New Therapy for Bypass Patients
Gene therapy for the heart can stimulate the growth of new blood vessels that bypass clogged arteries and provide increased blood flow to the organ, two groups of researchers reported last week.
The two teams have treated about 30 people with the technique, and most patients have reported decreased chest pain and improved quality of life following the therapy, the researchers said at an American Heart Assn. meeting in Dallas.
The studies are a follow-up to reports last year that the technique could be used to provide improved circulation in legs with arteries blocked by clots.
Experts cautioned that it could be several years before the therapy is used routinely but speculated that it could eventually help many of the 1 million Americans who undergo bypass surgery each year. About half of those surgeries fail within a year when the new arteries also become clogged.
The two teams took different routes to their treatments. Dr. Jeffrey Isner and his colleagues at St. Elizabeth’s Medical Center in Boston made a small slit in the chest to access the blocked vessels and injected the gene for a protein called vascular endothelial growth factor, or VEG-F, which stimulates the production of new blood vessels.
Isner’s team injected the genes into 16 heart attack victims who suffered severe chest pain but were too sick for bypass surgery. Of the 11 patients who have been followed for at least three months, six are entirely free of pain, he said.
Dr. Ronald Crystal and his colleagues at Cornell Medical School in New York City used a modified cold virus to carry the VEG-F gene into 14 patients. They have concluded that the treatment is safe but have not yet shown that it increases blood flow.
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A variety of other reports were presented at the Dallas meeting, including one suggesting that the upcoming holiday season is particularly hazardous for people at risk of heart problems.
Dr. Robert Kloner of Good Samaritan Hospital reviewed 220,000 deaths in Los Angeles from 1985 to 1996 and found that the risk of death from heart disease is 33% higher in winter than in summer.
The risk begins to increase around Thanksgiving, reaches its peak at New Year’s and then gradually tapers off, with January being the worst month overall. Previous studies in other parts of the country suggested that this increase might be due to cold winter weather, but Kloner said that similar findings in Los Angeles suggest deaths are linked more to the stresses and overindulgence of the holidays.
Mornings typically present the highest risk of a heart attack, with Monday morning being the worst. Previously, researchers associated that risk with the stress of going back to work.
But Dr. Michael K. Kruska of Hanusch Hospital in Vienna, Austria, reviewed more than 1,500 fatal heart attacks in that city and concluded the risk was highest on Monday morning even for those who are retired. The retirees’ risk was 20% to 40% higher on Monday morning.
Although heart attacks at night are less common, they tend to be more serious, according to Dr. C. Michael Gibson of Allegheny General Hospital in Pittsburgh. He studied 1,246 heart attack cases and found that people who suffered their first heart attack at night were twice as likely to die or have a second heart attack while in the hospital.
To stave off such attacks, new studies suggest that people should consume more oats and nuts and, not surprisingly, should exercise more.
In a long-term study of female nurses headquartered at Brigham and Women’s Hospital in Boston, researchers found that women who consumed more than 5 ounces of nuts per week had a 35% lower risk of coronary heart disease than women who ate less than 1 ounce. Men seemed to benefit in a similar fashion in a study of male doctors.
Researchers speculated that the benefits were produced by alpha-linoleic acid, which is present in high concentrations in nuts and has previously been linked to a reduced risk of heart disease.
A team from Harvard Medical School and Tufts University studied 43 men and women who consumed diets high in oats and compared them to people who ate a similar diet in which the oats were replaced with wheat.
Those who ate oats showed a decrease in cholesterol levels of 34 milligrams per deciliter, compared to a decrease of only 13 mg/dL among those who ate the wheat diet. The oat eaters also reduced their systolic blood pressure (the top number) by 7 millimeters of mercury, compared to only 2 mm/Hg among the wheat eaters.
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Exercise is particularly beneficial to people with congestive heart failure (CHF), according to a team from the Duke University Medical Center. The hearts of people with CHF do not pump as well as they should, and victims become breathless and tired easily. Many doctors do not recommend exercise for fear that it will further damage heart muscle.
Dr. David Whellan and his colleagues studied 1,420 CHF patients for four years. They found that only 8% of those who exercised died, compared to 36% of those who did not exercise. “That makes exercise as effective as the best drugs we can offer these patients,” Whellan said.
One drug that is not used routinely to treat CHF patients can actually be very effective, according to a team from the University of Maryland Medical Center. The drug is metopropol, a beta-blocker that is generally not used because it initially makes the heart beat less effectively.
Dr. Steven S. Gottlieb reported, however, that if the drug is started at low doses that are increased slowly and carefully, it produces a 35% increase in survival. Their study of nearly 4,000 patients was stopped three years early because the drug was so effective.
