MYOCARDIAL INFARCTION FOLLOWING CAROTID ENDARTERECTOMY

Myocardial infarction has been the major cause of mortality following operation for cerebrovascular insufficiency. In our institution, a clinical diagnosis of coronary artery disease was made in 37 of 125 (29.6%) consecutive male patients having carotid endarterectomy. Six of these 37 patients developed postoperative myocardial infarction. In contrast, none of the 88 patients without coronary artery disease developed myocardial infarction. A more recently treated group of 20 patients who had undergone carotid artery surgery and had previously undergone coronary artery bypass for angina did not develop postoperative myocardial infarction. These data suggest that in patients with both coronary artery and carotid artery disease, prior or concomitant coronary artery bypass should be considered. Myocardial infarction has been the leading cause of early and late death following operation for cerebrovascular insufficiency.(1) DeBakey(2) found operative mortality in patients having surgery for cerebrovascular insufficiency directly related to the incidence of coronary artery disease. An increased operative mortality due to reinfarction has been found in patients recovering from recent myocardial infarction.(3) Cooley(4) found that in patients having aortocoronary bypass there was no increased operative mortality 30 days after myocardial infarction and this may apply to patients having carotid endarterectomy. Subendocardial postoperative infarction associated with minor T wave changes and slight enzyme elevation had a better prognosis than did transmural infarction causing significant Q waves, sequential ST and T wave changes and marked enzyme elevations.(5) The purpose of this study was to document our experience with myocardial infarction in patients undergoing carotid artery operation for clinical coronary artery disease. Consideration of the role of saphenous vein bypass in those patients with coronary artery disease was the background for this review even though the evidence that myocardial infarction can be prevented with saphenous vein bypass operation is only preliminary at the present time.(6)     

Platelet aggregation and antiplatelet agents in acute coronary syndromes

Antiplatelet agents are the cornerstone therapy of acute coronary syndromes. In the setting of ST elevation myocardial infarction, antiplatelet therapy prevent the prothrombotic effect of reperfusion therapy including thrombolysis and primary percutaneous coronary intervention. In non ST-elevation acute coronary syndromes, antiplatelet therapy prevent s complete coronary thrombotic occlusion and therefore the occurrence of ST elevation myocardial infarction. Antiplatelet agent benefit is related to the patient's risk profile. It is well established that combined antiplatelet therapy is the most effective in high risk patients. Several important issues have to be faced including the identification of non responders, dose adjustment and the management of temporary interruption of antiplatelet agents in stable coronary artery disease patients.     

The Pathogenesis of Human Myocardial Infarction

Coronary arteriography, dissection of the coronary arteries and histopathological examination of the heart were carried out in 150 autopsies to study the effect of coronary narrowing and occlusion, of the presence of collaterals, and of coronary artery predominance on the development of myocardial infarction. The thrombosis rate was related to the severity of coronary sclerosis. The development of collaterals was not enhanced by coronary sclerosis and occlusion, and collaterals did not protect the myocardium against reinfarction. Coronary occlusion was regularly demonstrable in recent myocardial infarct cases. The association of atrial and posterior ventricular infarcts was explained by occlusion of their common arterial branch. The interdependence between coronary sclerosis, thrombosis and myocardial infarction in human autopsy material emphasizes the importance of mural coronary artery disease in the genesis of coronary occlusion and myocardial infarction, and it is at variance with statistical data and experimental results.     

Risks of discontinuing anticoagulant therapy in a selected group of patients with atherosclerotic heart disease: a prospective study

In 134 patients with coronary artery disease, long-term oral anticoagulant therapy (mean duration, 56 months) for acute myocardial infarction (98 patients), acute coronary insufficiency (25 patients) or severe chronic angina (11 patients) was terminated abruptly in 50 patients (group 1) and gradually in 84 (group 2). The 134 patients represented a homogeneous population of patients with coronary artery disease since most patients older than 75 years and those with conditions known to increase the risks of thromboembolic complications were excluded. The two groups were comparable in terms of sex, age, presence of risk factors, duration of anticoagulant therapy, and presence of angina and abnormal resting electrocardiograms during therapy. Patients were evaluated 6 months after cessation of anticoagulant therapy and, since abrupt withdrawal of therapy did not carry a higher risk than gradual discontinuation, data for groups 1 and 2 were tabulated together.Of the 84 patients with angina at the end of therapy 15 experienced an increase in its severity and this symptom appeared in another patient (relapse rate, 18%). Angina progressed to fatal acute myocardial infarction in four (mortality, 3%) and nonfatal infarction in two; however, all six had extensive coronary artery disease and poor left ventricular function. The results of this study suggest that neither abrupt nor gradual cessation of anticoagulant therapy is associated with an inordinate exacerbation of heart disease.     

