Recurrent mitral regurgitation (MR) remains a limitation of mitral valve (MV) repair in patients with advanced degenerative MR (stages C2–D) and left ventricular (LV) enlargement. This retrospective single-center study, published in Heart, included 445 patients who underwent MV repair with either the Medtronic CG Future or Edwards Physio II semirigid annuloplasty prosthesis between 2005 and 2019. Patients with Barlow’s disease were excluded. LV–annulus mismatch was quantified using the ratio of LV end-systolic diameter (LVESD) to prosthetic orifice area (POA).

The primary endpoint was recurrent MR (≥grade 2), with death treated as a competing risk. 
Over a median follow-up of 6.0 years, 15.5% developed recurrent MR and 10.6% died. LVESD/POA was independently associated with recurrence (adjusted subdistribution HR 1.95; 95% CI 1.65–2.30; p<0.001). A threshold of 12.25 mm/cm² identified a mismatch cohort with higher 5-year cumulative recurrence (30% vs 14%; p=0.02) and faster LV re-enlargement. These findings were consistent after propensity-score matching. Mortality did not differ between groups.

An elevated LVESD/POA ratio was associated with higher MR recurrence and progressive remodeling. Preoperative assessment of LV–annulus proportionality may help optimize prosthesis sizing pending prospective validation.