Patsias Iani, Swanson Benjamin, Hudson Michael, Parikh Sachin, Nour Khaled, Jacobsen Gordon, McCord James
From the *Department of Cardiology, Henry Ford Hospital, Detroit, MI; †Department of Internal Medicine, Henry Ford Hospital, Detroit, MI; and ‡Biostatistics Department, One Ford Place, Detroit, MI.
Crit Pathw Cardiol. 2017 Sep;16(3):105-108. doi: 10.1097/HPC.0000000000000120.
Observation units (OUs) may be an efficient and effective setting to diagnose and risk stratify patients with coronary ischemia and myocardial infarction (MI). Given improved cardiac troponin I (cTnI) assays and expanded utilization of OUs, it is not uncommon for patients with mildly elevated cTnI to be evaluated in OUs. We investigated the serial cTnI results in OU patients to determine whether absolute or relative cTnI changes were useful for the diagnosis of MI.
This was a retrospective study of 260 patients placed in the OU from a single center in 2007, with an initial cTnI in the indeterminate range of 0.04-0.2 ng/ml (Siemens ultrasensitive), and a second cTnI was drawn at 6 hours. The diagnosis of MI was determined based on the third universal definition of MI by consensus review of 2 cardiologists, with adjudication by a third cardiologist in case of disagreement.
Of the 260 patients, 25 (9.6%) were determined to have MI at OU presentation. The optimal absolute and relative change in cTnI for MI diagnosis by receiver operating characteristic curve analysis were 0.02 ng/ml and 40%, respectively. There was initial cardiologist disagreement in 60% (15/25) of MI cases despite full review of serial cTnI and cardiac testing results. At 30 days, there were 3 adverse events: 2 deaths and 1 MI.
The diagnosis of MI in OU with low-level cTnI elevation is problematic. Furthermore, there is only marginal diagnostic utility of serial changes in cTnI in this patient population.
观察单元（OU）可能是诊断和对冠状动脉缺血及心肌梗死（MI）患者进行风险分层的有效场所。鉴于心肌肌钙蛋白I（cTnI）检测方法的改进以及OU使用的增加，cTnI轻度升高的患者在OU接受评估并不罕见。我们研究了OU患者的连续cTnI结果，以确定cTnI的绝对或相对变化是否有助于MI的诊断。
这是一项对2007年来自单一中心的260例入住OU的患者的回顾性研究，初始cTnI在0.04 - 0.2 ng/ml（西门子超敏法）的不确定范围内，6小时后抽取第二次cTnI。MI的诊断由2名心脏病专家通过共识审查根据MI的第三个通用定义确定，如有分歧则由第三名心脏病专家裁决。
260例患者中，25例（9.6%）在OU就诊时被确定患有MI。通过受试者操作特征曲线分析，用于MI诊断的cTnI最佳绝对和相对变化分别为0.02 ng/ml和40%。尽管对连续cTnI和心脏检查结果进行了全面审查，但在60%（15/25）的MI病例中，心脏病专家最初存在分歧。在30天时，发生了3起不良事件：2例死亡和1例MI。
在cTnI水平轻度升高的OU中诊断MI存在问题。此外，在该患者群体中，cTnI的连续变化仅具有边际诊断效用。
