Reperfusion assessment using myocardial contrast echocardiography in patients with ST-segment elevation acute myocardial infarction

In this study, 29 patients underwent myocardial contrast echocardiography after presentation with ST-segment elevation acute myocardial infarction but before coronary angiography using a continuous infusion of microbubbles and real-time imaging with a low mechanical index. Patients with transmural perfusion defects at presentation subsequently had much larger infarctions (as measured by peak creatine phosphokinase-MB fraction) than did those with normal perfusion, indicating that myocardial contrast echocardiography may be a useful means to determine adequacy of reperfusion after thrombolytic therapy and in the selection of patients for adjunctive treatment, such as "rescue angioplasty."     

Low-molecular-weight heparin in patients with acute ST-segment elevation myocardial infarction

One of the primary goals of physicians treating patients presenting to a hospital with acute ST-segment elevation myocardial infarction is to restore the flow of blood in the infarct-related artery as quickly as possible. Prompt and successful reperfusion limits the size of the myocardial infarction, reduces left ventricular dysfunction, and improves the patient's chance of survival. Approximately two thirds of patients with ST-segment elevation myocardial infarction do not present to a hospital capable of conducting urgent direct percutaneous coronary intervention or cardiac surgery when it is needed. They must receive pharmacological reperfusion therapy, a combination of fibrinolytic, antiplatelet, and anticoagulant drugs. Earlier and simpler administration of pharmacological reperfusion therapy could result in significantly improved outcomes. Fibrinolytic therapy, in combination with adjunctive antithrombin therapy that is simpler and quicker to administer (e.g., tenecteplase with enoxaparin), may be more efficacious and easier to use than regimens involving unfractionated heparin.     

Synergistic treatment of ST-segment elevation myocardial infarction with pharmacoinvasive recanalization

Both pharmacologic and mechanical approaches designed to limit infarct size by recanalization of infarct-related arteries have reduced mortality associated with ST-segment elevation myocardial infarction (STEMI). Early efforts to combine the two were attenuated because of complications encountered. Primary percutaneous coronary intervention (PCI) and thrombolysis became viewed as alternative rather than complementary modalities. Time to recanalization and adequacy of restoration of perfusion were found to be pivotal determinants of a favorable outcome with either approach. Because pharmacologic intervention can be initiated immediately in virtually any hospital, it is a promising initial step. Because PCI proffers more complete recanalization, it may be a particularly salutary initial or subsequent step. Because of unavoidable delay often confronting implementation of PCI, optimal advantage may accrue from the use of both approaches in combination. We seek to emphasize the potential synergy by referring to the combined approach as "pharmacoinvasive recanalization" rather than by the conventional term "facilitated PCI." Virtually all patients with STEMI can benefit from prompt, sustained, and complete coronary recanalization. Thus, investigations focusing on identification of pharmacologic regimens that can safely initiate recanalization as early as possible, minimize bleeding, and broaden the temporal window available for efficacy of subsequent, optimally timed PCI should provide particularly valuable information.     

ST-segment elevation on Q-leads during exercise in patients with ST-segment elevation at rest after myocardial infarction

INTRODUCTION: ST-segment elevation on Q-leads after an acute myocardial infarction is related to a greater infarct size. The meaning of a further exercise-induced ST-segment elevation in these patients has not been analyzed. METHOD: Thirty-six patients with ST-segment elevation on Q-leads were studied after a first acute myocardial infarction. Exercise testing and cardiac catheterization were performed at the first week. Left ventricular volumes (ml/m(2)); the extent of abnormal wall motion (AWM: chords); contractile reserve (AWM improvement with low dose dobutamine) and coronary patency in the culprit artery were analyzed. Cardiac catheterization was repeated at the sixth month in 20 patients; systolic recovery (AWM improvement), left ventricular volumes and coronary patency were again evaluated. RESULTS: Patients with exercise-induced ST-segment elevation in two or more Q-leads (n=21) showed lesser contractile reserve (6+/-6 vs. 12+/-7 chords, P=0.01) than patients without exercise-induced ST-segment elevation (n=13). AWM (F=8.1) and absence of exercise-induced ST-segment elevation (F=9.5; positive predictive value: 80%; negative predictive value: 68%) were the only independent predictors of contractile reserve. Nevertheless, this electrocardiographic sign was not related to left ventricular volumes, coronary patency or systolic function and it did not predicted late systolic recovery. CONCLUSIONS: In patients with baseline ST-segment elevation on Q-leads an exercise-induced ST-segment elevation is independently related to a lesser contractile reserve but not to the evolution of volumes or regional dysfunction during the first 6 months post-infarction. Therefore, the clinical value of this sign seems to be limited to the non-invasive detection of myocardial viability during the early post-infarction phase.     

