(184) Patterns and Determinants of Adherence to Medication Guideline in Myocardial Infarction (MI) Survivors: A Retrospective Cohort Study of 21,510 patients

Background: Clinical guidelines recommend use of (1) antiplatelet, (2) statin, (3) beta blocker (BB) or calcium channel blocker (CCB), and (4) angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) for secondary prevention following MI. Previous studies have shown the lack of adherence to guidelines but there are few data that examine sociodemographic or comorbidity patterning or whether it is associated with death in real world settings.

Objectives: To examine whether sociodemographic and comorbid factors were associated with adherence to medication guideline, and whether adherence was associated with all-cause mortality.

Methods: A retrospective cohort study was conducted on all 21,510 West of Scotland patients who aged over 50 years and survived at least one year after incident MI between 2012 and 2022. Guideline adherence was ascertained as at least two prescriptions for each of the four classes of medication in the first year post MI. Age, sex, Scottish Index of Multiple Deprivation (SIMD), year of incident MI, and pre-existing medical conditions (angina, stroke, heart failure (HF), hypertension, diabetes, chronic obstructive pulmonary disease (COPD), depression, and psychosis) were included as predictors of adherence, and adjusted for in the analysis of adherence and death.

Results: Among 21,510 MI patients, male sex and pre-existing hypertension and diabetes were associated with higher adherence, while higher deprivation, other cardiometabolic conditions, and mental health conditions were associated with lower adherence. Adherence was associated with 42% lower risk of death (HR 0.58; 95%CI 0.56-0.61) after adjusting for sociodemographic and comorbid factors. Consistent associations between adherence and death were found in all subgroups, including those with pre-existing cardiometabolic disease (HR 0.59; 95%CI 0.56-0.62), COPD (HR 0.59; 95%CI 0.55-0.65), and mental health conditions (HR 0.57; 95%CI 0.53-0.62).

Conclusions: Subsequent deaths in surviving MI patients could be related to non-adherence to guidelines on specified medications, particularly among those in deprived areas or with pre-existing conditions.