Obesity and the risk of early and late mortality after coronary artery bypass graft surgery.
BACKGROUND
Obesity is often considered to be a significant risk factor for postoperative mortality when selecting candidates for coronary artery bypass grafting (CABG).


METHODS
We included all patients undergoing a first isolated CABG at the Karolinska Hospital in Stockholm, Sweden, between 1980 and 1995 (n = 6728). Patients were categorized on the basis of body mass index (BMI): non-overweight (BMI <25 kg/m2), overweight (25 kg/m2 < or = BMI <30 kg/m2), and obese (BMI > or =30 kg/m2). Multivariate Cox regression was used to assess the risk of re-operation for bleeding, deep sternal wound infection, and early (< or =30 days) and late (< or =5 years) mortality rates.


RESULTS
The average length of follow-up was 6.5 years. There were 252 re-operations for bleeding, 53 deep sternal wound infections, and 628 deaths. Patients who were obese had a significantly lower risk of re-operation for bleeding (risk ratio [RR], 0.32; 95% CI, 0.19-0.53), but a greater risk of deep sternal wound infection (RR, 2.66; 95% CI, 1.21-5.88) compared with patients who were not overweight. However, patients who were obese and patients who were not overweight experienced similar 30-day (RR, 0.65; 95% CI, 0.34-1.27), 1-year (RR, 0.56; 95% CI, 0.29-1.10), and 5-year mortality rates (RR, 0.91; 95% CI, 0.66-1.25). Results for patients who were overweight were consistent with those of patients who were obese.


CONCLUSIONS
Patients who are obese are not at a greater risk of early and late mortality after CABG compared with patients who are not overweight, although they appear to have a lower risk of re-operation for bleeding and a greater risk of deep sternal wound infection. Therefore, obesity per se is not a contraindication for CABG.
Kim
Joseph
J
Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, Minn 55454, USA. kim_j@epi.umn.edu
Hammar
Niklas
N
Jakobsson
Kristina
K
Luepker
Russell V
RV
McGovern
Paul G
PG
Ivert
Torbjörn
T
D000787:Angina Pectoris / Q000150:complications / Q000401:mortality / Q000601:surgery*; D015992:Body Mass Index; D001026:Coronary Artery Bypass / Q000401:mortality*; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000401:mortality*; D019106:Postoperative Hemorrhage / Q000209:etiology; D011379:Prognosis; D012086:Reoperation; D012307:Risk Factors; D013223:Statistics as Topic; D013249:Sternum / Q000601:surgery; D013530:Surgical Wound Infection / Q000209:etiology; D013997:Time Factors