Myocardial autophagy variation during acute myocardial infarction in rats: the effects of carvedilol

Background The loss of cardiac myocytes is one of the mechanisms involved in acute myocardial infarction （AMI）-related heart failure. Autophagy is a common biological process in eukaryote cells. The relationship between cardiac myocyte loss and autophagy after AMI is still unclear. Carvedilol, a non-selective α1-and β-receptor blocker, also suppresses cardiac myocyte necrosis and apoptosis induced by ischemia. However, the association between the therapeutic effects of carvedilol and autophagy is still not well understood. The aim of the present study was to establish a rat model of AMI and observe changes in autophagy in different zones of the myocardium and the effects of carvedilol on autophagy in AMI rats. Methods The animals were randomly assigned to a sham group, an AMI group, a chloroquine intervention group and a carvedilol group. The AMI rat model was established by ligating the left anterior descending coronary artery. The hearts were harvested at 40 minutes, 2 hours, 24 hours and 2 weeks after ligation in the AMI group, at 40 minutes in the chloroquine intervention group and at 2 weeks in other groups. Presence of autophagic vacuoles （AV） in the myocytes was observed by electron microscopy. The expression of autophagy-, anti-apoptotic- and apoptotic-related proteins, MAPLC-3, Beclin-1, Bcl-xl and Bax, were detected by immunohistochemical staining and Western blotting. Results AVs were not observed in necrotic regions of the myocardium 40 minutes after ligation of the coronary artery. A large number of AVs were found in the region bordering the infarction. Compared with the infarction region and the normal region, the formation of AV was significantly increased in the region bordering the infarction （P 〈0.05）. The expression of autophagy- and anti-apoptotic-related proteins was significantly increased in the region bordering the infarction. Meanwhile, the expression of apoptotic-related proteins was significantly increased in the infarction region. In the chloroquine intervention group, a large number of initiated AVs （AVis） were found in the necrotic myocardial region. At 2 weeks after AMI, AVs were frequently observed in myocardial cells in the AMI group, the carvedilol group and the sham group, and the number of AVs was significantly increased in the carvedilol group compared with both the AMI group and the sham group （P 〈0.05）. The expression of autophagy- and anti-apoptotic-related proteins was significantly increased in the carvedilol group compared with that in the AMI group, and the positive expression located in the infarction region and the region bordering the infarction. Conclusions AMI induces the formation of AV in the myocardium. The expression of anti-apoptosis-related proteins increases in response to upregulation of autophagy. Carvedilol increases the formation of AVs and upregulates autophagy and anti-apoptosis of the cardiac myocytes after AMI.     

Thorombolytic therapy with rescue percutaneous coronary intervention versus primary percutaneous coronary intervention in patients with acute myocardial infarction: a multicenter randomized clinical trial

Background Although thrombolytic therapy with rescue percutaneous coronary intervention （PCI） is a common treatment strategy for ST-segment elevation acute myocardial infarction （STEMI）, scant data are available on its efficacy relative to primary PCI, and comparison was therefore the aim of this study. Methods This multicenter, open-label, randomized, parallel trial was conducted in 12 hospitals on patients （age 〈70 years） with STEMI who presented within 12 hours of symptom onset （mean interval 〉3 hours）. Patients were randomized to three groups： primary PCI group （n=101）; recombinant staphylokinase （r-Sak） group （n=-104）; and recombinant tissue-type plasminogen activator （rt-PA） group （n=-106）. For all patients allocated to the thrombolytic therapy arm, coronary angiography was performed at 90 minutes after drug therapy to confirm infarct-related artery （IRA） patency; rescue PCI was performed in cases with TIMI flow grade 〈2. Bare-metal stent implantation was planned for all patients. Results After randomization it required an average of 113.4 minutes to start thrombolytic therapy （door-to-needle time）and 141.2 minutes to perform first balloon inflation in the IRA （door to balloon time）. Rates of IRA patency （TIMI flow grade 2 or 3） and TIMI flow grade 3 were significantly lower in the thrombolysis group at 90 minutes after drug therapy than in the primary PCI group at the end of the procedure （70.5% vs. 98.0%, P 〈0.0001, and 53.0% vs. 85.9%, P 〈0.0001, respectively）. Rescue PCI with stenting was performed in 117 patients （55.7%） in the thrombolytic therapy arm. Rates of patency and TIMI flow grade 3 were still significantly lower in the rescue PCI than in the primary PCI group （88.9% vs. 97.9%, P=-0.0222, and 68.4% vs. 85.0%, P=0.0190, respectively）. At 30 days post-therapy, mortality rate was significantly higher in the thrombolysis combined with rescue PCI group than in primary PCI group （7.1% vs. 0, P=0.0034）. Rates of death/MI and bleeding complications were significantly higher in the thrombolysis with rescue PCI group than in the primary PCI group （10.0% vs. 1.0%, P=-0.0380, and 28.10% vs. 8.91%, P=-0.O001, respectively）. Conclusions Thrombolytic therapy with rescue PCI was associated with significantly lower rates of coronary patency and TIMI flow grade 3, but with significantly higher rates of mortality, death/MI and hemorrhagic complications at 30 days, as compared with primary PCI in this group of Chinese STEMI patients with late presentation and delayed treatments.     

