Dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ receptor inhibitor is the standard treatment for acute coronary syndrome (ACS).¹Wang D et al. BMC Cardiovasc Disord. 2018;18. Clopidogrel and ticagrelor are both P2Y₁₂ receptor antagonists.²Shand JA et al. Biomark Med. 2011;5(1):53-62. Clopidogrel is an irreversible antagonist with a variable degree of platelet inhibition within the population, whereas ticagrelor is an orally active reversibly binding inhibitor with rapid onset of induced platelet aggregation.²Shand JA et al. Biomark Med. 2011;5(1):53-62. Ticagrelor was studied in a large, multicentre, randomised, double-blind PLATO trial, and showed a 16% relative risk reduction in composite cardiovascular death, myocardial infarction (MI), or stroke compared to clopidogrel.²Shand JA et al. Biomark Med. 2011;5(1):53-62.

However, recent analysis of the SWEDEHEART Registry, has indicated that ticagrelor use among elderly MI patients was associated with a higher risk of bleeding and death than with clopidogrel.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 The results were recently published in Circulation.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645

SWEDEHEART is a nationwide registry in Sweden that includes all consecutive patients admitted to a coronary care unit with symptoms that suggest ACS.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 Variables including baseline patient characteristics, medication on admission, in-hospital therapies, complications, and discharge medicines are collected.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 Inverse probability treatment weighting (IPTW) was used in analysis to reduce selection bias as treatments were not randomly assigned.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 The registry was used to compare clinical outcomes with ticagrelor versus clopidogrel among MI patients aged ≥80.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645

Of the 14,005 patients aged ≥80 who survived until discharge after an MI, 31.6% had a ST-segment elevation MI (STEMI) and 68.4% had a non-ST segment elevation MI (NSTEMI).³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 The majority (60.2%) were prescribed clopidogrel, and 39.8% were prescribed ticagrelor.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 Patients who received ticagrelor were younger and had fewer comorbidities at presentation.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 After Inverse Probability of Treatment Weighting (IPTW) adjustment, baseline characteristics were balanced.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645

The unadjusted analysis showed that patients treated with ticagrelor had significantly fewer combined ischaemic events or combined ischaemic/bleeding events.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 However, after IPTW Cox regression there was no significant reduction in combined ischaemic or combined ischaemic/bleeding endpoints with ticagrelor compared with clopidogrel treatment.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 Ticagrelor-treated patients had a 20% and 28% lower risk of new MI or stroke, respectively, compared with clopidogrel patients within one year.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 However, patients receiving ticagrelor had a 17% higher risk of dying and a 48% higher risk of re-admission due to a bleeding event than those treated with clopidogrel.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 In patients younger than 80 years, there was an 18% lower risk of MI, 18% lower risk of stroke, and a 15% lower risk of death, but 32% higher risk of bleeding events.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645

The results of this analysis indicate that current guideline recommendations should be applied with caution to the elderly population.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 There has been significant uptake in ticagrelor use over the study period, and nearly three quarters of all elderly patients at the end of 2017 were prescribed ticagrelor at discharger after a MI.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645 Thus, there is a need for a randomised controlled study to examine the effects of antiplatelet medications in the elderly population.³Szummer Karolina et al. Circulation. doi: 10.1161/CIRCULATIONAHA.120.050645