【作者】 赖文文；

【导师】 刘映峰；

【作者基本信息】 南方医科大学 ， 心血管内科， 2013， 博士

【摘要】 背景对于急性心肌梗死患者而言,决定其左心室重构及死亡率的最重要的因素是心肌梗死面积,梗死面积又与存在缺血风险的心肌面积直接相关,而梗死相关动脉是否存在侧枝循环供血可以直接影响到这部分心肌的面积大小。侧枝循环供血可以延长从梗死开始后到发生不可逆转的透壁性心肌梗死的时间,从而为再灌注治疗争取更多的时间。相对而言,侧枝循环在有梗死前心绞痛或非前壁心肌梗死的患者中发生率较高,可能在梗死发生前即存在,或在梗死发生后的短时间内(比如数分钟内)即出现。关于侧枝循环对急性冠状动脉闭塞预后的影响的研究已经持续几十年时间。冠脉侧枝循环一直被认为是心肌缺血预适应机制的体现之一,与发育不良的侧枝循环对比,充分的侧枝循环意味着更小的梗死面积、更少的室壁瘤发生率以及更好的左心室功能。而大量的随访试验也证明了在慢性稳定性冠心病的患者中,充分的侧枝循环可以明显的降低非致命性心血管事件的发生率。对于急性心肌梗死而言,相关的研究结果略有不同。很多相关的动物研究已经明确地指出了侧枝循环对于减少心肌梗死后梗塞面积有显著的作用。而对溶栓治疗后血运重建失败的患者进行冠脉动脉造影检查也发现,存在侧枝循环的患者其左心室功能显著强于不存在侧枝的患者。有研究证明,对于前壁心肌梗死的患者而言,经冠状动脉造影证实的侧枝循环对于患者的血流动力学、在院死亡率等有显著的改善作用。但也有学者认为,对于急性心肌梗死直接PCI治疗的患者而言,冠脉侧枝循环无法显著地改善这类患者的预后。冠脉侧枝循环可以通过很多种方法来评估,本研究选择通过冠脉造影检查来评估冠脉侧枝循环,这是因为对于所有的PCI治疗的心肌梗死患者都需要通过冠脉造影来确定具体的病变范围、程度等,容易进行统计分析。本次的研究的目的是为了确定在发病12h内接受直接PCI治疗的急性ST段抬高型心肌梗死的患者中,经冠脉造影证实的侧枝循环是否与这类患者的梗塞面积、预后等相关。目的探讨冠脉侧枝循环对于急性ST段抬高型前壁心肌梗死直接PCI患者预后的影响,为未来侧枝循环在冠心病治疗的应用提供科学依据。材料及方法1.临床资料2008年9月至2012年9月期间,将符合以下标准的132例接受了PCI手术的急性ST段抬高型前壁心肌梗死的患者分为两组,A组为91例Rentrop分级为0级的患者,B组为41例Rentrop分级为1~3级的患者。术者为南方医科大学附属珠江医院心血管内科副高及以上职称的专家教授,均具有丰富的PCI操作经验,尽量减少因操作者因素所造成的差异。记录两组患者详细的病历资料、住院期间主要心血管不良事件和并发症发生情况及其临床转归情况。PCI成功的标准：靶血管管腔残余狭窄小于20%,术毕即刻血流TIMI3级。1.1研究对象纳入标准1)符合急性前壁心肌梗死诊断标准：①持续的剧烈胸痛>30min,并且在含服硝酸甘油后不缓解；②相邻两个或两个以上的胸导联心电图其ST段抬高≥0.1mV；③心肌的损伤标记物(肌酸激酶(CK)、CK同工酶(MB)、心肌的特异肌钙蛋白(即cTNT和cTNI)、肌红蛋白的异常升高,并且存在了动态演变。2)冠脉造影结果提示前降支TIMI血流0-1级。3)发病12h内行左前降支PCI血运重建者1.2研究对象排除标准：1)合并影响预期寿命的晚期恶性肿瘤患者；2)处于多器官功能衰竭、尿毒症等疾病终末期的患者；3)陈旧性心肌梗死患者4)严重的瓣膜性心肌病、扩张型和肥厚型心肌病者。5)PCI术前已行溶栓治疗1.3评估指标评估指标为：Killip分级、术后左心室射血分数、主要心血管不良事件和并发症发生率、术后住院时间。其中主要心血管不良事件和并发症包括：室壁瘤、心力衰竭、术后顽固性心绞痛、恶性心律失常、出血及院内死亡。患者的近期预后在本文中主要通过总的主要心血管不良事件和并发症的发病率、术后住院时间、LVEF来体现。2.统计学方法用SPSS19.0统计软件对所有数据进行统计分析。计量资料以均数±标准差(x±s)表示,组间差异的比较采有非配对t检验；计数资料以百分率来表示,组间比较采用卡方检验,如果P<0.05被认为差异有统计学意义。结果A、B两组患者的临床资料比较：1.年龄(62.13±14.39VS64.76±13.68)岁、甘油三酯(1.54±0.85VS1.26±0.72)mmol/L.低密度脂蛋白胆固醇(3.25±1.18VS3.10±1.09)mmol/L、缺血时间(6.99±3.56VS7.72±2.08)h、手术时间(69.10±20.90VS66.34±27.46)min.肌酐(64.87±15.85VS67.93±14.58)umol、L、术前血糖(9.14±4.41VS8.22±3.54)mmol/L,男性、糖尿病史、吸烟史、术中慢血流等所占的比例分别为(80.2%VS85.4%,16.5%VS12.2%,44.0%VS43.9%,8.8%VS9.8%),室壁瘤、心力衰竭、术后顽固性心绞痛、恶性心律失常、出血、院内死亡等事件在两组内所占的比例分别为11.0%VS4.9%、20.9%VS9.8%、27.5%VS14.6%、8.8%VS4.9%、3.3%VS2.4%、4.4%VS2.4%,这些数据在两组间的差异无统计学意义(P>0.05)。2.两组患者高血压史比例为45.1%VS26.8%(x2=3.933,P=0.047),总胆固醇为(5.24±0.99VS4.44±1.31)mmol/L(t=3.849,P=0.000),梗死前心绞痛发生比例为41.8%VS61.0%(x2=4.184,P=0.041),多支血管病变(血管病变数≥2)比例为37.4%VS56.1%(x2=4.044,P=0.044),主要心血管不良事件和并发症发生比例为44%VS24.4%(x2=4.598,P=0.032),Killip分级≥2级的比例为67.0%VS48.8%(x2=3.972,P=0.046),术后住院时间为(7.97±2.59VS6.59±1.87)d(t=3.080,P=0.003),LVEF为(40.34%±8.54%VS44.71%±8.12%)(t=-2.760,P=0.007),差异有统计学差异。结论对于急性ST段抬高型前壁心肌梗死直接PCI治疗的患者而言：1、年龄、性别、糖尿病史、吸烟史等对于侧枝循环的形成无显著影响；2、有高血压病史的患者侧枝循环发生率较低,存在梗死前心绞痛的患者其侧枝循环发生率高。3、高总胆固醇的患者其侧枝循环发生率较低,低密度脂蛋白胆固醇、甘油三酯与侧枝循环的形成无相关关系。4、存在侧枝循环的心肌梗死患者冠脉病变狭窄程度高,病变复杂。5、侧枝循环的存在可改善室壁运动,保护左心室功能,降低心肌梗死后总的主要心血管不良事件和并发症的发病率,对于患者近期预后有帮助。更多还原