Advances in antithrombin therapy for ST-elevation myocardial infarction

Thrombin is a pivotal molecule in acute myocardial infarction ( Ml) because of its extensive procoagulant and prothrombotic actions. Antithrombin therapy is an important component of the pharmacotherapy for acute Ml. The standard agent used in clinical practice, unfractionated heparin (UFH), is associated with the disadvantages of variable anticoagulant effect, inability to inhibit clot-bound thrombin, neutralization by platelet factor 4, and the propensity to cause thrombocytopenic complications. Novel thrombin inhibitors have been developed to overcome these disadvantages. Although possessing the property of inhibiting both fluid-phase and clot-bound thrombin, the direct thrombin inhibitor hirudin has been shown to give marginal benefits over UFH as adjunct to fibrinolysis in ST-elevation Ml. Bivalirudin, another direct thrombin inhibitor, is able to reduce reinfarction in patients treated with streptokinase and is a new anticoagulant treatment option in this setting. The pharmacokinetic characteristi     

Retrospective analysis of thrombolysis therapy for 64 cases of acute myocardial infarction with elevated ST segment

Objective:To explore the cardiac protective effect of integrative therapy in acute myocardial infarction(AMI) with elevated ST segment after reperfusion.Methods:Sixty-four AMI patients who having received decimalization by thrombolysis were assigned to two groups by retrospective analysis,36 patients in the treated group and 28 in the control group.Both were treated by intravenous administering of urokinase for thrombolysis,and to the treated group,intravenous dripping of Xueshuantong Injection(血栓通注射液,XS...     

Comparison of the veracity of real-time perfusion, harmonic angio, and ultraharmonic mocardial contrast imaging mode sine valuation of acute myocardial infarction area

Background Innovative advancements in ultrasound instrumentation present a number of imaging modalities for myocardial contrast echocardiography (MCE) in ischemic syndromes. How well they compare to each other in diagnostic accuracy in the detection of acute myocardial infarction is unclear. The purpose of this study was to assess the relative accuracy of 3 different imaging modes of MCE, low mechanical index (MI) real-time perfusion imaging (RTPI), triggered harmonic angio mode (HA), and ultraharmonic imaging mode (UH) in the detection of acute experimental myocardial infarction within the time frame suitable for potential reperfusion.
Methods MCE was performed in 10 open-chest dogs using RTPI, triggered HA and triggered UH modes at baseline and one hour after occlusion of left anterior descending coronary artery. Presence or absence of perfusion defects, and the perfusion defect size when present, were analyzed and compared with the infarct size delineated by triphenyltetrazolium chloride (TTC) staining.
Results The infarct area was (15.8±2.4)% by TTC staining; Perfusion defect area by MCE was similar to anatomic infarct area in all the three MCE approaches: (16.1±2.7)% by RTPI mode, (15.5±2.9)% by HA mode, and (15.5±3.0)% by UH mode. The sensitivity, specificity and overall diagnostic accuracy in the detection of myocardial infarction were 100%, 88%, and 94% for RTPI mode, 88%, 100%, and 94 % for HA mode, and 100%, 75%, and 88% for UH mode.
Conclusion All modes of MCE, RTPI, triggered HA mode and triggered UH mode have excellent diagnostic accuracy in the immediate hour of acute coronary occlusion within the optimal time frame suitable for reperfusion therapy.

