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

Aims: 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. Methods and results: : We analyzed outcome of 2833 patients from the MIDA-registry undergoing surgical correction of DMR. Patients were stratified by surgical indications: Class-I-trigger (symptoms, left ventricular end-systolic diameter≥40mm, or left ventricular ejection fraction<60%, n=1677), isolated-Class-IIa-trigger (atrial fibrillation [AF], pulmonary hypertension [PH], or left atrial diameter≥55mm, n=568), or no-trigger (n=588). Postoperative survival was compared after matching for clinical differences. Restricted-mean-survival time (RMST) was analyzed. 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%, 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 (HR:1.53, 95%CI:1.42-1.66). Isolated-Class-IIa-triggers conferred an excess mortality risk versus those without (HR:1.46, 95%CI:1.00-2.13, p=0.05). Among these patients, isolated-PH led to decreased postoperative-survival versus 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. Conclusions: : 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.