Roussel, Jean-Christian

Background The prevalence and impact of right ventricular dysfunction (RVD) in degenerative mitral regurgitation (DMR) is unknown. We aimed to determine whether RVD assessed by echocardiography in routine clinical practice is independently associated with mortality in patients with DMR. Methods and Results We used data from the MIDA‐Q (Mitral Regurgitation International DAtabase‐Quantitative) registry, which included patients with isolated DMR due to mitral valve prolapse from January 2003 to January 2020 from 5 tertiary centers across North America, Europe, and the Middle East. A cohort of 2917 (mean age: 66 years, 70.8% male patients, follow‐up: 5.2 [3.3–8.3] years) consecutive patients with severe DMR was included and long‐term mortality was analyzed. RVD, identified in 426 (14.6%) patients, was associated with reduced 8‐year survival (55%±3% versus 77%±1%; P <0.001), overall and in all subgroups of patients, even after comprehensive adjustment including left ventricular dilatation and dysfunction, DMR severity, pulmonary pressures, and surgery (adjusted hazard ratio, 1.44 [95% CI, 1.17–1.77]; P <0.001). This excess mortality was observed under medical management (adjusted hazard ratio, 1.57 [95% CI, 1.20–2.05]; P =0.001) and after surgical correction of mitral regurgitation (adjusted hazard ratio, 1.45 [95% CI, 1.02–2.05]; P =0.039). Patients with RVD undergoing surgery within 3 months of diagnosis experienced a better 8‐year survival (73%±4% versus 43%±4%; P <0.001), even after adjustment (adjusted hazard ratio, 0.44 [95% CI, 0.29–0.67]; P <0.001) despite an increase of 1‐month postoperative mortality (7.1% versus 0.5% for patients without RVD; P <0.001). Conclusions RVD is observed in 14.6% of severe DMR and exhibits a powerful and independent association with excess mortality partially attenuated by mitral surgery. Therefore, assessment of right ventricular systolic function should be included in routine DMR evaluation and in the clinical decision‐making process.

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 &lt; 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.