- Prescribing criteria have been suggested for proprotein convertase subtilisin kexin-9 (PCSK-9) inhibitors but few studies exist of their real-world effectiveness. Methods: This study audited PCSK-9 inhibitor therapy in 105 consecutive patients from two hospital centres-a university hospital (UH; n = 70) and a district general hospital (DGH; n = 35). Baseline characteristics including cardiovascular disease risk factors, NICE qualification criteria, efficacy and side effects were assessed. Results: Baseline LDL-C levels were similar in both centres. NICE criteria were met for 2.05 items in the whole study (UH patients 1.7 and DGH patients 2.7). District general hospital patients were more likely to have familial hypercholesterolaemia (89 vs 69%; P =.02); intolerance to statins (94 vs 52%; P <.001) and polyvascular disease (42% vs 17%; P =.005). Prescriptions (evolocumab 73%; alirocumab 23%) were collected by 76% of patients (UH 64% vs DGH 100%). Therapy was discontinued by time of review in 15% of patients (UH 7% vs DGH 25%; P =.02). In adherent patients PCSK-9 inhibitor treatment reduced TC by 28% (2.24 +/- 2.39 mmol/L; P <.001) and LDL-C by 49% (2.10 +/- 1.33 mmol/L; P <.001). A LDL-C < 2.5 mmol/L was achieved in 30% of patients and <2.0 mmol/L in 20%. PCSK-9 therapy was effective and safe in patients with increased lipoprotein (a), diagnosed muscle diseases (including myopathies and muscular dystrophy) or poststatin rhabdomyolysis, nephrotic syndrome or HIV disease. Mixed results were obtained in patients with significant mixed hyperlipidaemia. Conclusions: This study suggests that PCSK-9 inhibitors are effective but that prescriptions should not be changed to long-term delivery until patients have been reviewed and shown to be adherent.