Update on mechanical intervention in acute myocardial infarction

The role of pharmacologic interventions in acute myocardial infarction (i.e., a combination of intravenous nitroglycerin, intravenous β-blocker, oral aspirin, and intravenous thrombolysis), has become more standardized, whereas the role of mechanical intervention remains to be defined. Mechanical intervention includes percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting. The number of carefully controlled, randomized trials is limited, particularly with surgery. Nevertheless, in optimal circumstances, when performed within the first few hours of myocardial infarction, surgery can be beneficial in reducing mortality, especially with anterior location of infarct. Surgery may not prevent reinfarction. However, the results of nonrandomized surgical trials done 10 years ago are difficult to compare with modern-day treatment of myocardial infarction with the availability of new agents and PTCA. Angioplasty can be performed safely in the acute phase of myocardial infarction but may not be the ideal choice for all patients. The results may be more optimal if performed when the patient is stable. Clinical factors associated with favorable and unfavorable outcomes have been identified. Mortality is not significantly affected by early versus late PTCA. Certain selected patients benefit from PTCA, particularly those in cardiogenic shock, in whom PTCA has made a dramatic improvement in outcome. To achieve maximal benefit, intervention should be performed early, within the first hours of symptoms. Further well-designed studies may help clarify the role mechanical techniques will play in future combinations of interventional therapy.