Classification of Myocardial Infarction: Frequency and Features of Type 2 Myocardial Infarction

Background

The classification of myocardial infarction into 5 types was introduced in 2007 as an important component of the universal definition. In contrast to the plaque rupture–related type 1 myocardial infarction, type 2 myocardial infarction is considered to be caused by an imbalance between demand and supply of oxygen in the myocardium. However, no specific criteria for type 2 myocardial infarction have been established.

Methods

We prospectively studied unselected hospital patients who had cardiac troponin I measured on clinical indication. The diagnosis and classification of myocardial infarction were established, and the frequency and features of type 2 myocardial infarction were investigated by use of novel developed criteria.

Results

From January 2010 to January 2011, a total of 7230 consecutive patients who had cardiac troponin I measured were evaluated, and 4499 patients qualified for inclusion. The diagnosis of myocardial infarction was established in 553 patients, of whom 386 (72%) had a type 1 myocardial infarction and 144 (26%) had a type 2 myocardial infarction. Patients in the group with type 2 myocardial infarction were older and more likely to be female, and had more comorbidities. The proportion of patients without significant coronary artery disease was higher in those with type 2 myocardial infarction (45%) than in those with type 1 myocardial infarction (12%) (P < .001). Tachyarrhythmias, anemia, and respiratory failure were the most prevalent mechanisms causing type 2 myocardial infarction.

Conclusions

In a cohort of patients with myocardial infarction who were admitted consecutively through 1 year, the category of type 2 myocardial infarction comprised one fourth when diagnosed by the use of newly developed criteria. Approximately half of patients with type 2 myocardial infarction had no significant coronary artery disease.     

The Analgesic Effect of Oxygen in Suspected Acute Myocardial Infarction: A Substudy of the DETO2X-AMI Trial

Objectives

In this substudy of the DETO2X-AMI (An Efficacy and Outcome Study of Supplemental Oxygen Treatment in Patients With Suspected Myocardial Infarction) trial, the authors aimed to assess the analgesic effect of moderate-flow oxygen supplementation in patients with suspected acute myocardial infarction (AMI) treated with percutaneous coronary intervention (PCI) and to study the effect of oxygen supplementation on the use of opiates and sedatives during PCI.

Subendocardial Myocardial Infarction

Abstract: Subendocardial myocardial infarction. N. Bayley, D. Hunt, C. Penington and J. G. Sloman, Aust. N.Z. J. Med., 1982, 12, pp. 166–169.
Sixty–one consecutive patients with acute subendocardial myocardial infarction (SEAMI) and 223 consecutive patients with transmural infarction (TMI) seen in a coronary care unit were followed for one year. All patients were less than 70 years of age. The patients with SEAMI had a higher frequency of previous infarction (34% vs 21%, p< 0–025), less cardiac failure (44% vs 65%, p<0005), and were more often free from arrhythmias (61 % vs 31%, p<0001) than patients with TMI. Hospital mortality was less in patients with SEAMI (0% vs 8%, p < 0 05) but total mortality to one year was similar (15% vs 17%). Amongst patients with SEAMI, two died within two weeks of infarction but all other deaths occurred at least six weeks after infarction.
Patients with SEAMI and a history of previous infarction had a higher one year mortality than patients without such a history (29% vs 7%, p < 0 05). Coronary angiography with a view to coronary artery surgery should be considered in the former group.     

The Prognosis for Patients Referred with Suspected Acute Myocardial Infarction

ABSTRACT. Engby B, Strunge P, Olsen J. (Department of Internal Medicine, Horsens Hospital, Horsens, Denmark.) The prognosis for patients referred with suspected acute myocardial infarction. A follow-up investigation of the prognosis of 381 patients admitted with suspected acute myocardial infarction (AMI) has been carried out in respect of later AMI or death. During hospitalization the patients were divided into groups with particular attention to patients with no demonstrable myocardial infarction but with ischaemic heart disease (non-AMI) and patients with confirmed AMI. All patients were subjected to follow-up for 43 months (range 37–54). The mortality from cardiovascular causes after four years was 26.2% of 130 non-AMI patients and 25.8% of AMI patients. The majority of new infarctions were found in the AMI patients, but with even increase in both groups, 50% occurring within the first 12 months. The groups were studied with regard to earlier manifestations of ischaemic heart disease and heart failure during hospitalization, without any difference being observed. Due to the poor prognosis the question is raised whether non-AMI patients as a group should be offered prophylactic therapy.     

