Use of reperfusion therapies in elderly patients with acute myocardial infarction

Almost one-third of patients with acute myocardial infarction (AMI) are aged > 75 years, and this proportion is expected to increase as the population ages. Mortality and complication rates are particularly high in the elderly, yet reperfusion therapies, including thrombolysis and primary percutaneous transluminal coronary angioplasty (PTCA), are under-utilised among eligible patients. There is a concern, whether real or perceived, that the risks of such therapies may outweigh the potential benefits. Presently, there are no randomised clinical trials of thrombolytic therapy in the elderly that definitively assess its efficacy in patients aged > 75 years. In the meta-analysis of randomised trials by the Fibrinolytic Therapy Trialists, thrombolysis was associated with a mortality reduction among patients aged > 75 years, though this reduction did not meet formal statistical significance. Because the point estimates for mortality reduction were in the direction that favoured use of thrombolytic therapy, the American Heart Association/American College of Cardiology AMI guidelines recommend thrombolysis as a Class 2a therapy in this age group. Observational studies using data from the Cooperative Cardiovascular Project database and the National Registry of Myocardial Infarction have recently cast some doubt on the benefit of thrombolysis among the elderly, but definitive answers from a randomised trial are still lacking. Meanwhile, primary PTCA, which has been compared to thrombolysis in both trial and observational settings, appears to offer the mortality benefit of reperfusion with lower stroke rates. Since primary PTCA is not widely available, efforts must be made to maximise available therapies in the elderly. Early diagnosis is essential, as is prompt reperfusion among eligible patients, since delay is so strongly associated with mortality with both thrombolysis and PTCA. Finally, newer, more fibrin-specific thrombolytics may decrease the bleeding risk associated with thrombolytic therapy.