Emory University School of Medicine, Atlanta, Georgia (M.H., J.H.K., A.S.T., B.K., C.L., I.A., K.W., R.R., A.A., F.C., M.M.G., N.A., P.S., B.B.L., J.D.B., L.S.S., A.A.Q.).
Emory University, Atlanta, Georgia (Y.K., P.P., L.W., M.K.).
Ann Intern Med. 2018 Dec 4;169(11):751-760. doi: 10.7326/M18-0670. Epub 2018 Nov 6.
Many patients with coronary artery disease (CAD) are routinely referred for surveillance stress testing despite recommendations against it.
To determine whether low levels of resting high-sensitivity cardiac troponin I (hs-cTnI) can identify persons without inducible myocardial ischemia.
Observational study.
A university-affiliated hospital network.
Persons with stable CAD: 589 in the derivation group and 118 in the validation cohort.
Presence of inducible myocardial ischemia was determined by myocardial perfusion imaging with technetium-99m single-photon emission computed tomography during either treadmill or pharmacologic stress testing. Resting plasma hs-cTnI was measured within 1 week of the stress test, and the negative predictive value (NPV) for inducible ischemia was calculated. The derivation cohort was followed for 3 years for incident cardiovascular death and myocardial infarction.
In the derivation cohort, 10 of 101 patients with an hs-cTnI level below 2.5 pg/mL had inducible myocardial ischemia (NPV, 90% [95% CI, 83% to 95%]) and 3 of 101 had inducible ischemia involving at least 10% of the myocardium (NPV, 97% [CI, 92% to 99%]). In the validation cohort, 4 of 32 patients with an hs-cTnI level below 2.5 pg/mL had inducible ischemia (NPV, 88% [CI, 71% to 96%]) and 2 of 32 had ischemia of 10% or greater (NPV, 94% [CI, 79% to 99%]). After a median follow-up of 3 years in the derivation cohort, no adverse events occurred in patients with an hs-cTnI level below 2.5 pg/mL, compared with 33 (7%) cardiovascular deaths or incident myocardial infarctions among those with an hs-cTnI level of 2.5 pg/mL or greater.
The data may not be applicable to a population without known CAD or to persons with unstable angina, and the modest sample sizes warrant further validation in a larger cohort.
Very low hs-cTnI levels may be useful in excluding inducible myocardial ischemia in patients with stable CAD.
National Institutes of Health.
尽管有相关建议，但许多患有冠状动脉疾病 (CAD) 的患者仍会常规接受监测应激测试。
确定静息状态下高敏心肌肌钙蛋白 I（hs-cTnI）水平较低是否可以识别无诱发性心肌缺血的人群。
观察性研究。
大学附属医院网络。
稳定性 CAD 患者：推导组 589 例，验证队列 118 例。
通过运动或药物应激测试期间锝-99m 单光子发射计算机断层扫描来确定是否存在诱发性心肌缺血。应激测试后 1 周内测量静息血浆 hs-cTnI，并计算诱发性缺血的阴性预测值 (NPV)。对推导队列进行了 3 年的心血管死亡和心肌梗死的随访。
在推导队列中，101 例 hs-cTnI 水平低于 2.5 pg/mL 的患者中有 10 例存在诱发性心肌缺血（NPV，90%[95%CI，83%至 95%]），有 3 例至少 10%的心肌存在诱发性缺血（NPV，97%[CI，92%至 99%]）。在验证队列中，101 例 hs-cTnI 水平低于 2.5 pg/mL 的患者中有 4 例存在诱发性缺血（NPV，88%[CI，71%至 96%]），有 2 例 10%或更大的缺血（NPV，94%[CI，79%至 99%]）。在推导队列的中位随访 3 年后，hs-cTnI 水平低于 2.5 pg/mL 的患者未发生不良事件，而 hs-cTnI 水平为 2.5 pg/mL 或更高的患者中，有 33 例（7%）发生心血管死亡或新发心肌梗死。
数据可能不适用于无已知 CAD 的人群或不稳定型心绞痛患者，且样本量较小，需要在更大的队列中进一步验证。
hs-cTnI 水平非常低可能有助于排除稳定性 CAD 患者的诱发性心肌缺血。
美国国立卫生研究院。
