Neochordae implantation versus leaflet resection in mitral valve posterior leaflet prolapse and dilated left ventricle: a propensity score matching comparison with long-term follow-up

Background: Uncorrected severe mitral regurgitation due to posterior prolapse/flail leads to left ventricular dilatation. At this stage, mitral valve repair becomes mandatory to avoid permanent myocardial injury. However, which technique among neochoardae implantation and leaflet resection provides the best results in this scenario remains unknown. Methods: We selected 332 patients with left ventricular dilatation and severe degenerative mitral regurgitation due to posterior leaflet prolapse who underwent neochoardae implantation (85 patients) or posterior leaflet resection (247 patients) at our Institution between 2008 and 2020. A propensity score matching analysis was carried on to decrease the differences at baseline. Results: Matching yielded 85 neochordae implantations and 85 posterior leaflet resections. At 10-years, freedom from cardiac death and freedom from mitral valve reoperation, was 92.6 ± 6.1% vs 97.8 ± 2.1% and 97.7 ± 2.2% vs 95±3% in the neochordae group and in the posterior leaflet resection group respectively.The mitral regurgitation ≥2+ recurrence rate was 23.9±10% in the neochordae group and 20.8 ± 5.8% in the posterior leaflet resection group (p = 0.834) at 10-years. At last follow-up, neochordae group showed a higher reduction of left-ventricular end-diastolic diameter (44mm vs 48 mm; p = 0.001) and a better ejection fraction (60% vs 55%; p < 0.001) compared to posterior leaflet resection group. Conclusions: In this subgroup of patients, both neochordae implantation and leaflet resection provide excellent durability of the repair in the long-term. Neochordae implantation might have a better effect on dilated left ventricle.