     

Diver CE versus Guardwire Plus for thrombectomy in patients with inferior myocardial infarction: a trial of aspiration of thrombus during primary angioplasty for inferior myocardial infarction

Background Different feasible and safe thrombectomy and distal protection devices have been used in clinical practice. The efficiency and safety of adjunct thrombectomy using Diver CE device (Invatec, Italy) versus Guardwire Plus device (Medtronic, USA) before percutaneous coronary intervention (PCI) were compared in patients with acute inferior ST-segment-elevation myocardial infarction (STEMI) for less than 12 hours, thrombolysis in myocardial infarction (TIMI) flow grade 0 to 1, and total occlusion of the proximal right coronary artery (≥3 mm in diameter) in a prospective randomized single-center study. Methods The primary end point was the magnitude of ST-segment resolution (STR) (>70% ) measured immediately, 90 minutes and 6 hours after PCI, myocardial blush grade and slow flow or no-reflow. Secondary end points were left ventricular end-diastolic volume (LVEDV), left ventricle ejection fraction (LVEF) and major adverse cardiac events (MACEs) including death, myocardial infarction, target vessel revascularization and stroke at 30 days.Results A total of 122 patients were equally divided into Diver CE group and Guardwire Plus group, which were comparable by age ((60±14) years vs (60±13) years), male (82% vs 84%), diabetes (31% vs 28%), previous coronary artery disease (25% vs 23%), onset-to-angiogram ((350±185) min vs (345±180) min), and use of glycoprotein IIb/IIIa inhibitor (11% vs 13%). The magnitude of ST-segment resolution was similar in the two groups as ST-segment resolution >70% (57% vs 59%; P>0.05). Similar slow flow/no-reflow rates were observed in the Diver CE group (8%) and the Guardwire Plus group (7%). TIMI flow grade 3 was obtained in 95% vs 97% patients, respectively (P>0.05). Myocardial blush grade 3 was similar (70% vs 72%; P>0.05). Thirty-day clinical outcome was comparable (LVEF, 0.54±0.12 vs 0.53±0.11; death, 3% vs 3%; myocardial infarction, 2% vs 0%; and target vessel revascularization, 2% vs 2%; P>0.05, respectively). Conclusions Removal of thrombus burden with the Diver CE catheter before stenting leads to similar improvement of myocardial reperfusion in patients with inferior STEMI and total occlusion of the proximal right coronary artery (≥3 mm in diameter) compared with the Guardwire Plus device, as illustrated by a reduced risk of distal embolization and improved ST-segment resolution.     

Correlation between balloon release pressure and no-reflow in patients with acute myocardial infarction undergoing direct percutaneous coronary intervention

Background Balloon release pressure may increase the incidence of no reflow after direct percutaneous coronaryintervention （PCI）. This randomized controlled study was designed to analyze the correlation between balloon releasepressure and no-reflow in patients with acute myocardial infarction （AMI） undergoing direct PCI.Methods There were 156 AMI patients who underwent PCI from January 1, 2010 to December 31, 2012, and weredivided into two groups according to the stent inflation pressure： a conventional pressure group and a high pressure group.After PCI, angiography was conducted to assess the thrombolysis in myocardial infarction （TIMI） grade with related artery.Examinations were undertaken on all patients before and after the operation including cardiac enzymes, total cholesterol,low-density lipoprotein, blood glucose, homocysteine, 13-thromboglobulin （I3-TG）, Hamilton depression scale （HAMD） andself-rating anxiety scale （SAS）. After interventional therapy, the afore-mentioned parameters in both the conventionalpressure group and high pressure group were again analyzed.Results The results showed that CK-MB, HAMD, SAS were significantly different （P 〈0.05） in all patients after PCI,especially the CK-MB in the high pressure group （（25.7_＋7.6） U/L vs. （76.7＋11.8） U/L）. CK-MB, HAMD, SAS, and I3-TGwere comparative before PCI but they were significantly changed （P 〈0.05） after intervention. No-reflow phenomenonoccurred in 13 patients in the high pressure group, which was significantly higher than in the conventional pressure group（17.11% vs. 6.25%, P 〈0.05）.Conclusion In stent implantation, using a pressure less than 1823.4 kPa balloon to release pressure may be the betterchoice to reduce the occurrence of no-reflow followinq direct PCI.     

