Contemporary percutaneous reperfusion therapy for acute myocardial infarction in the elderly

Elderly patients with acute myocardial infarction have not been specifically studied in the context of a large randomized clinical trial. Estimates of the efficacy of available treatments are gleaned from subset analyses of clinical trials, retrospective analysis and single center experiences. In western countries the population is aging and a disproportionate number of myocardial infarctions occur in the elderly. Usage of appropriate therapy in this age group is becoming increasingly important given the potential for benefit but also the potential for harm. Recent publications have found steady improvement in outcomes in the elderly population utilizing contemporary interventions. (J Geriatr Cardiol 2005;2(1) :48-53).     

Does reperfusion therapy reduce complications in acute inferior myocardial infarction?

Both right ventricular infarction and complete atrioventricular block were frequently seen in patients with acute inferior myocardial infarction before the introduction of reperfusion therapy (RT). However, the effect of reperfusion therapy on these 2 complications is not well known. To evaluate the effect of reperfusion therapy in them, we retrospectively studied the in-hospital outcome of 103 consecutive patients with acute inferior myocardial infarction within 72 hr after the onset, 23 with right ventricular infarction and 36 with complete atrioventricular block. Patients were divided into 2 groups: RT group (n = 63) in which Thrombolysis in Myocardial Infarction (TIMI) III flow was obtained by reperfusion therapy within 24 hr after the onset, and the non-RT group (n = 40) in which TIMI III flow was not obtained or did not receive reperfusion therapy. Patients with right ventricular infarction in the RT group had a larger proportion of proximal occlusion of the right coronary artery and the absence of preinfarction angina. There were no effects of perfusion on complete atrioventricular block. In 23 patients with right ventricular infarction and 36 patients with complete atrioventricular block, in-hospital stay, duration of using temporary pacing and Swan-Ganz catheter were shorter in the RT group than the non-RT group. Reperfusion therapy does not decrease the incidence of both complications. However, successful reperfusion therapy results in a rapid improvement in hemodynamic instability and atrioventricular conduction injury, and early hospital discharge. Preinfarction angina may be associated with a protective effect against the development of these 2 complications.     

Reperfusion arrhythmias: are they only a marker of epicardial reperfusion or continuing myocardial ischemia after acute myocardial infarction?

Reperfusion arrhythmias are associated with epicardial reperfusion but may also be a sign of vascular reperfusion injury which can be seen as no-reflow phenomenon on coronary angiography and predicts in-hospital complications and recovery of left ventricular (LV) function. No-reflow phenomenon (thrombolysis in myocardial infarction [TIMI] 相似文献   

Combination thrombolytic therapy and percutaneous coronary intervention: the future for revascularisation for acute myocardial infarction?

It seems theoretically sound to consider rescue percutaneous coronary intervention (PCI) in patients with failed thrombolysis. However, randomised controlled data in this setting are limited. In this brief review we will present those trials analysing the role of rescue PCI in patients with acute myocardial infarction and failed thrombolysis, and consider appropriate management strategies in this setting.     

Metabolically controlled reperfusion in acute myocardial infarction: should the polarizing solution be given subselectively?

BACKGROUND: In working rat hearts, metabolic support of injured tissue enhances recovery after acute myocardial infarction. Clinical experience with a systemic "polarizing solution" supports this claim. OBJECTIVES: In a dog model of ischemia/reperfusion, we tested the feasibility of subselectively supplying adapted metabolic substrates before instituting blood reperfusion. METHODS: Thirty-five dogs underwent ligation of the proximal left anterior descending artery and collaterals for 90 minutes. The animals were randomly assigned to receive direct blood reperfusion (Group I), intracoronary glucose, insulin, and potassium (Group II), or intracoronary glucose, insulin, and potassium plus propionyl-L-carnitine (PLC) (Group III). After 30 minutes of artificial reperfusion, prograde blood flow was resumed in groups II and III. A routine necropsy was performed 3 to 5 days later. Primary endpoints were severe arrhythmias, death, markers of infarct size, and specific histologic features. RESULTS: We excluded 4 dogs for technical reasons and 2 others for preexisting cardiomyopathy. In the remaining 29 animals, large apical infarctions were documented ventriculographically during arterial ligation. One dog died of irreversible ventricular fibrillation during the initial ischemic period, and 9/28 dogs (32.1%) died during early reperfusion. Ventricular fibrillation was more common with 10% (versus 5%) dextrose concentrations and was eliminated by PLC. Irreversibly injured (versus jeopardized) areas of myocardium were more common in Group III (85.9 19.3%) than in Groups I and II (16.9 10.8%). CONCLUSION: Subselective infusion of metabolically supportive solutions during acute myocardial infarction is technically feasible. To prevent osmotic endothelial damage, the perfusate must have a low (< 5%) dextrose content.     

Acute myocardial infarction: what is new?

Current recommendations on the management of acute myocardial infarction and the use of thrombolysis are reviewed.     

Cellular cardiomyoplasty in acute myocardial infarction: where are we now?

Cellular cardiomyoplasty is an investigational technique that may have the potential to reduce myocardial infarct size and improve cardiac function in patients with ischemic heart disease. However, experience with this approach is still limited to a few small trials, some of which were not blinded or had other design problems. The mechanism of benefit, long-term safety, and clinical efficacy of cellular cardiomyoplasty require further study.     

Glycometabolic status and acute myocardial infarction: has the time come for glucose-insulin-(potassium) therapy?

Abstract
Glucose-insulin-potassium infusion as a metabolic therapy was first advocated for the management of acute myocardial infarction (AMI) in 1960s. Over the subsequent decades, enthusiasm for its use has been patchy, especially with the availability of other effective treatments such as reperfusion therapy for AMI. Several clinical studies in the mid-1990s revived the interest in the glycometabolic aspects of patients with AMI. The somewhat conflicting results of these recent studies have generated debate over the significance of the glycometabolic state following acute coronary occlusion and the role of insulin-based infusion therapy. Although most of the available evidence is in favour of an insulin-based therapy, there are still many aspects of this therapy that require clarification. More evidence will be required from further clinical trials before it is adopted in routine clinical practice. (Intern Med J 2003; 33: 443−449)     

Stem cell therapy for myocardial infarction: are we missing time?

The success of stem cell therapy in myocardial infarction (MI) is modest, and for stem cell therapy to be clinically effective fine-tuning in regard to timing, dosing, and the route of administration is required. Experimental studies suggest the existence of a temporal window of opportunity bound by the acute inflammatory response on one hand and by scar formation on the other. In the meantime, microenvironmental factors must favor stem cell homing, survival, differentiation, and integration for stem cell therapy to be effective. Clinical data on the optimal timing of treatment are scarce. Experimental studies and clinical subgroup analyses can provide a clue and useful guidance for further research. In this review, the fundamental mechanisms as well as trial results important for the determination of the optimal timing of stem cell therapy following MI are summarized and discussed. We conclude that optimization of stem cell therapy requires further research on the fundamental mechanisms responsible for stem cell homing, survival, differentiation, and integration. Clinically, randomized trials with bone-marrow-derived stem cells should be conducted timing therapy at different points within the first month after MI, which seems to be the most promising period for this cell type.