Background and Importance According to the latest recommendations, the need to achieve lower cholesterol levels has become more important. Therefore, the use of protein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has been increasing recently.

Aim and Objectives To establish patients’ adherence to evolocumab therapy, a PCSK9 inhibitor, and to analyse the reduction of patients’ LDL-C levels.

Material and Methods Descriptive retrospective observational study carried out between January and December 2021 in a third-level hospital. Patients with three or more dispensations of evolocumab were selected. The number of prefilled pens and the date when it was supplied were considered to calculate compliance. Demographics and clinical data (prescription and LDL-C values: pre-treatment, after 12 weeks, and at the end of the study) were compiled through the medical record.

Results 139 patients were included in the study, 79 males (57.25%) with a median age of 62.97 years (IQR 15.53). 73 patients (52.90%) were prescribed due to secondary prevention and the remainder due to familial hypercholesterolemia. All patients received 140 mg every 2 weeks.

Patients were divided into three groups (1, 2, and 3) according to their medication adherence (≥ 90%, 75 – 89.99%, and <75% respectively). 90 patients (65.22%) were in group 1, 30 (21.74%) in group 2 and 18 (13.04%) in group 3.

After 12 weeks of treatment, a reduction of LDL-C levels by at least 50% was observed in 71 patients (78.79%) from group 1, 23 (76.67%) from group 2, and 11 (61.11%) from group 3. The reduction percentage medians were -69.18% (IQR 26.69), -68.64% (IQR 28.89), and -54.56% (IQR 44.69) respectively for each group. Results in group 1 and 2 are better than existing literature data (table 1). Group 3 obtained worse efficacy results.

Conclusion and Relevance Low adherence seems to decrease LDL-C reduction capacity, while moderate compliance seems to maintain it. Further research is required, nevertheless, these results would support the possibility of decreasing the frequency of administration, favouring the adherence to treatment and reducing costs.

Conflict of Interest No conflict of interest