Angiographically evident thrombus following fibrinolytic therapy is associated with impaired myocardial perfusion in STEMI: a CLARITY-TIMI 28 substudy.

AIMS: The presence of residual thrombus following fibrinolytic therapy for ST-segment elevation myocardial infarction (STEMI) may predispose to greater embolization and microvascular dysfunction. METHODS AND RESULTS: We hypothesized that even in the presence of a patent epicardial artery, residual thrombus would be associated with worsened TIMI myocardial perfusion grades (TMPG), independent of epicardial flow. Data were analysed from the angiograms of 2684 patients enrolled in the CLARITY-TIMI 28 trial, with angiographically patent arteries (TIMI 2/3 flow) at a median of 88 h following fibrinolytic therapy. Thrombus in a patent epicardial artery was observed more frequently among patients with shorter times from randomization to angiography, among patients with non-left anterior descending infarctions, and among patients treated with placebo (vs. clopidogrel). Thrombus was associated with more frequent TIMI 2 flow (35.1 vs. 22.1%, P < 0.001), higher corrected TIMI frame counts (CTFC) (42 vs. 33 frames, P < 0.001), and a lower incidence of normal TMPG 3 (48.7 vs. 63.9%, P < 0.001), irrespective of treatment with clopidogrel or placebo. In multivariable analyses, thrombus remained associated with higher CTFC (P < 0.001) and worse TMPG (OR 1.6 for TMPG 0/1/2, P < 0.001) after adjustment for baseline covariates as well as known correlates of TMPG. The association between thrombus and impaired TMPG remained even after further adjustment for CTFC or TIMI flow grade. CONCLUSION: Residual angiographic thrombus following fibrinolytic therapy in STEMI patients is associated with impaired myocardial perfusion, independent of epicardial flow. This finding emphasizes the roles of platelet aggregation and distal embolization in the pathogenesis of microvascular dysfunction in STEMI.     

急性心肌梗死患者经皮冠状动脉介入治疗术后心肌灌注水平对心肌存活性的影响

目的:应用TIMI心肌灌注分级(TMP)分析急性心肌梗死(AMI)患者行经皮冠状动脉介入治疗(PCI)后心肌灌注状况对心肌存活性的影响。方法:所有使梗死相关动脉(IRA)达到TIMI3级血流的AMI患者,根据PCI后即刻冠状动脉造影的TMP分级评价的心肌灌注状况,分为A组(TMP为2～3级,57例),B组(TMP为0～1级,31例)。运用静息及含服硝酸甘油介入99mTc-MIBI心肌灌注断层显像(MPI)来评价2组的存活心肌并于12周再次行静息99mTc-MIBI心肌灌注断层显像(MPI)评价存活心肌的恢复情况。结果:术后1周心肌存活面积A组高于B组[(5.43±4.89):(4.12±4.15),P<0.05],术后12周A组心肌缺损面积改善程度较B组明显[A组由(26.54±12.71)降至(17.86±11.59),P<0.05),B组由(39.37±16.31)降至(37.19±10.79),P>0.05]。结论:AMI患者行PCI术后心肌组织灌注TMP分级2～3级,可提高存活心肌的数量,心肌恢复较快。     

Clinical methods to determine coronary flow and myocardial perfusion

In this overview, currently available clinical methods to measure flow in the coronary circulation will be discussed. Methods only applicable in the experimental laboratory or in the anaesthetized patient during cardiac surgery, will not be described. We distinguish between methods that measure global blood flow, and methods that determine regional flow, either at the level of the coronary arteries or at the level of the myocardium. Since it is difficult to measure coronary flow in absolute values, flow reserve is often used as an alternative. Flow reserve is calculated by dividing maximal flow, usually pharmacologically induced, by basal flow. Consequently, assessment of flow reserve requires only measurements of relative changes of coronary flow. The applicability and relative merits and limitations of the techniques are discussed.     

