Adults with sleep apnea often have more heart trouble than those who sleep soundly, research from the American Heart Association demonstrates.

It’s estimated that about 90 percent of people with sleep apnea have never had an official diagnosis, so if a loved one says you gasp for air as you sleep, don’t ignore the news.

Sleep apnea is a disorder in which breathing becomes shallow or stops altogether during sleep. It can result in extreme fatigue .

Researchers looked at almost 4,500 adults 40 and older who were free of heart problems when the study began. All adults were tested for sleep apnea and then for the next eight years researchers kept track of the differences in the heart health of those with the condition and those without.

“Men with severe obstructive sleep apnea were 58 percent more likely to develop new congestive heart failure over eight years of follow up compared to men without sleep apnea,” says Daniel Gottlieb, study author and associate professor at Boston University’s School of Medicine. 

The researchers also discovered that men under the age of 70 were at much higher risk of developing coronary heart disease, a condition in which fat deposits clog blood vessels, which can lead to chest pain, blockages or a heart attack.

This is different from congestive heart failure, which is a continued weakening of the heart, leaving it less and less able to pump enough blood to keep the body going. 

Women in the study didn’t suffer from these heart and vessel problems and researchers aren’t sure whether it’s because women as a group have less sleep apnea than men or because of other factors. Gottlieb says more research is needed to understand the differences in the sexes.

Researchers suspect the connection between sleep apnea and heart trouble all begins with the shutting off of air as you sleep. Patients gasp for breath as their throats narrow or collapse preventing the flow of air into the lungs.

The lack of oxygen sets the body into a type of panic raising blood pressure, stressing the heart, and pouring sugar into the blood.

Gottlieb says those in the study with severe cases had an average of 30 breathing interruptions per hour lasting at least 10 seconds.

About 70 percent of patients suffering from the condition are obese and it’s believed added fat in the upper airway may be partly to blame. Sleep apnea is more common in those with diabetes and high blood pressure.

Fortunately getting treatment can make a great difference. Therapies include using a device to keep the airway open during sleep, or an oral appliance that is worn at night, and in some cases surgery.

“Sleep apnea is a very treatable condition and it appears that treatment may prevent the adverse health consequences of sleep apnea including heart disease, heart attack, stroke and congestive heart failure,” explains Gottlieb.

Dr. Richard Stein cardiologist and spokesperson for the American Heart Association says weight loss through diet and exercise may help those battling the condition.

He adds, “If you are obese, hypertensive or diabetic, if your partner in bed says you are snorting or snoring, if you’re waking up unrested, you should go to your doctor and ask if you have sleep apnea.”

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Severe obstructive sleep apnea (OSA) raised the risk of heart failure for middle-aged and older men — and significantly raised the risk of coronary heart disease in men up to age 70, according to research reported in Circulation: Journal of the American Heart Association.

After adjusting for known heart risk factors, researchers found that men with the most severe OSA faced a 58 percent higher risk of developing heart failure than those without OSA. And those ages 40 to 70 with the most severe OSA had a 68 percent higher risk of developing coronary heart disease than those without OSA.

“The Sleep Heart Health Study is the first to demonstrate prospectively that sleep apnea is associated with an increased incidence of heart failure,” said Daniel J. Gottlieb, M.D., M.P.H., lead study author and associate professor at Boston University’s School of Medicine.

“It’s also the first large community-based study specifically designed to examine the association of sleep apnea with either coronary heart disease or heart failure. Previous work has focused more narrowly on patients receiving care at sleep clinics,” said  Gottlieb.

In obstructive sleep apnea, the airway collapses during sleep, leaving patients struggling to breathe.

In the study, researchers defined severe apnea as an hourly average of 30 or more breathing interruptions causing oxygen depletion and lasting at least 10 seconds.

This can cause blood oxygen to drop and can rouse people from sleep with a burst of adrenaline that increases blood pressure, which may contribute to vascular problems.

OSA is common, affecting 24 percent of adult men and nine percent of adult women, said Gottlieb, who is also director of the Sleep Disorders Center at VA Boston Healthcare System.

Research from the Sleep Heart Health Study also breaks ground because it included many women, Gottlieb said.

