The influence of low (81 mg) versus high (325 mg) doses of ASA on the incidence of sirolimus-eluting stent thrombosis

Abstract

Background: Conflicting opinion exists regarding the optimal dose of acetyl salicylic acid (ASA) to be given after percutaneous coronary intervention (PCI) with drug-eluting stents (DES). We sought to evaluate the influence of ASA dose on the incidence of unexplained subacute and late stent thrombosis in the era of DES.

Methods: We performed a retrospective analysis of the incidence of subacute and late stent thrombosis in our patient population over a 2-year period. The analysis was limited to patients being discharged and maintained on a daily ASA dose of either 81 mg or 325 mg and having received at least 1 sirolimus-eluting stent.

Results: During the study period, 1,093 patients (1,807 separate PCI procedures) met the inclusion criteria. The incidence of unexplained subacute and late stent thrombosis was 1.1% in the study population (12 out of 1,093 patients). When considering the total number of individual procedures performed on the study population during the study period (1,807 procedures), the incidence of unexplained subacute or late stent thrombosis was 0.7%. Six were subacute and 6 were late thrombosis. No significant difference was observed in the incidence of stent thrombosis between the 2 ASA dose groups. Seven patients had stent thrombosis in the 81 mg group (1.2% of 583 patients), while 5 had thrombosis in the 325 mg group (1% of 510 patients); p = 0.727.

Conclusion: In conclusion, we found no significant difference in the incidence of unexplained subacute or late stent thrombosis with the use of an 81 mg versus 325 mg dose of aspirin post-PCI with sirolimus-eluting stents.