负荷量阿托伐他汀对稳定型冠心病患者非心脏手术围手术期保护作用的研究

目的:探讨负荷量阿托伐他汀对稳定型冠心病患者非心脏的择期外科手术围手术期主要不良心脏事件的保护作用。方法:将拟行非心脏外科手术的60名稳定型冠心病患者随机分为负荷量阿托伐他汀组(n=30)和对照组(n=30),其中负荷量阿托伐他汀治疗组在术前12小时给予阿托伐他汀80 mg顿服,术前2小时阿托伐他汀40 mg顿服,且每晚服用阿托伐他汀40 mg,对照组术前每晚服用阿托伐他汀20 mg,而后进行非心脏的外科手术(主要病种为慢性胆囊结石胆囊炎、慢性阑尾炎、消化性溃疡、疝气),术后负荷量组给予每晚服用阿托伐他汀40 mg,对照组每晚服用阿托伐他汀20 mg。比较两组围手术期主要不良心脏事件(包括心脏性猝死,急性心肌梗死,非计划性血运重建)的发生情况。结果:对照组出现1例急性前壁ST段抬高型心肌梗死并行急诊前降支介入再灌注治疗和7例无症状型心肌梗死,负荷量阿托伐他汀组出现1例无症状型心肌梗死,围手术期心肌梗死发生率较对照组明显降低(P0.05)。结论:负荷量阿托伐他汀可显著降低稳定型冠心病患者非心脏的择期外科手术围手术期主要不良心脏事件如心肌梗死,特别是无症状型心肌梗死的发生率,但该结果尚需大样本多中心随机对照临床试验进一步证实。     

Early exercise testing after treatment with thrombolytic drugs for acute myocardial infarction: importance of reciprocal ST segment depression.

OBJECTIVE--To investigate the clinical importance of reciprocal ST depression induced by exercise testing early after acute myocardial infarction in patients treated with thrombolysis. DESIGN--Prospective observational study. SETTING--District general hospital in London. SUBJECTS--202 patients (170 men) aged 33-69 with acute myocardial infarction treated with thrombolysis. MAIN OUTCOME MEASURES--All patients underwent exercise testing and coronary arteriography. ST depression induced by exercise was classified as either reciprocal (associated with ST elevation) or isolated (occurring on its own). The relation between reciprocal ST depression and the following end points was studied: characteristics of the infarct, left ventricular ejection fraction, extent of coronary artery disease on arteriography, and presence of angina induced by exercise. RESULTS--Reciprocal ST depression occurred almost exclusively in Q wave infarctions and was associated with a lower overall ejection fraction than isolated ST depression. It tended to be associated with persistent occlusion of the coronary artery related to the infarct and did not indicate remote ischaemia due to multivessel coronary disease. Unlike isolated ST depression, reciprocal ST depression was not associated with angina induced by exercise. CONCLUSIONS--Reciprocal ST depression induced by exercise is usually associated with extensive Q wave infarctions and persistent occlusion of the artery related to the infarct. It does not seem to indicate reversible ischaemia and should not be used as a non-invasive marker of multivessel disease in the assessment of requirements for further investigation soon after acute myocardial infarction.     

Early and long-term outcome of elective stenting of the infarct-related artery in patients with viability in the infarct-area: Rationale and design of the Viability-guided Angioplasty after acute Myocardial Infarction-trial (The VIAMI-trial)