Researchers found no link between OSA and heart problems in women, who are about half as likely as men to have sleep apnea, making it difficult to detect an apnea-heart disease link. This is an area for further study, he said.

The 1,927 men and 2,495 women were 40 or older and free of heart problems when the study began. Twenty-four percent of the men and 11 percent of the women had at least moderately severe obstructive sleep apnea.

Researchers assessed participants’ health for a median follow-up of 8.7 years.

The ages of the study subjects may have limited researchers’ ability to detect a stronger link between apnea and coronary heart disease, Gottlieb said.

Coronary heart disease risk from sleep apnea may be greatest at a relatively young age, with previous research suggesting increased risk of cardiovascular related death from sleep apnea in individuals ages 30 to 50.

Furthermore, sleep apnea is typically diagnosed years or decades after its onset. So, the requirement that study subjects be free of heart problems at enrollment would have excluded people who already suffered heart disease consequences that might be linked to long-term apnea, Gottlieb said.

By contrast, heart failure tends to occur more frequently in elderly people. Heart failure is a chronic weakening of the heart, leaving it unable to pump enough blood to meet the body’s needs.

Coronary heart disease is a narrowing of the coronary arteries that reduces blood flow to the heart.

The study didn’t include enough minorities to detect trends for specific racial or ethnic groups, Gottlieb said.

Given the evidence that men 40 to 70 years old with obstructive sleep apnea face a higher risk of coronary heart disease, “it’s really time for us to perform clinical trials to assess whether coronary heart disease risk can be reduced in patients with severe sleep apnea by treating the apnea,” he said.

The most common treatment, called continuous positive airway pressure, involves the use of a machine that forces air into the airways to prevent breathing interruptions.

“The take-away from our study is that obstructive sleep apnea is a serious condition that warrants medical treatment,” said Gottlieb. “Many patients don’t experience symptoms of obstructive sleep apnea, such as daytime sleepiness, or if they do, don’t mention it during routine medical exams. It’s important for anyone who suspects they have obstructive sleep apnea to discuss it with their primary care physician.” 

The National Heart, Lung, and Blood Institute funded the study.

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Metabolic disorders such as obesity and diabetes appear to share risk factors with and may influence the development of Alzheimer’s disease and other forms of dementia, according to several reports published in the March 2009 issue of Archives of Neurology, one of the JAMA/Archives journals.

Women with the cluster of cardiovascular risk factors known collectively as the metabolic syndrome appear likely to develop cognitive impairment over a four-year period. Kristine Yaffe, M.D., of the University of California, San Francisco, and the San Francisco Veterans’ Affairs Medical Center, and colleagues assessed 4,895 older women (average age 66.2) who did not have cognitive impairment at the beginning of the study.

Of the 497 (10.2 percent) women who had the metabolic syndrome 7.2 percent (36) developed cognitive impairment during a four-year period, compared with 4.1 percent (181 of 4,398) of those who did not have the metabolic syndrome. Each additional component of the syndrome — such as abdominal obesity, high blood pressure and low HDL cholesterol levels — was associated with a 23 percent increase in risk of cognitive impairment.

“As the obesity and sedentary lifestyle epidemic escalates throughout the world, identification of the role of these modifiable behaviors in increasing risk for development of deleterious outcomes, such as cognitive impairment, is critical,” the authors conclude.

“Future research should assess whether identification of cognitive impairment among patients with the metabolic syndrome or more aggressive clinical control of the factors that compose the metabolic syndrome might lessen the risk of developing cognitive impairment in elderly people,” the authors added.

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Sleeping less than seven-and-a-half hours per day may be associated with future risk of heart disease, according to a report in the November 10, 2008, issue of Archives of Internal Medicine, one of the JAMA/Archives journals. In addition, a combination of little sleep and overnight elevated blood pressure appears to be associated with an increased risk of the disease.

“Reflecting changing lifestyles, people are sleeping less in modern societies,” according to background information in the article. Getting adequate sleep is essential to preventing health conditions such as obesity and diabetes as well as several risk factors for cardiovascular disease including sleep-disordered breathing and night-time hypertension (high blood pressure).

