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.     

重组人尿激酶原对老年性ST段抬高心肌梗死患者近期心血管事件影响分析

目的探讨组人尿激酶原对老年性ST段抬高心肌梗死患者近期心血管事件影响分析。方法选择2014年2月~2016年8月本院收治的急性ST段抬高型心肌梗死老年患者90例,按溶栓药物不同分为观察组和对照组,各45例。对照组采用尿激酶进行溶栓,观察组采用注射用重组人尿激酶原溶栓。两组患者在溶栓前静推肝素,后续以 700~1000U/h 维持。观察两组患者血管再灌注情况,,比较两组患者心电图ST段回落情况,对比两组患者的肌钙蛋白I(cTn-I)、肌酸激酶同工酶(CK-MB)峰值水平,胸痛缓解时间,观察两组患者治疗前后纤溶酶原激活物抑制物（PAI-1）、人组织纤溶酶原激活物（t-PA）,观察两组患者溶栓后不良心血管事件发生率及出血不良事件发生率。结果溶栓后,对照组患者TIMI I级8例,TIMI II级17例,TIMI III级20例,血管再通率达82.22;观察组患者TIMI I级4例,TIMI II级20例,TIMI III级21例,血管再通率达91.11,两组患者差异不显著（P>0.05）;对照组溶栓后完全回落24例,部分回落14例,无回落7例。观察组溶栓后完全回落28例,部分回落16例,无回落1例,两组患者ST段无回落相比较具有统计学差异,（P<0.05）;治疗后,两组患者血清中cTn-I、CK-MB的表达水平差异不显著（P>0.05）,观察组患者胸痛缓解时间短于对照组,差异具有统计学意义（P<0.05）;治疗前,两组患者血清中PAI-1、t-PA水平无明显差异（P>0.05）。治疗后,两组患者血清中PAI-1降低、t-PA的表达升高,与治疗前相比差异显著（P<0.05）,观察组PAI-1降低程度大于对照组,t-PA的表达升高程度小于对照组,差异具有统计学意义（P<0.05）;治疗后,对照组出现3例复发性心肌梗死、3例频发心绞痛、2例心力衰竭、3例恶性心律失常,总不良心血管事件11例,出血事件9例;观察组出现1例复发性心肌梗死、1例频发心绞痛、0例心力衰竭、1例恶性心律失常,总不良心血管事件3例,出血事件2例,观察组患者溶栓后总心血管不良事件及出血事件均显著低于对照组,差异显著（P<0.05）。结论使用重组人尿激酶原对老年ST段抬高型心肌梗死患者进行溶栓,具有疗效肯定,对人体纤溶系统影响较小,患者溶栓后心血管不良事件及出血事件发生率较小,安全性高的优势,因此值得临床医师推广使用     

ST-segment elevation myocardial infarction

Opinion statement ST-segment elevation myocardial infarction (MI) is an emergency medical condition. Expediting the steps leading to coronary reperfusion is of critical importance in improving survival after acute MI. After the diagnosis of acute MI is made, patients should be treated with oxygen, aspirin, nitroglycerin, beta-blockers, heparin, and analgesics, barring any contraindications. If an experienced cardiac catheterization laboratory is available within 60 to 90 minutes, then catheter-based reperfusion therapy is recommended; otherwise, thrombolysis should be considered as an alternate therapy. Therapy with a reduced-dose thrombolytic agent and a glycoprotein IIb/IIIa receptor inhibitor appears to be of an added benefit in establishing TIMI (Thrombolysis in Myocardial Infarction) 3 flow, but this approach awaits final approval prior to widespread use. The adjunctive use of glycoprotein IIb/IIIa receptor inhibitors with percutaneous transluminal coronary angioplasty, with or without stenting, appears to be beneficial and is being used more frequently in the acute setting. Coronary angiography should be performed in patients who fail to respond to thrombolytic therapy or who have evidence of recurrent ischemia. This procedure should not be routinely performed in patients who have responded to thrombolytic therapy. Four to 6 days after an acute MI event, assessment of left ventricular function is recommended. Submaximal exercise test (with or without nuclear or echocardiographic imaging) should be considered in patients prior to discharge from the hospital—an exception can be made in patients with one-vessel disease treated successfully with percutaneous transluminal coronary angioplasty. After discharge, a regular exercise test should be obtained 4 to 6 weeks after an uncomplicated acute MI event. Secondary prevention measures such as weight loss, cessation of smoking, aspirin, beta-blockers, lipid-lowering agents, and angiotensin-converting enzyme inhibitors should be considered in all patients, barring contraindications.     