门控核素心肌灌注显像判断冠状动脉支架再狭窄的价值

目的:探讨门控核素心肌灌注显像(G-MPI)对冠状动脉(冠脉)支架再狭窄的诊断价值.方法:65例冠脉支架术后3个月以上的患者行两日法负荷/静息99Tcm-甲氧基异丁基异腈(MIBI) G-MPI,所有患者的G-MPI与冠脉造影(CAG)均在同期的1个月内完成,其中先做CAG检查的患者未进行再次血运重建术.以CAG为标准,分析G-MPI诊断冠脉支架再狭窄的价值.结果:65例患者的88支冠脉共置入105枚支架,随访CAG发现38.5%(25/65)的患者出现支架再狭窄,发生再狭窄的支架数为29.5%(31/105);根据典型症状诊断支架再狭窄的敏感性、特异性和准确性分别为64.0%、22.5%、38.5%;心电图运动平板试验(ETT)诊断支架再狭窄的敏感性、特异性、准确性分别为41.2%、71.9%、61.2%;G-MPI诊断支架再狭窄的敏感性、特异性、准确性分别为92.9%、86.7%、88 6%,其准确性明显优于ETT(χ2=14.173,P<0.001)和症状(χ2=42.781,P<0.001).结论:G-MPI诊断冠脉支架术后再狭窄具有良好的价值.     

Contemporary clinical characteristics,treatment, and outcomes of angiographically confirmed coronary stent thrombosis: Results from a multicenter California registry

Objectives : To describe the contemporary treatment and outcomes for patients with angiographically confirmed (definite) stent thrombosis (ST). Background : Limited data are available on contemporary treatment patterns and outcomes of patients with ST in the United States. Methods : In this multicenter California registry, consecutive cases of definite ST over 5 years were identified. Clinical characteristics, in‐hospital outcomes, and long‐term survival are reported. Results : One hundred and sixty five consecutive episodes of ST were identified in 153 patients from January 2005 to February 2010. The distribution of acute (≤24 hr), subacute (24 hr to 30 days), late (30 days to 1 year), and very late (≥1 year) ST was 3.9%, 21.8%, 17.6%, and 50.3%, respectively. Only 41.2% of patients were on dual antiplatelet therapy at the time of presentation, while 22.4% of patients were on none. Of the 61.4% of patients treated with restenting, 71.1% of them received a drug‐eluting stent. Procedural success was 88.1%, and in‐hospital death, stroke, and CABG occurred in 5.5%, 0.6%, and 6.1% of subjects, respectively. All‐cause mortality at 1 year was 14.3%. Although female gender, diabetes mellitus (DM), bifurcation disease, ejection fraction <40%, and cardiogenic shock at the time of presentation were associated with an increased risk of in‐hospital mortality, only DM (P = 0.047) and bifurcation disease (P = 0.027) remained independent predictors of in‐hospital death. Conclusion : In‐hospital mortality from definite ST is lower than previously reported, but long‐term mortality remains high. DM and bifurcation disease, but not type of percutaneous therapy, are independently associated with in‐hospital mortality. © 2011 Wiley Periodicals, Inc.     

Normalisation of abnormal coronary fractional flow reserve associated with myocardial bridging using an intracoronary stent

Although intracoronary stenting procedures have been advocated for the successful treatment of myocardial ischaemia associated with myocardial bridging, the physiological rationale for this approach remains unexplored. The case of a 70 year old man with symptoms of cardiac ischaemia associated with a left anterior descending coronary artery bridge is described, where use of an intracoronary stent abolished the angiographic abnormalities and also restituted pronounced abnormalities of coronary fractional flow reserve.


Keywords: angioplasty; myocardial bridge; coronary flow reserve; stent     

^99Tcm-MIBI门控心肌灌注显像评价尼可地尔对冠状动脉慢血流的疗效

目的 采用^99Tcm-MIBI门控心肌灌注显像（GMPI）技术观察尼可地尔对冠状动脉慢血流（CSF）的临床疗效.方法 选取经冠状动脉造影诊断为CSF的患者83例,按照随机抽签分为对照组42例和尼可地尔组41例.对照组给予常规抗心绞痛药物治疗,尼可地尔组在对照组用药基础上加服尼可地尔.于治疗前和治疗后6个月分别行GMPI检查以评估心肌受损的程度.结果 用药6个月后,尼可地尔显著改善患者心肌缺血总评分和平均缺血心肌节段数（P=0.001,P=0.000）.但治疗前后,两组患者左心室射血分数（LVEF）、左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）比较,差异均无统计学意义（P＞0.05）.结论 尼可地尔能进一步改善CSF患者的心肌灌注.     