Kazuo Eguchi, M.D., Ph.D., at Jichi Medical University, Tochigi, Japan, and colleagues monitored the sleep of 1,255 individuals with hypertension (average age 70.4) and followed them for an average of 50 months. Researchers noted patients’ sleep duration, daytime and nighttime blood pressure and cardiovascular disease events such as stroke, heart attack and sudden cardiac death.

During follow-up, 99 cardiovascular disease events occurred. Sleep duration of less than 7½ hours was associated with incident cardiovascular disease. “The incidence of cardiovascular disease was 2.4 per 100 person-years in subjects with less than 7½ hours of sleep and 1.8 per 100 person-years in subjects with longer sleep duration,” the authors write.

Patients with shorter sleep duration plus an overnight increase in blood pressure had a higher incidence of heart disease than those with normal sleep duration plus no overnight increase in blood pressure, but the occurrence of cardiovascular disease in those with a longer sleep duration vs. those with a shorter sleep duration was similar in those who did not experience an overnight elevation in blood pressure.

“In conclusion, shorter duration of sleep is a predictor of incident cardiovascular disease in elderly individuals with hypertension,” particularly when it occurs with elevated nighttime blood pressure, the authors note. “Physicians should inquire about sleep duration in the risk assessment of patients with hypertension.”

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People with even minimally symptomatic obstructive sleep apnea (OSA) may be at increased risk for cardiovascular disease because of impaired endothelial function and increased arterial stiffness, according to a study in the November 2008 issue of American Journal of Respiratory and Critical Care Medicine.

Their findings suggested that minimally symptomatic OSA is a cardiovascular risk factor to a degree not previously known.

"It was previously known that people with OSA severe enough to affect their daytime alertness and manifest in other ways are at increased risk of cardiovascular disease, but this finding suggests that many more people — some of whom may be completely unaware that they even have OSA — are at risk than previously thought," said lead author Malcolm Kohler, MD, Oxford Centre for Respiratory Medicine, Oxford, United Kingdom.

To determine the exact nature of some of these effects, Kohler and colleagues performed a controlled, cross-sectional study to assess differences in endothelial function, arterial stiffness, and blood pressure in 64 patients with minimally symptomatic obstructive sleep apnea. Patients were matched with 15 control subjects without obstructive sleep apnea.

"In our study, the augmentation index, was significantly higher in patients with minimally symptomatic OSA compared with matched controls," said Kohler.

"We also found impaired endothelial function as indicated by decreased vascular reactivity of their arteries compared with control subjects without OSA," Kohler added.

The difference in arterial stiffness between obstructive sleep apnea patients and control subjects, Dr. Kohler said was "comparable in size to the effect seen after four weeks’ continuous positive airway pressure (CPAP) therapy in patients with moderate to severe symptomatic OSA."

This suggests that asymptomatic or minimally symptomatic patients with OSA may enjoy a cardiovascular benefit from CPAP or BiPAP therapy.

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Bad news for sleep-deprived individuals:
another health issue tied to lack of sleep

Participants in a study who slept on average an hour longer per night than other participants had an associated lower incidence of coronary artery calcification, which is thought to be a predictor of future heart disease, according to a study in the combined December 24/31, 2008, issue of the Journal of the American Medical Association (JAMA).

Risk factors for coronary artery calcification (the accumulation of calcified plaques visible by computed tomography [a method of imaging body organs]) include established heart disease risk factors such as male sex, older age, glucose intolerance, tobacco use, dyslipidemia (disorders of lipoprotein metabolism, which includes high cholesterol levels), high blood pressure, obesity, raised inflammatory markers and attaining a low educational level.

Recent data suggest sleep quantity and quality are connected to several of these risk factors.

“Some of these correlations have only been documented in studies in which sleep is measured by self-report, which may be biased or insufficiently accurate,” the authors noted in the article.

Christopher Ryan King, B.S., of the University of Chicago, and colleagues tested whether objectively measured sleep duration predicted the development of calcification over five years of follow-up. The study included 495 participants from the Coronary Artery Risk Development in Young Adults [CARDIA] study, who were black and white men and women age 35-47 years.