替罗非班在急性ST段抬高心肌梗死急诊介入治疗中的应用

冠状动脉粥样斑块破裂或蚀损及继发性血栓形成是导致急性心肌梗死(AMl)的主要发病机制。近年来随着ST段抬高型心肌梗死(STEMI)直接经皮冠状动脉介入治疗(PCI)的广泛开展,及多重抗血小板药物的联合治疗,明显降低了AMI患者的死亡率及再梗死率等不良心血管事件。国内外众多研究已证实糖蛋白(GP)Ⅱb/Ⅲa受体拮抗剂的应用可以提供有效的抗血小板作用,减少血栓负荷和继发的远端微循环栓塞,有助于真正恢复冠脉血流和心肌组织水平灌注,使PCI前后获益。     

Clinical trials with ST-segment elevation myocardial infarction

It is with great interest that we read the article ‘Outcomesof patients in clinical trials with ST-segment elevation myocardialinfarction among countries with different gross national incomes’by Orlandini et al     

Gender differences in mortality in patients with ST-segment elevation myocardial infarction

Objective:Women with ST-segment elevation myocardial infarction (STEMI) have worst outcomes than men. The objective of the study was to determine gender differences in mortality in patients with STEMI.Methods:Cohort study including patients with STEMI. We recorded demographic and clinical data, laboratory tests, and in-hospital mortality in patients who underwent primary angioplasty and pharmacoinvasive strategy. Kaplan–Meier analysis was used to assess mortality differences between both genders.Results:A total of 340 patients were analyzed, 296 males and 44 females. Mean age of the female group was 64.3 ± 12.3 years. About 98% of females were among Killip-Kimball Class I-II. They had higher risk scores compared to man, longer ischemic time and first medical contact with a difference in comparison to man of 47 and 60 min, respectively. Mortality was 9.1% (4) in the female group.Conclusions:Although the proportion of women had higher mortality than man, we did not found any difference with statistical significance probably due to the lack of representation. We need more awareness in the female population about STEMI, since longer first medical contact time and longer total ischemic time might be one possible explanation of a higher mortality.Key words: Myocardial infarction, Gender difference, ST-segment elevation myocardial infarction, Mortality     

Sirolimus-eluting stents in real-world patients with ST-segment elevation acute myocardial infarction

Recently, the use of sirolimus-eluting stents (SES) has been demonstrated to significantly reduce the rate of adverse events among selected patients with ST-segment elevation acute myocardial infarction (STEMI). We present real-world experience from a single center registry evaluating the safety and efficacy of primary percutaneous coronary intervention (PCI) in unselected patients with STEMI using SES. Clinical outcome at 300-day follow-up in two cohorts of 225 consecutive patients who underwent bare metal stent (BMS) (January 2004-February 2005, n = 123) or SES (March 2005-December 2006, n = 102) implantation was examined. The primary endpoint was a composite of major adverse cardiovascular events (MACE: death, nonfatal reinfarction, and target vessel revascularization [TVR]). The incidence of short-term MACE was similar between the SES group and BMS group (30-day rate of MACE: 4.9% versus 8.9%, P = 0.30). Angiographically documented stent thrombosis within 30 days after primary PCI was not diagnosed in any patient in the SES group and occurred in 1 patient treated with BMS (0 versus 0.8%, P = 1.0). At 300 days, SES implantation significantly reduced the incidence of MACE (7.8% versus 22.8%, hazard ratio [HR] 0.32 [95% confidence interval (CI) 0.15 to 0.71], P = 0.005), mainly due to a marked reduction in the risk of TVR (1.0% versus 17.1%, HR 0.05 [95% CI 0.01 to 0.39], P < 0.001). There was no new onset of documented stent thrombosis between 30 and 300 days in either group. Thus, this real-world registry confirmed the safety and efficacy of SES with remarkably lower rates of TVR and MACE in the setting of primary PCI for unselected patients with STEMI in a real-world scenario.     

Enoxaparin for the treatment of acute myocardial infarction with persistent ST-segment elevation