Impact of acute beta-blocker therapy for patients with non-ST-segment elevation myocardial infarction

Purpose

Early use of beta-blockers is a quality indicator for the treatment of patients with non-ST-segment elevation myocardial infarction (NSTEMI), despite limited data from randomized clinical trials in this population. We sought to determine the impact of acute beta-blocker therapy on outcomes in patients with NSTEMI.

Subjects and Methods

We examined acute (<24 hours) beta-blocker use in 72,054 patients with NSTEMI from 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 (CRUSADE) initiative at 509 US hospitals from 2001-2004. We analyzed patient and provider factors associated with beta-blocker use and the impact of beta-blocker therapy on unadjusted, risk-adjusted, and propensity matched outcomes in the overall sample and among selected high-risk subgroups.

Results

A total of 82.5% of patients without documented contraindications received acute beta-blocker therapy. Factors strongly associated with acute beta-blocker use included prior beta-blocker use, higher presenting systolic blood pressure, lower heart rate, lack of signs of heart failure, and cardiology care. Acute beta-blocker use was associated with lower in-hospital mortality (unadjusted 3.9% vs 6.9%, P <.001, adjusted odds ratio 0.66, 95% confidence interval 0.60-0.72), lower adjusted mortality among most of 6 subgroups determined by propensity to receive acute beta-blockers, and lower adjusted mortality in patients with and without signs of heart failure and in those <80 years and those ≥80 years old.

Conclusions

The majority of NSTEMI patients receive acute beta-blocker therapy. Certain patient subgroups remain undertreated. Because treatment with acute beta-blockers was associated with improved clinical outcomes in nearly all patient subgroups assessed, broader use in patients with NSTEMI appears warranted.     

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     

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.     

Factors explaining the under-use of reperfusion therapy among ideal patients with ST-segment elevation myocardial infarction

Aims To determine the relative impact of time to hospital arrival,baseline cardiovascular risk (i.e.TIMI mortality risk index),intracerebral haemorrhage risk, and comorbid disease burdenon the likelihood of not receiving reperfusion therapy amongST-segment elevation myocardial infarction (STEMI) patientswithout contraindications to treatment. Methods and results Retrospective population-based cohort of3994 patients admitted to 103 acute care hospitals with chestpain and STEMI within 12 h of symptom onset in Ontario,Canada, between 1999 and 2001. Patients with one or more documentedabsolute or relative contraindication (n=909) were excludedfrom the analyses. Reperfusion therapy was defined as the receiptof either fibrinolysis or primary percutaneous coronary intervention.Multivariable analysis and likelihood ² was used to quantifythe importance of each factor in predicting the non-utilizationof therapy. In total, 23.1% of patients received no reperfusiontherapy. Listed in order from greatest to least importance,predictors of non-utilization of reperfusion therapy includedincreasing time to hospital presentation (likelihood ² 31.6,P<0.001), higher intracerebral haemorrhage risk (likelihood² 27.1, P<0.001), higher baseline cardiovascular risk (likelihood² 25.4, P<0.001), and greater number of chronic comorbidconditions (likelihood ² 15.4, P<0.001). The importance ofeach factor on non-utilization was independent, additive, notexplained by age effects alone, or driven by subgroups traditionallyunder-represented in clinical trials. Conclusion Care gaps in the use of reperfusion therapy widenwith both increasing baseline cardiovascular risk and increasingintracerebral haemorrhage risk. Future studies should examinewhether the implementation of clinical decision tools whichallow for more accurate risk–benefit tradeoff predictionsimprove the treatment gaps when using life-saving therapiesin this patient population.     

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.     

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     

Primary percutaneous coronary intervention for patients presenting with ST-segment elevation myocardial infarction: process improvement in a rural ST-segment elevation myocardial infarction receiving center

Background

Rural ST-segment elevation myocardial infarction (STEMI) care networks may be particularly disadvantaged in achieving a door-to-balloon time (D2B) of less than or equal to 90 minutes recommended in current guidelines.

ST-Elevation Myocardial Infarction Process Upgrade Project

A multidisciplinary STEMI process upgrade group at a rural percutaneous coronary intervention center implemented evidence-based strategies to reduce time to electrocardiogram (ECG) and D2B, including catheterization laboratory activation triggered by either a prehospital ECG demonstrating STEMI or an emergency department physician diagnosing STEMI, single-call catheterization laboratory activation, catheterization laboratory response time less than or equal to 30 minutes, and prompt data feedback.

Evaluating success

An ongoing regional STEMI registry was used to collect process time intervals, including time to ECG and D2B, in a consecutive series of STEMI patients presenting before (group 1) and after (group 2) strategy implementation. Significant reductions in time to first ECG in the emergency department and D2B were seen in group 2 compared with group 1.

Conclusions

Important improvement in the process of acute STEMI patient care was accomplished in the rural percutaneous coronary intervention center setting by implementing evidence-based strategies.