None of the participants had no evidence of detectable coronary calcification on computed tomography scans at the start of the study in 2000-2001.

Potential confounders (factors that can possibly influence the results; age, sex, race, education, apnea risk, smoking status) and mediators (lipids, blood pressure, body mass index, diabetes, inflammatory markers, alcohol consumption, depression, hostility, self-reported medical conditions) were measured at both the start of the study and at five-year follow-up.

Sleep metrics (wrist actigraphy [monitors rest and activity] measured sleep duration and sleep fragmentation, daytime sleepiness, overall sleep quality, self-reported sleep duration) were examined for association with new calcification, based on computed tomography performed in 2005-2006.

The incidence of calcification at five years was 12.3 percent (n = 61 participants). After adjusting for age, sex, race, education, smoking and apnea risk, the researchers found that one hour more of sleep per night decreased the estimated odds of calcification by 33 percent.

The magnitude of the observed association was similar to sizable differences in established coronary risk factors (e.g., one additional hour of sleep reduced risk similarly to a reduction of 16.5 mm Hg in systolic blood pressure). No potential mediators appreciably altered the magnitude or significance of sleep. Alternative sleep metrics were not significantly associated with calcification.

“We have found a robust and novel association between objectively measured sleep duration and five-year incidence of coronary artery calcification,” the authors wrote in their findings.

“This study further demonstrates the utility of a simple objective measure of sleep that can be used at home. Future studies will be needed for crucial extensions to these results," the authors added.

"First, these results need confirmation in other cohorts. Second, does sleep moderate the rate at which calcification accumulates? Third, will objective sleep tie to coronary disease event outcomes over the long term? While calcification predicts such outcomes, it is difficult to know how and if the predictors of calcification themselves will determine outcomes, or if their impact will be purely mediated by their effect on calcification. Finally, if this association is born out, interventional studies will be needed to guide clinical advice,” they concluded.

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Sleeping less than seven and a half hours per day may be associated with future risk of heart disease, according to a report in the November 10 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. In addition, a combination of little sleep and overnight elevated blood pressure appears to be associated with an increased risk of the disease.

"Reflecting changing lifestyles, people are sleeping less in modern societies," according to background information in the article. Getting adequate sleep is essential to preventing health conditions such as obesity and diabetes as well as several risk factors for cardiovascular disease including sleep-disordered breathing and night-time high blood pressure.

Kazuo Eguchi, M.D., Ph.D., at Jichi Medical University, Tochigi, Japan, and colleagues monitored the sleep of 1,255 individuals with hypertension (average age 70.4) and followed them for an average of 50 months. Researchers noted patients’ sleep duration, daytime and nighttime blood pressure and cardiovascular disease events such as stroke, heart attack and sudden cardiac death.

During follow-up, 99 cardiovascular disease events occurred. Sleep duration of less than 7.5 hours was associated with incident cardiovascular disease. "The incidence of cardiovascular disease was 2.4 per 100 person-years in subjects with less than 7½ hours of sleep and 1.8 per 100 person-years in subjects with longer sleep duration," the authors write.

Patients with shorter sleep duration plus an overnight increase in blood pressure had a higher incidence of heart disease than those with normal sleep duration plus no overnight increase in blood pressure, but the occurrence of cardiovascular disease in those with a longer sleep duration vs. those with a shorter sleep duration was similar in those who did not experience an overnight elevation in blood pressure.

"In conclusion, shorter duration of sleep is a predictor of incident cardiovascular disease in elderly individuals with hypertension," particularly when it occurs with elevated nighttime blood pressure, the authors note. "Physicians should inquire about sleep duration in the risk assessment of patients with hypertension."

Editor’s Note: This study was supported in part by grants-in-aid from the Foundation for the Development of the Community, Tochigi, Japan; the Banyu Fellowship Program, sponsored by Banyu Life Science Foundation International; and the National Heart, Lung and Blood Institute. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

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People with even minimally symptomatic obstructive sleep apnea (OSA) may be at increased risk for cardiovascular disease because of impaired endothelial function and increased arterial stiffness, according to a study from the Oxford Centre for Respiratory Medicine in the United Kingdom.

