By MyHealthNewsDaily staff

For heart attack survivors, living close to a roadway may be hazardous for their health, a new study suggests.

The results show that heart attack survivors who lived about 300 feet (100 meters) from a major roadway at the time of their heart attack were 27 percent more likely to die over the next 10 years compared with those who lived at least 3,200 feet (1,000 m) from a roadway.

Those who lived between 650 to 3,200 feet (200 to 1,000 m) away from a roadway had a 13 percent higher risk of dying in 10 years.

Exposure to air pollution and traffic noise from the roadway may explain the link, said study researcher Dr. Murray Mittleman, a physician at Beth Israel Deaconess Medical Center in Boston.

Long-term exposure to air pollution is known to increase the risk of death from heart disease, and some studies have shown exposure to traffic noise increases blood pressure, the researchers said.

The study involved 3,547 people who were hospitalized for a heart attack at 64 medical centers in the United States between 1989 and 1996. Participants' average age at the beginning of the study was 62.

Over a 10-year follow-up period, 1,071 participants died: 63 percent of cardiovascular disease, 12 percent of cancer, 4 percent of respiratory failure and 0.4 percent in traffic accidents.

The closer patients lived to a major roadway, the more likely they were to die during the follow-up period. The results held even after the researchers accounted for factors that could affect a person's risk of death, including age, smoking status, proximity to a hospital and household income.

The researchers said the study was limited in that they don't know whether participants moved after their heart attack, or if new roadways were built closer to participants' homes, but either of these scenarios could affect the results.  For instance, a patient who moved closer to a roadway would have been misclassified in the study.

The American Heart Association suggests clinicians educate their patients on the risks posed by air pollution, and encourage patients with cardiovascular disease to avoid unnecessary exposure to traffic, the researchers said.

The study will be published in the May 8 issue of the journal Circulation.  

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Short-term exposure to air pollution -- just a day or a week in some cases -- may kick off a heart attack or stroke, scientists now say.

Two new studies reveal that the risk of heart attack or stroke can jump after high-pollution days, especially for people who already have predisposing health problems.

Up to a week of exposure to most major types of air pollution may be enough to trigger a heart attack, a new analysis published in the latest issue of the Journal of the American Medical Association finds. Heart attack risk went up by almost 5 percent with high carbon monoxide levels and almost 3 percent with higher levels of air particles for up to seven days.

The risk of stroke jumped 34 percent after 24 hours of exposure to moderate air pollution, according to a study published in the latest issue of the Archives of Internal Medicine.

The increase in stroke risk was greatest within 12 to 14 hours of exposure to fine particulate matter and was most strongly associated with pollution from traffic.

No one knows exactly how much pollution will trigger a heart attack or brain attack, but experts suggest that vulnerable people protect themselves by minimizing time spent breathing air contaminated with a heavy dose of fine particles.

“What we can say is that exposure to a high level of pollution is harmful to people at risk,” said Dr. Hazrije Mustafic, the lead author of the analysis that examined data for pollution and heart attack risk in 34 previous studies.

“They must avoid the most polluted places, like highways, for example,” said Mustafic, a cardiologist and a researcher in cardiovascular epidemiology at the University of Paris Descartes, INSERM Unit 970. “We do not know how long of an exposure causes an excess risk of heart attack, but the relationship is linear.”

In other words, Mustaficsaid, as exposure increases, both in terms of time and intensity, so does the risk of a heart attack.   

The best recourse for those with cardiovascular disease may be to keep a close eye on local pollution levels, experts say. And government agencies are making that easier and easier.  The Environmental Protection Agency, for example, has a downloadable app that provides information on local air quality.

While short-term exposures to pollution can’t explain every stroke or heart attack, they do have a significant impact, experts said.

In 2007, for instance, there were 184,000 hospitalizations for stroke in the Northeastern U.S., said Gregory Wellenius, lead author of a paper on stroke risk published in the latest issue of the Archives of Internal Medicine.

“We estimate that 6,000 of those stroke hospitalizations could have been prevented,” Wellenius said.

His research study is the first to look at how short-term exposure to pollution impacts stroke risk. And, even though he found an increased risk, Wellenius is hesitant to offer advice until other studies duplicate his findings.

