Clogged arteries yielding to combination of drugs

November 27, 1990|By Sue Miller | Sue Miller,Evening Sun Staff

FOR HEART patients with blocked arteries, the battle to survive is not won with a bypass operation alone.

Such patients remain at very high risk of having a heart attack and often need further treatment with cholesterol-fighting drugs.

At medical centers here and across the country, cardiologists now are using combinations of the drugs in what is known as "aggressive therapy" to combat coronary artery disease.

Those practicing it include Dr. David A. Meyerson at University of Maryland Medical Center and Dr. Michael Miller at Johns Hopkins Hospital.

They are using cholesterol-lowering drugs such as lovastatin, which as recently as two years ago was thought to be unsafe. Since then, however, studies have shown that this and other drugs can be used effectively, without damaging side effects.

"This therapy does not make heart disease disappear, but it improves it and has the effect of preventing other critical events," says Meyerson, director of UM's Center for Preventive Cardiology.

"When someone already has heart disease, a physician has to be aggressive or else his patient is just going to have heart attack after heart attack and he's going to die."

It's important to realize that once a person has had a heart attack, the risk for repeat coronary events is five or six times greater than before the first attack, says Miller, of the Hopkins Center for Preventive Cardiology.

Heart disease is the leading cause of death in America. Statistics show there are 7.2 million people in the United States who have heart disease, and about 500,000 of them die of heart attacks every year. A like number survive attacks but go on to have repeat episodes.

Lovastatin, also known by the trade name Mevicor, inhibits the action of the enzyme that is responsible for an overproduction of cholesterol by the livers of many people. Nicotinic acid or Niacin also acts on the liver and has the effect of lowering cholesterol.

AT UM, lovastatin is combined with colestipol or Colestid, a bile acid drug, that prevents cholesterol from ever being released in the system. Or Niacin is combined with Colestid.

At Hopkins, patients usually are started on one drug, either Mevicor or a medication like cholestryamine, another bile acid drug. But, if the cardiologists are using Mevicor to begin with, they might try cholestryamine on top of it to get the desired low cholesterol level, according to Miller.

"We think if a person has a high cholesterol, that we need to bring it down," he says. "But we just start off slowly because you have to monitor the patient."

Cardiologists throughout the country's major medical centers have had heightened concern about preventing repeat episodes of life-threatening attacks ever since Dr. Greg Brown of the University of Washington Medical School reported his early findings before the American Heart Association a year ago.

A full account of his work over the last four years, published this month in the New England Journal of Medicine, is being hailed as a landmark study.

His research examined the effects of the same combinations of anti-cholesterol drugs now being used at UM in people who had high levels of LDL, or low-density lipoprotein. LDL is also known as the "bad" cholesterol because it clings to arterial walls where it promotes a buildup of plaque.

Plaque, made up mostly of cholesterol and fibrous material, causes arteries to narrow and eventually shut down.

Brown also looked at the effects of the drugs in people who had blocked coronary arteries and a family history of heart disease.

"Brown's work is monumental," says Miller. "It's monumental because it shows for the first time that with combinations of these drugs you can achieve marked reduction of coronary lesions.

"In patients who received combination drugs, the progression of disease was one half as much and the regression was triple compared to the patients who did not get the drugs."

At UM, cardiologists have a goal for patients with active heart disease: cholesterol levels below 170 and LDL cholesterols at the 100 level or slightly below, Meyerson says.

At Hopkins, specialists try to reduce the cholesterol level to about 150 or below, says Miller. "The national guidelines want you to get it to just under 200, but we want to try to get it down lower than that."

In a bypass operation, Meyerson explains, the veins put in to bypass the blocked coronary arteries are even more susceptible to plaque buildup than the original arteries.

Within five to eight years, he says, the vein grafts have been blocked by the same process that ruined the native vessels.

Plaque also can return following balloon angioplasty. In this procedure, an inflated balloon-tipped catheter is used to open up arteries by squashing plaque to the sides of arterial walls.

"It's critical to lower cholesterol in people who have had one heart attack, angina or required a bypass or angioplasty because if you don't, their disease is guaranteed to recur," Meyerson says.

With time, fears that the drug Mevicor might cause liver and skeletal-muscle problems have disappeared. And a major, multi-center study, involving several thousand people, has shown that the incidence of cataracts in Mevicor users is negligible.

"The majority of my patients who are taking Mevicor don't know that they are on any medicine whatsoever," says Meyerson. "Niacin is a little more difficult to use because it does have some side effects that are unpleasant, like feeling flushed and abdominal cramping. But, if the drug is used correctly, these things can be overcome."

As for lovastatin, it "now appears to be very safe, probably safer than we originally thought," says Miller.

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