Abstract 16946: The Optimal Surgical Procedure of Mitral Valve Repair According to Risk Analysis of Postoperative Functional Mitral Stenosis

Abstract

Background: Functional mitral stenosis (FMS) after mitral valve repair (MVr) is associated with pulmonary hypertension in the late period, increasing the risk of re-operation and deterioration of long-term outcomes. However, the risk factors for FMS after MVr, especially the impact of surgical procedures, have not been thoroughly investigated. Hypothesis: We hypothesize that procedures of valve repair, including prosthetic ring orifice area (ROA), may be associated with FMS in the late period. Methods: We retrospectively evaluated 205 patients who underwent MVr using full annuloplasty rings between 2011 and 2021 at our institution. FMS was defined as mean trans-mitral pressure gradient (TMPG) ≥8 mmHg measured by annual echocardiography. ROA was determined by calculating the internal area of each valve type and size. Perioperative factors such as repair techniques, ROA, and ROA divided by BSA (ROAi) were used to analyze risk factors for FMS. The mean follow-up period was 4.8±0.4 years. Results: MVr was performed using artificial chordae in 110 cases and intervention in valve leaflet in 83 cases (resection suture: 43, cleft closure: 26, plication: 12, and edge-to-edge repair: 8). We also utilized semi-rigid full ring in all cases (26 or less: 15, 28: 53, 30: 73, 32: 49, 34 or more: 15). We identified postoperative FMS in 23 cases (11.2%, 2.5±0.9 years after MVr) with TMPG of 9.0 ± 0.7 mmHg. In the FMS group, decreasing TR-PG in the late period was not achieved after MVr. TR-PG in the late period was also significantly higher in the FMS group (28.3 ± 5.8 vs. 20.3 ± 2.1 mmHg, p=0.01). The freedom from re-operation for MV and re-hospitalization for heart failure rate was not significantly different in the two groups (93.6% vs. 95.5%, p=0.32, 87.7% vs. 90.6%, p=0.36, respectively). However, the freedom from MACE rate was lower in the FMS group (81.4% vs. 86.3%, p=0.11). Univariate analysis demonstrated that intervention in valve leaflet (OR 2.53, p=0.04) and ROAi (OR 0.98, p=0.005) were significant risk factors for FMS. Conclusion: Although further follow-up is mandatory, these results suggested that the use of sufficiently large prosthetic ring and avoidance of intervention in valve leaflet are efficient for preventing FMS and improving clinical outcomes after MVr.