Clinical impact of dyspnoea after ticagrelor treatment and the effect of switching to clopidogrel in patients with myocardial infarction.

Abstract

BACKGROUND Dyspnoea is frequent during ticagrelor-based dual antiplatelet therapy (DAPT) for acute myocardial infarction (AMI). However, its clinical characteristics or management strategy remains uncertain. METHODS The study assessed 2,617 AMI patients from the Ticagrelor versus Clopidogrel in Stabilized Patients with AMI (TALOS-AMI) trial. Dyspnoea during 1-month ticagrelor-based DAPT and following DAPT strategies with continued ticagrelor or de-escalation to clopidogrel from 1 to 12 months were evaluated for drug adherence, subsequent dyspnoea, major adverse cardiovascular events (MACE), and bleeding events. RESULTS Dyspnoea was reported by 538 patients (20.6%) during 1 month of ticagrelor-based DAPT. Adherence to allocated DAPT over the study period was lower in the continued ticagrelor arm than the de-escalation to clopidogrel, particularly among the dyspnoeic population (81.1% vs. 91.5%, p<0.001). Among ticagrelor-treated patients with dyspnoea, those switched to clopidogrel at 1 month had a lower frequency of dyspnoea at 3 months (34.3 vs. 51.7%, p<0.001) and 6 months (25.5% vs. 38.4%, p=0.002) than those continued with ticagrelor. In patients with dyspnoea in their 1-month ticagrelor-based DAPT, de-escalation was not associated with increased MACE (1.3% vs. 3.9%, hazard ratio [HR] 0.31, 95% confidence interval [CI] =0.08-1.11, p=0.07) or clinically relevant bleeding (3.2% vs. 6.2%, HR 0.51, 95% CI 0.22-1.19, p=0.12) at 1 year. CONCLUSIONS Dyspnoea is a common side effect among ticagrelor-based DAPT in AMI patients. Switching from ticagrelor to clopidogrel after 1 month in AMI patients may provide a reasonable option to alleviate subsequent dyspnoea in ticagrelor-relevant dyspnoeic patients, without increasing the risk of ischaemic events (NCT02018055).