“It was previously known that people with OSA severe enough to affect their daytime alertness and manifest in other ways are at increased risk of cardiovascular disease, but this finding suggests that many more people — some of whom may be completely unaware that they even have OSA — are at risk than previously thought,” said lead author of the study, Malcolm Kohler, M.D.

The study will be published in the first issue for November 2008 of the American Thoracic Society‘s American Journal of Respiratory and Critical Care Medicine.

“Only one out of approximately five subjects with [clinically defined obstructive sleep apnea] complains of excessive daytime sleepiness in population studies,” wrote Geraldo Lorenzi-Filho, M.D., Ph.D. in an editorial in the same issue of the Journal. “[I]t is now recognized that OSA triggers a cascade of biological reactions, including increased sympathetic activity, systemic inflammation, oxidative stress, and metabolic alterations that are potentially harmful to the cardiovascular system.”

To determine the exact nature of some of these effects, Kohler and colleagues performed a controlled, cross-sectional study to assess differences in endothelial function — often a harbinger for cardiovascular problems to come — arterial stiffness and blood pressure in patients with minimally symptomatic obstructive sleep apnea.

The researchers compared 64 patients who had proven obstructive sleep apnea to matched control subjects without obstructive sleep apnea.

Their findings suggested that minimally symptomatic obstructive sleep apnea is a cardiovascular risk factor to a degree not previously known.

“In our study, the augmentation index, a measure of central arterial stiffness that independently predicts cardiovascular events in high-risk populations, was significantly higher in patients with minimally symptomatic OSA compared to matched controls,” said Kohler.

“We also found impaired endothelial function as indicated by decreased vascular reactivity of their arteries compared to control subjects without OSA,” Kohler added.

The difference in arterial stiffness between obstructive sleep apnea patients and control subjects, Kohler said was “comparable in size to the effect seen after four weeks’ continuous positive airway pressure (CPAP) therapy in patients with moderate to severe symptomatic OSA.”

This suggests that asymptomatic or minimally symptomatic patients with obstructive sleep apnea may enjoy a cardiovascular benefit from CPAP therapy.

Kohler and his colleagues at the Oxford Centre for Respiratory Medicine are currently investigating the effects of six-month CPAP therapy on arterial stiffness and endothelial function as part of an international randomized controlled trial — Multi-center Obstructive Sleep Apnoea Interventional Cardiovascular Trial, also known as “MOSAIC” — which will show the impact of CPAP therapy on cardiovascular risk in patients with minimally symptomatic obstructive sleep apnea.

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A comparison of two diagnostic methods used to detect deep vein thrombosis, or DVT — a blood clot in a deep vein in the leg or thigh — of the lower extremities indicates that a simpler method, with wider availability, has rates of DVT detection that are equivalent to a more complex method, according to a study in the October 8, 2008 issue of JAMA.

The imaging technique, compression ultrasonography, is a highly accurate method for the detection of DVT and has replaced other diagnostic methods in common practice. Two ultrasonography diagnostic methods often used are two-point and whole-leg.

With two-point ultrasonography, compression is applied to two veins, and benefits include simplicity, reproducibility and broad availability. It may be performed with virtually all ultrasound scanners, irrespective of age or model.

"Its major limitation is the need to repeat the test once within one week in patients with normal findings at presentation to detect calf DVT extending to the proximal [near the point of origin] veins. Repeat testing may be safely avoided in patients with a normal D-dimer test [blood test used to help rule out active blood clot formation] at presentation," the authors write.

The advantages of whole-leg ultrasonography include the ability to exclude isolated calf DVT, allowing for one-day treatment of all patients, without additional testing.

Conversely, it needs top-quality ultrasound equipment and experienced operators; therefore, it is often unobtainable after hours and during the weekends. Despite the lack of definite evidence, whole-leg ultrasonography is thought to be better than serial two-point ultrasonography, and as a consequence, many patients with suspected DVT need to wait hours or even days before whole-leg ultrasonography is obtained and are frequently (unnecessarily) administered anticoagulants in the meantime, according to background information in the article.