Safety and efficacy of early administration of tirofiban in patientswith acute ST-segment elevation myocardial infarction undergoingprimary percutaneous coronary intervention： a meta-analysis

Background Tirofiban has been widely used as an adjunctive pharmacologic agent for revascularization in patientsundergoing percutaneous coronary intervention, and the outcomes appear attractive. However, the potential benefits fromearly administration of tirofiban in patients with acute ST-segment elevation myocardial infarction （STEMI） undergoingpdmarv percutaneous coronary intervention （PPCI） remain unclear.     

Effects of Tongguan Capsule(通冠胶囊)on Post-myocardial Infarction Ventricular Remodeling and Cardiac Function in Rats

<正>Objective:To observe the effects of Tongguan Capsule(通冠胶囊,TGC) on post-myocardial infarction ventricular remodeling and heart function in rats.Methods:A rat model of acute myocardial infarction (AMI) was established by coronary ligation.Experimental rats were randomized to 4 groups including three model groups(Group A:captopril 5 mg/kg·day,n=7;Group B:TGC 10 g/kg·day,n=7;and Group C:placebo, n=8),and a sham-control group(Group D:blank control,n=6).Animals were treated for 4 weeks.The cardiac function of rats was assessed at the end of the experiment based on left ventricular ejection fraction(LVEF) and left ventricular short axis fractional shortening(LVFS) detected by colored echocardiography;meanwhile, the condition of ventricular remodeling was observed through the levels of left ventricular mass(LVM),plasma aldosterone(ALD),myocardial angiotensinⅡ(AngⅡ) and myocardial collagen measurements.Results:At the end of the experiment,LVEF and LVFS in Group A and B were improved significantly,while those in Group C were unchanged,the LVEF in Group A,B,C,and D was 0.57±0.46,0.61±0.08,0.36±0.55 and 0.76±0.02,respectively;and their LVFS was 0.31±0.52,0.34±0.04,0.23±0.57 and 0.45±0.03,respectively.The difference was statistically significant when comparing the two indexes in Group A and B with those in Group C and D(P0.05).LVM,levels of plasma ALD and myocardial AngⅡwere lower in Group A and B than in Group C,but a comparison between Group A and B showed an insignificant difference in lowering LVM and ALD,while the lowering of AngⅡwas more significant in Group B than in Group A(754.7±18.7 pg/mL vs 952.6±17.6 pg/ mL,P0.05).Morphological examination showed that in Group A and B the swollen myocardial cells had shrunk, with regularly arranged myocardial fibers and decreased collagen proliferation,but the improvements in Group B were more significant.Conclusion:TGC could markedly improve the post-infarction ventricular remodeling and cardiac function in rats,showing that the efficacy was better than or equal to that of captopril.     

Apoptosis, myocardial fibrosis and angiotensin Ⅱ in the left ventricle of hyp ertensive rats treated with fosinopril or losartan

Objective To investigate the different effects of an angiotensin Ⅱ type 1 (AT(1)) receptor antagonist, losartan, and an angiotensin converting enzyme (ACE) inhibitor, fosinopril, on cardiomyocyte apoptosis, myocardial fibrosis, and angiotensin Ⅱ (AngⅡ) in the left ventricle of spontaneously hypertensive rats (SHRs). Methods SHRs of 16-week-old were randomly divided into 3 groups: SHR-L (treated with losartan, 30 mg·kg(-1)·d(-1)), SHR-F (treated with fosinopril, 10 mg·kg(-1)·d(-1)), and SHR-C (treated with placebo). Each group consisted of 10 rats. Five rats, randomly selected from each group, were killed at the 8th and 16th week after treatment. Cardiomyocyte apoptosis, collagen volume fraction (CVF), perivascular collagen area (PVCA) and AngⅡ concentrations of plasma and myocardium were examined. Results Compared with the controls at the 8th and 16th week, systolic blood pressures were similarly decreased in both treatment groups. Left ventricular weight and left ventricular mass indexes were significantly lower in both treatment groups. However, the latter parameter at the 16th week was reduced to a less extent in the fosinopril group than that in the losartan group. Compared with the controls, cardiomycyte apoptotic index was significantly reduced at the 8th week only in the fosinopril group, and at the 16th week in both treatment groups. The index of the fosinopril group was lower than that of the losartan group at the latter endpoint examined. Compared with the controls, the left ventricular collagen volume fraction and perivascular collagen area at the 8th and 16th weeks were significantly reduced in the SHRs treated with either fosinopril or losartan. However, the collagen volume fraction at the latter endpoint in the fosinopril group was lower than that in the losartan group. Compared with the controls at endpoints, plasma and myocardium Ang Ⅱ levels were significantly increased in the losartan group. However, plasma Ang Ⅱ concentrations were not altered, and myocardium AngⅡ concentrations at the 8th and 16th weeks were significantly reduced in the fosinopril group. Conclusions Both losartan and fosinopril could effectively inhibit cardiomyocyte apoptosis and myocardial fibrosis and reverse heart hypertrophy. Fosinopril may be more effective in these cardioprotective effects, suggesting that the effects of both drugs are related to the inhibition of myocardium renin-angiotension-aldsterone system.     

