Patients' Beliefs About Their Cardiovascular Medications After Acute Coronary Syndrome: A Prospective Observational Study

Background: Adherence to secondary preventive pharmacotherapy after an acute coronary syndrome (ACS) is generally poor and is associated with recurrent cardiovascular events. Patients' beliefs about their medications are a strong predictor of intentional nonadherence.Methods: This prospective, observational study assessed adult patients' beliefs about their post-ACS medications, using the Beliefs About Medicines Questionnaire (BMQ), and adherence, using the Medication Adherence Report Scale (MARS-5) at St. Paul's Hospital in Vancouver, Canada during May-December, 2022. The BMQ and MARS 5 were administered in-hospital and at 4 weeks after discharge. Outcomes included difference in BMQ necessity-concerns differential (BMQ-NCD) from hospitalization to 4-week follow-up and factors associated with the BMQ-NCD.Results: Forty-seven participants completed the 4-week follow-up. The mean age was 64 years, and 83% were male. Most presented with a non-ST-segment-elevation ACS. No difference occurred in BMQ-NCD (7.3 vs 6.6, P = 0.29) or MARS-5 scores from discharge to 4 weeks (22.8 vs 23.7, P = 0.06); however, the BMQ specific-necessity sub scale score decreased significantly (20.3 vs 18.8, P = 0.002). South Asian and Middle Eastern ethnic origins, compared to European, were associated with a higher BMQ-NCD. Part-time employment and male sex were associated with a lower BMQ-NCD.Conclusions: Participants held favourable beliefs about their post-ACS medications, which were largely unchanged from hospitalization to 4 weeks postdischarge, except for beliefs about the necessity of taking their medications. Those of European descent, those with part-time employment, and males had the lowest BMQ-NCD. Self-reported adherence was high. Ongoing reassessment of patients' beliefs about the necessity of taking their post-ACS medications may be warranted to mitigate further decline in BMQ-NCD.