Jørgensen Peter Hartmund, Nybo Mads, Jensen Marianne Kjær, Mortensen Poul Erik, Poulsen Tina Svenstrup, Diederichsen Axel Cosmus Pyndt, Mickley Hans
Department of Cardiology, Odense University Hospital, Odense C, Denmark.
Interact Cardiovasc Thorac Surg. 2014 May;18(5):544-50. doi: 10.1093/icvts/ivt558. Epub 2014 Jan 26.
The clinical classification of myocardial infarction (MI) into five types was introduced in 2007 as a component of the universal definition. A Type 5 MI was defined as a MI related to coronary artery bypass surgery. In a setting of patients undergoing elective coronary artery bypass grafting, we set out (i) to describe the pattern of multiple serial cardiac troponin I (cTnI) measurements within 72 h postoperatively and (ii) to determine the optimal cardiac troponin I cut-off value in ruling in or ruling out a Type 5 MI.
In 2011-2012, patients with two- and three-vessel disease scheduled for elective on-pump coronary artery bypass grafting were considered. Samples for cTnI were drawn before and 0, 2, 4, 6, 12, 24, 48 and 72 h after surgery. Analysis for cardiac troponin I was performed by use of the Abbott Architect c16000 system with an upper reference limit (URL) of 30 ng/l. The diagnosis of a Type 5 MI was prospectively made by a consultant cardiologist and was based on clinical, electrocardiographic and imaging data together with routine sampling and measurements of cTnI, but without knowledge of the results of serial study cTnI measurements.
Of the 141 eligible patients, 99 (70%) qualified for final enrollment. In 8 patients (8%), the clinical diagnosis of a Type 5 MI was made. Patients without Type 5 MI (n = 91) had a median cTnI peak value of 7675 ng/l compared with 20 500 ng/l in Type 5 MI patients (P = 0.01). By use of receiver operating characteristic curves, optimal cut-off values for identifying Type 5 MI were defined as 7970 ng/l (corresponding to 266 times the URL) 12 h postoperatively and 9950 ng/l (corresponding to 331 times the URL) 24 h postoperatively. These cut-off values resulted in negative predictive values of 0.99 (12 h) and 0.99 (24 h). Positive predictive values were 0.23 (12 h) and 0.35 (24 h).
In clinically stable patients undergoing elective coronary artery bypass grafting, measurements of cTnI are useful in ruling out a Type 5 MI.
2007年引入了心肌梗死（MI）的临床五型分类法，作为通用定义的一部分。5型心肌梗死被定义为与冠状动脉旁路移植术相关的心肌梗死。在接受择期冠状动脉旁路移植术的患者中，我们旨在（i）描述术后72小时内多次连续检测心肌肌钙蛋白I（cTnI）的模式，以及（ii）确定用于诊断或排除5型心肌梗死的最佳心肌肌钙蛋白I临界值。
纳入2011年至2012年计划接受择期体外循环冠状动脉旁路移植术的双支和三支血管病变患者。在手术前以及术后0、2、4、6、12、24、48和72小时采集cTnI样本。使用雅培Architect c16000系统检测心肌肌钙蛋白I，参考上限（URL）为30 ng/l。5型心肌梗死的诊断由心脏科顾问医生前瞻性做出，基于临床、心电图和影像学数据以及cTnI的常规采样和检测，但不知道连续cTnI检测的结果。
141例符合条件的患者中，99例（70%）最终入选。8例患者（8%）被临床诊断为5型心肌梗死。非5型心肌梗死患者（n = 91）的cTnI峰值中位数为7675 ng/l，而5型心肌梗死患者为20500 ng/l（P = 0.01）。通过绘制受试者工作特征曲线，确定诊断5型心肌梗死的最佳临界值为术后12小时7970 ng/l（相当于URL的266倍）和术后24小时9950 ng/l（相当于URL的331倍）。这些临界值的阴性预测值分别为0.99（12小时）和0.99（24小时）。阳性预测值分别为0.
