Aims
Non-adherence to guideline-directed medical therapy may worsen outcomes in chronic heart failure (CHF). Objectively assessed adherence in patients presenting with acutely decompensated heart failure (ADHF) remains largely unexplored. This study evaluated adherence to medication in patients with ADHF presenting in the emergency department.
Methods and results
This cross-sectional study assessed medication adherence using both indirect (self-reported) and direct methods (qualitative toxicological analysis in urine). A total of 100 patients were included of whom 61% were men, with a mean age of 77.9 ± 10.1 years, and a median N-terminal pro-B-type natriuretic peptide level of 4846 pg/ml. In 39% of patients, all prescribed CHF medications were detected in urine, indicating full adherence. Partial adherence was observed in 39% of patients with one prescribed CHF medication not detected. Non-adherence, defined as the absence of ≥2 prescribed drugs, was observed in 22% of patients. Non-adherent patients had a significantly higher number of CHF medications prescribed compared with partially adherent (p = 0.0047) and adherent (p = 0.0002) patients and had a significantly higher pill burden than adherent patients (p = 0.002). Non-adherent patients were younger than partially adherent (p = 0.0144) and adherent (p = 0.0054) patients. Adherent patients were significantly more likely to have an abnormal DemTect cognitive screening test result (p = 0.049). Medication prepared by a third party, such as caregiver or pharmacist, reduced the likelihood of both non- and partial adherence. Self-reported adherence monitoring was found to be inaccurate.
Conclusions
Adherence to CHF medication in patients presenting with ADHF was low. Non-adherence represents a significant contributor to worsening CHF, potentially leading to ADHF hospitalization. Further research is needed to develop feasible and validated tools for assessing medication adherence in CHF and ADHF, using toxicological testing as reference standard.
