Intermountain Medical Center, Intermountain Heart Institute, Intermountain Healthcare, Salt Lake City, UT; University of Utah School of Medicine, Department of Internal Medicine, Division of Cardiology, Salt Lake City, UT.
Intermountain Medical Center, Intermountain Heart Institute, Intermountain Healthcare, Salt Lake City, UT.
Am Heart J. 2021 Sep;239:129-134. doi: 10.1016/j.ahj.2021.05.013. Epub 2021 May 27.
Several recent trials have evaluated invasive versus medical therapy for stable ischemic heart disease. Importantly, patients with significant left main coronary stenosis (LMCS) were excluded from these trials. In the ISCHEMIA trial, these patients were identified by a coronary CT angiogram (CCTA), which adds time, expense, and contrast exposure. We tested whether a coronary artery calcium scan (CACS), a simpler, less expensive test, could replace CCTA to exclude significant LMCS.
We hypothesized that patients with ≥50% LMCS would have a LM CACS score > 0. As a corollary, we postulated that a LM CACS = 0 would exclude patients with LMCS. To test this, we searched Intermountain Healthcare's electronic medical records database for all adult patients who had undergone non-contrast cardiac CT for quantitative CACS scoring prior to invasive coronary angiography (ICA). Patients aged <50 and those with a heart transplant were excluded. Cases with incomplete (qualitative) angiographic reports for LMCS and those with incomplete or discrepant LM CACS results were reviewed and reassessed blinded to CACS or ICA findings, respectively.
Among 669 candidate patients with CACS followed by ICA, 36 qualifying patients were identified who had a quantitative CACS score and LMCS ≥ 50%. Their age averaged 71.8 years, and 81% were men. Angiographic LMCS averaged 72% (range 50%-99%). Median time between CACS and ICA was 6 days. Total CACS score averaged 2,383 Agatston Units (AU), range 571-6,636. LM CACS score averaged 197 AU, range 31-610. Importantly, no LMCS patient had a LM CACS score of 0 vs 57% (362/633) of non-LMCS controls (P < .00001).
Our results support the hypothesis that an easily administered, inexpensive, low radiation CACS can identify a large subset of patients with a very low risk of LMCS who would not have the need for routine CCTA. Using CACS to exclude LMCS may efficiently allow for safe implementation of an initial medical therapy strategy of patients with stable ischemic heart disease in clinical practice. These promising results deserve validation in larger data sets.
几项最近的试验评估了稳定型缺血性心脏病的有创治疗与药物治疗。重要的是，这些试验排除了有明显左主干冠状动脉狭窄（LMCS）的患者。在 ISCHEMIA 试验中，这些患者是通过冠状动脉 CT 血管造影（CCTA）确定的，这增加了时间、费用和造影剂暴露。我们测试了一种更简单、更便宜的冠状动脉钙化扫描（CACS）是否可以替代 CCTA 来排除严重的 LMCS。
我们假设 LMCS 程度≥50%的患者 LM CACS 评分>0。作为推论，我们假设 LM CACS=0 可以排除 LMCS 患者。为此，我们在 Intermountain Healthcare 的电子病历数据库中搜索了所有在接受有创冠状动脉造影（ICA）前进行过非对比心脏 CT 定量 CACS 评分的成年患者。排除年龄<50 岁和心脏移植患者。对不完全（定性）LMCS 血管造影报告的病例以及不完全或不一致的 LM CACS 结果的病例进行了回顾，并分别根据 CACS 或 ICA 结果进行了盲法评估。
在 669 名接受 CACS 检查后进行 ICA 的候选患者中，确定了 36 名符合条件的患者，他们的定量 CACS 评分和 LMCS≥50%。他们的平均年龄为 71.8 岁，81%为男性。血管造影 LMCS 平均为 72%（范围 50%-99%）。CACS 和 ICA 之间的中位时间为 6 天。总 CACS 评分平均为 2383 个 Agatston 单位（AU），范围为 571-6636。LM CACS 评分平均为 197 AU，范围为 31-610。重要的是，没有 LMCS 患者的 LM CACS 评分是 0，而 57%（362/633）的非 LMCS 对照组患者的 LM CACS 评分是 0（P<.00001）。
我们的结果支持以下假设，即一种易于管理、价格低廉、辐射量低的 CACS 可以识别出一大类 LMCS 风险极低的患者，他们不需要常规进行 CCTA。使用 CACS 排除 LMCS 可能会有效地允许在稳定型缺血性心脏病患者的临床实践中安全地实施初始药物治疗策略。这些有前途的结果值得在更大的数据集上进行验证。
