Augmenting the good cholesterol.

A reconstituted version of good cholesterol may lessen the amount of plaque that accumulates in coronary arteries and might render the plaque that's already there less dangerous, researchers find.

High-density lipoprotein (HDL) molecules are protein shells that ferry excess cholesterol out of blood, artery walls, and other tissues for safe disposal. But some people make too little HDL, permitting a buildup of cholesterol in problematic low-density lipoprotein (LDL) shells. Researchers tested an experimental drug formed by merging a body compound, called apolipoprotein A-I, and a soybean compound. The combination works like HDL to remove LDL from the blood.

Cardiologist Jean-Clande Tardif of the University of Montreal and his colleagues gave 89 people four weekly infusions of the combination drug, while 47 other patients received placebo infusions. All the volunteers already had some athero sclerosis, and nearly all were taking a statin drug to lessen LDL.

Over 7 weeks, those getting the combination drug experienced plaque shrinkage of 3.4 percent, whereas those getting a placebo had only a 1.6 percent drop.

Furthermore, plaques in volunteers getting reconstituted HDL showed characteristics that make the plaques unlikely to lead to dangerous blood-clot formation, Tardif says. The report appears in the March 26 Journal of the American Medical Association.

The findings contrast with bad news regarding the once-promising HDL increaser torcetrapib (SN: 5/1/04, p. 285). Tardif and others report in the March 29 New England Journal of Medicine that that drug failed to shrink arterial plaques and hiked blood pressure.