Assessing the Impact of Medication Adherence on Long-Term Cardiovascular Outcomes

Area of Science:

• Cardiovascular Medicine
• Pharmacoeconomics
• Health Outcomes Research

Background:

• Guideline-recommended therapies are effective in reducing major adverse cardiovascular events (MACE) post-myocardial infarction (MI) or in atherosclerotic disease (ATH).
• However, patient adherence to these crucial therapies remains suboptimal, potentially limiting their effectiveness.

Purpose of the Study:

• To investigate the association between medication adherence levels and long-term MACE.
• To evaluate the impact of adherence on direct medical costs in patients with MI or ATH.

Main Methods:

• A large health insurer claims database was used to identify patients hospitalized for MI or diagnosed with ATH.
• Medication adherence was assessed using the proportion of days covered for statins and ACE inhibitors, categorizing patients into fully adherent (≥80%), partially adherent (40%-79%), and nonadherent (<40%).
• Primary outcome was a composite of all-cause death, MI, stroke, or coronary revascularization; annual direct medical costs were also estimated.

Main Results:

• In the post-MI cohort (n=4,015), full adherence was associated with significantly lower MACE rates compared to nonadherent (18.9% vs. 26.3%) and partially adherent (18.9% vs. 24.7%) groups at 2 years.
• In the ATH cohort (n=12,976), full adherence also showed significantly lower MACE rates versus nonadherent (8.42% vs. 17.17%) and partially adherent (8.42% vs. 12.18%) groups.
• Full adherence led to substantial cost savings in MI hospitalizations, with reductions of $369-$440 (post-MI) and $371-$907 (ATH) compared to lower adherence levels.

Conclusions:

• Full adherence to guideline-recommended therapies significantly reduces MACE and healthcare costs in patients with MI or ATH.
• A threshold of >80% adherence shows a significant benefit in post-MI patients, while maintaining at least 40% adherence is necessary for sustained benefits.
• Developing novel strategies to enhance medication adherence is critical for improving cardiovascular outcomes and reducing healthcare expenditures.