1. Introduction

Abstract

The 2021 guidelines primary panel selected clinically relevant questions and produced updated recommendations, on the basis of important new findings that have emerged since the 2016 guidelines. In patients with clinical atherosclerosis, abdominal aortic aneurysm, most patients with diabetes or chronic kidney disease, and those with low-density lipoprotein cholesterol ≥ 5 mmol/L, statin therapy continues to be recommended. We have introduced the concept of lipid/lipoprotein treatment thresholds for intensifying lipid-lowering therapy with nonstatin agents, and have identified the secondary prevention patients who have been shown to derive the largest benefit from intensification of therapy with these agents. For all other patients, we emphasize risk assessment linked to lipid/lipoprotein evaluation to optimize clinical decision-making. Lipoprotein(a) measurement is now recommended once in a patient’s lifetime, as part of initial lipid screening to assess cardiovascular risk. For any patient with triglycerides ˃ 1.5 mmol/L, either non-high-density lipoprotein cholesterol or apolipoprotein B are the preferred lipid parameter for screening, rather than low-density lipoprotein cholesterol. We provide updated recommendations regarding the role of coronary artery calcium scoring as a clinical decision tool to aid the decision to initiate statin therapy. There are new recommendations on the preventative care of women with hypertensive disorders of pregnancy. Health behaviour modification, including regular exercise and a heart-healthy diet, remain the cornerstone of cardiovascular disease prevention. These guidelines are intended to provide a platform for meaningful conversation and shared-decision making between patient and care provider, so that individual decisions can be made for risk screening, assessment, and treatment.

Introduction

The 2021 Canadian Cardiovascular Society (CCS) dyslipidemia guidelines have been updated to reflect new clinical trial and epidemiologic evidence published since the previous guidelines in 2016.1 The primary panel posed a number of population, intervention, comparator, and outcomes (PICO) questions to develop recommendations and inform clinical practice on the basis of a detailed literature review. The PICO format is a common standard used for guidelines development, to aid clinicians in determining whether the recommendations apply to their own patients with outcomes relevant to their practice. Initially, 13 different PICO questions were posed and then rated on the basis of the availability and significance of new evidence and importance to be included in the updated guidelines. The primary panel members voted on the initial 13 PICO questions formulated (see Supplemental Appendix S1 Supplemental Appendix S1, S2, S3 etc.), resulting in the identification of 6 key PICO questions, which are included in this update. Using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) standards, individual studies and composite literature were reviewed for each PICO question with regard to the quality of the available evidence and the presence of publication or interpretive bias. We have included the updated recommendations within this update, and the results of voting on each recommendation are shown in Supplemental Appendix S2. For recommendations to go forward a two-thirds voting majority was required. Individuals with conflicts of interest were recused from voting on relevant recommendations. We have introduced the concept of “treatment thresholds” for intensifying lipid-lowering therapy with nonstatin lipid-lowering agents on the basis of new evidence with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and icosapent ethyl (IPE). Because of the increased focus on apolipoprotein B (ApoB) and non-high-density lipoprotein cholesterol (HDL-C) in this update, values for ApoB and non- HDL-C have been modified (from previous versions of these guidelines) to accurately represent the same percentile equivalents as low-density lipoprotein (LDL) cholesterol (LDL-C) for all recommended thresholds (see Supplemental Appendix S3). The goal of the process was to produce an objective, nonbiased document on the basis of the best available evidence to allow clinicians and patients to make collaborative treatment decisions. These guidelines are not absolute, but are to be used in the context of oneon-one discussion between practitioner and patient and consideration of the patient’s values and preferences. Dyslipidemia is an important risk factor for atherosclerotic cardiovascular (CV) disease (ASCVD), and these guidelines inform risk assessment, treatment, and surveillance options for at-risk populations. These guidelines were undertaken under the auspices of the Guideline Committee of the CCS without any support or involvement from outside groups, including industry.