临床风险积分、心肌梗死溶栓试验血流分级和联合风险积分对急性冠状动脉综合征预后评估价值的比较

目的 比较临床风险积分、心肌梗死溶栓试验(TIMI)血流分级以及联合应用临床风险积分和TIMI血流分级(简称:联合风险积分)对急性冠状动脉综合征(ACS)预后的评估价值.方法 选择2004年12月至2006年6月在本院住院并接受冠状动脉造影或支架置入的ACS患者,分别用临床风险积分、TIMI血流分级和联合风险积分进行预后评估.以心原性死亡和非心原性死亡为一级终点;以非致命性卒中、心力衰竭、再发心肌梗死和心绞痛为二级终点.绘制受试者工作特性曲线(ROC),比较这3种方法的预后评估价值.结果 入选ACS患者206例,失访11例(5.34%).平均年龄(67.57±9.88)岁,男性135例(69.2%).平均随访(11.41±5.33)个月,8例达到一级终点,17例达到二级终点.临床风险积分、TIMI血流分级和联合风险积分较好拟合本组患者总事件和一级终点的分布.对总事件的评估:临床风险积分曲线下面积(AUC)=0.67,P=0.006;TIMI血流分级AUC=0.68,P=0.004;联合风险积分AUC=0.73,P＜0.001.经配对比较,发现临床风险积分与TIMI血流分级、TIMI血流分级与联合风险积分和临床风险积分与联合风险积分之间差异无统计学意义;对一级终点的评估,临床风险积分AUC=0.54,P=0.19;TIMI血流分级AUC:0.73,P=0.028;联合风险积分AUC=0.76,P=0.014.经配对比较,P值分别是0.451、0.784和0.204.对二级终点的评估,临床风险积分AUC=0.67,P=0.018;TIMI血流分级AUC=0.64,P=0.052;联合风险积分AUC=0.69,P=0.009.经配对比较,P值依次是0.734、0.470和0.667.三种方法对一、二级终点的评估价值差异均无统计学意义.结论 临床风险积分、TIMI血流分级和联合风险积分对ACS总事件评估价值相似.联合风险积分不仅对总事件评估有预测价值,而且对一级终点和二级终点也有预测价值.     

Spontaneous late improvement of myocardial viability in the chronic infarct zone is possible, depending on persistent TIMI 3 flow and a low grade stenosis of the infarct artery

OBJECTIVE: In the chronic phase of myocardial infarction, the relation between myocardial recovery and infarct related artery status remains unclear. The spontaneous changes in rest-redistribution thallium defect size were prospectively studied over six months in 52 patients with chronic Q wave myocardial infarction. DESIGN: Changes in rest thallium defect size, thallium uptake in the infarct area, and radionuclide left ventricular ejection fraction were compared to the quantitative coronary angiogram data. Two groups of patients were considered: patients with a percentage of stenosis below 100% (group 1, n = 31); and patients with an occluded artery (group 2, n = 21). RESULTS: In the overall population, the mean (SD) defect size decreased from 28.2 (17.2)% to 24.9 (19.3)% of the whole myocardium (p = 0.01), while, in this area, the thallium uptake increased from 62.9 (13.7)% to 66. 9 (15.6)% (p < 0.001). At the time of inclusion, the defect size, thallium uptake, and ejection fraction were similar in both groups. In group 1 patients only, the reduction in defect size correlated with the improvement in ejection fraction (r = 0.41, p = 0.02) and was related to the percentage of coronary artery stenosis. TIMI 3 patients reduced the defect size while other patients increased this defect (-5.1 (7.0)% v +11.0 (14.4)%, p < 0.001). In contrast, no significant relations were found in group 2 patients. CONCLUSION: Late spontaneous recovery in thallium defect can occur in patients with a patent infarct related artery, depending on the TIMI flow grade and a low grade stenosis of the infarct related artery, and is associated with functional improvement.     

The effect of balloon dilatation on post-stenotic myocardial perfusion before and after stimulation of coronary flow reserve: evaluation by the densitometric parameter ''mean rise time''

Summary From densitometric evaluation of digital subtraction cineangiocardiograms the parameter Mean Rise Time (MRT), defined as the time from the onset of local myocardial contrast medium opacification to the point of maximal opacification can be derived; this parameter revealed a close correlation with the results on myocardial perfusion obtained by Thallium-201 scintigraphy. A prolonged Mean Rise Time was indicative of an impairment of myocardial perfusion.We have developed a heart-phase gated real-time digitization procedure and computer-supported method for the densitometric estimation of the MRT to obtain information about the effect of coronary balloon dilatation on myocardial perfusion before and after stimulation of coronary flow reserve by Moxaverin. In 22 patients with single vessel coronary artery disease Moxaverin caused a significant prolongation of the post-stenotic MRT (2.3±1.2s (mean ± s.d.) vs. 2.9±1.1s, p<0.05), while after successful dilatation of the obstructive lesion a significant shortening of the MRT was found after stimulation of the coronary flow reserve (2.5±1.2s vs. 1.9±0.9s, p<0.05). A highly significant decrease in MRT after Moxaverin was measured post-dilatation in comparison to the initial pre-dilatation results (2.9±1.1s vs. 1.9±0.9s, p<0.005); this shows that the effect of successful balloon dilatation on the post-stenotic myocardial perfusion can be described very well by this parameter. These results demonstrate that information about post-stenotic myocardial perfusion during interventional heart catheterization can be obtained from digital densitometry.     

