Heart

Aspirin Therapy for Heart Disease, Stroke Prevention Not for Everyone

Benefits and Risks of Aspirin Therapy Determined on Case-by-Case Basis

By Salynn Boyles
WebMD Health News

Reviewed by Laura J. Martin, MD

Jan. 12, 2012 -- Many people who have never had a heart attack or stroke take an aspirin every day to lower their risk for these events.

While some may benefit, for many others the benefits appear to be outweighed by an increased risk for potentially serious and even life-threatening bleeding, a new study shows.

Researchers analyzed data from nine large studies, including three published since 2007, which followed participants for an average of six years.

Aspirin therapy was not associated with a reduction in deaths due to heart attack and stroke, but it was associated with a significant increase in risk for bleeding, says researcher Kausik K. Ray, MD.

"The benefits of aspirin therapy are clear for patients who have a history of heart attack or stroke," Ray says. "This is not the case, however, for patients who may have risk factors for [heart disease and stroke] but have no such history."

Aspirin: No Decrease in Heart, Cancer Deaths

The analysis included more than 100,000 people who had never had a heart attack or stroke and participated in trials in the United States, Europe, and Japan.

About half the participants took either low-dose (75-100 milligrams) or full-strength (300-500 milligrams) aspirin daily or every other day. Everyone else took placebos.

Over an average follow-up of six years, about 1,500 nonfatal and 500 fatal heart attacks and about 1,500 fatal and nonfatal strokes were recorded.

Aspirin therapy was associated with a 10% decrease in heart attacks and strokes, which was largely explained by a reduction in nonfatal heart attacks, Ray says.

But patients on the aspirin regimens were also 31% more likely to experience significant bleeding.

Aspirin therapy has been shown in several previous studies to be associated with a reduced risk of death from cancer, but the association was not seen in the new analysis, which was published in the Archives of Internal Medicine.

Ray and colleagues from the Cardiac and Vascular Sciences Research Center at St. George's University of London conclude that for many patients with no history of heart attack or stroke, aspirin adds little to strategies proven to reduce heart disease and stroke risk.

These strategies include drug treatments that regulate blood pressure and cholesterol, and lifestyle changes such as smoking cessation, weight loss, and regular exercise.

Before Taking Aspirin, Talk to Your Doctor

The researchers add that more study is needed to identify patients who have not had heart attacks or strokes for whom the benefits of aspirin therapy outweigh the risks.

"In the absence of such information, a reappraisal of current guidelines appears to be warranted, particularly in countries where a large number of otherwise healthy adults are prescribed aspirin," the researchers write.

Cardiologist Samia Mora, MD, of the Brigham and Women's Hospital and Harvard Medical School, says patients need to discuss their individual risk for heart attack and stroke with their doctor before embarking on an aspirin therapy regimen.

In an editorial published with the paper, Mora writes that for low-risk patients the data "argue against the routine use of aspirin for primary prevention of [heart disease and stroke]."

"Right now, we really need to assess risk on a case-by-case basis," she says. "For someone with a strong family history of heart attack or stroke, for example, a daily aspirin may be warranted even in the absence of other risk factors."

New York University cardiologist Nieca Goldberg agrees that patients should always discuss their individual risks with their doctor before starting aspirin therapy.

SOURCES: Kondapally, S.R. Archives of Internal Medicine, published online Jan. 9, 2012.Kausik K. Ray, MD, professor of cardiovascular disease prevention, Cardiac and Vascular Sciences Research Centre, St. George's University of London, U.K.Samia Mora, MD, MHS, division of cardiovascular disease and preventive medicine, Brigham and Women's Hospital, Harvard Medical School, Boston.Nieca Goldberg, MD, cardiologist; medical director, New York University Langone Center for Women's Health, New York.

WEDNESDAY, Jan. 11 -- Many people may not feel their heart race when they are having an irregular heartbeat known as atrial fibrillation, but these silent symptoms double their risk of stroke, a new study finds.

Of 2,580 study participants with pacemakers who did not have a history of atrial fibrillation, more than one-third experienced pacemaker-documented episodes that lasted for more than six minutes, researchers said. However, 85 percent of these people did not realize it because there were no obvious symptoms. Pacemakers are placed in the chest to control abnormal heart rhythms. The results appear in the Jan. 12 issue of the New England Journal of Medicine.

The findings don't mean that everyone should be tested or treated for silent atrial fibrillation (AF), but they do argue for awareness and tighter control of known stroke risk factors such as high blood pressure.

"In patients with pacemakers, we do see a very high prevalence of silent AF that is not recognized by the patient," said study author Dr. Jeff Healey, an associate professor of medicine of the Michael G. DeGroote School of Medicine at McMaster University in Ontario, Canada. "Even though they are silent, these episodes are clearly associated with risk of stroke."

Individuals who had one silent atrial fibrillation episode within the first three months of the study were twice as likely to have a stroke, when compared to their counterparts who did not experience any bouts, the study showed. An episode of atrial fibrillation was defined as an irregular heartbeat that lasted at least six minutes.

