The discontinuation of recommended therapy after myocardial infarction predisposes patients to serious thrombotic complications. The aim of this study was a comprehensive analysis of permanent as well as short- and long-term discontinuation of pharmacotherapy, taking into consideration the basic groups of medications and nonadherence determinants in a one-year follow-up in post-myocardial infarction (MI) patients.
Material and methods: The study was a single center cohort clinical trial with a one-year follow-up including 225 patients (73.3% men, 26.7% women) aged 62.9 ± 11.9 years. In eight cases (3.6%), the follow-up duration was less than one year due to premature death. The following factors were analyzed: lack of post-discharge therapy initiation; short-term therapy discontinuation (<30 days); long-term therapy discontinuation (≥30 days); and permanent cessation of therapy. The analysis of therapy discontinuation was performed based on prescription filling data.
Results: Occupational activity (Odds Ratio (OR) 5.15; 95% Confidence interval (CI) 1.42-18.65; p = 0.013) and prior MI (OR 5.02; 95% CI 1.45-16.89; p = 0.009) were found to be independent predictors of a lack of post-discharge therapy initiation with P2Y12 receptor inhibitors. We found no independent predictors of lack of post-discharge therapy initiation with other medications, whether analyzed separately or together. Age above 65 years (Hazard Ratio (HR)-1.59; 95% CI 1.15-2.19; p = 0.0049) and prior revascularization (HR-1.44; 95% CI 1.04-2.19; p = 0.0273) were identified as independent predictors of therapy discontinuation. Multilogistic regression analysis showed no independent predictors of the cessation of any of the medications as well as the permanent or temporary simultaneous discontinuation of all medications.
Conclusions: The vast majority of post-MI patients discontinue, either temporarily or permanently, one of the essential medications within one year following myocardial infarction. The most likely medication class to be discontinued are statins. Older age and prior cardiac revascularization are independent determinants of therapy discontinuation.
Keywords: P2Y12 receptor inhibitors; adherence; angiotensin converting enzyme inhibitors (ACEI); myocardial infarction; statins.