Abstract 17188: Calcific Degenerative Mitral Disease vs Myxomatous Degeneration: Crystallizing the Differences

Introduction: Myxomatous (M) and other non-M, non-ischemic valve pathologies are often all classified as “degenerative mitral valve disease.” We have seen at TEE and surgery a subgroup of older patients with normal or reduced leaflet area, leaflet cholesterol deposition, annular fibrosis and calcification and thickened chordae - at most only two are ruptured. We classify these pts as “calcific degenerative (D).” Hypothesis: Pts with D have different outcomes and require different techniques than pts with M. Methods: Since 1994, D and M have been recorded prospectively and separately; 205 patients had D pathology, 654 had M. Results: D pts were more often female: 63% (130/205) vs. M, 32% (209/654) p<0.0001; older : 69.20±11.34 vs. 60.86±13.42 years, p<0.0001; had a lower preop EF: 55.97±12.82 vs. 61.80±9.10, p<0.0001; smaller preop annular AP diameter: 41.59±5.60 vs. 44.36±4.00, p<0.0001; more concurrent AVRs: 8.8% (18/205) vs. M: 3.5% (23/654) p=0.0038; had fewer posterior chordal replacements: 4.06±1.54 vs. 4.67±1.53, p=0.0016 and smaller ring sizes D: 28.22±3.06 vs. M: 30.72±2.86, p<0.0001. Periop mortality was higher in D: 3.9% (8/205) in D vs 1.2% (8/654) of M pts, p=0.0293. Late 10-yr survival (Kaplan-Meier) was D, 37.94%, and for M, 71.3%, p<0.0001. Late 10-yr freedom from reoperation (Kaplan-Meier) was for D, 95.6% and for M, 93.2%, p=0.375. Late 10-yr freedom from significant mitral regurgitation (MR) (Kaplan-Meier) was for D, 79.9%, and for M, 85.9%, p=0.269. Cox regression for predictors of mortality identified age (relative risk (RR) 1.078, p<0.0001), sex (RR 0.715, p=0.0320) preop EF (RR 0.985, p=0.0220), concomitant CAB (RR 1.614, p=0.0058), posterior leaflet repaired (RR 0.581, p=0.0058) or both posterior and anterior leaflet repaired (RR 0.500, p=0.0150), and leaflet calcification, (RR 1.734, p=0.0440); for predictors of reoperation, age (RR 0.971, p=0.048) and sex (RR 2.914, p=0.040); and for a predictor of late MR, annuloplasty ring size (RR 1.242, p=0.0094). Conclusions: These data confirmed that the D group had distinct clinical and pathological features which can be identified preoperatively and intraoperatively. Leaflet resection is not successful in these patients. Reconstructive techniques are preferred.