Abstract 15944: Aspirin Use for Primary Prevention in High-Risk Patients: Insights From a Large Healthcare Network

Abstract

Background: Recently, the value of routine use of aspirin in primary prevention for atherosclerotic cardiovascular disease (ASCVD) has come into question. We investigated patients with a high 10-year ASCVD risk profile to evaluate the magnitude of protection afforded by aspirin with and without statin in prevention of ASCVD events. Methods: Primary prevention patients were stratified based on 10-year ASCVD risk (High [20%]). Aspirin use was categorized over the 6-year follow-up period as “None”, “seldom” (<30% of follow up time), “sometimes” (>30 to =<70%), and often used (≥70% of the time). Cox regression models were used to assess HRs of MI, ischemic stroke and mortality with aspirin or statin use alone compared to a combination of aspirin and statin. Results: 69,955 patients qualified as “high” 10-year ASCVD risk. In fully adjusted models, aspirin use ≥ 30% was associated with significantly lower risk of MI [HR ASA use ≥ 70% 0.76 (0.72-0.80), p <0.001], ischemic stroke [HR ASA use ≥ 70% 0.83 (0.77-0.90), p <0.007], and mortality [HR ASA use ≥ 70% 0.78 (0.74-0.82), p <0.001] in high-risk patients compared to no aspirin use ( Table ). Compared to patients on both a statin and aspirin, patients on statin alone had increased risk of MI [HR 1.30 (1.06-1.60), p = 0.013]. Patients on aspirin alone had increased risk of MI [HR 1.74 (1.34-2.26), p <0.001] and mortality [HR 1.70 (1.27-2.28), p < 0.0004] versus those on aspirin and statin. Patients not on any aspirin or statin were at significantly increased risk for MI [HR 2.28 (2.08-2.49), p<0.001], ischemic stroke [HR 1.77 (1.56-2.00), p<0.001), and mortality [HR 2.16 (1.60-2.90), p<0.001] compared to those taking both aspirin and statin. Conclusions: Low dose aspirin may still have a role in primary prevention of ASCVD events amongst high-risk patients when added to statin therapy. Risk-benefit profile of each high-risk primary prevention patient should be assessed for initiating or discontinuing low dose aspirin therapy