Faculty Bibliography

BACKGROUND: This study analyzes a single institutional experience with minimally invasive mitral valve operations of 6 years, reviewing short-term morbidity and mortality and long-term echocardiographic follow-up data. METHODS: Seven hundred fourteen consecutive patients had minimally invasive mitral valve procedures between November 1995 and November 2001; concomitant procedures included 91 multiple valves and 18 coronary artery bypass grafts. Of these 714 patients, 561 patients had isolated mitral valve operations (375 repairs, 186 replacements). Mean age was 58.3 years (range, 14 to 96 years; 30.1% > 70 years), and 15.4% of patients had previous cardiac operations. Arterial cannulation was femoral in 79.0% and central in 21%, with the port access balloon endo-occlusion used in 82.3%. Cardioplegia was transjugular retrograde (54.1%) or antegrade (29.4%). Right anterior minithoracotomy was used in 96.6% and left posterior minithoracotomy in 2.2%. RESULTS: Hospital mortality for primary isolated mitral valve repair was 1.1% and 5.8% for isolated mitral valve replacement. Overall hospital mortality was 4.2% (30 of 714). Mean cross-clamp time was 92 minutes and mean cardiopulmonary bypass time was 127 minutes. Postoperatively, median ventilation time was 11 hours, intensive care unit time was 19 hours, and total hospital stay was 6 days. Complications for all patients included permanent neurologic deficit (2.9%), aortic dissection (0.3%); there was no mediastinal infection (0.0%). Follow-up echocardiography demonstrated 89.1% of the repair patients had only trace or no residual mitral insufficiency. CONCLUSIONS: This study demonstrates that the minimally invasive port access approach to mitral valve operations is reproducible with low perioperative morbidity and mortality and with late outcomes that are equivalent to conventional operations

OBJECTIVE: To analyze the effectiveness of new techniques of mitral valve reconstruction (MVR) that have evolved over the last decade, such as aggressive anterior leaflet repair and minimally invasive surgery using an endoaortic balloon occluder. SUMMARY BACKGROUND DATA: MVR via conventional sternotomy has been an established treatment for mitral insufficiency for over 20 years, primarily for the treatment of patients with posterior leaflet prolapse. METHODS: Between June 1980 and June 2001, 1,195 consecutive patients had MVR with ring annuloplasty. Conventional sternotomy was used in 843 patients, minimally invasive surgery in 352 (since June 1996). Anterior leaflet repair was performed in 374 patients, with increasing use over the last 10 years. Follow-up was 100% complete (mean 4.6 years, range 0.5-20.5). RESULTS: Hospital mortality was 4.7% overall and 1.4% for isolated MVR (1.1% for minimally invasive surgery vs. 1.6% for conventional sternotomy; =.4). Multivariate analysis showed the factors predictive of increased operative risk to be age, NYHA functional class, concomitant procedures, and previous cardiac surgery. The 5-year results for freedom from cardiac death, reoperation, and valve-related complications among the 782 patients with degenerative etiology are, respectively, as follows ( >.05 for all end points): for anterior leaflet repair, 93%, 94%, 90%; for no anterior leaflet repair, 91%, 92%, 91%; for minimally invasive surgery, 97%, 89%, 93%; and for conventional sternotomy, 93%, 94%, 90%. CONCLUSIONS: These findings indicate that late results of MVR after minimally invasive surgery and after anterior leaflet repair are equivalent to those achievable with conventional sternotomy and posterior leaflet repair. These options significantly expand the range of patients suitable for mitral valve repair surgery and give further evidence to support wider use of minimally invasive techniques

BACKGROUND: Vascular endothelial cell apoptosis is central in atherosclerosis and intimal hyperplasia. Transforming growth factor (TGF)-beta1 induces endothelial cell apoptosis through unidentified mechanism(s). Although TGF-beta1 signals through the Smad proteins, in some nonendothelial cell types it also activates the mitogen-activated protein kinase (MAPK) (extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 MAPK [p38(MAPK)]). p38(MAPK) relays apoptotic signals in several cell types. We hypothesized that TGF-beta1 activates endothelial cell MAPKs and induces apoptosis through p38(MAPK) activation. METHODS: Human umbilical vein or bovine capillary endothelial cells were incubated with TGF-beta1 for 0.5 to 12 hours. MAPK activation was characterized by Western blotting with antibodies to phosphorylated extracellular signal-regulated kinase 1/2, p38(MAPK), or c-Jun N-terminal kinases 1/2. To study apoptosis, extracts of cells incubated with TGF-beta1 for 6 hours with or without MAPK inhibitors were characterized by Western blotting analysis of poly (ADP-Ribose) polymerase degradation. RESULTS: TGF-beta1 induced p38(MAPK), extracellular signal-regulated kinase 1/2, and c-Jun N-terminal kinase 1/2 activation and increased apoptosis. Inhibition of p38(MAPK) significantly reduced TGF-beta1-induced apoptosis. In contrast, inhibition of other signaling pathways was ineffective. CONCLUSIONS: TGF-beta1 induces endothelial cell apoptosis through p38(MAPK) activation. Because TGF-beta1 is upregulated in vascular remodeling, p38(MAPK) is a potential target to prevent endothelial cell apoptosis during this process

OBJECTIVE: This study reviews the 223 consecutive mitral valve operations for ischemic mitral insufficiency performed at New York University Medical Center between January 1976 and January 1996. The results for mitral valve reconstruction are compared with those for prosthetic mitral valve replacement. METHODS: From January 1976 to January 1996, 223 patients with ischemic mitral insufficiency underwent mitral valve reconstruction (n = 152) or prosthetic mitral valve replacement (n = 71). Coronary artery bypass grafting was performed in 89% of cases of mitral reconstruction and 80% of cases of prosthetic replacement. In the group undergoing reconstruction, 77% had valvuloplasty with a ring annuloplasty and 23% had valvuloplasty with suture annuloplasty. In the group undergoing prosthetic replacement, 82% of patients received bioprostheses and 18% received mechanical prostheses. RESULTS: Follow-up was 93% complete (median 14.6 mo, range 0-219 mo). Thirty-day mortality was 10% for mitral reconstruction and 20% for prosthetic replacement. The short-term mortality was higher among patients in New York Heart Association functional class IV than among those in classes I to III (odds ratio 5.75, confidence interval 1.25-26.5) and was reduced among patients with angina relative to those without angina (odds ratio 0.26, confidence interval 0.05-1.2). The 30-day death or complication rate was similarly elevated among patients in functional class IV (odds ratio 5.53; confidence interval 1.23-25.04). Patients with mitral valve reconstruction had lower short-term complication or death rates than did patients with prosthetic valve replacement (odds ratio 0.43, confidence interval 0.20-0.90). Eighty-two percent of patients with mitral valve reconstruction had no insufficiency or only trace insufficiency during the long-term follow-up period. Five-year complication-free survivals were 64% (confidence interval 54%-74%) for patients undergoing mitral valve reconstruction and 47% (confidence interval 33%-60%) for patients undergoing prosthetic valve replacement. Results of a series of statistical analyses suggest that outcome was linked primarily to preoperative New York Heart Association functional class. CONCLUSIONS: Initial mortalities were similar among patients undergoing prosthetic replacement and valve reconstruction. Poor outcome was primarily related to preexisting comorbidities. Patients undergoing valve reconstruction had fewer valve-related complications. Valve reconstruction resulted in excellent durability and freedom from complications. These findings suggest that mitral valve reconstruction should be considered for appropriate patients with ischemic mitral insufficiency