Clinical relevance of angiographic coronary collaterals during primary coronary intervention for acute ST-elevation myocardial infarction

Background Collaterals to occluded infarct-related coronary arteries （IRA） have been observed after the onset of acute ST-elevation myocardial infarction （STEMI）.We sought to investigate the impact of early coronary collateralization,as evidenced by angiography,on myocardial reperfusion and outcomes after primary percutaneous coronary intervention （PCI）.Methods Acute procedural results,ST-segment resolution （STR）,enzymatic infarct size,echocardiographic left ventricular function,and major adverse cardiac events （MACE） at 6-month follow-up were assessed in 389 patients with STEMI undergoing primary PCI for occluded IRA （TIMI flow grade 0 or 1） within 12 hours of symptom-onset.Angiographic coronary collateralization to the occluded IRA at first contrast injection was graded according to the Rentrop scoring system.Results Low （Rentrop score of 0 or 1） and high （Rentrop score of 2 or 3） coronary collateralization was detected in 329 and 60 patients,respectively.Patients with high collateralization more commonly had prior stable angina and right coronary artery occlusion,but less often had left anterior descending artery occlusion.At baseline,these patients presented with less extent of ST-segment elevation and lower serum levels of creatine kinase myocardial band （CK-MB） and cardiac troponin Ⅰ （cTnl）.Procedural success rate,STR,corrected TIMI flame count,and area under the curve of CK-MB and cTnl measurements after the procedure were similar between patients with high collateralization and those with low collateralization （for all comparisons P＞0.05）.There were no differences in left ventricular ejection fraction and rates of MACE at 6 months according to baseline angiographic collaterals to occluded IRA.Conclusions In patients with acute STEMI undergoing primary PCI within 12 hours of symptom-onset,coronary collateralization to the occluded IRA was influenced by clinical and angiographic features.Early recruitment of collaterals limits infarct size at baseline,but has no significant impact on myocardial reperfusion after the procedure and subsequent left ventricular function and clinical outcomes.     

Three hours continuous injection of adenosine improved left ventricular function and infarct size in patients with ST-segment elevation myocardial infarction

Background  The definitive treatment for myocardial ischemia is reperfusion. However, reperfusion injury has the potential to cause additional reversible and irreversible damage to the myocardium. One likely candidate for a cardioprotection is adenosine. The present study aimed at investigating the effect of intravenous adenosine on clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). 

Methods  Patients with STEMI within 12 hours from the onset of symptoms were randomized by 1:1:1 ratio to receive either adenosine 50 µg∙kg^-1∙min^-1 (low-dose group, n=31), or 70 µg∙kg^-1∙min^-1 (high-dose group, n=32), or saline 1 ml/min (control group, n=27) for three hours. Drugs were given to the patients immediately after the guide wire crossed the culprit lesion. Recurrence of no-reflow, TIMI flow grade (TFG) and TIMI myocardial perfusion grade (TMPG), and collateral circulation were recorded. The postoperative and preoperative ST segment elevation sum of 18-lead electrocardiogram (ECG) and their ratio (STsum-post/STsum-pre) were recorded, as well as the peak time and peak value of CK-MB enzyme. Serial cardiac echo and myocardial perfusion imaging were performed at 24 hours and 6 months post-stenting. The primary endpoint was left ventricular function, and infarct size. The secondary end-point was the occurrence of cardiac and non-cardiac death, non-fatal myocardial infarction, and heart failure.

