Prosthetic annulus size mismatch and recurrent mitral regurgitation after repair in advanced degenerative disease

Recurrent mitral regurgitation (MR) remains a major limitation of mitral valve (MV) repair in patients with advanced degenerative MR (asDMR) and left ventricular (LV) enlargement. We investigated whether the disproportion between LV size and prosthetic annulus dimension predicts long-term MR recurrence and adverse LV remodelling after restrictive annuloplasty.

This retrospective study included 445 patients with asDMR (stages C2-D) who underwent MV repair with either the Medtronic CG Future or Edwards Physio II annuloplasty prosthesis between 2005 and 2019. The ratio of LV end-systolic diameter (LVESD) to prosthetic orifice area (POA) quantified LV-annulus mismatch. Recurrent MR (≥grade 2) was the primary endpoint, with death treated as a competing risk. The optimal LVESD/POA threshold was derived using maximally selected rank statistics. Propensity-score matching (1:1) adjusted for baseline differences and longitudinal LV changes were analysed by generalised least-squares modelling.

During a median follow-up of 6.0 years, 15.5% of patients developed recurrent MR and 10.6% died. LVESD/POA was independently associated with recurrence (adjusted subdistribution HR 1.95, 95% CI 1.65 to 2.30; p<0.001). A threshold of 12.25 mm/cm² identified a 'mismatch' cohort with higher 5-year cumulative MR recurrence (30% vs 14%, p=0.02) and faster postoperative LV re-enlargement compared with the non-mismatch group. These findings were consistent after propensity matching. Mortality did not differ between groups.

In patients with asDMR, a larger LVESD-to-POA ratio identifies those at elevated risk of recurrent regurgitation and progressive LV remodelling after repair. Preoperative echocardiographic assessment of LV-annulus proportionality may help optimise prosthesis sizing and improve long-term durability of MV repair. Prospective multicentre validation is warranted.

Chinese Clinical Trial Registry (ChiCTR2400088114).