Patient adherence to drug therapy and clinical outcomes after recurrent myocardial infarction

Objective: To study patients' adherence to drug therapy after recurrent myocardial infarction and evaluate its impact on the incidence of cardiovascular events. Materials and Methods: A prospective study included 53 patients discharged after recurrent myocardial infarction (RMI). Follow-up was conducted for 12 months, assessing adherence at 1, 3, 6, and 12 months across five classes of medications: acetylsalicylic acid, P2Y12 inhibitors, statins, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACE inhibitors/ARBs), and beta-blockers. Results: At discharge, all patients received acetylsalicylic acid, P2Y12 inhibitors, and statins. 92.5% took ACE inhibitors/ARBs, 94.3% - beta-blockers. After 12 months, the proportion of patients taking 4-5 classes of drugs decreased from 81.1% to 35.8% (p<0.001). The most pronounced decrease was noted for P2Y12 inhibitors (from 100% to 34.0%), beta-blockers (from 94.3% to 47.2%), and ACE inhibitors/ARBs (from 92.5% to 50.9%). The MACE rate in the low/partial adherence group (grades 0-3 at month 6) was 3.3 times higher than in the high adherence group (40.0% vs. 12.1%; p=0.018; OR=3.30; 95% CI 1.14-9.58). Factors that reduced adherence included age 70 years and older (p=0.022), rural residence (p=0.022), financial difficulties (p<0.001), and lack of relatives' support (p=0.008). Conclusion: In patients following a recurrent myocardial infarction, adherence to drug therapy declines during the first year. This is particularly noticeable with regard to the second antiplatelet agent and neurohormonal modulators. Poor adherence increases the risk of adverse outcomes threefold. The identified sociodemographic factors indicate the need to develop targeted support programs to improve the effectiveness of secondary prevention.