Changes in Body Mass Index and Late Postoperative Outcomes in Elderly Coronary Artery Bypass Grafting Patients: A Follow-up Study

Abstract

The purpose of this study was to describe the extent to which late postoperative health outcomes vary as a function of change in body mass index (BMI) in persons 65 years of age undergoing elective coronary artery bypass grafting (CABG). The mean age of the 90 persons in the original sample was 72.27 (±4.85) years. At follow-up (x = 18.73,s = 2.56 months postsurgery), 90% (n = 79 alive,n = 2 deceased, proxy completed interview) were contacted; 73% (n = 59) completed the telephone interview; and 9% (n = 8) were alive but lost to follow-up. BMI (kg/m2) was calculated from self-reported weight at follow-up. Outcomes included the Physical Component Summary (PCS) scale of the SF-36 Health Survey and readmission data. Thex (s ) for BMI at preoperative, postoperative, postdischarge, and follow-up were 28.1 (4.9) kg/ m2 , 28.76 (4.9) kg/m2, 27.11 (4.8) kg/m2, and 27.95 (4.7) kg/m2, respectively. BMI changed over time,P < 0.05. Those who were readmitted lost more weight between preoperative and postdischarge than those who were not readmitted (x BMI = –2.26 vs.x BMI = –1.35),t = 2.17,df = 27.05,P = 0.04. Those who lost less weight between preoperative and postdischarge were less likely to be readmitted,.2 = 5.755 (1),P = 0.02, with 25% sensitivity and 92% specificity. Thex (sx) for PCS at preoperative, postdischarge, and follow-up were 36.93 (1.62), 35.72 (1.27), and 42.26 (1.45), respectively, reflecting change over time,F = 11.43 (2),P < 0.001. At follow-up, older elective CABG patients do not appear to regain weight lost between preoperative and postdischarge; however, self-reported physical health is improved. Also, initial weight loss is related to readmissions.