Modena, Maria Grazia

Abstract 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 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. Conclusion 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.

Background— Left atrium (LA) enlargement is common in organic mitral regurgitation (MR) and is an emerging prognostic indicator. However, outcome implications of LA enlargement have not been analyzed in the context of routine clinical practice and in a multicenter study. Methods and Results— The Mitral Regurgitation International DAtabase (MIDA) registry enrolls patients with organic MR due to flail leaflets, diagnosed in routine clinical practice, in 5 US and European centers. We investigated the relation between LA diameter and mortality under medical treatment and after mitral surgery in 788 patients in sinus rhythm (64±12 years; median LA, 48 [43 to 52] mm). LA diameter was independently associated with survival after diagnosis (hazard ratio, 1.08 [1.04 to 1.12] per 1 mm increment). Compared with patients with LA <55 mm, those with LA ≥55 mm had lower 8-year overall survival ( P <0.001). LA ≥55 mm independently predicted overall mortality (hazard ratio, 3.67 [1.95 to 6.88]) and cardiac mortality (hazard ratio, 3.74 [1.72 to 8.13]) under medical treatment. The association of LA ≥55 mm and mortality was consistent in subgroups. Similar excess mortality associated with LA ≥55 mm was observed in asymptomatic and symptomatic patients ( P for interaction, 0.77). In patients who underwent mitral surgery, LA ≥55 mm had no impact on postoperative outcome ( P >0.20). Mitral surgery was associated with greater survival benefit in patients with LA ≥55 mm compared with LA <55 mm ( P for interaction, 0.008). Conclusions— In MR caused by flail leaflets, LA diameter ≥55 mm is associated with increased mortality under medical treatment, independent of the presence of symptoms or left ventricular dysfunction.