Results  A total of 90 STEMI patients were studied. No-reflow immediately after stent procedure was seen in 11 (35.5%) patients in the control group, significantly different from 6.3% in the low-dose group or 3.7% in the high-dose group (both P=0.001). STsum-post/STsum-pre in the low-dose and high-dose groups was significantly different from the control group (low-dose group vs. control group, P=0.003 and high-dose group vs. control group, P=0.001), without a dose-dependent pattern (P=0.238). The peak value of CK-MB enzyme was significantly reduced in the high-dose group compared to the control group (P=0.024). Compared to the left ventricular ejection fraction (LVEF) in control group, LVEF in the low-dose group increased by 5.8% at 24 hours (P=0.012) and by 10.9% at 6 months (P=0.007), LVEF in the high-dose group increased by 9.5% at 24 hours (P=0.001) and by 10.0% at 6 months (P=0.001), respectively. Significant reduction of infarct size by 24.2% was detected in the high-dose group vs. low-dose or control groups (P=0.008). There was no significant difference regarding secondary endpoints at 6 months among the treated groups. Cardiac function by NYHA classification in both the low-dose and the high-dose groups was improved significantly (P=0.013, P=0.016).

Conclusion  Intravenous adenosine administration might significantly reduce the recurrence of no-reflow, with resultant improved left ventricular systolic function. High-dose adenosine was further associated with significant reduction of infarct size.

     

Impact of primary percutaneous coronary intervention on blood perfusion in nonculprit artery in patients with anterior ST elevation myocardial infarction

Background Recent studies have demonstrated that epicardial flow in nonculprit arteries,which has been assumed to be normal,was slowed in the setting of ST-elevation myocardial infarction (STEMI).Howev...     

转院方式对ST段抬高心肌梗死患者直接PCI及其预后的影响

目的：比较农村地区院间不同转院方式对ST段抬高心肌梗死（ STEMI）患者再灌注及其预后的影响。方法回顾性调查2011年1月至2013年7月间入院、农村地区发病、6 h内完成首次医疗接触（ FMC）并转诊到本院的STEMI患者155例,根据院间转运方式分为基层医院直接转院组（直接转院组）及经一、二级医院逐级转院组（间接转院组）,比较2组间早期再灌注情况及住院病死率。结果直接转院组64例、逐级转院组91例;直接转院组中发病12 h内患者接受直接经皮冠状动脉介入治疗（PCI）率高于间接转院组（64．1％ vs．30．8％,P＜0．001）,直接PCI比非直接PCI的OR＝4．025（95％ CI 1．934～8．377,P＝0．000）,总缺血时间较短〔（6．92±1．89）h vs．（9．37±1．66）h,P＜0．001〕。直接转院组住院死亡1例,逐级转院组住院死亡6例,2组间病死率无显著性差异（1．6％vs．6．6％,P＝0．241）,死亡患者均未接受PCI。结论 FMC后的STEMI患者转院至具备PCI条件的医疗单位有较高的直接PCI率;逐级转院方式使更多的患者延迟至12 h以后到达三级医院。     

急性ST段抬高心肌梗死患者行急诊冠状动脉介入治疗术中无复流影响因素分析

目的 探讨急性ST段抬高心肌梗死（ST-segment elevation myocardial infarction,STEMI）患者行急诊冠状动脉介入术（percutaneous coronary intervention,PCI）中发生无复流的影响因素。方法 将2012年6月至2013年1月本院收治的行急诊PCI治疗的急性STEMI患者（n=92）,分为正常复流组（n=73）和无复流组（n=19）。通过比较两组的临床症状来分析无复流发生的相关影响因素。结果 急性STEMI患者行急诊PCI后无复流发生率为20.7%（19/92）,无复流组与正常复流组相比,两组之间入院时的收缩压（SBP）、2型糖尿病患病数、肌钙蛋白T峰值、发病到再灌注时间、球囊扩张次数和靶血管植入支架数量差异均有统计学意义（P<0.05）;经多因素logistic 回归分析显示入院SBP<100 mmHg （1 mmHg=0.133 kPa）、合并2型糖尿病、球囊扩张次数、肌钙蛋白T峰值、右冠状动脉病变和发病至再灌注时间是急诊PCI术后无复流发生的危险因素。结论 急性STEMI患者行急诊PCI后无复流发生与入院SBP<100 mmHg、合并2型糖尿病、球囊扩张次数、肌钙蛋白T峰值、右冠状动脉病变及发病至再灌注时间这6种临床因素具有相关性。     

经皮冠状动脉内介入与静脉溶栓治疗急性心肌梗死的对比研究

目的 分析经皮冠状动脉介入治疗与静脉溶栓治疗急性心肌梗死的疗效并进行比较.方法 对该院2002年5月～2004年9月间收治的158例急性心肌梗死病人,进行非随机分组,介入治疗组97例,静脉溶栓组61例,比较分析两组病人死亡率、再通率、心血管事件发生率和心功能情况.结果 经皮冠状动脉介入治疗组无论是降低死亡率、提高再通率,还是减少心血管事件发生率及心功能改善方面均明显优于静脉溶栓组.结论 急性心肌梗死病人采取经皮冠状动脉介入治疗,能及时有效的开通梗死相关动脉,挽救濒死的心肌,改善心功能,降低死亡率,是此种疾病的首选治疗方法.     