Enoxaparin (E) is a low-molecular-weight heparin which has been proven more effective than unfractionated heparin (UFH) for the treatment of non-ST-segment elevation acute coronary syndromes. Limited and inconclusive on the other hand, are the data on the use of E in acute myocardial infarction with persistent ST-segment elevation (STEAMI). Therefore, we performed a review of the literature in order to evaluate the level of evidence relative to the efficacy and safety of E in such a clinical setting. The effect of E in STEAMI has been evaluated in 7 clinical studies, including a total of about 9500 patients. Compared to placebo, E resulted more effective on the incidence of the combined end-point of death, re-infarction and recurrent angina in the study by Glick et al. and on the patency of the infarct-related artery in the AMI-SK study. Compared to UFH, E resulted more effective on the incidence of the combined end-point of death, reinfarction and unstable angina in the study by Baird et al. and of in-hospital re-infarction and refractory ischemia rates in both ASSENT-3 and ASSENT-3 PLUS, while the effect on the patency of the infarct-related artery, which was evaluated in HART-II and ENTIRE-TIMI 23, resulted non univocal. Overall, bleeding complications were more frequent than with placebo and comparable to UFH, with the exception of ASSENT-3 PLUS where pre-hospital administration of E was associated with a doubled incidence of intracranial bleeding (although only in patients older than 75 years). In conclusion, the administration of E, in association with aspirin and thrombolytics, already appears a possible therapeutic option for the treatment of STEAMI, due to its good efficacy and safety profile, along with its easiness of use. However, prior to have its use recommended, the current B level of evidence of a superior efficacy and safety compared to UFH needs to be reinforced. Further-more, some open issues relative to the use of E in particular settings (aged patients, in association with glycoprotein IIb/IIIa inhibitors and during percutaneous coronary revascularization) need to be clarified.     

改善急性ST段抬高型心肌梗死的生存链

急性ST段抬高型心肌梗死的生存链近来受到关注,本文就缩短从患者发生症状至医院就诊以及从患者到达医院至球囊扩张(PCI治疗)两个时间段的文献报道作一综述,希望能推动我国急性ST段抬高型心肌梗死的治疗.     

急性ST段抬高型心肌梗死患者嗜酸性粒细胞的变化

目的观察急性ST段抬高型心肌梗死(STEMI)患者嗜酸性粒细胞(EO)的变化及意义,及其与心力衰竭事件发生率的关系。方法 STEMI患者584例为STEMI组,稳定型心绞痛(SAP)患者582例为SAP组;依据EO计数高低,将STEMI组分为EO降低组与EO非降低组,对比两组肌钙蛋白Ⅰ峰值、心力衰竭事件发生率。结果入院时STEMI组EO计数水平较SAP组更低,差异有统计学意义(P0.05);与EO非降低组相比,EO降低组肌钙蛋白Ⅰ峰值水平更高、住院期间心力衰竭事件发生率更高,差异有统计学意义(P0.01)。结论 EO水平降低是急性STEMI患者短期不良预后指标。     

急诊冠状动脉介入术强化阿托伐他汀治疗的临床疗效

目的:探讨急性ST段抬高心肌梗死(STEMI)急诊经皮冠状动脉介入治疗(PCI)术前单次口服大剂量阿托伐他汀和术后强化阿托伐他汀治疗的临床疗效。方法:选择STEMI并行急诊PCI治疗的118患者,随机分为2组:强化组(61例)术前阿托伐他汀80mg口服,术后40mg/d;常规组(57例)仅于术后给予阿托伐他汀20mg/d。两组均给予常规冠心病二级预防治疗。主要研究终点是术后30d主要心脏不良事件(MACE)发生率,次要研究终点包括心肌灌注TMPG分级、术后即刻和术后6hST段回降率(STR)和阿托伐他汀治疗前、后生化指标的变化。结果:PCI术后强化组CK-MB峰值明显低于常规组[(230.20±128.84)U/L∶(285.28±149.55)U/L,P<0.05]。PCI术后6h强化组STR≥50%的比例明显高于常规组(86.9%∶71.9%,P<0.05)。与常规组相比,强化组治疗30d后LDL-C、高敏C反应蛋白(hs-CRP)明显下降(P<0.05)。结论:STEMI急诊PCI术前大剂量阿托伐他汀80mg口服和术后40mg/d治疗安全有效,能够明显改善PCI术后6hSTR,降低CK-MB峰值和术后30d的LDL-C和hs-CRP。     

Excess heparin dosing among fibrinolytic-treated patients with ST-segment elevation myocardial infarction

Background

Although the use of heparin with fibrinolytics is associated with more rapid ST-segment resolution and increased infarct-related artery patency among patients with ST-segment elevation myocardial infarction (STEMI), its associated increase in bleeding risk is well documented and might be augmented by excess heparin dosing.

Methods

We sought to characterize the incidence and associated bleeding risk of excess heparin dosing among patients with STEMI treated with fibrinolysis who were enrolled in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines initiative. Excess dosing was defined as a bolus more than 60 U/kg or an infusion more than 12 U/kg/h per American College of Cardiology/American Heart Association guidelines and was further stratified into major and mild excess (major defined as a bolus > 70 U/kg or infusion >15 U/kg/h).

