Enteric-Coated vs. Uncoated Aspirin: Balancing Effectiveness and Safety in CVD Prevention

 A recent secondary analysis of the ADAPTABLE (Aspirin Dosing: A Patient-Centric Trial Assessing Benefits and Long-term Effectiveness) trial clarified that enteric-coated aspirin is not superior over uncoated aspirin in terms of safety and effectiveness nor it confers any substantial advantage in terms of bleeding risk. 

The study was published in the journal JAMA Cardiology. 

In the intricate realm of cardiovascular health, aspirin has long been a trusted ally, aiding in the prevention of heart attacks and strokes. For years, clinicians have recommended enteric-coated aspirin to mitigate gastrointestinal bleeding risks in patients with coronary artery disease. However, questions have lingered about whether this formulation compromises the effectiveness of the drug. Hence researchers conducted a post hoc secondary analysis of the ADAPTABLE trial to assess whether receipt of enteric-coated vs uncoated aspirin is associated with effectiveness or safety outcomes. 

The ADAPTABLE study, a meticulous analysis involving 15,076 patients with atherosclerotic cardiovascular disease, delved into the realm of aspirin formulations. Specifically,  this study investigated the effects of enteric-coated versus uncoated aspirin on both the effectiveness and safety of the medication. For years, clinicians have leaned towards enteric-coated aspirin to mitigate gastrointestinal bleeding risks. However, the study's findings challenged this practice, sparking significant discussions in the medical community.

Participants were regrouped based on their self-reported aspirin formulations at baseline. Enteric-coated aspirin, traditionally believed to decrease gastrointestinal bleeding risks, was compared directly with its uncoated counterpart. The primary effectiveness endpoint was the cumulative incidence of the composite of myocardial infarction, stroke, or death from any cause, and the primary safety endpoint was major bleeding events. Additionally, the analysis explored the impact of aspirin dosage, comparing high (325 mg) and low (81 mg) daily doses. 

Key findings: 

• Among the total participants, 69.0% took enteric-coated aspirin and 31.0% took uncoated aspirin.
• Surprisingly, the study debunked the myth that enteric-coated aspirin compromises its efficacy.
• The analysis, encompassing participants who self-reported their aspirin formulations, showed no substantial difference in effectiveness or safety outcomes between those taking enteric-coated aspirin and those opting for the uncoated version.
• This revelation was groundbreaking, indicating that the protective benefits of aspirin were not significantly impacted by its coating, contrary to longstanding beliefs. 
• Even when considering the dosage, the study's outcomes remained consistent. Both enteric-coated and uncoated aspirin formulations demonstrated comparable results, challenging the notion that dosage played a pivotal role in the medication's effectiveness or safety. 

Thus, In the ever-evolving landscape of medicine, the ADAPTABLE study has illuminated a path toward a better understanding of aspirin's complexities. As the coating conundrum unravels, the medical community stands at the cusp of a paradigm shift, armed with newfound knowledge that challenges traditional practices and invites innovative approaches. This revelation not only redefines the way we perceive aspirin but also paves the way for more personalized and effective cardiovascular care, promising a healthier future for millions worldwide. 

Further reading: Sleem A, Effron MB, Stebbins A, et al. Effectiveness and Safety of Enteric-Coated vs Uncoated Aspirin in Patients With Cardiovascular Disease: A Secondary Analysis of the ADAPTABLE Randomized Clinical Trial. JAMA Cardiol. Published online October 04, 2023. doi:10.1001/jamacardio.2023.3364