Seventy-eight-year-old Joseph Dollard golfs several times a week. He supplements that with swimming, gardening and long walks. You would not guess from his lean physique and bright eyes that he had a heart attack at age 34, or that he's been taking a daily dose of pills ever since to avoid another.
Among them was a 325 milligram aspirin pill, prescribed by a cardiologist 40 years ago and continued by Dollard's current cardiologist, Dr. Paul Gurbel of Sinai Hospital. But the results of a recent study by Gurbel and his team at Sinai's Center for Thrombosis Research indicate Dollard may be better off taking half that much.
In the future, doctors are expected to be able to customize the aspirin doses they prescribe for heart patients. More research, Gurbel hopes, will lead to a standardized test that helps determine ideal dosage. His study found that, on average, 162 milligrams of aspirin appear to be the most effective dose in controlling heart disease.
The study was funded by Sinai Hospital and by aspirin maker Bayer HealthCare, from whom Gurbel received an honoraria. It was published in this month's issue of Circulation.
A separate study made public yesterday sheds more light on the body's response to aspirin. In the July 6 issue of the Journal of Proteome Research, Spanish scientists report they have identified blood proteins that seem to be involved in aspirin resistance, a condition that prevents many patients from reaping the drug's beneficial effects in protecting against heart disease and stroke.
Aspirin's origins go back to 400 B.C., when Hippocrates recommended the use of willow tree bark, which, like aspirin, contains salicin, as a painkiller. The drug has been found to be helpful in treating and/or preventing heart attack, stroke, Alzheimer's disease and colon cancer.
In a large study led by the Mayo Clinic and published in the June issue of the Journal of the National Cancer Institute, researchers concluded that regular aspirin use may significantly reduce the incidence of cancer and heart disease.
Postmenopausal women who reported taking aspirin had a 16 percent reduced risk of getting cancer, and a 13 percent reduced risk of cancer death, compared with other women in the study who did not take it. The risk of dying of coronary artery disease was reduced by 25 percent, and the risk of dying from all causes was reduced 18 percent compared with those who never took aspirin.
Patients with coronary heart disease develop hardened blocks of fat in the walls of their arteries, affecting the area through which blood is supposed to easily flow from the heart. When these fat deposits rupture, small components in the blood called platelets form blood clots. Clots can block blood flow, which results in a heart attack.
Aspirin prevents platelets from coagulating and forming clots, reducing the risk of life-threatening attacks in heart patients by 25 percent to 44 percent.
Ten percent of Americans suffer from some form of coronary heart disease and many take doctor-recommended doses of aspirin. Yet there has been an absence of research on platelet aggregation, Gurbel said.
"It amazes me. In diabetes patients we check sugar levels. We monitor insulin in diabetes patients and we monitor blood pressure-regulating medication in [blood pressure] patients," he said, "yet we do not assess the effects of aspirin on platelet aggregation in heart patients."
At Sinai, Dollard participated as a volunteer, agreeing to have his blood analyzed by Gurbel and his team while taking three different doses of aspirin - 81 milligrams, 162 milligrams and 325 milligrams - each for four weeks.
The American Heart Association recommends between 75 milligrams and 162 milligrams of aspirin daily for high-risk patients who have heart disease.
"Based on our data, I would favor the 162 milligrams dose," said Gurbel, though his research also showed that this might not be the right choice across the board. "In some patients, the 162 milligrams dose may be too much and be associated with a bleeding hazard," he said.
The constant danger with aspirin is that by preventing clots and thinning the blood, it can result in excessive bleeding.
"If your risk to have a heart attack or stroke is greater than 1 percent per year, the benefit of taking aspirin is greater than the risk," said Dr. Nauder Faraday, co-director of the Cardiac Surgical Intensive Care Unit at Johns Hopkins Hospital.
More broadly speaking, Gurbel's work is a step away from a one-size-fits-all approach.
"The whole concept of personalized medicine is something that's emerging. It's in vogue," said Dr. Robert Myerburg, a cardiologist at the University of Miami Medical School. "If we can look at how platelets respond, we can look at what dosage to give them," he said.
Dr. Robert Poston, a cardiac surgeon at the University of Maryland Medical Center who also researches platelet functioning, welcomed Gurbel's research. "People don't like to think it's that complicated when it comes to blood clotting," Poston said, "but as a surgeon I see some people who bleed like crazy and other people who are bone dry and heal themselves quickly.
"This might be a sign that some platelets are more functional than others," he said.
Faraday said there are many people interested in this area. "The goal would be to tailor the aspirin dose to the individual patient's needs using the right laboratory measurement." At the moment, it is unclear why certain patients have stickier platelets that require a higher dose of aspirin. "It does not appear related to age or weight," Gurbel said.
There is more work to be done. "You have got to first prove that this [varying doses] makes a difference, and this will require a long-term clinical study," Myerburg said. The study done by Gurbel involved about 100 patients, but a more conclusive study, Gurbel said, would "require enrolling over 10,000 patients."
Still, based on the results of his study, Gurbel has upped his own dose of aspirin from 81 milligrams to 162 milligrams. While the doctor has never had a heart attack and believes he is in good health, he takes a preventive dose daily because of a family history of heart disease.
Meanwhile, Dollard, his patient, has reduced his daily dose. He now takes 162 milligrams of aspirin, which the study showed offered more ideal platelet control for him.
"I don't feel anything different," Dollard said of his lowered dose, "but if the doctor thinks it works better, that's fine with me."
Lowers risk of death during a heart attack
Helps prevent recurrent mini-strokes
Reduces risk of heart attack and stroke
Reduces recurrence of colon cancer and may reduce risk of developing any cancers
May reduce risk of Alzheimer's disease
For statistics on heart disease in the United States, go to americanheart.org and click on Heart & Stroke Encyclopedia, then the letter "C," and Cardiovascular Disease Statistics
To read the Circulation article by Dr. Paul Gurbel's team at Sinai Center for Thrombosis Research, go to circ.ahajournals.org/, type "Gurbel" in the search field, then check the box next to the aspirin article and click "Go."