直接冠状动脉介入治疗支架内血栓形成的发生率、危险因素及预后

目的分析过去5年期间常规开展ST段抬高性心肌梗死(STEMI)直接经皮冠状动脉介入治疗(PCI)支架内血栓形成的发生率、危险因素以及对预后的影响.方法 1999年3月至2004年2月5年期间常规对311例STEMI患者经股动脉或桡动脉施行直接PCI.男250例,女61例,平均年龄60.4岁(26～85岁).围手术期采用阿司匹林、氯吡格雷或噻氯匹定、肝素进行标准的三联抗血小板/抗凝治疗.对全部患者随访两个月以上.结果直接PCI手术操作成功率99%(308/311).8例发生9例次支架内急性/亚急性或后期血栓形成,发生率为2.6%(8/308).其中急性血栓形成5例,亚急性或后期血栓形成3例.这8例患者均有血栓形成的多个高危因素.8例中住院死亡3例,其余5例有明显的左心室收缩功能障碍.结论 STEMI直接PCI后的血栓形成发生率较高,小直径的长支架和缺乏有效的抗血小板治疗可能是血栓形成的主要危险因素,血栓形成患者的死亡率高,临床长期预后差.     

Functional assessment of sequential coronary artery fistula and coronary artery stenosis with fractional flow reserve and stress adenosine myocardial perfusion imaging

Coronary artery fistula is an abnormal connection between one coronary artery to another coronary artery or cardiac chambers. The coronary artery fistula may cause significant shunting of blood and cause “pseudo-stenosis” or “steal phenomenon”. This will also accentuate pre-existing mild-moderate de novo coronary lesions with resultant greater pressure gradient difference across the lesions. Thus, fractional flow reserve can be a useful tool to guide intervention decision on the coronary artery fistula. There are very few published reports regarding the use of FFR to assess coronary artery fistula. In fact, there is no outcome data regarding the deferment of coronary artery fistula intervention when the FFR is not physiologically significant. This case highlighted the use of FFR to evaluate the functional significance of coronary fistula in the setting of ischemia evaluation and it was proven to be safe to defer intervention with good 3 year clinical outcome. Stress adenosine myocardial perfusion imaging correlated with the FFR result.     

Effects of coronary artery narrowing,collaterals, and left ventricular function on the pattern of myocardial perfusion

We evaluated effects of the degree of diameter narrowing of the coronary arteries (50–69%, 70–89%, ≥90%); extent of coronary disease [one-vessel disease (1VD), two-vessel (2VD), three-vessel (3VD)]; collaterals; and left ventricular function on the pattern of exercise thallium-201 perfusion in 121 patients; 30 patients with normal coronary angiograms, 37 with 1VD, 24 with 2VD, and 30 with 3VD. Fifteen patients had Q waves on ECG, 29 patients had akinetic segments on the left ventriculogram, and 46 patients had collaterals. The results suggest the following: 1) Patients with 59–69% narrowing of one vessel have normal exercise perfusion. 2) All patients with 1VD have abnormal exercise perfusion if the degree of narrowing is ≥90%, unless the right coronary artery (RCA) is the vessel involved. 3) Patients with 2VD and 3VD generally have abnormal exercise perfusion unless all the narrowings are <90%, or the RCA is the only vessel with ≥90% narrowing, or the stress is submaximal. 4) Collaterals do not protect against development of abnormal exercise perfusion; they feed the most severely narrowed vessel, and perfusion abnormalities are ordinarily seen in the distribution of such severely narrowed vessels. 5) Neither the presence of Q waves on the ECG nor an akinetic segment on the left ventriculogram correlates with defects in the redistribution images; residual defects may be seen in the delayed images despite the absence of prior myocardial infarction, and normal images may be seen despite the presence of akinetic segments in the left ventriculogram.