We have investigated the relation between occurrence of myocardial oxidative stress and functional recovery during postischemic reperfusion in 20 selected patients subjected to aortocoronary bypass grafting. Patients were selected for having normal percent ejection fraction and left ventricular end-diastolic pressure before the operation. Occurrence of oxidative stress was assessed by measuring the formation and release of oxidized glutathione (GSSG) in the coronary sinus immediately before aortic cross-clamp, 1, 5, 10, and 20 minutes after removal of aortic cross-clamp, and 10 and 20 minutes after the end of cardiopulmonary bypass. Reduced glutathione (GSH), lactate, and creatine phosphokinase release were also monitored with the same timing. Standard hemodynamic measurements were recorded by means of a triple-lumen thermodilution pulmonary artery catheter before sternotomy, 15 minutes after the end of cardiopulmonary bypass, and during the 24 hours after termination of cardiopulmona-ry bypass. Reperfusion in patients after a short period of ischemia (less than 30 minutes; group 1) resulted in a small and transient release in the coronary sinus of GSSG and GSH and in a progressive improvement of hemodynamic parameters reaching a stable state 4 hours after the operation. In patients with a period of ischemia longer than 30 minutes (group 2), reperfusion induced a marked and sustained release of lactate, GSH, and GSSG; the arteriocoronary sinus difference for GSSG was still negative after the end of cardiopulmonary bypass. The arteriocoronary sinus difference for creatine phosphokinase also remained negative for as long as 20 minutes after cardiopulmonary bypass, and the rate of functional recovery was significantly delayed, reaching the values of group 1 only 12 hours after the operation. In these patients there was a positive correlation (r=0.88, p<0.01) between the duration of ischemia and the myocardial arteriovenous difference for GSSG. In addition, there was a negative correlation between the arteriocoronary sinus difference for GSSG and cardiac index measured 2, 4, and 6 hours after the operation. These data suggest for the first time that, depending on the severity of the ischemic period, oxidative stress occurs during reperfusion of patients with coronary artery disease who are subjected to heart surgery and that it may be linked with a delay in postoperative recovery of cardiac function. (Circulation 1990;81:201-211)
From January 1987 to July 1994, 299 consecutive patients ranging from 4 to 80 years of age underwent mitral repair for pure valve insufficiency due to degenerative disease (59%), rheumatic disease (23%), endocarditis (12%) or ischemic heart disease (6%). During the initial period, a variety of reparative methods were used following the principles originally described by Carpentier. More recently, in our institution other surgical techniques have been introduced: specifically, prolapse of the anterior leaflet was corrected either by replacing the chordae with polytetrafluoroethylene (PTFE) sutures or simply by anchoring the prolapsing free edge to the facing edge of the posterior leaflet ("edge-to-edge" technique). Chordal transposition has also been used occasionally to correct the prolapse of the anterior leaflet. The hospital mortality rate was 1.3%. According to actuarial methods, the overall survival rate was 94% at 7 years, and freedom from reoperation was 86%. Significant incremental risk factors for reoperation were: no use of prosthetic ring, correction of the prolapse of the anterior leaflet by triangular resection or chordal shortening and ischemic etiology of the mitral insufficiency (freedom from reoperation at 7 years was 61%, 56% and 51%, respectively). In the late postoperative period (mean follow-up 3.6 years), 95% of the patients were in NYHA class I or II; four patients had thromboembolic episodes, two hemorrhagic complications and two endocarditis. No patient in whom the prolapse of the anterior leaflet was corrected by the recently introduced technique has required reoperation. The anterior mitral leaflet prolapse was therefore neutralized as an incremental risk factor for reoperation and this has contributed to the improved overall results of mitral valve repair.
Mitral valve replacement is a suitable option for patients with chronic ischemic mitral regurgitation and impaired left ventricular function. It provides better results in terms of freedom from reoperation with comparable valve-related complication rates.
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