Efficacy and Safety of Aspirin-free versus Aspirin-based Strategies in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

Abstract: Aspirin (ASA) is the cornerstone of the acute coronary syndrome primary and secondary prevention. Still, its role is debated in some high bleeding risk patients or cases that underwent second-generation drug-eluting stents with a better scaffold. This study compared the efficacy and safety of aspirin-free versus aspirin-based strategies in patients with ACS undergoing PCI. We systematically searched PubMed, Embase, Scopus, and ScienceDirect for studies comparing aspirin-based versus aspirin-free strategies in patients with ACS undergoing PCI. Pooled relative risk (RR) with 95% CI was calculated using a fixed effects model or a random effects model if heterogeneity was present. Significance was set at P < 0.05. Thirty studies including 207,938 patients (N = 104,062 in the ASA arm, and 103,876 in the ASA-free arm) were included in this study. There was a statistically significant reduction in risk of all-cause mortality RR 0.93, 95% CI, 0.87–0.99, P -value = 0.024, I 2 = 0%, BARC 2–5 RR = 0.68, 95% CI, 0.58–0.81, P -value = <0.01, I 2 = 0%, BARC 3 or 5 RR= 0.71, 95% CI, 0.60–0.82, P -value= <0.01, I 2 = 0%, TIMI major bleeding RR = 0.66, 95% CI, 0.50–0.86, P -value= 0.02, I 2 = 0%, TIMI minor or major bleeding RR= 0.61, 95% CI, 0.52–0.72, P -value= <0.01, I 2 = 0%, and ISTH major bleeding with aspirin-free strategy RR= 0.52, 95% CI, 0.42–0.64, P -value= <0.001, I 2 = 0%. Other secondary outcomes showed statistically nonsignificant results. The aspirin-free strategy showed lower all-cause mortality and bleeding, supporting its efficacy and safety in high bleeding risk patients.