Lehrke Stephanie, Steen Henning, Sievers Hans H, Peters Hanno, Opitz Armin, Müller-Bardorff Margit, Wiegand Uwe K H, Katus Hugo A, Giannitsis Evangelos
Johns Hopkins University, Department of Cardiology, Baltimore, MD, USA.
Clin Chem. 2004 Sep;50(9):1560-7. doi: 10.1373/clinchem.2004.031468. Epub 2004 Jun 24.
Increased cardiac troponins in blood are observed after virtually every open heart surgery, indicating perioperative myocardial cell injury. We sought to determine the optimum time point for blood sampling and the respective cutoff value of cardiac troponin T (cTnT) for risk assessment in patients undergoing cardiac surgery.
In a series of 204 patients undergoing scheduled open heart surgery, mainly for coronary artery bypass grafting (n = 132) or valve repair (n = 27), cTnT concentrations were measured before and 4 and 8 h after cross-clamping and then daily for 7 days. Individual risk was assessed by use of the Cleveland Clinic Foundation Risk score and intraoperative risk indicators such as duration of cardiopulmonary bypass, cross-clamping, and perioperative release of cardiac markers. Patients were followed for 28 months.
Cardiac mortality, all-cause mortality rates, and rates of nonfatal acute myocardial infarction (AMI) at 28 months were 6.9%, 8.8%, and 6.8%, respectively. cTnT was higher in patients with Q-wave AMI or postoperative heart failure requiring inotropic support, and in nonsurvivors. The ROC curve revealed a cTnT > or = 0.46 microg/L at 48 h as the optimum discriminator for long-term cardiac mortality. Stepwise logistic regression identified higher Cleveland Clinic Risk Score [odds ratio (OR) = 2.6 per point], cross-clamp time >65 min (OR = 6.6), and cTnT (OR = 4.9) as significant and independent predictors of long-term cardiac mortality.
A single postoperative cTnT measurement can be used to estimate myocardial cell injury that impacts long-term survival after open heart surgery. It adds independently to established risk indicators.
几乎每次心脏直视手术后血液中的心肌肌钙蛋白都会升高，这表明围手术期心肌细胞受到损伤。我们试图确定心脏手术患者进行血液采样的最佳时间点以及心肌肌钙蛋白T（cTnT）用于风险评估的相应临界值。
在一系列204例接受择期心脏直视手术的患者中，主要是冠状动脉搭桥术（n = 132）或瓣膜修复术（n = 27），在阻断血流前、阻断血流后4小时和8小时以及随后7天每天测量cTnT浓度。通过使用克利夫兰诊所基金会风险评分和术中风险指标（如体外循环时间、阻断血流时间和围手术期心脏标志物的释放）评估个体风险。对患者进行了28个月的随访。
28个月时的心脏死亡率、全因死亡率和非致命性急性心肌梗死（AMI）发生率分别为6.9%、8.8%和6.8%。Q波型AMI或术后需要使用正性肌力药物支持的心力衰竭患者以及非存活者的cTnT水平较高。ROC曲线显示，48小时时cTnT≥0.46μg/L是长期心脏死亡率的最佳判别指标。逐步逻辑回归确定较高的克利夫兰诊所风险评分[比值比（OR）=每分2.6]、阻断血流时间>65分钟（OR = 6.6）和cTnT（OR = 4.9）是长期心脏死亡率的显著且独立的预测因素。
单次术后cTnT测量可用于评估影响心脏直视手术后长期生存的心肌细胞损伤。它独立于已有的风险指标增加了预测价值。
