Extended use of dual antiplatelet therapy among older adults with acute coronary syndromes and associated variables: a cohort study

BACKGROUND: Current guidelines recommend extending the use of dual antiplatelet therapy (DAPT) beyond 1 year in patients with an acute coronary syndrome (ACS) and a high risk of ischaemia and low risk of bleeding. No data exist about the implementation of this strategy in older adults from routine clinical practice. METHODS: We conducted a Spanish multicentre, retrospective, observational registry-based study that included patients with ACS but no thrombotic or bleeding events during the first year of DAPT after discharge and no indication for oral anticoagulants. High bleeding risk was defined according to the Academic Research Consortium definition. We assessed the proportion of cases of extended DAPT among patients 65 ≥ years that went beyond 1 year after hospitalisation for ACS and the variables associated with the strategy. RESULTS: We found that 48.1% (928/1,928) of patients were aged ≥ 65 years. DAPT was continued beyond 1 year in 32.1% (298/928) of patients ≥ 65; which was a similar proportion as with their younger counterparts. There was no significant correlation between a high bleeding risk and DAPT duration. Contrastingly, there was a strong correlation between the extent of coronary disease and DAPT duration (p < 0.001). Other variables associated with extended DAPT were a higher left ventricle ejection fraction, a history of heart failure and a prior stent thrombosis. CONCLUSION: There was no correlation between age and extended use of DAPT beyond 1 year in older patients with ACS. DAPT was extended in about one-third of patients ≥ 65 years. The severity of the coronary disease, prior heart failure, left ventricle ejection fraction and prior stent thrombosis all correlated with extended DAPT.