended from January 2003 to January 2020. All patients undergoing mitral valve surgery within 1 year of registry enrolment were selected. A total of 2276 patients [65 (55–73) years, 32% male] across five centres met study eligibility criteria. Over a median follow-up of 5.6 (3.6 to 8.7) years, 278 patients (12.2%) died. In a comprehensive multivariable Cox regression model adjusted for age, EuroSCORE II, symptoms, left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LV ESD) and DMR severity, the number of secondary outcome determinants was independently associated with post-operative all-cause mortality, with adjusted hazard ratios of 1.56 [95% confidence interval (CI): 1.11–2.20, P = 0.011], 1.78 (95% CI: 1.23–2.58, P = 0.002) and 2.58 (95% CI: 1.73–3.83, P < 0.0001) for patients with one, two, and three or four secondary outcome determinants, respectively. A model incorporating the number of secondary outcome determinants demonstrated a higher C-index and was significantly more concordant with post-operative mortality than models incorporating traditional Class I indications alone [the presence of symptoms (P = 0.0003), or LVEF ≤60% (P = 0.006), or LV ESD ≥40 mm (P = 0.014)], while there was no significant difference in concordance observed compared with a model that incorporated the number of Class I indications for surgery combined (P = 0.71).
Conclusion
In this large cohort of patients treated surgically for DMR, the presence and number of secondary outcome determinants was independently associated with post-surgical survival and demonstrated better outcome discrimination than traditional Class I indications for surgery. Randomised controlled trials are needed to determine if patients with severe DMR who demonstrate a cardiac phenotype with an increasing number of secondary outcome determinants would benefit from earlier surgery.
Structured Graphical Abstract
Graphical Abstract
CI = confidence interval, DMR = degenerative mitral regurgitation, FTR = functional tricuspid regurgitation, HR = hazard ratio, LA = left atrium, LAVI = left atrial volume index, PA = pulmonary artery, sPAP = systolic pulmonary artery pressure, TR = tricuspid regurgitation, US = United States