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

Abstract

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. 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 <2.0mmol/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. 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 <2.0mmol/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 3months. 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. 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.