Department of Surgery, Section of Cardiac Surgery, Washington Hospital Center, Washington, DC 20010-2975, USA.
Ann Thorac Surg. 2011 Jun;91(6):1852-8. doi: 10.1016/j.athoracsur.2011.03.022.
Postoperative atrial fibrillation (AF) frequently complicates coronary artery bypass grafting (CABG) operations. As the frequency of obesity has increased in the United States, the number of obese patients undergoing CABG has kept pace. This study sought to define the association between body mass index (BMI) and postoperative AF.
We studied 12,367 consecutive patients with no history of AF who underwent isolated CABG operations. BMI was stratified according to Centers for Disease Control and Prevention criteria, and differences in baseline clinical and operative characteristics were adjusted through multivariate logistic regression models.
The unadjusted incidence of new-onset postoperative AF demonstrated a U-shape with regard to BMI. The highest incidence (34%) was found in the "lean" stratum (BMI<18.5 kg/m2), followed by 32% in the "severely obese" (BMI≥40 kg/m2) stratum. Lower incidences were found in the "normal" stratum (30%), in the "obese" stratum (28%), and the lowest incidence (26%) was in the overweight stratum. Observed incidence was 50% greater than the expected incidence in the "severely obese" stratum (32% vs 21%). In multivariate regression analysis adjusted for age and other covariates, BMI remains a strong risk factor for new-onset postoperative AF. Compared with normal BMI, obesity (odds ratio, 1.24; 95% confidence interval, 1.08 to 1.42) and severe obesity (odds ratio, 2.00; 95% confidence interval, 1.54 to 2.57) both emerged as strong risk factors for postoperative AF. No association was found between a lean BMI and postoperative AF (odds ratio, 1.14; 95% confidence interval, 0.66 to 1.98).
After adjusting for potential confounders, obesity, as reflected by the body mass index, remains an independent predictor of postoperative AF.
术后心房颤动（AF）常并发于冠状动脉旁路移植术（CABG）。随着美国肥胖症发病率的增加，接受 CABG 的肥胖患者数量也在不断增加。本研究旨在确定体重指数（BMI）与术后 AF 的关系。
我们研究了 12367 例无 AF 病史的连续患者，这些患者接受了单纯的 CABG 手术。根据疾病控制和预防中心的标准对 BMI 进行分层，通过多变量逻辑回归模型调整基线临床和手术特征的差异。
未经调整的新发术后 AF 发生率与 BMI 呈 U 形。最高发生率（34%）见于“消瘦”组（BMI<18.5kg/m2），其次是“严重肥胖”组（BMI≥40kg/m2）（32%）。发生率较低见于“正常”组（30%）、“肥胖”组（28%），发生率最低（26%）见于超重组。观察到的发生率比“严重肥胖”组的预期发生率高 50%（32%比 21%）。在调整年龄和其他协变量的多变量回归分析中，BMI 仍然是新发术后 AF 的强烈危险因素。与正常 BMI 相比，肥胖（比值比，1.24；95%置信区间，1.08 至 1.42）和严重肥胖（比值比，2.00；95%置信区间，1.54 至 2.57）均成为术后 AF 的强烈危险因素。消瘦 BMI 与术后 AF 无关（比值比，1.14；95%置信区间，0.66 至 1.98）。
在调整潜在混杂因素后，肥胖症（反映为 BMI）仍然是术后 AF 的独立预测因子。
