Efficacy and safety of buffered and enteric-coated forms of acetylsalicylic acid in patients with stable coronary artery disease: results of the observational retrospective study PARADIGM

Objective: Comparative assessment of the efficacy and safety of two forms (75 mg/day gastro-soluble buffered and 100 mg/day enteric-coated) of acetylsalicylic acid (ASA) in patients with stable coronary artery disease (CAD) and determination of the impact of these forms on the incidence of cardiovascular complications (CVC), bleeding, and other gastrointestinal (GI) adverse events, as well as treatment adherence.

Materials and methods: This observational, retrospective, single-center, non-interventional study included 2,112 patients of both sexes with stable CAD. Of these, 1166 (55.21%) were in the group receiving the gastro-soluble form of ASA and 946 (44.79%) were in the group of patients taking the enteric-coated form. To reduce the risk of systematic error and increase the reliability of the results, pseudo-randomization was performed using the «nearest neighbor» pair selection method based on the PSM (Propensity Score Matching) index for 8 characteristics (gender, age, arterial hypertension (AH), history of myocardial infarction (MI), percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), type 2 diabetes mellitus (DM2), chronic kidney disease (CKD)). Two clinically comparable groups were formed: 829 patients receiving the enteric-coated form of ASA and 829 patients taking the gastro-soluble buffered form of ASA. The primary composite efficacy endpoint included the incidence of MI, stroke, transient ischemic attack (TIA), unstable angina (UA), and cardiovascular death. Secondary efficacy endpoints included the incidence of rehospitalization and myocardial revascularization. Safety outcomes included the incidence of bleeding according to the BARC scale, hemorrhagic stroke, and erosive and ulcerative esophageal, gastric, and duodenal ulcers. Adherence to therapy was assessed using the Morisky-Green scale.

Results: In the group taking the gastro-soluble form of ASA (Cardiomagnyl 75 mg/day), the incidence of vascular events was 44% lower than among patients taking enteric-coated forms (4.34% vs. 7.70%; odds ratio (OR) = 0.56; 95% confidence interval (CI): 0.38–0.82; p=0.004). Duodenal erosion was more common among those taking enteric-coated forms (3.3% vs. 0.5%; 95% CI: 1.87–4.34 and 0.16–1.12, p< 0.001). The same was true for minor bleeding grades 1–2 according to BARC (0.1% vs. 1.1%; 95% CI: 0.04–0.73 and 0.53–2.10, p=0.011). The readmission rate was also higher in the enteric-coated ASA group (18.8% vs. 26.4%; 95% CI: 15.97–21.08 and 21.12–27.39, p< 0.001). No significant differences were found in the adherence assessment.

Conclusion: In real-world clinical practice, administration of the gastro-soluble, buffered ASA (Cardiomagnyl) is associated with significant advantages in terms of efficacy and safety compared to the enteric-coated form.