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WEDNESDAY, Aug. 13 (HealthDay News) -- Air pollution has short-term and long-term toxic effects on the heart and blood vessels, causing increased hospitalization for cardiac illness, and even cause death, a new report says.

The article, expected to be published in the Aug. 26 issue of the Journal of the American College of Cardiology, looks at previous research that finds inhaled pollutants set off an increase in "reactive oxygen species" -- superoxiding molecules that damage cells -- that cause not only inflammation in the lungs, but also trigger harmful effects in the heart and cardiovascular system.

"We used to think air pollution was a problem that primarily affects the lungs. We now know it is also bad for the heart," Dr. Robert A. Kloner, director of research at the Heart Institute of the Good Samaritan Hospital in Los Angeles, said in a journal news release.

Ultrafine air pollutants, such as those from car exhaust, may pass into the bloodstream and damage the heart and blood vessels directly, recent research has suggested. Studies conducted at the Heart Institute found that ultrafine air pollutants can cause an immediate drop in coronary blood flow and the heart's pumping function, and tend to cause arrhythmias to develop.

Researchers have also found increased levels of air pollution are tied to emergency hospital admissions for heart attack, chest pain and congestive heart failure, and even to death from heart disease, arrhythmias, heart failure and cardiac arrest.

"Air pollution can be dangerous at levels that are within the accepted air quality standards," said Dr. Boris Z. Simkhovich, a senior research associate at the Heart Institute of the Good Samaritan Hospital.

The report takes on special urgency given air pollution has been a major concern of athletes and spectators at the recent Beijing Olympics.

"Patients with cardiovascular disease shouldn't exercise outside on days with increased air pollution levels. On very polluted days, they should consider staying inside, and, during the winter, they should limit exposure to fireplace smoke," Kloner said. "Of course, the real solution is to reduce air pollution."

More information

The American Academy of Family Physicians has more about the possible effects of air pollution  .

MONDAY, Aug. 11 (HealthDay News) -- Cardiac resynchronization therapy (CRT) can help heart failure patients' hearts beat more efficiently and effectively, but most U.S. hospitals don't use it as it should be used, a new report finds.

CRT involves doctors implanting a device that paces the heart's main chambers to beat in sync.

"Studies have shown that, when used in combination with optimal medical therapy, CRT is associated with a 50 percent reduction in hospitalization for heart failure and a 36 percent reduction in mortality, or death," study author Dr. Adrian F. Hernandez, an assistant professor of medicine in the Duke Clinical Research Institute at Duke University, said in a news release. "We did this study to analyze if and how this new therapy is being used in U.S. hospitals."

According to the published analysis of 33,898 heart failure patients admitted to hospitals between January 2005 through September 2007, only 12.4 percent were discharged with CRT.

"That's a small percentage when you consider that we estimate 30 percent to 50 percent of hospitalized patients with heart failure were eligible for CRT based on previous studies," Hernandez said.

Those who did receive the devices tended to have more severe heart failure, as well as a history of heart attacks (58 percent in the CRT group versus 45 percent in the non-CRT group). They also tended to have a history of atrial fibrillation (38 percent versus 27 percent).

While clinical trials have shown that CRT helps patients with a left ventricular ejection fraction (LVEF) -- which shows how well the heart pumps -- of 35 percent or less, only 14.3 percent of the patients with this condition received CRT.

"That means that there are a lot of patients who potentially could benefit from the device who aren't receiving it," Hernandez said. "We also found that 10 percent of patients discharged with a new CRT implant had an LVEF of greater than 35 percent, which suggests that those patients are over-treated. They have not been shown in trials to benefit from the therapy."

Geography and race may play a role in whether CRT is used. For example, heart failure patients treated at northeastern U.S. hospitals were 60 percent less likely to receive CRT than those in other U.S. regions. Black patients were 55 percent less likely than whites to receive the devices.

Hernandez said the findings show that hospitals need to have "systematic practices" to employ best evidence. He also said heart failure patients should investigate their own condition and be their own advocate to get optimal care.

The study findings were published in the Aug. 12 issue of Circulation: Journal of the American Heart Association.

More information

The U.S. Food and Drug Administration has more about cardiac pacemakers.

MONDAY, Aug. 11 (HealthDay News) -- Some obese people don't seem to be at increased risk for heart disease, while some normal-weight people have a number of heart disease risk factors, according to two studies.

In the first study, German researchers analyzed 314 people, ages 18 to 69, and divided them into four groups: normal weight, overweight, obese but still sensitive to insulin, and obese with insulin resistance.

People in the overweight and obese groups had more total body and visceral fat (abdominal fat around the organs) than those with normal weight. But obese people with insulin resistance had more fat within their skeletal muscles and their livers than obese people without insulin resistance. Obese people with insulin resistance also had thicker walls in the carotid arteries, an early sign of narrowing of the arteries -- a condition called atherosclerosis.

Insulin sensitivity and artery wall thickness were the same in obese people without insulin resistance and in normal-weight people.

"In conclusion, we provide evidence that a metabolically benign obesity can be identified and that it may protect from insulin resistance and atherosclerosis," Dr. Norbert Stefan and colleagues at the University of Tubingen wrote. "Furthermore, our data suggest that ectopic (misplaced) fat accumulation in the liver may be more important that visceral fat in the determination of such a beneficial phenotype in obesity."

