Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China.
AJR Am J Roentgenol. 2012 Mar;198(3):548-62. doi: 10.2214/AJR.11.7072.
The purpose of the study was to investigate dual-phase MDCT for assessing obstructive lesions and the extent and severity of the subtending myocardium at risk in patients presenting with chest pain syndromes 9 or more months after having undergone revascularization for the treatment of ST-segment elevation myocardial infarction (STEMI).
Dual-phase 64-MDCT was performed on 135 patients with recurring chest symptoms 9 months or more after revascularization (mean ± SD, 23 ± 11 months after index invasive angiogram for treatment of STEMI). Obstructive lesions (≥ 50% stenosis) were detected by MDCT angiography and the extent of myocardium at risk was detected by delayed phase 3D myocardium maps. A myocardium at-risk score based on MDCT findings was defined as the extent of myocardium at risk governed by the coronary lesion and weighted by lesion severity. Results were compared with stress-redistribution (201)Tl-SPECT and invasive angiography.
In restenotic, new, progressive, and previously obstructive lesions that are not currently progressive, analysis of assessable segments (1966/2025, 97.1%) obtained true-positive detection rates of 88.1%, 88.6%, 82.9%, and 100%, respectively; false-negative detection rates were 5.3%, 1.6%, 2.9%, and 8.8%. In 124 patients (91.9%) in whom all segments were assessable, the MDCT-based myocardium at-risk score correlated with the SPECT-based summed difference score (SDS) (r = 0.841, p < 0.001). For detecting SPECT-based SDS ≥ 1 and SDS > 3, areas under the receiver operating characteristic curve for the MDCT-based myocardium at-risk score were 0.874 (95% CI, 0.805-0.942) and 0.938 (95% CI, 0.895-0.981), with optimal cutoff values of 2.68 and 5.01, respectively.
Dual-phase MDCT is useful in detecting different patterns of obstructive lesions and the extent of myocardium at risk as an alternative for therapeutic planning in patients presenting with late symptoms after treatment for acute myocardial infarction.
本研究旨在通过双相 MDCT 评估胸痛综合征发生 9 个月以上并接受经皮冠状动脉介入治疗（PCI）的患者中阻塞性病变以及梗死相关心肌的范围和严重程度。
对 135 例胸痛复发（PCI 治疗 ST 段抬高型心肌梗死（STEMI）后 9 个月或以上，平均±标准差 23±11 个月）的患者进行双相 64 层 MDCT 检查。MDCT 血管造影术检测到阻塞性病变（≥50%狭窄），延迟相 3D 心肌图检测到危险心肌的范围。根据 MDCT 结果定义基于 MDCT 发现的危险心肌评分，该评分根据冠状动脉病变的严重程度来确定危险心肌的范围。结果与应激再分布（201）Tl-SPECT 和血管造影进行比较。
在再狭窄、新病变、进展性病变和之前无进展但目前进展性病变的可评估节段（1966/2025，97.1%）中，阳性检出率分别为 88.1%、88.6%、82.9%和 100%，假阴性检出率分别为 5.3%、1.6%、2.9%和 8.8%。在 124 例（91.9%）所有节段均可评估的患者中，基于 MDCT 的危险心肌评分与基于 SPECT 的总和差评分（SDS）具有相关性（r=0.841，p<0.001）。对于检测 SDS≥1 和 SDS>3 的 SPECT ，基于 MDCT 的危险心肌评分的受试者工作特征曲线下面积分别为 0.874（95%可信区间，0.805-0.942）和 0.938（95%可信区间，0.895-0.981），最佳截断值分别为 2.68 和 5.01。
双相 MDCT 可用于检测不同类型的阻塞性病变和梗死相关心肌的范围，是急性心肌梗死后出现迟发性症状患者治疗计划的一种替代方法。