“This is just one study,” said Wellenius, who performed the research at Harvard’s Beth Israel Deaconess Medical Center and is now an assistant professor of epidemiology at Brown University. “It was done in Boston, a city notable because it has relatively low pollution levels. The study should be replicated in other parts of the country.”

The researchers did find that even moderate amounts of pollution can cause harm, said Roger Peng, an associate professor of biostatistics at the Johns Hopkins School of Public Health.

“They found a pretty sizable effect on ischemic stroke for a range of people at a relatively low level – one that is well under the national air quality standards,” Peng said.

The study is underscoring the point that “there is no safe level,” of pollution Peng added.

The culprit in both studies is particulate matter, tiny bits of material and droplets, known as PM2.5s. The particles come from a variety of sources, including power plants, factories, trucks and cars.

“These are very small particles, about a 30^thof the diameter of a human hair, ” Peng explained.

Peng suggested that people concerned about air quality download from the AIRNow app from the EPA’s website. The app works on both Apple and Android phones and allows users to get pollutant and ozone levels for more than 400 cities across the nation.

On bad air days, people at risk for heart attack or stroke might want to be careful about exercising outside, Peng said.

Other researchers go even further.  

“If you have any kind of cardiovascular risk factor it might be prudent to avoid anything that could make you breath hard and bring more junk into your lungs,” said Patrick Kinney, a professor of environmental health sciences at the Mailman School of Public Health at Columbia University. “The trouble with some of these pollutants is that they can get inside, too.”

The two new studies extend what scientists had already learned about pollution and cardiovascular disease, Kinney said. Earlier research showed that long-term exposure to pollutants could lead to clogged arteries, just as smoking cigarettes can, Kinney said.

While people can try to limit their personal exposure to these tiny particles, the best approach would be to get pollution levels down, Kinney said.

“To me this suggests the need to push for cleaner air,” he added. “If all cars and trucks were electric powered you wouldn’t have to worry as much.”

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The loss of a loved one can literally turn heartache into heartbreak, a new study shows.

Researchers found the risk of a heart attack jumped to 21 times higher than normal in the day following the death of a close relative or friend, according to the study published in the journal Circulation.

And that spike occurred even in people at low risk of heart attack, said the study’s lead author, Elizabeth Mostofsky, a post-doctoral research fellow at the Beth Israel Deaconess Medical Center and the Harvard School of Public Health.

“That’s why this study sends such an important message,” Mostofsky said. “If you see someone dealing with grief you need to recognize if they’re having symptoms of a heart attack. You need to realize that they might not just be dealing with grief, but might need medical attention.”

Between 1989 and 1994, the researchers interviewed 1,985 adult heart attack survivors while the patients were still in the hospital. Their average age was just under 62 and they were followed until 2007. Men seemed to be more affected than women, she added.

"Men have a higher risk than women when they lose a spouse," she explained.

Mostofsky and her colleagues found that the most dangerous time was within the first 24 hours after the death of a close friend or relative, with the risk of heart attack spiking 21 times higher than normal. The risk slowly fell off with time, but was still elevated to six times normal in the week following the death.

While the chance of a heart attack among the bereaved was higher for those with risk factors, it was still significant for those at low risk. And that’s why people need to be aware of the danger, Mostofsky said.

Unfortunately, it’s easy to misinterpret heart attack symptoms such as tightness in the chest, stomach pain, light-headedness, nausea and shortness of breath, as signs of grieving, she added. But someone who is grieving and experiencing these symptoms requires medical attention.

Scientists aren’t sure exactly how intense grief leads to heart attack, but there are some theories.

“People are dealing with depression, anger and anxiety,” Mostofsky said. “That can lead to increases in heart rate and blood pressure. It can also lead to a coagulation response in which the blood is more likely to become sticky and clot and that can lead to a blockage and then a heart attack.”

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A woman's risk of having a heart attack may begin to rise even before she is born, a new study suggests, and the findings may help researchers better understand the nature of heart disease in women.

The study found women's risk of having a heart attack increased more than eight times if they had changes in certain genes; these changes were previously found to be brought on by stress experienced in the womb, such as not getting enough nutrients.

"Health really starts in the womb," said study researcher Bas Heijmans, a molecular epidemiologist at Leiden University Medical Center in The Netherlands.

