Systematic review of the clinical impact of dual antiplatelet therapy discontinuation after acute coronary syndromes

Aims: The aim of this systematic literature review was to assess the consequences of dual antiplatelet therapy discontinuation on clinical outcomes after acute coronary syndromes.Methods and results: A systematic literature search was conducted in PubMed to identify studies reporting data on patients who discontinued dual antiplatelet therapy (planned or unplanned) following acute coronary syndromes and on the clinical impact of dual antiplatelet therapy discontinuation. To be included, more than 50% of the study population had to have had acute coronary syndrome as their index event or, if less than 50%, outcomes data must have been reported separately for the group with acute coronary syndromes. Thirty publications covering 29 studies were identified for inclusion. There was much heterogeneity across studies regarding the included patient populations, treatment durations and outcome definitions and ascertainments. Dual antiplatelet therapy discontinuation was most commonly based on physician decision. Twenty-six studies reported that clopidogrel was prescribed as part of dual antiplatelet therapy. Dual antiplatelet therapy duration was positively associated with a lower risk of all-cause mortality (seven/eight studies), cardiovascular mortality (two/two studies), non-fatal myocardial infarction (two/three studies) and stent thrombosis (five/five studies) in patients and/or patient subgroups in studies without randomised treatment designs, although such associations were not observed in the one study that randomly assigned patients to treatment (i.e. planned discontinuation).Conclusions: Results from our systematic literature review generally support the benefit of longer-term dual antiplatelet therapy after acute coronary syndromes; however, further research is needed to determine the optimal length of dual antiplatelet therapy in patients after acute coronary syndrome, ideally using prospective studies.