Survival loss linked to guideline-based indications for degenerative mitral regurgitation surgery

Operating on patients with severe degenerative mitral regurgitation (DMR) is based on ACC/AHA or ESC/EACTS guidelines. Doubts persist on best surgical indications and their potential association with postoperative survival loss. We sought to investigate whether guideline-based indications lead to late postoperative survival loss in DMR patients. We analysed outcome of 2833 patients from the Mitral Regurgitation International Database registry undergoing surgical correction of DMR. Patients were stratified by surgical indications: Class I trigger (symptoms, left ventricular end-systolic diameter ≥ 40 mm, or left ventricular ejection fraction < 60%, n = 1677), isolated Class IIa trigger [atrial fibrillation (AF), pulmonary hypertension (PH), or left atrial diameter ≥ 55 mm, n = 568], or no trigger (n = 588). Postoperative survival was compared after matching for clinical differences. Restricted mean survival time (RMST) was analysed. During a median 8.5-year follow-up, 603 deaths occurred. Long-term postoperative survival was lower with Class I trigger than in Class IIa trigger and no trigger (71.4 ± 1.9, 84.3 ± 2.3, and 88.9 ± 1.9% at 10 years, P < 0.001). Having at least one Class I criterion led to excess mortality (P < 0.001), while several Class I criteria conferred additional death risk [hazard ratio (HR): 1.53, 95% confidence interval (CI): 1.42-1.66]. Isolated Class IIa triggers conferred an excess mortality risk vs. those without (HR: 1.46, 95% CI: 1.00-2.13, P = 0.05). Among these patients, isolated PH led to decreased postoperative survival vs. those without (83.7 ± 2.8% vs. 89.3 ± 1.6%, P = 0.011), with the same pattern observed for AF (81.8 ± 5.0% vs. 88.3 ± 1.5%, P = 0.023). According to RMST analysis, compare to those operated on without triggers, operating on Class I trigger patients led to 9.4-month survival loss (P < 0.001) and operating on isolated Class IIa trigger patients displayed 4.9-month survival loss (P = 0.001) after 10 years. Waiting for the onset of Class I or isolated Class IIa triggers before operating on DMR patients is associated with postoperative survival loss. These data encourage an early surgical strategy.