Karkouti Keyvan, Wijeysundera Duminda N, Beattie W Scott
Department of Anesthesia, University Health Network, University of Toronto, Toronto, Ontario, Canada, M5G 2C4.
Circulation. 2008 Jan 29;117(4):478-84. doi: 10.1161/CIRCULATIONAHA.107.718353. Epub 2008 Jan 2.
Preoperative anemia is an important risk factor for perioperative red blood cell transfusions, which are associated with postoperative morbidity and mortality. Whether preoperative anemia also is an independent risk factor for adverse outcomes after cardiac surgery, however, has not been fully elucidated.
In this multicenter cohort study, data were collected on 3500 consecutive patients who underwent cardiac surgery during 2004 at 7 academic hospitals. The prevalence of preoperative anemia, defined as hemoglobin <12.5 g/dL, and its unadjusted and adjusted relationships with the composite outcome of in-hospital death, stroke, or acute kidney injury were obtained. The overall prevalence of preoperative anemia was 26%, with values ranging from 22% to 30% at the participating hospitals. After the exclusion of patients who had severe preoperative anemia (hemoglobin <9.5 g/dL) or preoperative kidney failure and those who underwent emergency surgery, the composite outcome was observed in 7.5% of patients (247 of 3286). The unadjusted odds ratio for the composite outcome in anemic versus nonanemic patients was 3.6 (95% confidence interval, 2.7 to 4.7). The risk-adjusted odds ratios, obtained by multivariable logistic regression and propensity-score matching to control for important confounders (including comorbidities, institution, surgical factors, and blood transfusion), were 2.0 (95% confidence interval, 1.4 to 2.8) and 1.8 (95% confidence interval, 1.2 to 2.7), respectively.
Preoperative anemia is independently associated with adverse outcomes after cardiac surgery. Future studies should determine whether therapies aimed at treating preoperative anemia would improve the outcomes of patients undergoing cardiac surgery.
术前贫血是围手术期红细胞输注的重要危险因素，而红细胞输注与术后发病率和死亡率相关。然而，术前贫血是否也是心脏手术后不良结局的独立危险因素尚未完全阐明。
在这项多中心队列研究中，收集了2004年期间在7家学术医院连续接受心脏手术的3500例患者的数据。获得了术前贫血（定义为血红蛋白<12.5 g/dL）的患病率及其与院内死亡、中风或急性肾损伤复合结局的未调整和调整后的关系。术前贫血的总体患病率为26%，各参与医院的值在22%至30%之间。排除术前严重贫血（血红蛋白<9.5 g/dL）或术前肾衰竭的患者以及接受急诊手术的患者后，7.5%的患者（3286例中的247例）出现了复合结局。贫血患者与非贫血患者复合结局的未调整优势比为3.6（95%置信区间，2.7至4.7）。通过多变量逻辑回归和倾向评分匹配以控制重要混杂因素（包括合并症、机构、手术因素和输血）获得的风险调整优势比分别为2.0（95%置信区间，1.4至2.8）和1.8（95%置信区间，1.2至2.7）。
术前贫血与心脏手术后的不良结局独立相关。未来的研究应确定旨在治疗术前贫血的疗法是否会改善接受心脏手术患者的结局。
