Vascular Quality of Care Assessment: Clinicians' Adherence to Lipid-Lowering Therapy for Patients with Atherosclerotic Cardiovascular Disease

Background: Lipid-lowering medication can considerably lessen the risk for cardiovascular events in patients with atherosclerotic cardiovascular disease (ASCVD). Despite well-publicized guidelines and the accessibility of effective therapies, many patients do not attain their lipid goals and remain at high cardiovascular risk. Guidelines recommend statins as first-line therapy to reduce cardiovascular morbidity and mortality in ASCVD. We aimed to analyze admission lipid levels in a broad contemporary population of patients with ASCVD attending a vascular clinic or admitted to an inpatient vascular unit. Methods: Patients with known ASCVD, current cholesterol levels, and lipid-lowering medications were documented and compared with published current Canadian Cardiovascular Society Guidelines recommendations for achieving <2.0 mmol/L or >50% reduction in low-density lipoprotein cholesterol (LDL-C). Cholesterol levels (current and previous), demographic characteristics, cardiovascular risk factors, and medical therapy were assessed from available patient records. Results: Two hundred eight adult patients were identified. The mean age of the patients was 72 (+/- 10) years, and 76% were men. About half had peripheral arterial disease (n = 118, 56.7%), one-third had coronary artery disease (n = 78, 37.5%), and one-third had diabetes (n = 76, 36.5%). Most were hypertensive (n = 140, 67.3%) and half gave a history of dyslipidemia (n = 103, 49.5%). Most patients (n = 183, 88%) were taking a statin and the majority at a moderate-intensity dose (n = 79, 43.2%) or high-intensity dose (n = 101, 55.2%). However, 32.7% of patients (n = 68) did not reach target of LDL-C level of <2.0 mmol/L or had =50% reduction from the baseline level. Of the patients who did not reach goals, 7 (10.3%) did not fill their statin prescriptions in the last 3 months. Only 26 patients (12.5%) were also on ezetimibe, a guideline-recommended second-line therapy if targets are not reached with maximally tolerated statin therapy. One patient, who was able to reach target LDL-C, was on evolocumab monotherapy, a PCSK9 inhibitor, a contemporary nonstatin therapy that could be considered in ASCVD in those not at LDL-C goal. Of the 16 patients who were not prescribed any lipid-lowering therapy and did not reach target, 8 (50%) did not have any identified or documented reasons. Of the remaining 8 patients, 7 (87.5%) reported intolerance or side effects to statins only, and could benefit from nonstatin LDL-lowering therapy. Conclusions: In this observational study, we established suboptimal adherence to guideline recommendations for statin therapy and hesitancy to use nonstatin LDL-lowering agents in high-risk patients with ASCVD. These treatment gaps have an enormous effect on achieving improved cardiovascular clinical outcomes and must be tackled.