BACKGROUND: Although percutaneous coronary intervention (PCI) is becoming the standard therapy in ST-segment elevation myocardial infarction (STEMI), to date most patients, even in developed countries, are reperfused with intravenous thrombolysis or do not receive a reperfusion therapy at all. In the post-lysis period these patients are at high risk for recurrent ischemic events. Early identification of these patients is mandatory as this subgroup could possibly benefit from an angioplasty of the infarct-related artery.Since viability seems to be related to ischemic adverse events, we initiated a clinical trial to investigate the benefits of PCI with stenting of the infarct-related artery in patients with viability detected early after acute myocardial infarction. METHODS: The VIAMI-study is designed as a prospective, multicenter, randomized, controlled clinical trial. Patients who are hospitalized with an acute myocardial infarction and who did not have primary or rescue PCI, undergo viability testing by low-dose dobutamine echocardiography (LDDE) within 3 days of admission. Consequently, patients with demonstrated viability are randomized to an invasive or conservative strategy. In the invasive strategy patients undergo coronary angiography with the intention to perform PCI with stenting of the infarct-related coronary artery and concomitant use of abciximab. In the conservative group an ischemia-guided approach is adopted (standard optimal care).The primary end point is the composite of death from any cause, reinfarction and unstable angina during a follow-up period of three years. CONCLUSION: The primary objective of the VIAMI-trial is to demonstrate that angioplasty of the infarct-related coronary artery with stenting and concomitant use of abciximab results in a clinically important risk reduction of future cardiac events in patients with viability in the infarct-area, detected early after myocardial infarction.     

Statin therapy for prevention and treatment of acute and chronic cardiovascular disease: update on recent trials and metaanalyses

PURPOSE OF REVIEW: To summarize the evidence from recent clinical trials and metaanalyses on the efficacy of statin therapy to reduce death, myocardial infarction and stroke, and to review the effects of statins in patients with low LDL cholesterol, diabetes, end-stage renal disease, and acute coronary syndrome. RECENT FINDINGS: In large metaanalyses of randomized controlled trials relative risk reductions from statins compared with placebo for patients with manifest or with risk factors for coronary artery disease were 13% for overall mortality, 26% for fatal and nonfatal myocardial infarction, and 18% for fatal and nonfatal stroke. Evidence from large trials suggests that patients with type II diabetes compared with patients without diabetes have similar risk reductions from statins for cardiovascular events, but this benefit is not seen in patients with diabetes and end-stage renal disease. In patients with acute coronary syndrome, early treatment with high-dose atorvastatin reduces cardiovascular morbidity after the first 4 months following the event, but the impact on mortality endpoints remains less clear. Results from recent trials in patients with stable coronary artery disease or type II diabetes suggest that statins provide benefit at considerable low LDL cholesterol levels. Therefore, target values for LDL cholesterol of less than 1.8 mmol/l (<70 mg/dl) should be considered for all patients with coronary artery disease or equivalent coronary risk. SUMMARY: For patients at high risk of coronary artery disease there is growing evidence for the concept of 'the lower, the better' regarding LDL cholesterol levels. Ongoing trials are further investigating the safety of lower target values in patients at various risk of coronary artery disease.     

Diagnosis of Coronary Heart Diseases Using Gene Expression Profiling; Stable Coronary Artery Disease,Cardiac Ischemia with and without Myocardial Necrosis

Cardiovascular disease (including coronary artery disease and myocardial infarction) is one of the leading causes of death in Europe, and is influenced by both environmental and genetic factors. With the recent advances in genomic tools and technologies there is potential to predict and diagnose heart disease using molecular data from analysis of blood cells. We analyzed gene expression data from blood samples taken from normal people (n = 21), non-significant coronary artery disease (n = 93), patients with unstable angina (n = 16), stable coronary artery disease (n = 14) and myocardial infarction (MI; n = 207). We used a feature selection approach to identify a set of gene expression variables which successfully differentiate different cardiovascular diseases. The initial features were discovered by fitting a linear model for each probe set across all arrays of normal individuals and patients with myocardial infarction. Three different feature optimisation algorithms were devised which identified two discriminating sets of genes, one using MI and normal controls (total genes = 6) and another one using MI and unstable angina patients (total genes = 7). In all our classification approaches we used a non-parametric k-nearest neighbour (KNN) classification method (k = 3). The results proved the diagnostic robustness of the final feature sets in discriminating patients with myocardial infarction from healthy controls. Interestingly it also showed efficacy in discriminating myocardial infarction patients from patients with clinical symptoms of cardiac ischemia but no myocardial necrosis or stable coronary artery disease, despite the influence of batch effects and different microarray gene chips and platforms.     

Anticoagulant Therapy in Coronary Artery Disease: A Therapeutic Enigma

The authors'' experience with anticoagulant therapy in both the acute phase and the long-term management of myocardial infarction has proved disappointing. A review of the literature has failed to establish benefit when all patients with coronary artery disease are treated with anticoagulant drugs. A need for well-controlled studies still exists.     

