Aspirin May Be All Heart Patients Need to Prevent Clots

New research indicates that common aspirin is all most heart-attack patients need to protect against clots, and that the pain reliever acetaminophen can help protect against hardening of the arteries.

And taking the widely used blood pressure pills called angiotensin converting enzyme (ACE) inhibitors can cut the risk of heart attacks and death by nearly a quarter in people with bad hearts or diabetes, according to another study.

Both studies were presented Wednesday at a meeting of the American Heart Association in Atlanta.

The aspirin study, carried out by researchers at the Boston Veterans Administration Hospital and Yale University’s School of Medicine, found that heart attack survivors got no extra benefit from taking the powerful anti-clotting drug Coumadin with aspirin.

Drs. Louis Fiore of the VA and Michael Ezekowitz of Yale started the study six years ago hoping to find that aspirin and Coumadin taken together would give extra benefits to prevent further clotting in patients who have had a heart attack.

But it didn’t work out that way. One group of the 5,059 veterans in the study got daily doses of 162 milligrams of aspirin; the other half got 81 mg of aspirin and a variable dose of Coumadin.

"There was no difference between the two groups in terms of total mortality or cardiovascular mortality” or for non-fatal heart attacks or strokes, Ezekowitz said. "Aspirin is equally effective as the combination, and aspirin is recommended because it is less costly and doesn’t have to be monitored to regulate the dose.”

But Ezekowitz said the results will be further analyzed to see if any subgroups of patients might still benefit from the combination treatment. He noted that Coumadin is still the drug of choice for most patients who have a heart condition called atrial fibrillation, which involves improper function of the receiving chamber of the heart.

The ACE inhibitor study, carried out by researchers in North and South America and Europe over nearly five years, found that people who took the drug ramipril (Altace) lowered their risk of dying from heart attack, stroke or other cardiovascular disease by 22 percent compared to a control group that didn’t take the drug.

Researchers think the ACE inhibitors work by preventing the disruption of fatty plaque buildups on artery walls, thus avoiding blood clots and heart attacks.

The drug "has a directly protective effect on the blood vessel wall,” said Dr. Salim Yusef of McMaster University in Hamilton, Ontario, who led the study. He calculated that if the drug were given to 1,000 people with clogged arteries or diabetes for four years, it would prevent 150 cardiac events in 70 patients.

Those taking the drug also were less likely to require a heart bypass or angioplasty, to be diagnosed with diabetes or to suffer complications from diabetes.

The researchers said they suspect, but can’t prove, that other ACE inhibitors probably would have similar effects.

The acetaminophen study, described at the meeting by Dr. Addison Taylor, a professor at Baylor College of Medicine in Houston, involved a group of test rabbits whose cholesterol levels had been artificially increased.

Over 12 weeks, half of the rabbits were then given doses of the pain reliever scaled to the doses that might routinely be given to people. At the end of the study period, the rabbits’ aortas were examined and found to have 50 percent less fatty streaking in them than those of the animals not given acetaminophen.

In an earlier human study, Taylor and his colleagues had found that the pain reliever might act as an anti-oxidant, helping prevent artery damage.

While much more research is needed, Taylor said the new findings, along with work by other scientists, "are helping to build a body of evidence suggesting that acetaminophen may help protect against cardiovascular disease.”

(Lee Bowman covers health and science for Scripps Howard News Service. E-mail BowmanL(at)shns.com)

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