Lipid Testing, Lipid-Modifying Therapy, and PCSK9 (Proprotein Convertase Subtilisin-Kexin Type 9) Inhibitor Eligibility in 27 979 Patients With Incident Acute Coronary Syndrome

Abstract

Background: While registry-based studies have shown that as many as 1 in 2 patients with stable atherosclerotic cardiovascular disease would be eligible for PCSK9i (proprotein convertase subtilisin-kexin type 9 inhibitor) therapy, this has not been studied in a large population-based postacute coronary syndrome (ACS) cohort. Methods: We examined lipid testing performed in hospital or within 90 days of discharge and lipid-lowering therapies dispensed within 90 days of discharge in patients surviving for at least 1 year after their first ACS between 2012 and 2018 in the province of Alberta, Canada. We estimated the proportion of patients eligible for PCSK9i and the expected benefits of treatment. Results: Of the 27 979 patients (median age 64.0 years, 29.3% female, 28.0% diabetic), 3750 (13.4%) did not have lipid testing in-hospital or within 90 days postdischarge. Untested patients were more likely to be older, female, from rural areas, to have more comorbidities, to already be on cardioprotective therapies, to present with unstable angina, and were less likely to have invasive interventions (all P <0.0001). Of the 24 229 tested, 18 767 (77.5%) had at least one lipid value above guideline-recommended threshold (LDL [low-density lipoprotein] ≥1.8 mmol/L [70 mg/dL] and non-HDL [high-density lipoprotein] ≥2.6 mmol/L [100 mg/dL]), of which 7284 (38.8%) did not have repeat testing within the year after discharge. Lipid testing in hospital was associated with higher rates of initiation or escalation of statin therapy within 90 days of their ACS (adjusted odds ratio, 2.13 [95% CI, 1.97–2.30). In total, 9592 patients (39.6% of the tested cohort) would be eligible for PCSK9i use, which could result in 184 fewer cardiovascular events over 3.4 years, including cardiovascular death, nonfatal ACS (myocardial infarction or unstable angina requiring hospitalization), and ischemic stroke. Conclusions: Within 90 days of incident ACS, ≈80% of patients did not meet guideline-recommended lipid thresholds and more than one-third would potentially be eligible for PCSK9i.