Abstract
BACKGROUND: East Asians have shown different risk profiles for both thrombophilia and bleeding than Western counterparts. OBJECTIVES: The authors sought to evaluate the effect of low-dose aspirin for primary prevention between these populations. METHODS: We searched randomized clinical trials (RCTs) for intervention with low-dose aspirin (≤100 mg once daily) in participants without symptomatic cardiovascular disease until December 31, 2021. The number of events between the arms was extracted for analysis. Pooled risk ratios (RRs) and risk differences (RDs) were analyzed in each population. Outcomes included a major adverse cardiovascular event (MACE), cardiovascular death, myocardial infarction, stroke, and major bleeding (intracranial hemorrhage and major gastrointestinal bleeding). RESULTS: Two RCTs included 17,003 East Asians, and 9 RCTs had 117,467 Western participants. Aspirin treatment showed a similar effect in reducing the MACE rate (RR of East Asians: 0.87; 95% CI: 0.71-1.05; RR of Westerners: 0.90; 95% CI: 0.85-0.95) (P(interaction) = 0.721). In contrast, the risk of major bleeding during aspirin vs control was greater in the East Asian population (RR: 2.48; 95% CI: 1.86-3.30) compared with the Western population (RR: 1.45; 95% CI: 1.26-1.66) (P(interaction) = 0.001), which was driven by more frequent gastrointestinal bleeding (RR of East Asians: 3.29; 95% CI: 2.26-4.80 vs RR of Westerners: 1.56; 95% CI: 1.29-1.88) (P(interaction) < 0.001). The net RDs (RD of MACE plus RD of major bleeding) were 8.04 and 0.72 per 1,000 persons in East Asian and Western participants, indicating 124 and 1,389 of the net number needed to harm, respectively. CONCLUSIONS: Low-dose aspirin for primary prevention in East Asians must be cautiously prescribed because of the increased risk of major bleeding relative to Western counterparts.