Abreu Armando, Máximo José, Saraiva Francisca, Leite-Moreira Adelino
Cardiovascular R&D Center-UnIC@RISE, Department of Surgery and Physiology, Faculty of Medicine of the University of Porto, Porto, Portugal.
Department of Cardiothoracic Surgery, São João University Hospital Center, Porto, Portugal.
Interdiscip Cardiovasc Thorac Surg. 2023 Sep 2;37(3). doi: 10.1093/icvts/ivad161.
The aim of this sudy was to investigate the presence of an obesity paradox on the long-term mortality of patients undergoing primary isolated coronary artery bypass surgery and to uncover whether any discrepancy found could be attributable to cardiovascular or noncardiovascular causes.
Retrospective analysis of 5242 consecutive patients with body mass index (BMI) over 18.5 kg/m2 undergoing primary isolated coronary artery bypass surgery, performed from 2000 to 2015, in a Portuguese level III Hospital. The primary end point was long-term all-cause mortality. Secondary outcomes were long-term cause-specific mortality (cardiovascular and noncardiovascular). We fitted overall, and cause-specific hazard models, with BMI forced both as a categorical (using World Health Organization predefined cutoffs) and as a continuous variable.
Follow-up was 99.7% complete. The median follow-up time was 12.79 years (interquartile range, 9.51-16.61). The cumulative incidence functions failed to uncover any difference in 15-year all-cause (log-rank test, P = 0.400), cardiovascular (Gray's test, P = 0.996) and noncardiovascular mortality (Gray's test, P = 0.305) between BMI categories. Likewise, extensive multivariable-adjusted Cox regression and cause-specific hazards models failed to demonstrate in-between category differences, with BMI forced as a categorical variable. On the other hand, using BMI as a continuous variable, the model identified the optimal BMI as between 25.8 and 30.3 kg/m2 (nadir around 28.9 kg/m2), albeit this was dependent on the definition of the reference value.
In this longitudinal, population-level analysis of patients undergoing isolated primary coronary artery bypass grafting, we could not attest to any protective effect of obesity on long-term survival.
本研究旨在调查原发性单纯冠状动脉搭桥手术患者长期死亡率中肥胖悖论的存在情况，并探究所发现的任何差异是否可归因于心血管或非心血管原因。
对2000年至2015年在葡萄牙一家三级医院接受原发性单纯冠状动脉搭桥手术、体重指数（BMI）超过18.5kg/m²的5242例连续患者进行回顾性分析。主要终点是长期全因死亡率。次要结局是长期特定病因死亡率（心血管和非心血管）。我们拟合了总体和特定病因的风险模型，将BMI作为分类变量（使用世界卫生组织预先定义的临界值）和连续变量进行强制分析。
随访完成率为99.7%。中位随访时间为12.79年（四分位间距，9.51 - 16.61）。累积发病率函数未发现BMI类别之间在15年全因死亡率（对数秩检验，P = 0.400）、心血管死亡率（Gray检验，P = 0.996）和非心血管死亡率（Gray检验，P = 0.305）方面存在任何差异。同样，广泛的多变量调整Cox回归和特定病因风险模型在将BMI作为分类变量进行强制分析时，也未显示出类别之间的差异。另一方面，将BMI作为连续变量时，模型确定最佳BMI在25.8至30.3kg/m²之间（最低点约为28.9kg/m²），尽管这取决于参考值的定义。
在这项对接受单纯原发性冠状动脉搭桥术患者的纵向、人群水平分析中，我们无法证实肥胖对长期生存有任何保护作用。
