Non-adherence to prescribed medication is a serious limitation of long-term treatment in patients after myocardial infarction (MI), which can be associated with medical, social and economical consequences. Improvement of medication adherence has been shown to be a challenge for healthcare providers. The aim of this study was to evaluate changes in medication adherence and variability of adherence determinants during follow-up in patients after MI. A single-center, cohort observational study was conducted in 225 post-MI patients treated with primary coronary intervention (PCI) (27% women and 73% men) aged 30–91 years. Adherence was defined as availability of evaluated drugs within 1-year after discharge from hospital, based on completed prescriptions data obtained from the National Health Fund. The analysis of therapeutic plan realization (adherence to medication prescribed at discharge from hospital) embraced only reimbursed drugs: ACEIs (ramipril, perindopril), P2Y12 receptor inhibitors (clopidogrel) and statins (atorvastatin, simvastatin, rosuvastatin). Sufficient adherence was defined as ≥ 80%. During 1-year follow-up, adherence for all three drug classes was 64 ± 25%, with 67 ± 32% for ACEIs, 62 ± 34% for P2Y12 receptor inhibitor and 64 ± 32% for statins. A gradual decline in adherence was observed from 65% ± 26% in the first quarter of follow-up to 51% ± 34% in the last quarter of follow-up (p < 0.00001). Sufficient adherence for all drugs classes was found only in 29% of patients throughout the whole follow-up period (44% for ACEI, 36% for P2Y12 receptor inhibitor and 41% for statins). According to a multivariate analysis, age, prior CABG, level of education, place of residence, economic status and marital status were independent predictors of drug adherence. Whereas patients > 65 years and having a history of prior CABG more often had an insufficient adherence to drugs, married and hypertensive patients, city inhabitants and patients with higher education tended to have a sufficient drug adherence. Adherence to pharmacotherapy after myocardial infarction decreases over time in a similar manner for all pivotal groups of drugs prescribed after MI. A number of socioeconomic and clinical factors have been identified to affect medication adherence over time.

Antiplatelet agents are the mainstay treatment in the prevention and management of atherothrombotic complications. However, a substantial interpatient variability in response to clopidogrel has been reported. Furthermore, patients with coronary artery disease and lesser platelet inhibition in response to clopidogrel are at increased risk for cardiovascular events. Clopidogrel after absorption requires two-step oxidation by the hepatic cytochrome P450 to generate its active metabolite. Polymorphisms of genes encoding the cytochrome enzymes and P-glycoprotein involved in clopidogrel absorption are regarded as major determinants of the interindividual variability in the clopidogrel-induced platelet inhibition. In our review we discuss the prevalence and clinical significance of various alleles of the genes: CYP2C19 and ABCB1 in the setting of coronary artery disease. Allele CYP2C19*2 is associated with excess of ischaemic events including myocardial infarction and stent thrombosis. On the other hand, CYP2C19*17 allele poses a serious threat of bleeding. Data concerning the prognostic value of genetic variant 3435C→T of ABCB1 remain inconclusive.

Introduction: A substantial subset of patients after myocardial infarction (MI) discontinue pivotal medication early after discharge. In particular, cessation of antiplatelet treatment may lead to catastrophic ischemic events. Thus, adherence to prescribed medication in patients after MI is an issue of medical and social concern. Purpose: The aim of the study was to evaluate the level of adherence to treatment using a newly developed scale in patients after MI treated with percutaneous coronary intervention. Patients and methods: A single-center, prospective, observational cohort clinical study with a 6-month follow-up was performed. Patients with physical or cognitive impairment, prisoners, soldiers, and family members and coworkers of the researchers were excluded from the study. The impact of selected sociodemographic and clinical factors on adherence was evaluated in 221 patients (63 women and 158 men) aged 30 to 91 years. Results: The results obtained with the Adherence in Chronic Diseases Scale (ACDS) ranged from 7 to 28 points; with the average and median scored being 23.35 and 24, respectively. The ACDS score reflects the level of adherence to prescribed medication. The high ACDS scores (>26 points) were obtained in 59 (26.7%) patients, intermediate scores (21–26 points) in 110 (49.8%) and low scores (26 points) was found in 11.1% of patients with re-ACS vs 28.4% of the remaining ones (P=0.1). Lower scores (mean ± standard deviation) in re-ACS patients were found for items 2 and 3 of the ACDS: 3.11±0.68 vs 3.45±0.73 (P=0.02) and 3.28±0.89 vs 3.64±0.64 (P=0.04), respectively. Conclusion: Age and previous MI were found to be independent factors influencing adherence assessed with the ACDS.