DYSLIPIDEMIAS AND THE SECONDARY PREVENTION OF CORONARY HEART-DISEASE

Dyslipidemias in patients with coronary heart disease confer a greater risk of ischemic cardiac events than comparable dyslipidemias in peop le free of disease. A major dyslipidemia can be diagnosed in more than 80% of patients with established premature coronary heart disease. Th ese dyslipidemias constitute not only elevations of low-density lipopr otein cholesterol (hypercholesterolemia) but also indicate abnormaliti es in the metabolism of triglyceride-rich lipoproteins, high-density l ipoproteins, and lipoprotein(a). Clinical trials have demonstrated tha t therapy to lower low-density lipoprotein levels can delay angiograph ic progression of coronary stenoses and reduce recurrent cardiac event rates. These clinical benefits from low-density lipoprotein cholester ol lowering may occur as early as 6 to 12 months after initiation of t herapy. Intervention strategies for dyslipidemias are directed toward lowering the low-density lipoprotein cholesterol fraction to 90 to 100 mg/dl. This approach begins with dietary modification, weight loss, s moking cessation, and aerobic exercise. Patients with hypercholesterol emia refractory to nonpharmacologic intervention require lipid-lowerin g agents. The choice of lipid-lowering medications is influenced by co ncomitant abnormalities of lipoprotein metabolism, such as hypertrigly ceridemia or hypoalphalipoproteinemia. Treatment of primary dyslipidem ias other than hypercholesterolemia may be warranted in die presence o f other cardiac risk factors; however, a broader spectrum of clinical trial data is needed to support or refute this contention.