CHOLESTEROL-LOWERING DRUGS: PLAQUE REGRESSION IN CORONARY ARTERIES

CHOLESTEROL-LOWERING DRUGS: PLAQUE REGRESSION IN CORONARY ARTERIES was three times more frequent and progression only half as frequent in patients receiving drug therapy versus placebo in a study presented Nov. 14 at the 62nd Scientific Session of the American Heart Association in New Orleans. The study, conducted by Greg Brown, MD, University of Washington Medical Center, found that lesion progression occurred in 46% of the placebo group and definite regression in 11%, compared to 23% and 35% in the drug groups, respectively. Patients in the study were divided into three groups: one received niacin and the bile acid sequestrant colestipol (Upjohn's Colestid); another received lovastatin (Merck's Mevacor) and colestipol; and a third received a double placebo, except those with a low density lipoprotein (LDL) level above the 90th percentile, who received colestipol instead of a second placebo. The average blood cholesterol level of study participants was 270 mg/dl. Patients, all of whom were placed on a low-fat, low-cholesterol diet, were followed from January 1984 to September 1989. Angiograms were taken at the beginning and the end of the study and blindly analyzed using computer-assisted techniques. Brown reported that the frequency of events such as heart attack, death, bypass surgery and angioplasty during the study was 21% in the placebo group and only 5% in the drug-treated groups. The Brown study was supported by a grant from NHLBI. Basil Rifkind, MD, chief of the Lipid Metabolism-Atherogenesis Branch at NHLBI, added that the University of Washington study provides the first clinical evidence that HMG-CoA reductase inhibitors "are effective in substantially reducing blood cholesterol." Results of a second, 103-patient study conducted by David Blankenhorn, MD, University of Southern California School of Medicine, were also reported at the AHA scientific conference. Blankenhorn noted that patients with previous bypass surgery and serum cholesterol levels ranging from 185-350 mg/dl treated with a low-fat diet and colestipol/niacin for four years showed "significantly" reduced progression of plaque build-up in their native coronary arteries. Mevacor got a second piece of supportive news at the AHA meeting. Preliminary findings of the ongoing Expanded Clinical Evaluation of Lovastatin (EXCEL) Study were announced. The results showed that the drug does not produce cataracts and that the risks of elevated muscle and liver enzymes are very low. The 48-week, multi-center, placebo-controlled study was conducted using 8,245 patients on a lipid-lowering diet who had total cholesterol levels of 240-300 mg/dl. The study found "no evidence of an effect on the human lens," Merck, Sharp & Dohme researchers Geraldine Mantell, MD, and Theresa Burke, MD, stated. Another two-year ophthalmologic study is ongoing to add further evidence of lack of eye damage. As to the potential for asymptomatic transaminase elevations in the liver, the study found a "substantially lower incidence . . . than appears in the current package circular derived from the original clinical trials." While there continue to be instances of the adverse effect, researchers noted that it is reversible when Mevacor is discontinued and is "apparently dose-related and possibly mechanism-based."