[Value of evaluating the coronary collateral circulation by transluminal attenuation gradient in patients with chronic total occlusion and related influencing factors].

Objective: To observe the value of evaluating the coronary collateral circulation of chronic total occlusion (CTO) by transluminal attenuation gradient (TAG) and Rentrop grading, and analyze the influencing factors for coronary collateral circulation. Methods: A total of 179 CTO patients admitted to Beijing Anzhen hospital during June 2013 to August 2016 were included in this study.All patients received coronary computed tomographic angiography (CCTA) examination before coronary angiography.Finally, 75 patients (79 vessels) were enrolled.Patients were divided into two groups on the basis of Rentrop classification.The Rentrop 3 was defined as a well-developed coronary collateral circulation group, including 50 CTO vessels, Rentrop 2 or below was defined as poorly-developed collateral circulation group, including 29 vessels.TAG values in patients with various Rentrop grades were analyzed.Univariate and multivariate analysis were used to determine the predictors of collateral circulation. Results: TAG increased consistently in proportion to the angiographic extent of collateral flow (TAG was (-33.6±24.4), (-16.5±15.7) and (-12.8±15.8) HU/10 mm in patients with Rentrop grade 0 or 1, 2 and 3, respectively, P=0.007). Number of good collateral circulation vessels predicted by TAG≥15.6 HU/10 mm was 45(57.0%, 45/79), and 50 (63.3%, 50/79) by Rentrop grade (P=0.383). Prevalence of diabetes was significantly lower (20.8%(10/48) vs. 48.1%(13/27), P=0.01), while history of previous myocardial infarction (MI) was significantly higher (35.4%(17/48) vs. 11.1%(3/27), P=0.02) in patients with good collateral circulation than in patients with poor collateral circulation.The TAG of the good collateral circulation group was significantly higher than in poorly collateral circulation group ((-12.8±15.8) HU/10 mm vs. (-21.2±19.6) HU/10mm, P=0.041). Multiple logistic regression analysis revealed that history of MI (OR=0.196, 95%CI 0.041-0.936, P=0.041) and diabetes(OR=6.604, 95%CI 1.726-25.274, P=0.006) were independent predictors of coronary collateral circulation. Conclusions: TAG could be used to evaluate status of coronary collateral circulation.Presence of MI history and absence of diabetes history are the two independent predictors of well-developed coronary collateral circulation in CTO patients.目的： 评价冠状动脉CT血管成像(CCTA)腔内衰减梯度(TAG)与冠状动脉造影Rentrop分级诊断冠状动脉慢性完全闭塞(CTO)病变侧支循环的关系，并探讨CTO病变侧支循环建立的影响因素。 方法： 回顾性分析2013年6月至2016年8月就诊于北京安贞医院心内科经冠状动脉造影确诊CTO病变，且术前接受CCTA检查的167例患者，根据纳入及排除标准，最终入选75例CTO患者(79支病变血管)。根据Rentrop分级评价病变血管侧支循环进行分组，将Rentrop 3级定义为侧支循环良好组，病变血管数50支；侧支循环分级2级或以下定义为侧支循环不良组，病变血管数29支。比较不同Rentrop侧支循环分级时TAG变化，分析TAG与侧支循环的关系。采用多因素logistic回归分析影响侧支循环形成病变的因素。 结果： 冠状动脉造影Rentrop为0或1、2、3级时，TAG分别为(－33.6±24.4)、(－16.5±15.7)和(－12.8±15.8) HU/10 mm，随着侧支循环分级的升高，TAG呈增加趋势，差异有统计学意义(P＝0.007)。对79支病变血管，用TAG≥－15.6 HU/10 mm预测良好侧支循环血管数为45支(57.0%)，用Rentrop分级评价良好侧支循环血管数50支(63.3%)，差异无统计学意义(P＝0.383)。侧支循环良好组既往糖尿病患者比例明显低于侧支循环不良组[20.8%(10/48)比48.1%(13/27), P＝0.01]，良好侧支循环既往心肌梗死患者比率明显高于侧支循环形成不良组[35.4%(17/48)比11.1%(3/27)，P＝0.02]，侧支循环良好组TAG高于侧支循环不良组[(－12.8±15.8) HU/10 mm比(－21.2±19.6) HU/10 mm，P＝0.041]。多因素logistic回归分析显示，既往糖尿病(OR＝6.604，95%CI 1.726～25.274，P＝0.006)及心肌梗死史(OR＝0.196，95%CI 0.041～0.936，P＝0.041)是CTO病变侧支循环形成的独立影响因素。 结论： TAG可以用于预测冠状动脉完全闭塞病变的侧支循环。糖尿病是CTO病变侧支循环形成不良的影响因素，心肌梗死史有助于良好侧支循环的形成。.