Results

Among 964 fibrinolytic-treated patients with STEMI, 758 (79%) received adjunctive unfractionated heparin therapy. Of these, 368 patients (49%) received excess dosing of unfractionated heparin and 137 patients (18%) received major excess heparin dosing. Factors significantly associated with excess dosing included low body weight and female sex. Patients who received major excess dosing had higher unadjusted rates of major bleeding (19.2% vs 12.4%, P = .004) and transfusion (13.5% vs 4.7%, P = .0002) than patients without excess dosing. After adjustment, a trend persisted for the association with higher transfusion risk (odds ratio 1.39 [0.61-3.14]).

Conclusion

Approximately half of fibrinolytic-treated patients with STEMI in contemporary practice received an excess dose of unfractionated heparin. Careful attention to dosing is needed to limit the compounded bleeding risk when heparin is added to fibrinolytic therapy.     

Prehospital ticagrelor in ST-segment elevation myocardial infarction

The direct-acting platelet P2Y12 receptor antagonist ticagrelor can reduce the incidence of major adverse cardiovascular events when administered at hospital admission to patients with ST-segment elevation myocardial infarction(STEMI). Whether prehospital administration of ticagrelor can improve coronary reperfusion and the clinical outcome is unknown. Methods We conducted an international, multicenter, randomized, doubleblind study involving 1862 patients with ongoing STEMI of less than 6 hours' duration, comparing prehospital(in the ambulance) versus in-hospital(in the catheterization laboratory) treatment with ticagrelor. The coprimary end points were the proportion of patients who did not have a 70% or greater resolution of ST-segment elevation before percutaneous coronary intervention(PCI) and the proportion of patients who did not have Thrombolysis in Myocardial Infarction flow grade 3 in the infarct-related artery at initial angiography.Secondary end points included the rates of major adverse cardiovascular events and definite stent thrombosis at30 days. Results The median time from randomization to angiography was 48 minutes, and the median time difference between the two treatment strategies was 31 minutes. The two coprimary end points did not differsignificantly between the prehospital and in-hospital groups. The absence of ST-segment elevation resolution of 70% or greater after PCI(a secondary end point) was reported for 42.5% and 47.5% of the patients, respectively. The rates of major adverse cardiovascular events did not differ significantly between the two study groups. The rates of definite stent thrombosis were lower in the prehospital group than in the in-hospital group(0% vs. 0.8% in the first 24 hours; 0.2% vs. 1.2% at 30 days). Rates of major bleeding events were low and virtually identical in the two groups, regardless of the bleeding definition used. Conclusions Prehospital administration of ticagrelor in patients with acute STEMI appeared to be safe but did not improve pre-PCI coronary reperfusion.     

Bleeding risk in ST-segment elevation myocardial infarction

Coronary reperfusion of acute coronary syndromes with ST segment elevation requires medical treatment involving potential thrombolysis as well as very potent anticoagulant and antiplatelet medications. In such a therapeutic setting, the risk of bleeding complications may be high and should be taken into account accordingly. An accurate definition of these bleeding complications is crucial in order to compare all currently available treatments and strategies appropriately. The heterogeneous definitions often published in the literature make any valid interpretations of the results very difficult. These bleeding complications, which affect negatively the outcome of patients undergoing treatment should be adequately anticipated in our treatment strategies. An exhaustive knowledge of the bleeding risk factors is necessary in order to adjust the treatment modalities. The occurrence of bleeding may be related to the vascular approach used for cardiac catheterization. In this respect, the superiority of the radial approach has been widely demonstrated. In addition, certain instances of bleeding are not related to the vascular approach, such as digestive and neurological bleeding which can have very severe consequences. Consequently, it is necessary to adapt treatments with heterogeneous potential for bleeding to individual bleeding risk factors, which may be quantified by scores measuring the bleeding risk. Finally, treatment combinations must often be carefully tailored to the characteristics of each individual patient.     

Reperfusion paradox in ST-segment elevation myocardial infarction

A transformation in ST-segment elevation myocardial infarction (STEMI) care in the United States has unfolded. It asserts superior reperfusion with primary percutaneous coronary intervention (PPCI) over fibrinolysis on the basis of studies showing the former method to be superior for reperfusion of patients with STEMI. Although clear benefit has resulted from national programs directed toward achieving shorter times to PPCI in facilities with around-the-clock access, most patients present to non-PPCI hospitals. Because delay to PPCI for most patients with STEMI presenting to non-PPCI centers remains outside current guidelines, many are denied benefit from pharmacologic therapy. This article describes why this approach creates a treatment paradox in which more effort to improve treatment for patients with PPCI for acute STEMI often leads to unnecessary avoidance and delay in the use of fibrinolysis. Recent evidence confirms the unfavorable consequences of delay to PPCI and that early prehospital fibrinolysis combined with strategic mechanical co-interventions affords excellent outcomes. The authors believe it is time to embrace an integrated dual reperfusion strategy to best serve all patients with STEMI.