Enrico Bernardi, M.D., Ph.D., of the Civic Hospital in Conegliano, Italy, and colleagues conducted a study to determine if the two diagnostic strategies are equivalent for the treatment of patients with suspected DVT of the lower extremities. The randomized, multi-center study included 2,098 outpatients with a first episode of suspected DVT of the lower extremities who were randomized to undergo two-point (n = 1,045) or whole-leg (n = 1,053) ultrasonography.

Of patients in the two-point strategy group, the incidence of confirmed symptomatic venous thromboembolism, or VTE — blood clots in the deep veins of the legs or in the lungs — during the three-month follow-up period was 0.9 percent (seven of 801 patients). Of patients randomized to the whole-leg ultrasonography method, the incidence of confirmed symptomatic VTE during the follow-up period was 1.2 percent (9 of 763 patients).

"The observed difference between the two groups in terms of symptomatic VTE at the end of the three-month follow-up period was 0.3 percent, which is within the chosen equivalence limit," the authors write.

"Either strategy may be chosen based on the clinical context, on the patients’ needs, and on the available resources. [Two-point ultrasonography plus D-dimer] is simple, convenient, and widely available but requires repeat testing in one-fourth of the patients. [Whole-leg ultrasonography] offers a one-day answer, desirable for patients with severe calf complaints, for travelers, and for those living far from the diagnostic service, but is cumbersome, possibly more expensive, and may expose patients to the risk of (unnecessary) anticoagulation," the authors added.

(JAMA. 2008;300[14]:1653-1659)

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Simple guideline can identify which patients should be brought to

hospitals when emergency efforts to revive them aren’t working

When someone’s heart suddenly stops beating — a condition called cardiac arrest — there’s a lot that bystanders and ambulance crews can do to get it started again. If the victim doesn’t respond, when should such efforts stop, according to the findings of a study published in the Sept. 24, 2008 issue of the Journal of the American Medical Association.

And when should emergency crews rapidly transport a patient to a hospital with lights and sirens on, potentially endangering the lives of paramedics and other motorists and pedestrians — even though the care provided by the emergency crew is the same as what can be provided in the emergency department?

Currently, there’s no one “right” answer to these questions, which arise in the majority of the cardiac arrests that strike 166,000 Americans each year — and kill 93 percent of them. As a result, emergency medical services crews and hospital ER teams spend countless hours and healthcare resources on patients who have no chance of making it home alive – at the expense of other patients who need an ambulance or have spent hours in an ER waiting room.

A single standard guideline could help EMS and ER teams determine which cardiac arrest victims might benefit from a trip to the hospital, the study shows, while at the same time reducing futile efforts on patients who have no chance of surviving a cardiac arrest.

The study shows that EMS teams can use either a simple five- or three-part rule to determine when they should discontinue efforts to revive cardiac arrest patients on the scene where their heart stopped beating. The same rule will also tell them when they should keep trying to resuscitate the patient while transporting him or her to the nearest ER. The three-part rule may be sufficient to identify 99.8 percent of those who need to be transported to the hospital for further care, the researchers say.

A team from the University of Michigan Health System, Emory University, and the Henry Ford Health System, performed the study, using data from 5,505 cardiac arrest patients treated in eight metropolitan areas around the U.S. It did not include patients who suffered a cardiac arrest after a non-heart incident such as drowning. It was funded by the Centers for Disease Control and Prevention.

Comilla Sasson, M.D., M.S., is the study’s lead author and a Robert Wood Johnson Clinical Scholar at the U-M Medical School. An emergency physician herself, she began the study after many frustrating experiences in a Chicago ER where she had to stop caring for other critically ill patients whenever a cardiac arrest patient came in the door – no matter how futile it might be to try to bring the patient back, and no matter how time-sensitive the needs of the other patients in the ER.

Now at the U-M Department of Emergency Medicine, Sasson teamed up with an Emory University group that has been tracking cardiac arrest response. The Emory effort, called CARES, helps EMS crews and hospitals find ways to improve care.

“Many cardiac arrest patients are successfully resuscitated at the scene, with the help of automated external defibrillators and CPR, and the hospital is the right destination for them,” Sasson says. “The question has been what to do about patients who fail to respond, despite the best efforts of an EMS team. This study confirms previous findings, and shows that a standard rule could ensure that the right patients get to the hospital while allowing us to use scarce resources wisely.”

