Increased high-density lipoprotein cholesterol level and inhibition of atherosclerosis

A 50-year-old woman with angina pectoris, hyperlipidemia, and hypertension was admitted to our clinic because of a possible transient ischemic attack. Her mother died of a myocardial infarction (MI) at 55 years of age. On admission, the patient was treated with a maximal dose of simvastatin, 80 mg/day. Her total cholesterol level was 4.8 mmol/L and high-density lipoprotein (HDL) cholesterol level was 0.9 mmol/L. Ultrasound scanning showed echolucent atherosclerotic plaques in her carotid bifurcations.

This patient was at high risk for developing a future MI. She had manifest generalized atherosclerosis and unfavorable plaque morphology. Previous studies have shown plaque echolucency to be an independent risk factor for stroke and MI. Despite a high-dose HMG-CoA reductase in­hibitor (statin) regimen, the patient’s HDL cholesterol level remained low, and the total cholesterol/HDL cholesterol index was > 4.0. Results of epidemiologic studies suggest that a low HDL cholesterol level may be a risk factor comparable in importance to a high low-density lipoprotein cholesterol level and that the 2 risk factors are independent. According to the findings of our study, this patient would benefit from having her HDL cholesterol level increased. She was told to become more physically active and to take omega-3 capsules.

Recently, a great deal of interest has been focused on a new class of drugs, cholesterol ester transfer protein inhibitors, which can raise HDL cholesterol levels by as much as 50%. It remains to be seen whether these drugs will prevent subclinical atherosclerosis. Further studies with hard end points will need to be performed.