Adherence to angiotensin-converting-enzyme inhibitors and illness beliefs in older heart failure patients

Patient beliefs about heart failure (HF) may be important determinants of adherence. This study assessed levels of adherence to angiotensin-converting-enzyme inhibitors (ACEI) and examined whether beliefs about HF were associated with adherence to ACEI.

Fifty-eight patients with chronic stable HF (mean age 80.2 years SD +/- 4.6, 43% female) were recruited from two outpatient clinics in Dundee, UK. The Illness Perception Questionnaire-Revised was used to assess beliefs about HF. Adherence to ACEI was assessed by measuring serum levels of angiotensin-converting enzyme (sACE). Adherence to ACEI (defined as sACE < 5 U/L) was 72%. Beliefs about the time-line of HF and the consequences of HF accounted for 19% of the variability in adherence to ACEI in this sample. Heart failure patients who believed that their illness had a more chronic (longer term) time frame and had beliefs about the greater consequences of HF on their lives were less likely to adhere to ACEI.

Adherence to ACEI is sub-optimal. Beliefs about HF appear to be associated with objectively measured adherence to ACEI. Future studies should attempt to identify beliefs that consistently predict adherence and examine whether modifying these beliefs can increase adherence to HF medications.