NEGATIVE TREADMILL EXERCISE TEST RESULT WITH SUBSEQUENT MYOCARDIAL INFARCTION AND CORONARY ARTERY BYPASS: CASE REPORT

Myocardial infarction is a rare complication of maximal exercise testing.(1) In the case presented here, infarction occurred in a 54-year-old man, 14 minutes after he showed a normal response to maximal multistage treadmill exercise testing. The presence of coronary artery disease had been documented angiographically prior to exercise testing. After infarction, the patient underwent emergency double aortocoronary bypass to the left anterior descending and right coronary arteries with good results. Clinical evidence suggests that the extent of myocardial necrosis was reduced by timely surgical intervention. There is no conclusive explanation for this patient's normal response to maximal exercise testing in the presence of advanced coronary artery occlusive disease followed rapidly by infarction. The value of exercise testing is well established in assessing the existence or severity of coronary artery disease; a normal response, however, cannot be used as an infallible indication that critical coronary artery disease does not exist.     

The glutathione peroxidase 1 (GPX1) single nucleotide polymorphism pro198Leu: association with life span and coronary artery disease

In this study we genotyped polymorphism in GPX1 Pro198Leu (C > T) rs 1050450 in four groups: patients with coronary artery disease, long-livers - above 90 years, early died peoples (before 55 years) from cardiovascular diseases and Russian population as control group. We have found significant higher allele T frequency in men with coronary artery disease -34.84% (Chi2 = 5.228, p = 0.022; OR = 1.46) and in early died men from cardiovascular diseases--38.16% (Chi2 = 6.461, p = 0.011; OR = 1.69) compared with control men--26.8%. Moreover, significantly higher genotype TT frequency has been shown in patients with coronary artery disease and myocardial infarction before age 50--19.44% in comparison with control group--7.28% (Chi2 = 9.55, p = 0.002). The TT frequency in long-livers (4.39%) was the lowest and significantly different from coronary artery disease group--12.79% (Chi2 = 8.07, p = 0.0045) and from coronary artery disease subgroup with myocardial infarction before 50--19.44% (Chi2 = 14.49, p = 0.0001). Thus our results indicate that allele T (Leu) of GPX1 Pro198Leu (C > T) polymorphism is unfavorable for successful ageing. It predisposes to coronary heart disease, earlier myocardial infarction (before age 50) and earlier death (before age 55).     

Diagnostic re-classification and prognostic risk stratification of patients with acute chest pain

Unstable angina and myocardial infarction are prevalent manifestations of acute coronary artery disease, combined in the term ‘acute coronary syndromes’. The introduction of sensitive markers for myocardial necrosis has led to confusion regarding the distinction between small myocardial infarctions and ‘true’ unstable angina, and the application of ever more sensitive markers has accelerated the pace at which patients with unstable angina are being re-classified to non-ST-segment elevation myocardial infarction. But in how many patients with acute chest pain is myocardial ischaemia really the cause of their symptoms? Numerous studies have shown that most have <5 ng/l high-sensitivity cardiac troponin, and that their prognosis is excellent (event rate <0.5% per year), incompatible with ‘impending infarction’. This marginalisation of patients with unstable angina pectoris should lead to the demise of this diagnosis. Without unstable angina, the usefulness of the term acute coronary syndromes may be questioned next. It is better to abandon the term altogether and revert to the original diagnosis of thrombus-related acute coronary artery disease, myocardial infarction. A national register should be the next logical step to monitor and guide the application of effective therapeutic measures and clinical outcomes in patients with myocardial infarction.

     

Clinical applications of assessments of myocardial substrate utilization with positron emission tomography

Summary Positron emission tomography (PET) permits sequential, noninvasive assessment of myocardial perfusion and metabolism. Based on the pattern of substrate use, clinical studies have utilized PET to define the location and extent of myocardial infarction, to identify areas of jeopardized but viable myocardium, and to assess the metabolic response of the myocardium to pharmacological therapy as well as to interventions such as coronary thrombolysis and coronary artery bypass surgery. The ability to noninvasively assess specific metabolic pathways should facilitate our understanding of normal myocardial metabolism, its perturbations with cardiac disease, and thereby improve the diagnosis and treatment of the biochemical processes underlying cardiac dysfunction.     