【Abstract】 BackgroundAmong patients with acute myocardial infarction(AMI), infarct size is a major determinant of subsequent left ventricular remodeling and subsequent mortality. Infarct size is directly related to myocardial area at risk which can be influenced by the presence of collateral circulation to the infarct-related artery (IRA). Collatera flow can also prolong the maximal time of coronary occlusion before reperfusion when irreversible transmural myonecrosis develops. Collateral circulation may predate or develop early (within minutes) after loss of arterial patency and is more common in younger patients and those with a history of preinfarction angina and nonanterior myocardial infarction.The role of collateral circulation to the myocardium at risk in the setting of acute coronary occlusion has been of special interest in the last decades. The coronary collateral circulation has long been recognized as an alternative source of blood supply to a myocardial area jeopardized by ischemia. Well-grown versus poorly grown collateral arteries in humans have been suggested to exert a beneficial effect on infarct size, ventricular aneurysm formation, and ventricular function. A reduction in nonfatal cardiovascular events during various follow-up durations has been demonstrated among patients with versus those without angiographic coronary collaterals in the setting of chronic stable coronary artery disease.Animal studies have shown that collateral flow has a protective effect on infarct size in terms of reducing the area at risk.In humans, angiographic studies after thrombolytic therapy has shown better preserved left ventricular function in patients who responded to failure of reperfusion therapy with early collateral flow. In a selected population of patients with anterior myocardial infarction, angiographic evidence of collateral circulation was associated with better haemodynamics at presentation and lower in-hospital mortality.Other studiesshowed no clinical benefit of early collateral circulation in acute myocardial infarction treated with primary percutaneous coronary intervention (PCI).Coronary collateral flow may be identified by several different techniques. We studied coronary collateral flow as detected by angiography because it is easy to incorporate into the routine clinical practice of acute myocardial infarction treatment with PCI. Our aim was to determine whether early angiographic evidence of collateral circulation is related to infarct size, prognosis in patients in the acute phase of ST-segment-elevation anterior myocardial infarction treated with PCI within12h of the onset of symptoms.ObjectiveWe try to study the role of early collateral circulation in the acute phase of ST-segment-elevation anterior myocardial infarction treated with primary percutaneous coronary intervention, thus providing clinical evidence for the application of coronary collateral circulation.Method1.Clinical dataA total of132patients with ST-segment-elevation anterior myocardial infarction were enrolled from September2008to September2012, which meet the following criteria. All the patients were treated with PCI. According to the Rentrop grade we divided these patients into2groups:A group(non-collateral circulation group---Rentrop0grade, n=91)and B group(collateral circulation group---Rentrop1,2,3grade, n=41). All the operations were done by sophisticated cardiologist of Zhujiang Hospital of Southern Medical University with good experience in PCI to attenuate deviations of different operators. In each group, we collect clinical information detailed included:detailed medical records, major adverse cardiac events, complication and clinical outcome.1.1Inclusion criteria(1) Meet the diagnostic criteria of ST-segment-elevation anterior myocardial infarction:①symptoms of acute myocardial infarction lasting more than30min, not relieved by taking nitroglycerin;②with more than1mm (0.1mV) ST-segment elevation in two or more contiguous electrocardiographic chest leads;③abnormal myocardial injury marker with a dynamic process;(2) Coronary angiography confirmed to be anterior descending branch related infarction with TIMI0-1.