Is cardiac surgery safe in extremely obese patients (body mass index 50 or greater)?

We investigated the impact of extreme obesity (body mass index [kg/m(2)] 50 or greater) on short-term clinical outcomes and report 1-year mortality.

Fifty-seven patients were found to have a body mass index of 50 or greater among 14,449 patients who underwent cardiac surgery between July 2000 and June 2007. Multivariable logistic regression analyses were used to assess the independent influence of extreme obesity on the major outcomes.

Of the 57 patients, the mean age was 58 +/- 11 years, mean body mass index was 55.1, and 63% of the patients were women. Forty patients underwent elective surgery. Forty-one patients had isolated coronary artery bypass graft surgery. The overall operative mortality was 9%; the mortality was 5% in isolated coronary artery bypass graft surgery and 5% in elective surgery. Fifteen patients had nonelective isolated coronary artery bypass graft surgery, and 2 patients had emergent active endocarditis surgery. Off-pump coronary artery bypass graft surgery was performed on 23 patients (23 of 41, 54%). After adjusting for known preoperative and operative risk factors through a multivariate logistic model, extreme obesity did not emerge as a significant risk factor for operative mortality (odds ratio, 1.75; p = 0.47) and other adverse outcomes (p > 0.05) after elective surgery; however, extreme obesity was marginally associated with increased mortality (odds ratio, 2.69; p = 0.05) and was a risk predictor for longer intensive care unit stays (odds ratio, 2.43; p = 0.01) in overall surgery. The 1-year survival rate was 82.5%.

Extreme obesity is not a contraindication to elective cardiac surgery. Studies stratifying the risk factors of mortality for nonelective surgery in extremely obese patients may be warranted.