摘要
背景:我们假设急性缺血性脑卒中(AIS)患者左侧心室收缩功能障碍(LVSD)可导致缺血性核心高估，而侧支状态受损可能在一定程度上介导这一影响。
目的:通过CT灌注(CTP)及随访CT像元分析，探讨缺血性核心区CTP过高时的最佳阈值。方法:对连续208例前循环大血管闭塞AIS患者进行回顾性分析，初步CTP评估并成功再灌注，将其分为LVSD(左室射血分数(LVEF)比值<50%;n=40)，心功能正常(LVEF≥50%;n = 168)。当ctp衍生核大于最终梗死体积时，考虑缺血核高估。我们使用中介分析研究了心功能、核心高估概率和侧支评分之间的关系。采用基于像素的分析来确定缺血核心的最佳CTP阈值。
结果:LVSD与侧枝受损独立相关(aOR=4.28,95% CI 2.01 ~9.80, P<0.001)和核心高估(aOR=2.52,95% CI 1.07 ~ 5.72, P=0.030)。在中介分析中，对核心高估的总效应由LVSD的直接效应(+17%，P=0.034)和间接效应(+6%，P=0.020)所介导。
侧枝解释了26%的LVSD对核心高估的影响。与相对脑血流量(rCBF)阈值<35%、<30%和<20%相比，rCBF <25%的分界点具有最高的相关性(r=0.91)和最好的相关性与最终梗死体积(平均差3.2±7.3 mL)一致，以确定LVSD患者ctp来源的缺血核心。
结论:LVSD增加了缺血性核心高估基线CTP的可能性，部分原因是侧支状态受损，应考虑更严格的rCBF阈值。
关键词:CT灌注;中风;血栓切除术。
Abstract
Background: We hypothesized that left ventricular systolic dysfunction (LVSD) would lead to an ischemic core overestimation in patients with acute ischemic stroke (AIS), and impaired collateral status might partly mediate this effect.Objective: A pixel-based analysis of CT perfusion(CTP) and follow-up CT was undertaken to investigate the optimum CTP thresholds for the ischemic core if overestimation was found.
Methods: A total of 208 consecutive patients with AIS with large vessel occlusion in the anterior circulation, who received initial CTP evaluation and successful reperfusion, were retrospectively analyzed and divided into an LVSD (left ventricular ejection fraction (LVEF) ratio <50%; n=40) and a normal cardiac function (LVEF≥50%; n=168)group. Ischemic core overestimation was considered when the CTP-derived core was larger than the final infarct volume. We investigated the relationship between cardiac function, probability for core overestimation, and collateral scores using mediation analysis. A pixel-based analysis was undertaken to define the optimum CTP thresholds for ischemic core.
Results: LVSD was independently associated with impaired collaterals (aOR=4.28,95% CI 2.01 to 9.80, P<0.001) and core overestimation (aOR=2.52,95% CI 1.07 to 5.72, P=0.030). In mediation analysis, the total effect on core overestimation is composed of the direct effect of LVSD (+17%, P=0.034) and the mediated indirect effect of collateral status (+6%, P=0.020).
Collaterals explained 26% of the effect of LVSD on core overestimation. Compared with relative cerebral blood flow (rCBF) thresholds of <35%,<30%, and <20%, a rCBF <25% cut-off point had the highest correlation (r=0.91) and best agreement (mean difference 3.2±7.3 mL) with the final infarct volume to determine the CTP-derived ischemic core in patients with LVSD.
Conclusions: LVSD increased the possibility of ischemic core overestimation on baseline CTP,partly due to impaired collateral status, and a stricter rCBF threshold should be considered.
Keywords: CT perfusion; Stroke; Thrombectomy.