非急性心肌梗死性ST段抬高研究进展

心电图是决策急性心肌梗死再灌注治疗时机的基石.但ST段抬高型心肌梗死不是引起ST段抬高的惟一原因.ST段抬高的最常见原因为左室肥厚、左束支阻滞、早期复极以及室壁瘤.这些情况可能被误诊为ST段抬高型心肌梗死,而引起不应该的溶栓治疗或急诊冠状动脉造影.因此,要熟悉非急性心肌梗死性ST段抬高的心电图线索才有助于与真正的急性心肌梗死相鉴别.     

Acute Myocardial Infarction and Stress Cardiomyopathy Are Not Mutually Exclusive

Background

Stress cardiomyopathy is a transient cardiac syndrome characterized by reversible left ventricular systolic dysfunction precipitated by emotional or physiologic stress. The presence of obstructive coronary artery disease has been noted in stress cardiomyopathy.

Pharmacologic Reperfusion Therapy for Acute Myocardial Infarction

Acute myocardial infarction (MI) remains a significant problem in terms of morbidity, mortality and healthcare costs. Pharmacologic reperfusion therapies for MI are becoming increasingly complex. This review therefore places contemporary pharmacologic MI developments into perspective. An historical overview of pharmacologic reperfusion therapy for MI is provided, followed by an analysis of current limitations, treatment options, and present and likely future pharmacologic therapies. Adjunctive percutaneous and other treatments are also discussed, to clarify what is becoming a rapidly changing field.     

Sulfonylureas Are Not Associated With Increased Mortality in Diabetics Treated With Thrombolysis for Acute Myocardial Infarction

Background: Sulfonylurea compounds may impair ischemic preconditioning and endogenous fibrinolysis. Increased mortality has been reported in diabetics receiving these drugs prior to admission for acute myocardial infarction when treated by direct angioplasty. Although thrombolytics are currently employed far more frequently than direct angioplasty the effect of sulfonylureas on mortality in the setting of thrombolysis has not been previously addressed.Methods: Two hundred forty five diabetics treated with either accelerated t-PA or streptokinase in a national, multi-center, randomized comparison of argatroban vs. heparin (n=1200) were grouped by anti-diabetic treatment prior to hospitalization, and their outcomes were compared by retrospective analysis.Results: Baseline characteristics were similar in all groups (sulfonylureas: n=121, oral medications other than sulfonylureas: n=17, insulin: n=28, diet alone: n=79). Sulfonylurea use was not associated with increased mortality or adverse event rates. By logistic regression analysis with diet treatment as reference, only prior insulin use was associated with higher risk for mortality at 30 days and 1 year (odds ratios 4.5 and 5.22, respectively, p<0.05).Conclusions: Sulfonylureas use prior to admission is not associated with adverse outcomes in diabetics treated with thrombolytics for myocardial infarction. Since direct angioplasty may increase mortality in patients taking these drugs, a randomized trial is needed to specifically compare different strategies of acute reperfusion in diabetics.Abbreviated abstract. Increased mortality has been reported in diabetics using sulfonylureas when treated for myocardial infarction by direct angioplasty. No study has specifically addressed the effect of these drugs on outcomes in the setting of thrombolysis. In a retrospective analysis of 245 diabetics treated with thrombolysis in a randomized comparison of argatroban vs. heparin, outcomes were compared in relation to anti-diabetic therapy prior to admission. Sulfonyl-urea use did not adversely affect prognosis, which was worst among diabetics previously treated with insulin. In conclusion, sulfonylureas do not worsen outcomes of diabetics treated with current thrombolytic regimens in comparison with other anti-diabetic treatments.     