Specific features of the clinical course and angiographic pattern in chronic coronary artery occlusion

Particular features of coronary angiography and clinical presentation of coronary artery disease have been studied in patients with chronic total coronary occlusion. Chronic total coronary occlusion is defined as TIMI 0 or TIMI I type flow in the artery for more than three days. Patients with coronary occlusion have more severe course of coronary artery disease: they more often suffer myocardial infarction and high gradations of angina. Myocardial function is much more affected if there is occlusion of left descending artery, or there are no signs of intercoronary collaterals.     

纤维蛋白原与冠心病PCI介入治疗围术期心肌梗死的相关性

目的:探讨纤维蛋白原与冠心病介入治疗围术期心肌梗死的相关性。方法:2013年1月到2015年1月,选择在我院进行诊治的冠心病患者92例,都给予PCI介入手术治疗,在手术前后进行纤维蛋白原与心功能的测定,对围术期心肌梗死发生情况与临床资料进行调查与分析。结果:所有患者都介入手术治疗成功,术后LVESVI与LVEDVI值都明显低于术前(P0.05),而术后LVEF值明显高于术前(P0.05);术后患者的血浆纤维蛋白原值为3.66±0.42 g/L,明显低于术前的7.45±0.56 g/L(P0.05)。围手术期发生心肌梗死8例,发生率为8.7%。Spearman秩相关分析法结果显示心肌梗死发病与血浆纤维蛋白原、LVESVI、LVEDVI、LVEF值都存在明显相关性(P0.05),多元Logistic回归分析结果显示纤维蛋白原、LVESVI、LVEDVI、LVEF、年龄为导致冠心病围术期心肌梗死的主要危险因素(P0.05)。结论:介入手术治疗冠心病具有很好的效果,但是围术期心肌梗死的发生率比较高,纤维蛋白原能有效反应病变状况,在心肌梗死的发生发展中起着关键性作用。     

Myocardial infarction,hyperthyroidism and normal coronary arteries: report of two cases.

Myocardial infarction is uncommon in persons with hyperthyroidism and also uncommon in the absence of demonstrable coronary artery disease. Cardiac catheterization and selective coronary angiography were performed in two men following apparent myocardial infarctions. Both patients were 33 years of age, thyrotoxic and angiographically free of coronary artery abnormalities.     

Early exercise testing and coronary angiography after uncomplicated myocardial infarction.

In a prospective study 61 patients aged 55 years or less with uncomplicated myocardial infarction underwent treadmill stress testing at two weeks and coronary angiography at six weeks after infarction. Of the 44 patients who had a positive stress test, 43 had additional severe coronary artery disease confirmed by coronary angiography. Of the 17 patients who had a negative stress test for additional disease, coronary angiography identified only single-vessel disease in the infarct area in 15. The sensitivity of the stress test was 95% and the specificity 94%, though the number of patients in the study was small. Thus, exercise testing has considerable potential for the early identification of multiple-vessel disease in patients with uncomplicated myocardial infarction.     

急性心肌梗死患者冠状动脉病变严重性与脉压和脉压指数的关系

目的:探讨急性心肌梗死(AMI)患者冠状动脉病变严重程度与脉压和脉压指数的关系.方法:对185例AMI患者进行冠状动脉造影术,冠状动脉病变严重程度用冠状动脉病变支数和Gensini积分来表示,并测定收缩压(SBP)和舒张压(DBP)并计算脉压(PP)及脉压指数(PPI).结果:与脉压＜65mmHg的患者相比,脉压≥65mmHg的患者冠状动脉3支血管病变的患病率和Gensini积分显著增高(P＜0.01).与PPI＜0.500的患者相比,PPI≥0.500的患者冠状动脉3支血管病变的患病率和Gensini积分亦显著增高(P＜0.01).结论:PP和PPI与AMI患者冠状动脉病变程度密切相关,在临床上具有指导作用.     

Revascularization in the acute coronary syndromes

Coronary heart disease is the leading cause of death worldwide, and occurs when the coronary arteries are unable to supply adequate oxygenated blood to the myocardium, which in turn can lead to ischemia and infarction of myocardial tissue. There are three options for revascularization in the setting of acute coronary syndromes. In select patients, coronary artery bypass surgery remains an option. Thrombolytics were initially the mainstay of therapy, which has now shifted to angioplasty, with or without stents, when readily available. Revascularization has been demonstrated to improve patient outcomes, and has evolved rapidly in the recent past.