1. Introduction
Advances in diagnostic and therapeutic strategies have improved ischemic heart disease (IHD) outcomes over the last decades.1Particularly, the use of evidence-based pharmacological therapy (β blockers, renin-angiotensin-aldosterone system blockers, statins, and antiplatelet drugs) has been demonstrated to improve long-term prognosis by reducing mortality by up to 40%, stabilizing disease progression, reducing the risk of recurrence, and enhancing functional capacity.2,3 Nonetheless, despite these advancements, IHD remains the leading cause of morbidity and mortality in countries of all income groups,4 reflecting the suboptimal implementation of secondary prevention strategies and subsequent burden on global healthcare services. Likewise, the use of such medications is still low, with a nonadherence prevalence ranging from 40 to 80%,5 exhibiting health disparities among countries and socioeconomic status.4 In this context, most available data on medication adherence proceeds from developed countries and clinical trials,6 which may not reflect the actual situation of developing countries, especially in those with higher income-health inequalities. Thus, medication-taking behavior may require national consensus and individualized tools to address the problem in a population-based manner to overcome socioeconomic, cultural, and ethnic barriers. Although data exist on medication adherence for secondary prevention of cardiovascular disease (CVD) in developing countries, to the best of our knowledge, no study has explored potential reasons for nonadherence in Mexico. This study aimed to determine the level of adherence to secondary prevention therapy in patients with IHD and dyslipidemia in the National Institute of Cardiology ”Ignacio Chávez” and identify the key barriers contributing to medication nonadherence.