This risk increased with each additional risk for stroke such as high blood pressure and diabetes, Healey said. All participants were 65 or older and had a history of high blood pressure. Researchers followed the patients for about 2.5 years.

"We know that high blood pressure is a very important risk factor for stroke, and this study reinforces the importance of good primary care to pick up these risk factors," he said. "Further research will tell us if it makes sense to screen for silent AF in certain high-risk populations."

Another expert said common sense should prevail.

"We should not check everyone for silent AF," said Dr. Marc Gillinov, a heart surgeon at the Cleveland Clinic. "If you feel palpitations or your heart racing, let your doctor know, but otherwise I would not rush to the doctor. The cause of the stroke is unknown in about 25 percent of people, and a lot of us think maybe subclinical AF plays a role. This study helps answer that piece of the puzzle."

Many questions remain, he said. "The big question is how much AF is too much because the drugs used to treat AF are very powerful and have their own issues with safety," he says. "Does one six-minute episode buy you a lifetime of anticoagulants, or do you need 10 times that amount?"

Dr. Neil Sanghvi, an electrophysiologist at Lenox Hill Hospital in New York City, said the new study was "thought-provoking." He said people should discuss their personal risk factors for stroke with their doctor to come up with a plan. "The average patient who has no symptoms should just have a conversation with their physician," he added.

SOURCES: Neil Sanghvi, M.D., electrophysiologist, Lenox Hill Hospital, New York City; Jeff Healey, M.D., associate professor, medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada; Marc Gillinov, M.D., heart surgeon, Cleveland Clinic, Ohio; Jan. 12, 2012, New England Journal of Medicine

Most Cases of Heart Stopping Linked to Pre-existing Conditions

By Kathleen Doheny
WebMD Health News

Reviewed by Laura J. Martin, MD

Jan. 11, 2012 -- When a runner dies during a marathon because their heart stops, it's big news -- and can be scary to the 2 million runners who participate in U.S. long-distance events each year.

However, the risk of cardiac arrest during long-distance races is relatively low, according to new research. A cardiac arrest occurs when the heart stops beating, and it's generally more serious than a heart attack.

Over a 10-year period, 59 runners, or 1 in 184,000 participants in half or full marathons, suffered cardiac arrest, says researcher Aaron Baggish, MD, associate director of the Cardiovascular Performance Program at Massachusetts General Hospital. He is also the cardiologist for the Boston Marathon. There were nearly 11 million participants during the decade studied.

Those who run a full marathon, 26.2 miles, are at higher risk of heart problems than those who run the half, he found. Men are at higher risk than women.

"It appears the half marathon is safer and better tolerated than the marathon," says Baggish. "Most of the problems we saw were marathon-related."

The study is published in The New England Journal of Medicine.

The new research, believed to be the first comprehensive study of marathon and half-marathon participants, may change the stereotypes. "The public perception is that marathons and half marathons are dangerous endeavors," Baggish says.

Veteran runners, on the other hand, may feel overly protected because of their healthy lifestyle, he says.

While the number of race-related deaths due to cardiac arrest has risen, "the increase in the number of cardiac deaths only parallels the increased number of participants," Baggish tells WebMD.

In 2000, fewer than 1 million participated in U.S. long-distance races. In 2010, 2 million did.

Marathons & Cardiac Arrest: Analysis

Baggish and his team tracked cases of cardiac arrest in half marathons and marathons in the U.S. from Jan. 1, 2000, through May 31, 2010.

They interviewed survivors or the family members of those who died. They reviewed medical records. They looked at post-death data.

Forty of the cardiac arrests occurred during marathons; 19 during half marathons.

Eighty-six percent of those who suffered cardiac arrest, or 51 of the 59, were men. The average age of those who had cardiac arrest was 42. Cardiac arrest was most likely to occur during the last quarter of the event.

Of those 59 cardiac arrests, 42 were fatal. Baggish says that death rate -- 71% -- is better than the 92% rate generally found when cardiac arrest occurs, when people are at home or in other isolated areas.

He credits the medical services at races and bystanders who performed CPR with this higher survival rate.

Next, Baggish looked at the causes. He had enough medical information to evaluate the cause for 31 of the 59 runners. An abnormal thickening of the heart muscle, known as hypertrophic cardiomyopathy, was often the confirmed or probable cause of death.

Among those who survived, underlying heart disease was the most common problem. Baggish found the risk of cardiac-related death over the 10-year period was 1 per 259,000 long-distance runners. Other research suggests that this risk is equal to or lower than that for other physical activity such as triathlons, college athletics, and jogging, he says.

Marathons & Cardiac Arrest: Perspective

The study findings offer valuable information, says Ravi Dave, MD, a cardiologist at Santa Monica-UCLA Medical Center & Orthopaedic Hospital in Los Angeles. He reviewed the study findings for WebMD.