对应导联ST段压低在急性ST段抬高心肌梗死患者中的临床价值

目的探讨对应导联ST段压低(reciprocal ST-segment depression,RSTD)在急性ST段抬高心肌梗死(acute ST-elevationmyocardial infarction,STEMI)患者中的临床重要性。方法选取2011年1月至2012年1月共318例STEMI并接受经皮冠状动脉造影(coronary artery angiography,CAG)的患者。根据入院时第1份心电图(electrocardiogram,ECG)是否出现RSTD,将患者分为RSTD组和非RSTD组,评价2组患者基线情况和CAG等结果。结果急性下壁心肌梗死在RSTD组中更常见。RSTD组较非RSTD组患者的收缩压(systolic blood pressure,SBP)和左室射血分数(left ventricular ejection fraction,LVEF)更低、Killip分级更高、肌酸激酶同工酶(creatinekinase-MB,CK-MB)和肌钙蛋白I(troponin I,TnI)的峰值更高、ST段抬高程度更高、合并心房纤颤、传导阻滞和心源性休克的概率更大、多支病变更常见、主动脉内球囊反搏术(intra-aortic balloon pump,IABP)的使用率更高、而且院内病死率更高(P<0.05)。结论伴RSTD的STEMI患者存在不稳定的血流动力学状态,且预后不佳。ECG可以较好地区分高危患者,从而指导治疗方案。     

Direct intracoronary delivery of tirofiban during primary percutaneous coronary intervention for ST-elevation myocardial infarction

ST-segment elevation myocardial infarction (STEMI)is usually caused by acute occlusion of an infarct-related coronary artery (IRA),resulting from rupture or erosion of an atherosclerotic plaque and subsequent platelet aggregation and thrombosis.1-3Prompt reperfusion is the key aspect of the optimal management,4-7 and timely expert primary percutaneous coronary intervention (PCI) becomes the best reperfusion strategy with respect to improvement in survival and reduction of combined clinical endpoints in the treatment of STEMI.8-11 Given the high thrombotic risk of patients with STEMI,pretreatment with a high clopidogrel loading dose before primary PCI was advised to reduce distal thrombotic embolization and angiographic no-reflow and improve clinical outcomes.12,13 The use of adjunctive intravenous glycoprotein (GP) Ⅱb/Ⅲa inhibitors following oral dual-antiplatelet therapy enhances thrombus disaggregation by inhibiting fibrinogen binding to the active receptor complex and subsequently disrupting platelet cross-linking,14 and improves IRA patency and myocardial perfusion,14 and has been recommended as class Ⅱa (at the time of primary PCI) or Ⅱb (before primary angiography and PCI)indication in the recent practice guidelines for the management of patients with STEMI.9,10 Tirofiban (a small-molecule platelet GP Ⅱb/Ⅲa inhibitor) seems even more attractive,because of its consistent and rapidly reversible platelet inhibition at increased dose and efficient penetration into the platelet-fibrin thrombus.15 In a broad population of largely unselected patients undergoing primary PCI for STEMI,tirofiban was associated with a noninferior complete resolution of ST-segment elevation (an indirect measure of myocardial reperfusion after PCI14,16) compared with abciximab,17 and was well tolerated and effective in reducing ischemic acute coronary syndrome complications in patients with mild-to-moderate renal insufficiency.18 Previous studies have shown that an upstream low dose of tirofiban favorably ameliorates IRA patency and reperfusion of the infarct area compared with down-stream use,19 and routine initiation of high-bolus dose of tirofiban could further improve clinical outcome after primary PCI.20 These observations highlight that further platelet aggregation inhibition besides high-dose clopidogrel is mandated in patients with STEMI undergoing primary PCI.     

