1 Department of Health Science and Technology, The Faculty of Medicine, Aalborg University, VBN2 Public Health and Epidemiology Group, The Faculty of Medicine, Aalborg University, VBN3 The Faculty of Medicine, Aalborg University, VBN4 unknown
BACKGROUND: Dual anti-platelet treatment with clopidogrel and aspirin is indicated for most patients after myocardial infarction. We examined the risk/benefit relationship of dual anti-platelet treatment according to age in a nationwide cohort of 30,532 myocardial infarction patients without revascularization. METHODS: Patients admitted with first-time myocardial infarction in 2002-2010, not undergoing revascularization, were identified from nationwide Danish registers. Dual anti-platelet treatment use was assessed by claimed prescriptions. Stratified into age groups, risk of bleeding, all-cause mortality and a combined endpoint of cardiovascular death, recurrent myocardial infarction and ischaemic stroke was analysed by Cox proportional-hazard models and tested in a propensity-score matched population. RESULTS: A total of 21,302 users and 9230 non-users of dual anti-platelet treatment were included (mean age 67.02 (±13.8) years and 64.7% males). Use of dual anti-platelet treatment decreased with age: 80% (<60 years), 76% (60-69 years), 66% (70-79 years) and 52% (>79 years). We found a reduced risk of cardiovascular death, recurrent myocardial infarction and ischaemic stroke in users <60 years (Hazard ratio (HR) =0.69; 95% confidence interval (CI) 0.59-0.80), 60-69 years (HR=0.64; 95% CI 0.56-0.73), 70-79 years (HR=0.80; 95% CI 0.72-0.89) and >79 years (HR=0.92; 95% CI 0.84-1.01, NS). Risk of bleeding increased with dual anti-platelet treatment use in patients aged <60 years (HR=1.63; 95% CI 1.17-2.26), 60-69 years (HR=1.22; 95% CI 0.97-1.59, NS), 70-79 years (HR=1.42; 95% CI 1.17-1.72) and >79 years (HR=1.46; 95% CI 1.22-1.74). Similar tendencies in all four age groups were found in the propensity-matched population. CONCLUSION: Dual anti-platelet treatment use was less likely among elderly patients although similar effects regarding both risk and benefit were found in all age groups. Increased focus on initiating dual anti-platelet treatment in elderly, non-invasively treated myocardial infarction patients is warranted.
European Heart Journal : Acute Cardiovascular Care, 2016