The findings will help doctors determine which tests may help identify potential problems in runners, he says. An echocardiogram, for instance, can help identify the heart muscle thickening, Dave says. This test uses sound waves to create a picture of the heart.

A stress test, done on a treadmill, can help identify those who have severe blockages, he says.

Those planning to run long-distance events should get a medical checkup, Dave says. "You need to indicate to the physician the reason for the checkup: that you are running," he tells WebMD.

It is better, Dave says, for beginners to do a half marathon before progressing to a full marathon.

Marathons & Heart Attacks: Advice

"Every person new to the sport should talk to their doctor about [heart] risk," Baggish says. A doctor will order tests based on factors such as a runner's age and family history of heart problems, he says.

Long-distance running, he says, "is overall a safe activity." However, ''leading the running lifestyle doesn't completely protect you from heart disease."

Baggish reports no disclosures. Some co-authors report receiving consulting fees from Lupin Pharmaceuticals and Furiex Pharmaceuticals, grant funding from GlaxoSmithKline and Novartis, and lecture fees from Merck, Pfizer, Abbott, and others.

SOURCES: Aaron Baggish, MD, associate director, Cardiovascular Performance Program, Massachusetts General Hospital; assistant professor of medicine, Harvard Medical School; cardiologist, Boston Marathon.Ravi Dave, MD, cardiologist, Santa Monica-UCLA Medical Center & Orthopaedic Hospital; associate professor of medicine, David Geffen School of Medicine, University of California Los Angeles.Kim, J. New England Journal of Medicine, Jan. 12, 2012.

TUESDAY, Jan. 10 --Studies have shown that vitamin D is critical for bone health and could have a protective benefit for the heart, but new research suggests that too much of it could actually be harmful.

"Clearly, vitamin D is important for your heart health, especially if you have low blood levels of vitamin D. It reduces cardiovascular inflammation and atherosclerosis, and may reduce mortality, but it appears that at some point it can be too much of a good thing," study leader Dr. Muhammad Amer, an assistant professor in the division of general internal medicine at the Johns Hopkins University School of Medicine, said in a Hopkins news release.

In conducting the study, published in the Jan. 15 issue of the American Journal of Cardiology, researchers examined five years of data from a national survey of more than 15,000 adults. They found that people with a normal levels of vitamin D had lower levels of a c-reactive protein (CRP), a marker for inflammation of the heart and blood vessels.

On the other hand, when vitamin D levels rose beyond the low end of normal, CRP also increased, resulting in a greater risk for heart problems.

"The inflammation that was curtailed by vitamin D does not appear to be curtailed at higher levels of vitamin D," Amer explained.

The researchers concluded that people should be aware of the potential risks associated with taking supplements, particularly vitamin D.

"People taking vitamin D supplements need to be sure the supplements are necessary," Amer said. "Those pills could have unforeseen consequences to health even if they are not technically toxic."

It is unclear why higher levels of vitamin D are not beneficial for the heart, the researchers said.

-- Mary Elizabeth Dallas

SOURCE: Johns Hopkins Medicine, news release, Jan. 4, 2012

TUESDAY, Jan. 10 -- Asian-Americans are more likely to die in the hospital following a heart attack than whites, new research reveals, although this disparity was reduced over time in hospitals participating in a quality improvement program.

In the study, doctors examined certain measures of care -- such as whether a patient was prescribed aspirin or ACE inhibitors (heart drugs) at the time of discharge -- on 107,403 Asian-American and white heart attack patients. The study encompassed five years, from 2003 to 2008.

Asian-Americans were less likely to be given aspirin or counseling on how to quit smoking after they left the hospital. They were also more likely than whites to receive lipid-lowering therapy.

The study also showed that Asian-Americans were nearly twice as likely as whites to die in the hospital following a heart attack.

However, as the quality of care improved for these patients, health disparities between the two groups decreased.

The statistics came from the database of the "Get With The Guidelines-Coronary Artery Disease" program developed by the American Heart Association. The study appears Jan. 10 in the AHA journal Circulation: Cardiovascular Quality and Outcomes.

The researchers said the difference in heart attack deaths could be due to Asian-Americans in the study being much older, with other risk factors for heart disease, such as diabetes, hypertension, heart failure and smoking. The health disparities could also be the result of language barriers or other cultural differences, they said in the release.

After taking these additional risk factors into account, the study found the differences in death rates between whites and Asian-Americans were still reduced under the quality improvement program.

"This improved care is more significant and sustainable the longer hospitals participate in the program," study leader Dr. Feng Qian, a research assistant professor in the anesthesiology department at the University of Rochester Medical Center in New York, said in the AHA release.

"Health disparities are a serious public health concern in the United States and we've seen that different racial and ethnic groups often receive unequal treatment for the same diagnosis," Qian said. "For that reason, different ethnic and racial groups may have different outcomes. Future studies should look more specifically at differences in care among racial subgroups as well as at more long-term outcomes."

-- Mary Elizabeth Dallas

SOURCE: American Heart Association, news release, Jan. 7, 2012