iMD - Applied Therapeutics_ The Clinical Use of Drugs, 12e - 8_ Dyslipidemias, Atherosclerosis, and Coronary Heart Disease

Dyslipidemias, Atherosclerosis, and Coronary Heart Disease

Core Principles

  1. Relationship Between Cholesterol Levels and Atherosclerosis Risk

    • Atherosclerosis risk is directly related to increasing levels of serum cholesterol.

    • Cholesterol, particularly low-density lipoprotein cholesterol (LDL-C), is pivotal in the pathogenesis of atherosclerosis.

    • Guidance for Treatment: The AHA/ACC guidelines recommend management for high-risk patients, including those with ASCVD and familial hypercholesterolemia (FH).

  2. Evaluation of Dyslipidemia

    • Patients with dyslipidemia must be evaluated for secondary causes of elevated LDL-C or triglycerides (TGs) that may stem from medications or clinical conditions.

    • Establish thresholds for initiating therapeutic lifestyle changes (TLC) and pharmacotherapy based on clinical atherosclerosis presence or cardiovascular (CV) risk.

  3. Intervention and Lifestyle Changes

    • TLC trials should be universal; however, pharmacotherapy should begin alongside TLC in high-risk patients.

    • Monitoring for adverse effects of medications is crucial.

  4. Statins as First-line Therapy

    • Statins are the primary agents for reducing high LDL-C, marked by their significant ability to lower LDL-C levels and reduce morbidity and mortality from atherosclerosis.

    • Patients must be informed about potential adverse effects from statin use, ensuring optimal therapeutic benefits are achieved.

Lipid Metabolism

  1. Understanding Cholesterol Production

    • Cholesterol is synthesized and acquired from systemic circulation, with production peaking at midnight and lessening during the day.

    • Statins inhibit HMG-CoA reductase, the enzyme regulating a critical step in cholesterol production, resulting in reduced cholesterol synthesis and increased LDL receptor density.

  2. Cholesterol Storage and Utilization

    • Cells store free cholesterol as cholesteryl esters (CEs), facilitated by enzymes like ACAT, which plays a role in lipid absorption and storage.

    • Triglycerides are crucial for energy storage and transport in lipoproteins.

Lipoprotein Classification and Properties

  1. Types of Lipoproteins

    • Lipoproteins consist of various classes, including VLDL, LDL, and HDL, each with distinct roles in cholesterol/fat transport.

    • Increased small LDL and decreased HDL sizes correlate with elevated CHD risk.

  2. Impact of Lipoproteins on Health

    • LDL carries the majority of cholesterol in blood and plays a central role in atherosclerosis. HDL facilitates reverse cholesterol transport, aiding in cardiovascular protection.

Dyslipidemia Management

  1. Medicinal Approaches

    • Combination Therapy: Often necessary for addressing lipid abnormalities, especially in severe cases or those at higher risk.

    • Statins, fibrates, and ω-3 fatty acids are integral in lowering TGs, managing cholesterol levels, and preventing CV events.

  2. Clinical Evidence and Recommendations

    • Consistent management through lifestyle intervention and pharmacotherapy is essential for reducing atherosclerotic events.

    • Recent trials have emphasized the efficacy of combination therapies to enhance lipid management and improve cardiovascular outcomes.

Advanced Treatment Options

  1. Emerging Therapies

    • PCSK9 Inhibitors and Bempedoic Acid have emerged as crucial adjuncts for patients requiring further LDL-C reductions despite statin use.

    • The role of inclisiran and evinacumab in managing severe dyslipidemias showcases the advancement in cholesterol therapies.

  2. Ongoing Monitoring and Patient Education

    • Regular follow-ups, lifestyle reinforcement, and understanding patient-specific factors are necessary to optimize therapy.

    • Patients should be trained to manage symptoms associated with medications and understand potential interactions.