Chicago ? Intravenous doses of a synthetic component of “good” cholesterol reduced artery disease in just six weeks in a small study with startlingly big implications for treating the nation’s No. 1 killer.

“The concept is sort of liquid Drano for the coronary arteries,” said Dr. Steven Nissen, a Cleveland Clinic cardiologist who led the study.

Larger and longer studies need to be done to determine whether the experimental treatment will translate into fewer deaths, but the early results are promising, said Dr. Daniel Rader, director of preventive cardiology at the University of Pennsylvania School of Medicine.

The treatment used a laboratory-produced version of an unusually effective form of HDL, the good cholesterol that helps protect against heart disease by removing plaque, or fatty buildups, from the bloodstream.

“This is clearly on the level of a breakthrough that will have far-reaching implications,” pointing the way toward a rapid treatment for fatty buildups, said Dr. Bryan Brewer, chief of molecular diseases at the National Heart, Lung and Blood Institute.

The surprisingly quick results, though preliminary, shatter a long-standing belief that heart disease is a slow-progressing disease that takes a long time to undo, said Rader, who wrote an editorial accompanying the study in today’s Journal of the American Medical Assn.

While some existing medicines target HDL, most conventional drug treatment works by reducing levels of LDL cholesterol, the bad kind that contributes to the formation of plaques that can clog arteries and lead to heart attacks.

Nissen’s study is part of a burgeoning area of research that focuses on treatments that raise HDL levels or improve HDL’s plaque-fighting abilities.

Nissen said he envisions the treatment being used in combination with other therapy including LDL-lowering drugs, but that commercial use is probably a few years off and will depend on the outcome of larger studies.