Fibrinolytic treatment for elderly patients with acute myocardial infarction

Fibrinolytic treatment is the standard of care for eligible patients presenting early with acute ST segment elevation myocardial infarction (MI) to hospitals where rapid triage to primary angioplasty is unavailable. Although fibrinolytic treatment of elderly patients is generally accepted,(1) a recent paper raised questions about its safety and efficacy. In this editorial, we will review the relevant studies and provide perspective on this controversy. The observational study by Thiemann and colleagues was conducted using the Cooperative Cardiovascular Project (CCP) database of 210 996 patients treated for acute myocardial infarction during February 1994 and July 1995.(2) Patients were excluded if they had absolute contraindications to fibrinolytic treatment, left bundle branch block (LBBB), were admitted to hospitals with on-site angioplasty, transferred between hospitals or had other potential confounders for the administration of fibrinolytics. Patients > 86 years of age (6156 patients) and those not receiving aspirin and/or heparin were also excluded. The final cohort consisted of 7864 patients, 48% of eligible patients aged 65 to 75 years, and 34% of eligible patients aged 76 to 86. Greater than 70% of patients in both groups received tissue plasminogen activator (t-PA) as the fibrinolytic agent, and all patients received aspirin and heparin. Among patients 65 to 75 years old the 30 day crude mortality rates were 6.8% for patients treated with fibrinolytic therapy compared to 9.8% in the control group. However, among patients > 75 years of age, the 30 day crude mortality rate was 18.0% with fibrinolytic treatment versus 15.4% without treatment, resulting in a mortality hazard ratio of 1.38. Thiemann and colleagues concluded that in a nationwide clinical practice, flbrinolytic treatment for patients > 75 years of age is unlikely to confer survival benefit, and may have a significant survival disadvantage. How should we interpret the data which clearly contradicts previous randomised clinical trials, and a published meta-analysis supporting benefit among elderly patients? Does our current fibrinolytic strategy put certain groups of patients at increased risk?