Outcomes of primary percutaneous coronary intervention for acute ST-elevation myocardial infarction in patients aged over 75 years

Background The optimal reperfusion strategy in elderly patients with ST-elevation myocardial infarction （STEMI） remains unclear. The purpose of this study was to evaluate the safety, in-hospital and one-year clinical outcomes for patients 〉75 years of age with STEMI receiving primary percutaneous coronary intervention （PCI）, compared with those treated by conservative approach. Methods One hundred and two patients 〉75 years of age with STEMI presented 〈12 hours were randomly allocated to primary PCI （n=50） or conservative therapy only （n=52）. The baseline characteristics, in-hospital outcome and major adverse cardiac events （MACE）, including death, non-fatal myocardial infarction and target vessel revascularization at one-year clinical follow-up were compared between the two groups. Results Age, gender distribution, risk factors for coronary artery disease, infarct site and clinical functional status were similar between the two groups, but the patients in primary PCI group received less low-molecular- weight heparin during hospitalization. Compared with conservative group, the patients in primary PCI group had significantly lower occurrence rate of re-infarction and death and shortened hospital stay. The composite endpoint for in-hospital survivals at 30-day follow-up was similar between the two groups, but one-year MACE rate was significantly lower in the primary PCI group （21.3% and 45.2%, P=0.029）. Left ventricular ejection fraction was not significantly changed in both groups during follow-up. Multivariate analysis revealed that primary PCI （OR=0.34, 95% CI： 0.21-0.69, P =0.03） improved MACE-free survival rate for STEMI patients aged 〉 75 years. Conclusion Our results indicated that primary PCI was safe and effective in reducing in-hospital mortality and one-year MACE rate for elderly patients with STEMI.     

No-reflow protection and long-term efficacy for acute myocardial infarction with Tongxinluo: a randomized double-blind placebo- controlled multicenter clinical trial (ENLEAT Trial)

Background No-reflow after emergency percutaneous coronary intervention （PCI） for acute ST segment elevation myocardial infarction （STEMI） is related to the severe prognosis. The aim of this study was to evaluate the efficacy of Tongxinluo, a traditional Chinese medicine, on no-reflow and the infarction area after emergency PCI for STEMI.Methods A total of 219 patients （female 31, 14%） undergoing emergency PCI for STEMI from nine clinical centers were consecutively enrolled in this randomized, double-blind, placebo-controlled, multicenter clinical trial from January 2007 to May 2009. All patients were randomly divided into Tongxinluo group （n=108） and control group （n=111）, given Tongxinluo or placebo in loading dose 2.08 g respectively before emergency PCI with asprin 300 mg and clopidogrel 300 mg together, then 1.04 g three times daily for six months after PCI. The ST segment elevation was recorded by electrocardiogram at hospitalization and 1, 2, 6, 12, 24 hours after coronary balloon dilation to evaluate the myocardial no-flow; myocardial perfusion scores of 17 segments were evaluated on day 7 and day 180 after STEMI with static single-photon emission computed tomography （SPECT） to determine the infarct area.Results There was no statistical significance in sex, age, past history, chest pain, onset-to-reperfusion time, Killip classification, TIMI flow grade just before and after PCI, either in the medication treatment during the follow up such as statin, β-blocker, angiotensin converting enzyme inhibitor （ACEI） or angiotensin receptor blocker （ARB） between two groups. There was significant ST segment restoration in Tongxinluo group compared to the control group at 6 hours （（-0.22±0.18） mV vs. （-0.18±0.16） mV, P=0.0394）, 12 hours （（-0.24 ± 0.18） mV vs. （-0.18±0.15） mV, P=0.0158） and 24 hours （（-0.27±0.16） mV vs. （-0.20±0.16） mV, P=0.0021） reperfusion; and the incidence of myocardial no-reflow was also reduced significantly at 24-hour reperfusion （34.3% vs. 54.1%, P=0.0031）. The myocardial perfusion scores of 17 segments evaluated by static SPECT was improved significantly on day 7 and day 180 after STEMI in Tongxinluo group compared to the control group （0.61±0.40 vs. 0.76±0.42, P=0.0109 and 0.51 ±0.42 vs. 0.66±0.43, P=0.0115, respectively）.There was no significant difference in severe adverse events between two groups.Conclusion Tongxinluo as a kind of traditional Chinese medicine could reduce myocardial no-reflow and infarction area significantly after emergency PCl for STEMI with conventional medicine therapy.