Therapy and Prevention - Cardiac Surgery

Of 300 consecutive patients undergoing primary operation for mitral valve replacement combined with coronary bypass grafting, 22 (7.3%) died in-hospital. Multivariate testing of preoperative and operative descriptors identified radiographic cardiac enlargement, preoperative paced rhythm or atrial fibrillation, 70% or more left main coronary obstruction, and serum bilirubin of more than 2 mg% as factors associated with an increase in in-hospital mortality. Follow-up of the 278 hospital survivors (mean interval 48 months, range 2 to 165 months) documented survival of 85%, 66%, and 31% and an event-free survival of 65%, 46%, and 21 % at 2, 5, and 10 postoperative years, respectively. Cox proportional-hazard regression models of late risk implicated in-hospital ventricular arrhythmias, left ventricular dysfunction, and rheumatic or ischemic causes of mitral valve disease in decreasing long-term survival. In addition, patients with bioprostheses without warfarin anticoagulation had better survival and event-free survival than those with bioprostheses taking warfarin and those with mechanical prostheses with or without warfarin. Circulation 71, No. 6, 1179-1190, 1985. PATIENTS with a combination of coronary atherosclerosis and mitral valve disease represent a continuing challenge to cardiologists and surgeons. Coronary bypass grafting is an effective operation for patients with isolated coronary atherosclerosis, consistently relieving angina and, for some subgroups of patients, also prolonging survival.1-' Mitral valve replacement improves the symptoms of most patients with hemodynamically significant mitral valve dysfunction, is lifesaving for patients with acute, severe mitral insufficiency, and may improve survival for patients with chronic mitral valve dysfunction as well.4 5 However, the risks of operations combining mitral valve replacement with coronary bypass grafting have been high; reported rates of perioperative death range from 14% to 24%.>° Furthermore, the few data available regarding long-term survival document substantial late attrition of operative survivors.8 Analysis of the causes of From the Departments of Cardiothoracic Surgery and Biostatistics and Epidemiology, Cleveland Clinic Foundation. Address for correspondence: Bruce W. Lytle, M.D., Department of Cardiothoracic Surgery, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44106. Presented in part at the American Heart Association 57th Scientific Sessions, Miami, November 1984. Received Jan. 16, 1985; accepted March 7, 1985. Vol. 71, No. 6, June 1985 treatment failure is difficult because patients with mitral valve and coronary artery disease are a heterogenous group in terms of the causes of their mitral valve dysfunction, the extent of coronary atherosclerosis, left ventricular function, hemodynamic status at operation, and many other patient-related factors. Intraoperative management, prosthesis selection, and anticoagulation strategies add further variables. To document the results of operation and to identify the factors influencing early and late risk, the first 300 patients undergoing primary operation for mitral valve replacement combined with coronary artery bypass grafting were reviewed. Methods Methods of patient identification, data collection, and patient follow-up have been previously described.'1 The study group comprised the first 300 consecutive patients undergoing a primary cardiac operation limited to mitral valve replacement combined with coronary bypass grafting. These criteria excluded patients undergoing cardiac reoperation, mitral valve reconstruction, or concomitant aneurysmectomy, aortic valve surgery, or carotid operation. Both elective and emergency cases are included. All patients underwent operation between January 1, 1970 and August 1, 1983. Preoperative data. The preoperative clinical variables examined are listed in table 1. 1179 by gest on O cber 5, 2017 http://ciajournals.org/ D ow nladed from