Manual Aspiration Thrombectomy in Acute Myocardial Infarction: A Clinical Experience

Multiple clinical studies have failed to establish the role of routine use of thrombectomy in ST-elevation myocardial infarction (STEMI) patients. There is a paucity of data on the impact of thrombectomy in unselected STEMI patients outside clinical trials. We sought to evaluate the clinical variables and outcomes associated with the performance of thrombectomy in STEMI patients. We retrospectively examined the clinical outcomes in all STEMI patients who underwent successful percutaneous intervention (PCI) at our center. Patients were divided into two groups, one with patients who underwent conventional PCI and another with patients who had thrombus aspiration in addition to conventional PCI. We compared the baseline clinical characteristics, laboratory investigations, re-infarction rates, and all-cause mortality. Total 477 consecutive STEMI patients were identified. Overall, 29% (139) of the patients underwent conventional PCI and 71% (338) of the patients were treated with aspiration thrombectomy and PCI. In addition to the presence of thrombus, patients with nonanterior infarction, and patients with hemodynamic instability requiring intra-aortic balloon pump support were more likely to undergo thrombectomy. Thrombectomy was associated with higher enzymatic infarction (creatine kinase: 2,796 [2,575] vs. 1,716 [1,662]; p < 0.0001; CK-MB: 210.6 [156.0] vs. 142.0 [121.9], p < 0.0001). However, thrombectomy was not associated with any difference in 30 day reinfarction rate (3.3 vs. 2.9%, p = 0.83), mortality (5.0 vs. 7.2%, p = 0.35), or composite of death and 30 day reinfarction (7.7 vs. 9.4%, p = 0.55). We observed that STEMI patients with anterior infarction and hemodynamic instability were more likely to undergo thrombectomy during primary PCI.     

急性心肌梗死生化标志物的研究进展

急性心肌梗死是临床常见的危重疾病,血液中生化标志物的测定是反映心肌损伤的重要手段之一。生化标志物凭其高度的敏感性及特异性,在急性心肌梗死的诊断、危险分层及评估预后中发挥了非常重要的作用。目前已有越来越多的心肌梗死生化标志物在临床中得到应用。现就急性心肌梗死损伤生化标志物的最新研究进展做一综述。     

Acute Myocardial Infarction in Diabetic Patients

ABSTRACT. All patients hospitalized during a 3-year period with an acute myocardial infarction were followed for the occurrence of reinfarction or death. The patients with diabetes mellitus (n=95) were compared with the non-diabetic population (n=545). The diabetics had a higher mortality rate (relative death rate of 1.44 vs. 0.93, p<0.01) and a higher frequency of reinfarctions (18.9 vs. 10.8%, p=0.04) than the non-diabetic population. A larger proportion of the diabetics had suffered a previous infarction, but the excess mortality was also present in those without a previous infarction. Established risk factors for death after myocardial infarction, such as age, infarct size, infarct localization and heart size, could not account for the difference in mortality. It is suggested that the increased mortality among the diabetics may be due to an increase in the rate of progression of the atherosclerotic heart disease.     

生物材料治疗心肌梗死疾病的应用进展

心肌梗死是严重危及人类健康的致死性及致残性疾病,尽管药物、介入及外科手术策略的进展极大降低了心肌梗死患者的病死率,但很难从根本上使已经坏死或纤维化的心肌恢复正常.心脏组织工程为冠心病的治疗开创了新思路,适当的生物材料不但可以为梗死后受损的心肌细胞提供基质支撑,还具有促进损伤组织自身修复的内在可能.现综述生物材料对于心肌梗死疾病的治疗应用.     

Acute Myocardial Infarction During Transesophageal Echocardiography

We describe the occurrence of acute myocardial infarction during transesophageal echocardiography (TEE) in a patient with atrial fibrillation and underestimated angina. Such a case has not been previously reported in the literature. This case illustrates one of the possible complications of TEE, leading us to suggest systematic sedation in patients with angina in whom TEE is envisaged.     