The findings support the idea that conditions during early life, such as the habits of a mother during pregnancy, influence her baby's risk of later developing heart disease, Heijmans said.  Ultimately, the researchers would like to find genetic "signatures " that can tell the tale of someone's early life, such as an exposure to alcohol or cigarette smoke. Those signatures could then be used as markers for the persons' risk of disease later in life, Heijmans said.

The findings are published in the Nov. 17 in the International Journal of Epidemiology.

DNA in early life
The study involved 1,654 participants ages 70 to 82 who hadn't had a heart attack before the study's start. After three years, 122 people had suffered a heart attack. The researchers compared the DNA of these individuals to that of 126 participants who had not experienced a heart attack, but were similar in age and other characteristics.

The researchers looked for changes, called epigenetic changes, in six genes known to be influenced by the in utero environment. During such a change, a chemical "tag" is added to a section of DNA.

They found epigenetic changes in two of the genes were associated with an increased risk of heart attack. Women with a tag on one gene were 2.8 times more likely to have a heart attack, and women with a tag on both genes were 8.6 times more likely to have a heart attack, compared with women who didn't have these changes.

However, more work is needed to validate the results. The new study was conducted in adults, so the researchers don’t know exactly what experiences the participants had during the prenatal period.

Men and women
No association between changes in the genes and heart attack risk was found for men. The researchers aren't sure why this is,but it could be that men tend to have heart attacks at earlier ages than the participants included in the study, masking the effect of the gene changes in the study group, Heijmans said.

Because the study was small, these estimates of increased risk for women should be interpreted with caution, Heijmans said. Larger studies that included a wider range of age groups are needed to determine more accurate risk estimates, Heijmans said.

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Teen athletes at risk for sudden cardiac death may be falling through the cracks because doctors are skipping parts of screening exams, a new study shows.

In pre-season physicals for high school sports, fewer than 6 percent of doctors followed the potentially life-saving screening guidelines suggested by the American Heart Association, according to a report presented at the Heart Association’s annual meeting.

While doctors typically listen to young athletes’ hearts and record blood pressures, they often fail to ask important questions designed to ferret out heart disease risk. For example, 67 percent of surveyed doctors said they didn’t always ask teens whether any family members suffered from heart problems.

Even more alarming – barely half of the physicians were even aware that the AHA guidelines existed.

More than 7 million teens play high school sports, according to Dr. Nicolas Madsen, a cardiology fellow at Seattle Children’s Hospital of the University of Washington. Studies show that sudden death occurs at a rate of one in 30,000 to 40,000. That translates into 175 to 233 deaths each year among high school athletes. 

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Recently, there’s been a push to add more tests, such as electrocardiograms, to the standard student-athlete physical, said Madsen, the study’s lead author. But we can’t know whether those additional tests are necessary until all physicians are following current guidelines to the letter, Madsen added.

For the new study Madsen and his colleagues sent out surveys to every family practice doctor and every pediatrician in Washington State. The response was high with 72 percent of pediatricians and 56 percent of family practitioners returning surveys.

Doctors did most poorly when it came to asking about the heart health of teens and their families.

• 28 percent didn’t always ask if a teen had chest pain during exercise
• 22 percent didn’t always ask if the teen ever experienced unexplained fainting
• 26 percent didn’t always ask about a family history of early deaths
• 67 percent didn’t always ask about a family history of heart disease.

While it’s heartening to see that most doctors did remember to ask about sudden deaths in a teen’s family, it’s distressing to see that more than two thirds of doctors weren’t always asking about a family history of heart disease in their exams, Madsen said.

That means that doctors could be missing families in which there were recognized heart problems, but no one had died.

For Dr. Gaurav Arora the biggest surprise in the new study was the number of physicians who said they didn’t always ask about chest pain or fainting.

“Those are red flags in young athletes,” said Arora, associate director of electrophysiology at the Children’s Hospital of Pittsburgh and an assistant professor of pediatrics at the University of Pittsburgh.

One explanation for the new findings is that there is no single form being used by doctors doing pre-season physicals for student athletes, Arora said. Things would be a lot simpler if everyone used the same screening criteria.

Beyond that, Arora said, “we need better education across the board for all providers doing screening.”

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