A deeper look at heart’s mysteries
Not so long ago, heart disease was not considered a major problem among women.
As recently as 1995, more than one-third of physicians surveyed did not even know that it was the leading cause of death among women, killing half a million each year. Even today, many doctors may not appreciate the risks because women often have different symptoms than men.
Women suffering chest pain often go to a cardiologist only to find there are no obstructions in their large arteries, reported cardiology specialist Rhonda Cooper-DeHoff of the University of Florida College of Medicine in research presented last week at a Chicago meeting of the American Heart Assn. Although frequently diagnosed with heartburn and told they have nothing to worry about, she said, women with chest pain are four times as likely to die from heart disease as women without pain.
The results of her study were among those presented at the annual meeting of heart specialists and researchers. Other studies included fresh evidence that blows to the chest can be fatal for young athletes despite the use of protective equipment, and that stents can be avoided in some obstructed arteries.
Cooper-DeHoff and her colleagues studied 564 women with chest pain who underwent angiography that showed no blockages of their coronary arteries, and they compared them with 1,000 women with no documented heart disease.
They found that, within five years, nearly 12% of the women with chest pain had been hospitalized for heart failure, had suffered a heart attack or stroke or had died, compared with just under 3% of the women in the control group.
She speculated that smaller arteries in the affected women had become glazed with plaque, triggering symptoms. The plaque is not detectable using standard angiography.
“The message here is that you do not want to tell a woman who comes to you and says ‘I have chest pain’ not to worry,” she said.
Other researchers found that women with heart failure -- an inability of the heart to pump enough blood to the body’s tissues -- tend to live longer than men with heart failure and have a less severe form of the disease. For that report, Dr. Camille Frazier of Duke University and her colleagues studied the two most common forms of heart failure, ischemic and non-ischemic.
In the ischemic form, heart muscle is damaged over a long period of time as blood flow to the heart is blocked by accumulating plaque in the coronary arteries, often leading to a heart attack. In the non-ischemic form, there is no history of coronary artery disease and no heart attack.
The researchers combined data on 11,642 patients in five large clinical trials; 24% of the patients were women.
Frazier told attendees at the meeting that, during the follow-up period of nearly a year, 18.6% of women with ischemic heart failure died, compared with 20.9% of men. Among those with non-ischemic heart failure, 18.2% of women died, compared with 21.9% of men. The lower death rates occurred despite the fact that the women were, on average, older than the men and had higher rates of diabetes and high blood pressure.
Blows to the chest
Also at the meeting, Dr. Barry J. Maron of the Minneapolis Heart Institute Foundation reported that commercial gear may not protect young athletes from sudden death caused by a blow to the chest. The condition is called commotio cordis -- “commotion of the heart” -- and results from a blunt blow that triggers an irregular heart rhythm called ventricular fibrillation.
Maron established the National Commotio Cordis Registry at the institute in 1995 to track cases. Of the 182 cases recorded to date, 85 occurred during practice or competition for organized sports and 39% of these deaths occurred in athletes wearing chest protectors. Their average age was 15 years.
The other 97 deaths occurred during recreational sporting activities.
Among athletes, 14 were hockey players, 10 were football players, six were lacrosse players and three were baseball players.
Experiments at the New England Medical Center and Tufts University School of Medicine have shown that ventricular fibrillation can be produced by a baseball moving only 30 mph, but only if it hits the chest directly over the heart during a 20-millisecond interval when the lower heart chambers relax electrically.
“Hopefully, these data will support a stimulus for developing a truly effective chest barrier,” Maron said. Coaches also need to be more aware of the potential for the problem so that prompt resuscitation can be performed, he said.
No need for stents?
Wire mesh tubes called stents are now widely used to prop open previously blocked coronary arteries following angiography, and cardiologists increasingly have begun to use stents coated with drugs, which are thought to help keep the arteries open even more effectively.
Recent studies, however, have shown that, in many cases, the arteries become re-narrowed again despite the drugs. Some physicians also suspect that the drug-eluting stents are more dangerous than uncoated stents and that stents in general may contribute to re-narrowing of the arteries by irritating vessel walls.
A small study presented at the meeting and reported online in the New England Journal of Medicine suggests an alternative way to keep the vessels from closing -- coating the balloon used for angiography with a drug that inhibits plaque formation.
Dr. Bruno Schellar and his colleagues at Saarlandes University in Homburg/Saar, Germany, studied 52 patients who had previously received a stent only to have the artery close again. Half the patients had the artery re-opened with an uncoated balloon and half with a balloon coated with the drug paclitaxel.
Six months after the treatment, 43% of those treated with the uncoated balloon had a re-narrowing of the artery, compared with 5% of those treated with the paclitaxel-coated balloon, Schellar said.
He speculated that the coated balloon may be more effective than a stent because it distributes the drug more widely and irritates vessel walls less.
