Demographic changes in coronary artery bypass surgery and its effect on mortality and morbidity

Abstract

Over the past 4-5 years, possibly with the advent of percutaneoustransluminal coronary angioplasty (PTCA), there has been a changing patientpopulation for coronary artery bypass surgery (CABS) with a gradualincrease in the operative mortality. In an attempt to analyze the changingdemographics in patients undergoing CABS and its effect on operativemortality, we analyzed data from 5536 consecutive patients undergoingisolated CABS. There was 4151 patients less than 70 years of age and 1385patients greater than 70 years. Reoperative CABS procedures were performedin 385 patients, and CABS for post infarction unstable angina pectoris wasperformed in 578 patients. During the same time period, 2910 patientsunderwent PTCA. The mean age of bypass patients was 68.5 years with 38%being 70 years or older. The left ventricular ejection fraction in patientsundergoing CABS averaged 38%. The average number of bypasses performed was3.1. In comparison, patients presenting for PTCA were younger (average age55), had normal ejection fractions (average 55%) and were predominantlytreated for single or double vessel disease. The hospital mortality forelective CABS in patients less than 70 years of age was 1.8%, forreoperative CABS 3.6%, for post infarction unstable angina pectoris 4%, andfor patients greater than 70 years 8%, for a combined operative mortalityof 4.8%. These data suggest that because of the increasing number ofelderly patients (greater than 70 years of age), and the increasing numberof reoperative CABS cases and acute myocardial infarction patients withunstable angina pectoris presenting for CABS, the operative mortality willcontinue to rise.