Hartrumpf Martin, Kuehnel Ralf-Uwe, Albes Johannes M
Department of Cardiovascular Surgery, Heart Centre Brandenburg, University Hospital, Medical School Brandenburg, Bernau, Germany.
Interact Cardiovasc Thorac Surg. 2017 Jul 1;25(1):18-24. doi: 10.1093/icvts/ivx058.
Obesity is an ever-growing problem in contemporary cardiac surgery. Although it accounts for many perioperative comorbidities, it has not been shown to increase mortality. Body mass index (BMI) is therefore not considered in the European System for Cardiac Operative Risk Evaluation (EuroSCORE). We sought to confirm whether this holds true for our own single-centre patient population.
Data from 15 314 consecutive patients receiving major cardiac surgery at our institution were analysed. Gender, age, BMI, EuroSCORE, urgency, redo status and all-cause in-hospital mortality were derived from our database. Mortality was grouped into 4 BMI categories. We created a logistic regression model to identify predictors of mortality.
There were 11 034 males and 4280 females. Categorical mortality was 8.79% (underweight), 7.04% (normal weight), 5.16% (overweight), 6.30% (obese), rendering an inverse J-shaped pattern known as obesity paradox. Univariable regression detected significant predictors of mortality: rising age, female gender, urgent procedures, redo surgery ( P < 0.001). BMI was no predictor ( P = 0.575) but became significant with the multivariable analysis ( P = 0.004). Its effect on mortality was exclusively indirect, being mediated through age ( P < 0.001). Receiver-operating characteristics curve analysis also confirmed that BMI did not qualify as a risk factor. However, the overweight category was a predictor of lower mortality.
Our findings from >15 000 patients confirm the obesity paradox showing the least mortality in the overweight group. They support the current EuroSCORE model in that BMI is no independent predictor of early mortality. However, such patients still carry the risk of comorbidities. Likewise, special care is required with underweight patients who show the highest in-hospital mortality.
肥胖在当代心脏外科手术中是一个日益严重的问题。尽管肥胖导致许多围手术期合并症，但尚未显示其会增加死亡率。因此，欧洲心脏手术风险评估系统（EuroSCORE）未将体重指数（BMI）纳入考量。我们试图确认这一情况在我们单中心的患者群体中是否同样成立。
分析了我院连续接受心脏大手术的15314例患者的数据。性别、年龄、BMI、EuroSCORE、手术紧急程度、再次手术状态及全因住院死亡率均来自我们的数据库。将死亡率分为4个BMI类别。我们建立了一个逻辑回归模型以确定死亡率的预测因素。
男性11034例，女性4280例。分类死亡率分别为：体重过轻8.79%，正常体重7.04%，超重5.16%，肥胖6.30%，呈现出一种被称为肥胖悖论的倒J形模式。单变量回归检测到死亡率的显著预测因素：年龄增长、女性、急诊手术、再次手术（P＜0.001）。BMI不是预测因素（P = 0.575），但在多变量分析中具有显著性（P = 0.004）。其对死亡率的影响完全是间接的，通过年龄介导（P＜0.001）。受试者工作特征曲线分析也证实BMI不符合风险因素标准。然而，超重类别是较低死亡率的一个预测因素。
我们对超过15000例患者的研究结果证实了肥胖悖论，即超重组死亡率最低。这些结果支持当前的EuroSCORE模型，即BMI不是早期死亡率的独立预测因素。然而，这类患者仍有合并症风险。同样，体重过轻的患者住院死亡率最高，需要特别护理。