The study was published this week in the journal Archives of Internal Medicine.

In another study in the same issue of the journal, U.S. researchers assessed body weight and cardiometabolic abnormalities (including high blood pressure, elevated triglycerides, and low levels of "good" high-density lipoprotein cholesterol) in 5,440 adults who took part in the National Health and Nutritional Examination Surveys between 1999 and 2004.

People with none or one abnormality were considered metabolically healthy, while those with two or more abnormalities were metabolically abnormal.

"Among U.S. adults 20 years and older, 23.5 percent (approximately 16.3 million adults) of normal-weight adults were metabolically abnormal, whereas 51.3 percent (approximately 35.9 million adults) of overweight adults and 31.7 percent (approximately 19.5 million adults) of obese adults were metabolically healthy," wrote Rachel P. Wildman, of the Albert Einstein College of Medicine, and colleagues.

Normal-weight adults with metabolic abnormalities tended to be older, less physically active, and have larger waists than healthy normal-weight adults, the study said. Obese people with no metabolic abnormalities were more likely to be younger, black, more physically active and have smaller waists than those with metabolic risk factors.

"These data show that a considerable proportion of overweight and obese U.S. adults are metabolically healthy, whereas a considerable proportion of normal-weight adults express a clustering of cardiometabolic abnormalities," the researchers concluded. "Further studies into the behavioral, hormonal or biochemical and genetic mechanisms underlying these differential metabolic responses to body size are needed and will likely further the identification of possible obesity intervention targets and improve cardiovascular disease screening tools."

"Both reports emphasize the benign nature of fat accumulation outside the abdomen," Dr. Lewis Landsberg, of the Northwestern University Comprehensive Center on Obesity in Chicago, wrote in an accompanying editorial.

"In both studies, the detrimental effect of visceral fat accumulation and its surrogate, waist circumference, were clearly demonstrated, confirming older studies showing that waist circumference is a risk factor even in normal-weight individuals," he said.

The studies show it's important to calculate body mass index and measure waist circumference when assessing cardiovascular risk in overweight and obese patients, Landsberg noted.

More information

The U.S. Centers for Disease Control and Prevention has more about heart disease risk factors.

THURSDAY, July 17 (HealthDay News) -- Measuring proteins that carry cholesterol in the blood may give a better estimate of heart attack risk than measuring cholesterol, a major study finds.

The study focused on the ratio of two of the proteins, called apolipoprotein B100 (ApoB) and apolipoprotein A1 (ApoA1). The international team of researchers studied data on more than 27,000 people and found that the ratio of apolipoprotein B100 (ApoB) to apolipoprotein A1 (ApoA1) accounted for 54 percent of the risk of heart attack.

In contrast, the standard ratio of "bad" LDL cholesterol to "good" HDL cholesterol accounted for only 37 percent of the risk, researchers reported in the July 19 issue of The Lancet.

But the two testing methods are finely connected, said study lead researcher Dr. Matthew McQueen, professor of pathology and molecular medicine at McMaster University in Hamilton, Ontario, Canada.

"When you start looking at cholesterol and apolipoproteins, they are very closely related," McQueen said. "The protein that carries LDL cholesterol is ApoB, and the protein that carries HDL cholesterol is ApoA1. Clearly, you're not going to find differences [in a study] unless you do large numbers."

The finding directly contradicted a report last year from the renowned Framingham Heart Study, which found that measuring ApoB/ApoA1 ratios added nothing to standard risk assessments from ordinary blood cholesterol tests. The Framingham study -- which included about 3,300 middle-aged men, 291 of whom developed heart disease over 15 years -- was numerically much smaller than the new report, however.

"It's a question of statistical power in a study," agreed Dr. Lars Lind, professor of medicine at the University of Uppsala in Sweden, who wrote an accompanying editorial on the new findings in The Lancet. "This study is based on more than 10,000 cases. When it come to statistics, it is the number of cases that really counts," he said.

The fact that the study was done "not only in a large number of people but also in 52 countries and a variety of ethnic groups" also adds strength to the findings, McQueen said.

But that very variety could also be a weakness, said Dr. Peter Wilson, who took part in the Framingham study while at Boston University. He is now professor of medicine at Emory University in Atlanta. "It's not like they had a single community or controls from lots of different types all around the world," he reasoned.

Another weakness of the study was that it included people only after they had heart attacks, Wilson said. That means that "you can't talk about lipid [blood fats] risk before you get a heart attack," he said. "This is lipid risk only after you have a heart attack."

Finally, the study was conducted with frozen blood specimens, Wilson noted. "Cholesterol does better in fresh specimens," he said.

Despite those flaws, the new findings do add to indications that apolipoprotein testing has a major clinical role to play in the future, Wilson said. The American College of Cardiology has recently discussed such testing for people with diabetes, he said.

Even if such tests are better than the existing cholesterol tests, it will take time to introduce them into general medical practice, Wilson said. "The point is technology," he said. "Cholesterol tests are all reliable, and we know what they mean. We don't have experience with apolipoproteins in the clinical environment."

Automated apolipoprotein tests now are available, McQueen said. He said he uses them to add information to what is shown by conventional cholesterol testing.

The Uppsala hospital is trying to phase in apolipoprotein tests, Lind said. "We are giving them in tandem, so that people get adjusted to them," he said.

More information

Find out the basics on cholesterol at the American Heart Association  .