(3) Treated with PCI within12hours.1.2Exclusion criteria(1) Patients with advanced neoplastic disease;(2) On end-stages of disease such as multiple organ dysfunction syndrome, uremia and so on;(3) The history of old myocardial infarction;(4) Severe valvular hear disease, dilated and hypertropic cardiomyopathy;(5) Treated with thrombolysis before PCI.1.3Evaluation indexThe evaluation index includes:Killip classification, postoperative LVEF, major adverse cardiac events, Complications of myocardial infarction, postoperation hospitalization duration.2. Statistical methodAll the data underwent statistics test by SPSS19.0software. Continuous baseline and outcome variables are presented as mean±SD, the differences between groups have been compared by means of the T-test, whereas discrete variables are expressed as absolute values and percentages, compared by means of the chi-square test. Differences for the main effects were considered statistically significant at p<0.05(two-sided test).3.Results1.General conditions of two groups:age(62.13±14.39VS64.76±13.68)years, triglyceride (1.54±0.85VS1.26±0.72) mmol/L,LDL(3.25±1.18VS3.10±1.09)mmol/L, ischemic time (6.99±3.56VS7.72±2.08) h, time of operation(69.10±20.90VS66.34±27.46)min, creatinine (64.87±15.85VS67.93±14.58)mmol/L, blood glucose level (9.14±4.41VS8.22±3.54) mmol/L, The percentage of males(80.2%VS85.4%), DM(16.5%VS12.2%), smoking history(44.0%VS43.9%), slow reflow during PCI(8.8%VS9.8%). These data are comparative without statistical significance (P>0.05).2.The data with a remarkable difference (P<0.05):The proportions of hypertension, preinfarction angina, multivessel disease, MACE/Complication and Killip classification≧2were Respectively45.1%VS26.8%(x2=3.933, P=0.047),41.8%VS61.0%(x2=4.184,P=0.041),37.4%VS56.1%(x2=4.044,P=0.044),44%VS24.4%(x2=4.598, P=0.032),67.0%VS42.9%(x2=3.972, P=0.046), total cholesterol (5.24±0.99VS4.44±1.31) mmol/L (t=3.849, P=0.000), postoperation hospitalization duration (7.97±2.59VS6.59±1.87) d (t=3.080, P=0.003), LVEF (40.34%±8.54%VS44.71%±8.12%)(t=-2.760, P=0.007)ConclusionsFor the patients in the acute phase of ST-segment-elevation anterior myocardial infarction treated with PCI:1. There was no significant difference between A and B group about age, sex, DM and smoking history.2. The history of hypertension means a poor collateral circulation, while preinfarction angina suggests well-developed collaterals.3. Total cholesterol may inhibit the development of collaterals, while LDL and TG had no effect. 4. Severity of coronary artery disease is more complicated in STEMI patients with collateral circulations.5. The AMI patients who have collateral circulation are inclined to suffer multivessel lesions and complicated lesions, while collateral circulation have benefit on infarction area and left ventricular function.更多还原