Differential effects of dual antiplatelet therapy in patients presented with acute coronary syndrome vs. stable ischaemic heart disease after coronary artery bypass grafting

Aims

The current study sought to evaluate whether long-term clinical outcomes according to the use of dual antiplatelet therapy (DAPT) or single antiplatelet therapy (SAPT) differed between acute coronary syndrome (ACS) and stable ischaemic heart disease (SIHD) patients who underwent coronary artery bypass grafting surgery (CABG).

Methods and results

Between January 2001 and December 2017, 3199 patients with ACS (55.3%) and 2583 with SIHD (44.7%) who underwent isolated CABG were enrolled. The study population was stratified using DAPT or SAPT in ACS patients and SIHD patients. The primary outcome was a cardiovascular death or myocardial infarction (MI) at 5 years. After CABG, DAPT was more frequently used in patients with ACS than in those with SIHD [n = 1960 (61.3%) vs. n = 1313 (50.8%), P < 0.001]. Among patients with ACS, the DAPT group showed a significantly lower risk of cardiovascular death or MI at 5 years than the SAPT group [DAPT vs. SAPT, 4.0% vs. 7.8%, hazard ratio (HR) 0.521, 95% confidence interval (CI) 0.339–0.799; P = 0.003]. In contrast, among patients with SIHD, there was no significant difference in the rate of cardiovascular death or MI at 5 years between the use of DAPT and SAPT (4.0% vs. 4.0%, HR 0.991, 95% CI 0.604–1.626; P = 0.971). These findings were robust to multiple sensitivity analyses and competing risk analysis. In the subgroup analysis, the use of DAPT was associated with a significantly lower risk of cardiovascular death or MI among SIHD patients with a previous percutaneous coronary intervention (PCI), with a significant interaction between the use of DAPT and PCI history (interaction P = 0.011).

Conclusion

Among ACS patients who underwent CABG, the use of DAPT was associated with lower cardiovascular death or MI than the use of SAPT, but this was not the case in SIHD patients.

Trial registration

ClinicalTrials.gov, NCT03870815.