Sasson notes that many advanced EMS crews now have nearly all the tools and training that ERs have for reviving cardiac arrest patients, including artificial airways, heart-starting injectable drugs, and more. Many have radio contact with an emergency doctor at the local medical control authority. In addition, automated external defibrillators (AEDs) are now available in many public places for bystanders to use to restart a stopped heart, in the crucial minutes before an EMS team arrives.

But even still, some patients just don’t respond, or their heartbeats are too erratic for the AED to determine that a shock can be delivered. Then, the question for the EMS crew is whether it’s worth the risk to the patient, the crew, and nearby motorists and pedestrians to race to the hospital with sirens blaring and lights flashing, and then to tie up the ER team to try to revive the patient.

In the new study, EMS crews pronounced 947 (17 percent) of the 5,505 patients dead at the scene between late 2005 and early 2008. The other 4,558 were transported to one of 111 hospitals by one of 19 EMS agencies. But only 7.1 percent of those transported patients survived long enough to be discharged from the hospital alive.

Sasson and her colleagues, including Bryan McNally, M.D., MPH, and Arthur Kellermann, M.D., MPH of Emory’s Department of Emergency Medicine, analyzed the medical records from all 5,505 patients. They ran statistical analyses to determine which patients would have been transported, or survived, if EMS crews had applied the three-part or five-part rule, both of which were developed by a Canadian team as part of the Ontario Prehospital Advanced Life Support study.

The three-part rule, called a “basic life support” or BLS rule, calls for EMS teams to end their resuscitation efforts if a cardiac arrest occurred before EMS arrived, if no defibrillator was used (for instance, because there was none for a bystander to use, the EMS crew didn’t have one, or an AED did not detect a shockable rhythm), and if the team can’t get the patient’s blood to begin circulating again. All three must apply for resuscitation efforts to be stopped.

If ambulance and fire crews had applied the three-part rule, about 47 percent of all the cardiac arrest patients in the study would not have met the criteria to be transported by ambulance to the hospital. This means that 2,592 patients would have been pronounced dead at the scene – potentially saving 1,645 trips to the ER, compared with what actually happened.

The five-part rule, called the “advanced life support” or ALS rule, adds two more criteria to the list: the cardiac arrest had no witnesses at all, and no bystander attempted to perform CPR. If this more conservative rule had been applied to the 5,505 cardiac arrest victims in the study, 1,192 patients would have been declared dead at the scene, saving 245 trips to the ER.

Then, the researchers looked at what actually happened after the patients made it to the hospital, and compared it with what might have happened if the two rules had been applied.

Only 70 patients who would have been declared dead under the BLS rule survived the ER treatment and were admitted to the hospital. But only five were discharged from the hospital alive, and four of them were able to live a relatively normal life afterward. Meanwhile, only 24 patients who would have been declared dead under the more conservative ALS rule were able to be resuscitated in the ER. None of them survived long enough to be sent home from the hospital.

In other words, the BLS rule misclassified only 0.2 percent of patients, and the ALS rule classified all patients correctly. Either rule, the authors say, could be used — but the BLS rule would save the most emergency medical resources while still meeting ethical criteria for medical care.

“Through our study and others, the BLS rule has now been applied to more than 10,000 patients in the U.S. and Canada, with less than a 0.1 percent misclassification rate,” Sasson says. “Currently, EMS systems vary widely in the care they deliver to cardiac arrest patients. To implement the BLS rule more widely would standardize the care and transport of these patients, so that we can reduce the risk of injuries or death to EMS personnel and the public in high speed transports, decrease the pressure on our overcrowded ER’s, allow our ER staff to focus on patients who can be treated, and open up intensive care unit beds.”

In addition to Sasson, McNally and Kellerman, the study’s authors are A.J. Hegg, M.D., a third-year Emergency Department and Internal Medicine resident at Henry Ford Hospital in Detroit; Michelle Macy, M.D., of the U-M Department of Emergency Medicine, and Allison Park, MPH, of the CARES project. CARES stands for Cardiac Arrest Registry to Enhance Survival. Reference: , Vol. 300, No. 12.

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