Smoking Bans Reduce Risk Of Heart Attacks Associated With Secondhand Smoke

Smoking bans are effective at reducing the risk of heart attacks and heart disease associated with exposure to secondhand smoke, says a new report from the Institute of Medicine. The report also confirms there is sufficient evidence that breathing secondhand smoke boosts nonsmokers' risk for heart problems, adding that indirect evidence indicating that even relatively brief exposures could lead to a heart attack is compelling."It's clear that smoking bans work," said Lynn Goldman, professor of environmental health sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, and chair of the committee of experts that wrote the report. "Bans reduce the risks of heart attack in nonsmokers as well as smokers. Further research could explain in greater detail how great the effect is for each of these groups and how secondhand smoke produces its toxic effects. However, there is no question that smoking bans have a positive health effect."

About 43 percent of nonsmoking children and 37 percent of nonsmoking adults are exposed to secondhand smoke in the United States, according to public health data. Despite significant reductions in the percentages of Americans breathing environmental tobacco smoke over the past several years, roughly 126 million nonsmokers were still being exposed in 2000.

A 2006 report from the U.S. Surgeon General's office, The Health Consequences of Involuntary Exposure to Tobacco Smoke, concluded that exposure to secondhand smoke causes heart disease and indicated that smoke-free policies are the most economical and effective way to reduce exposure. However, the effectiveness of smoking bans in reducing heart problems has continued to be a source of debate.

The IOM committee conducted a comprehensive review of published and unpublished data and testimony on the relationship between secondhand smoke and short-term and long-term heart problems. Eleven key studies that evaluated the effects of smoking bans on heart attack rates informed the committee's conclusions about the positive effects of smoke-free policies. The studies calculated that reductions in the incidence of heart attacks range from 6 percent to 47 percent. Given the variations in how the studies were conducted and what they measured, the committee could not determine more precisely how great the effect is. Only two of the studies distinguished between reductions in heart attacks suffered by smokers versus nonsmokers. However, the repeated finding of decreased heart attack rates overall after bans were implemented conclusively demonstrates that smoke-free policies help protect people from the cardiovascular effects of tobacco smoke, the committee said.

The report also provides a detailed discussion of the evidence from animal research and epidemiological studies showing a cause-and-effect relationship between secondhand smoke exposure and heart problems. The committee was not able to determine the exact magnitude of the increased risk presented by breathing environmental tobacco smoke, but noted that studies consistently indicate it increases the risks by 25 percent to 30 percent. Although there is no direct evidence that a relatively brief exposure to secondhand smoke could precipitate a heart attack, the committee found the indirect evidence compelling. Data on particulate matter in smoke from other pollution sources suggest that a relatively brief exposure to such substances can initiate a heart attack, and particulate matter is a major component of secondhand smoke.

The report was sponsored by the U.S. Centers for Disease Control and Prevention. Established in 1970 under the charter of the National Academy of Sciences, the Institute of Medicine provides independent, objective, evidence-based advice to policymakers, health professionals, the private sector, and the public. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies.

Those With Severe H1N1 At Risk For Pulmonary Emboli, Researchers Find

University of Michigan researchers have found that patients with severe cases of the H1N1 virus are at risk for developing severe complications, including pulmonary emboli, according to a study published today in the American Journal of Roentgenology.A pulmonary embolism occurs when one or more arteries in the lungs become blocked. The condition can be life-threatening. However, if treated aggressively, blood thinners can reduce the risk of death.

“The high incidence of pulmonary embolism is important. Radiologists have to be aware to look closely for the risks of pulmonary embolism in severely sick patients,” said Prachi P. Agarwal, M.D., assistant professor of radiology at the U-M Medical School and lead author of the study.

“With the upcoming annual influenza season in the United States, knowledge of the radiologic features of H1N1 is important, as well as the virus’s potential complications. The majority of patients with H1N1 that undergo chest X-rays have normal radiographs. CT scans proved valuable in identifying those patients at risk of developing more serious complications as a possible result of the H1N1 virus,” says Agarwal.

Working with Agarwal on the research were Ella Kazerooni, M.D., director of U-M’s division of cardiothoracic radiology and professor of radiology and Sandro K. Cinti, clinical assistant professor in U-M’s Department of Internal Medicine. The research included 66 patients diagnosed with the H1N1 flu. Of those, 14 were patients that were severely ill and required Intensive Care Unit admission.

All 66 patients underwent chest X-rays for the detection of H1N1 abnormalities. Pulmonary emboli were seen in CT scans on five of the 14 ICU patients.

Another important finding is that initial chest radiographs were normal in more than half of the patients with H1N1, says Kazerooni.

“These findings indicate that imaging studies would have to be repeated in severely ill patients to monitor disease progression,” said Kazerooni. “It’s important to heighten awareness not only among the radiologists, but also among the referring clinicians.”

There was no outside funding for the research.

The study will be published in the December issue of the AJR.

'ECG For The Mind' Could Diagnose Depression In An Hour

An innovative diagnostic technique invented by a Monash University researcher could dramatically fast-track the detection of mental and neurological illnesses.Monash biomedical engineer Brian Lithgow has developed electrovestibulography which is something akin to an 'ECG for the mind'. Patterns of electrical activity in the brain's vestibular (or balance) system are measured against distinct response patterns found in depression, schizophrenia and other Central Nervous System (CNS) disorders.

The vestibular system is closely connected to the primitive regions of the brain that relate to emotions and behaviour, so Lithgow saw the diagnostic potential of measuring and comparing different patterns of electrovestibular activity.

Working with psychiatry researchers at Monash University's Alfred Psychiatry Research Centre (MAPrc) in Melbourne, Australia, he tested volunteers and found distinct response patterns, or "biomarkers", that distinguished different CNS diseases from each other and from regular electrovestibular activity.

Monash has teamed up with corporate partner Neural Diagnostics to develop and patent electrovestibulography, or EVestG™. It is hoped the simple, quick and inexpensive screening process for CNS diseases will eventually become standard practice in hospitals around the world.

"The patient sits in a specially designed tilt chair that triggers electrical responses in their balance system. A gel-tipped electrode placed in the individual's ear canal silences interfering noise so that these meaningful electrical responses are captured and recorded," the Monash researcher said. "The responses are then compared to the distinct biomarkers indicative of particular CNS disorders, allowing diagnosis to be made in under an hour."

Neural Diagnostics CEO Dr Roger Edwards said the implications of the new technique were huge.

"This could be one of the most significant inventions ever to come out of Monash. CNS disorders cost upwards of $US2 trillion globally and affect one in four people sometime in their lifetime. At present, diagnosing these conditions is done almost exclusively by qualitative measures, through questions and interviews, and it can take many years for sufferers to be correctly diagnosed," Dr Edwards said.

The technique is already attracting international interest and, if further testing goes to plan, it could be adopted in Australian and overseas hospitals within a few years.

"We are doing the necessary research and development and getting independent expert reports done, but results so far are cause for great optimism," Dr Edwards said.

MAPrc Director Professor Jayashri Kulkarni said, "Engineering and psychiatry are two disciplines that do not usually work together, but here at MAPrc, through our collaboration, we are at the forefront of translating biotechnology into clinical tools for psychiatric practice. While there is more work to be done, electrovestibulography could provide a major breakthrough in the diagnosis of mental illnesses".