Creatine Kinase and Recurrent Myocardial Infarction

ABSTRACT. Daily measurements of serum creatine kinase (CK) activity have been performed in 31 patients during hospitalization for acute myocardial infarction (MI). If CK was raised, isoenzyme B was analysed as well. In this way one probable silent MI and another two overt MIs were diagnosed. MI recurred within three months after discharge in another five patients. None of these eight patients showed even small increases in the daily CK activity when in hospital. This study does not support the concept that reinfarction is a stepwise damage of the myocardium.     

急性心肌梗死与高血糖

无论有无糖尿病病史,急性心肌梗死患者常伴有高血糖。急性血糖升高可对心血管造成许多有害影响,并可加重患者的不良转归。强化高血糖控制措施可改善急性心肌梗死患者的预后。因此,提高对急性心肌梗死与高血糖之间相关关系、产生机制及其防治的认识,具有重要的意义。     

急性心肌梗死患者中几种炎症因子与传统心肌损伤标志物的相关性研究

目的选取多个炎症因子—基质金属蛋白酶抑制剂1(TIMP1),基质金属蛋白酶9(MMP9),新蝶呤(Neopterin),观察其在急性心肌梗死(AMI),不稳定性心绞痛、稳定性心绞痛和正常人群中的不同表达水平以及与传统心肌损伤标志物之间的相互关系,以期探索其在AMI发病进展过程中的作用和用于预测急性心梗风险的可行性。方法从收住本院的患者中,入选AMI51例,不稳定性心绞痛48例,稳定性心绞痛54例,正常人44例。所有患者的确诊依据世界卫生组织诊断标准和中华医学会的相关指南。所有患者均接受冠脉造影检查,同时采集血标本。用ELISA法分别测定4组患者的MMP9,TIMP1和Neopterin浓度。所得数据使用SPSS统计软件处理,以P0.05作为有统计学意义的显著性差异。各个数据之间的相关采用单回归线性分析检验。结果 (1)基本临床资料:四组之间在年龄和高血脂,糖尿病发病率上无显著性差异,正常组男性,高血压和吸烟史相对其他组较少。稳定心绞痛和不稳定心绞痛高血压的发生率高于急性心梗。(2)传统的心肌损伤标志物和炎症因子检测结果:高敏C反应蛋白,肌酸激酶,肌酸激酶同工酶和肌钙蛋白I,急性心梗组皆高于其他3个组,有显著性差异。而其他三组之间并无显著性差异。(3)其他炎症因子检测结果:,MMP9、TIMP1、MMP9/TIMP1以及Neopterin各个指标,AMI组皆高于其他3组,有显著性差异。其他三个组相互之间并无显著性差异。(4)入选病人的Hs-CRP与Neopterin和CK呈良好的正相关性(P0.05),而MMP9/TIMP1与hs-CRP及CK皆无相关性。Neopterin与CK也无相关性。结论在AMI患者,炎症因子MMP9、TIMP1、Neopterin均明显升高,除Neopterin与Hs-CRP有良好相关性以外,其他的炎症因子与传统的心肌损伤标志物并无相关性。     

Coxsackie B Virus Antibodies in Myocardial Infarction

ABSTRACT. Evidence for the association between Coxsackie B virus infections and myocardial infarction was studied in a prospective follow-up examination. Using the micro neutralization test, 9 (15%) of 59 patients with acute myocardial infarction and 1 (2.6%) of 38 control patients showed a fourfold, or higher, antibody increase in paired serum samples against Coxsackie B1-5 viruses. This difference is significant (p≤0.05). None of the patients or controls revealed symptoms of a viral infection during the blood sampling. Virus isolation from throat and feces was negative in all patients and controls. This finding agrees with some previous studies suggesting that the Coxsackie B group may in some cases have a causal role in myocardial infarction, or may act as a triggering factor.