Featured Research

from universities, journals, and other organizations

Viral Infection Linked To Heart Attack And Stroke

Date:
December 24, 2002
Source:
American Heart Association
Summary:
Cytomegalovirus (CMV), a usually dormant virus that can cause mononucleosis, is associated with a higher risk of heart attack, stroke or cardiovascular death in people with heart disease, according to a report in Circulation: Journal of the American Heart Association.

DALLAS, Dec. 24 – Cytomegalovirus (CMV), a usually dormant virus that can cause mononucleosis, is associated with a higher risk of heart attack, stroke or cardiovascular death in people with heart disease, according to a report in today's rapid access Circulation: Journal of the American Heart Association.

In a study of more than 3,000 people, researchers investigated whether exposure to four common pathogens (disease-causing virus or bacteria) increased the risk of cardiovascular disease. The pathogens are CMV, Chlamydia pneumoniae (respiratory infections), Helicobacter pylori (ulcers), and hepatitis A (liver disease).

The researchers found that CMV exposure carried a higher risk for cardiovascular events or death, while the other pathogens, by themselves, were not related to increased risk. However, they also found that a person's "total pathogen score" predicted a small increase in risk for cardiovascular events. Thus, people exposed to all four pathogens had a higher risk compared with those exposed to just one of the four, says lead author Marek Smieja, M.D., Ph.D., assistant professor in the department of pathology and molecular medicine, McMaster University, Hamilton, Ontario, Canada.

Researchers have grappled with whether exposure to common infections contributes to heart disease. While there have been a large number of studies on such topics, most have been small and many lacked long-term follow up, Smieja says.

Smieja and colleagues studied blood that had been banked from 3,168 Canadians who participated in the Heart Outcomes Prevention Evaluation (HOPE) study. Patients in the study had cardiovascular disease or were at high risk for cardiovascular disease, stroke or diabetes. The researchers measured antibodies to the four pathogens. They measured levels of two different antibodies for Chlamydia pneumoniae (CP) – the CP IgG antibody, which is believed to stay in the body for several years after infection, and CP IgA, a much shorter-lived antibody. CP IgG was detected in 82.9 percent of participants and IgA was found in 63 percent. Researchers found that 61.7 percent of the participants had antibodies for Helicobacter pylori, 76 percent for hepatitis A and 70.4 percent had them for CMV.

The risk associated with blood levels of the various pathogens and patient outcomes of heart attack, stroke or cardiovascular death was assessed during 4.5 years of follow-up.

Heart attack, stroke or cardiovascular death occurred in 494 patients. The researchers found no connection between CP and cardiovascular disease.

"We're pretty comfortable saying that chlamydia is not an independent risk factor for heart disease," Smieja says. Helicobacter pylori and hepatitis A also showed no relationship to increased risk for cardiovascular events. The only pathogen linked to cardiovascular disease risk was CMV, which increased the risk of heart attack, stroke or cardiovascular death by about 24 percent.

In addition, the researchers found that people who had antibodies to all four pathogens were 41 percent more likely to suffer heart attack, stroke or die from cardiovascular disease than those who had antibodies for zero or one pathogen. Smieja concludes that the association between these infections and cardiovascular disease is too modest to recommend any routine testing for them. Future studies, he says, should look at additional infections, such as herpes 1 and 2, to collectively determine if they impact risk.

In an accompanying editorial, Joseph B. Muhlestein, M.D., associate professor of medicine at the University of Utah and director of cardiology research at LDS Hospital, Salt Lake City, Utah, says that while this study didn't show the same extent of burden from these pathogens that previous studies had, it does confirm that infections, especially cytomegalovirus, are associated with worsening cardiovascular events in people at high risk of cardiovascular disease. "Therefore, I would take it as confirmation that we need to continue to look at and study the relationship between a variety of infections and atherosclerosis," he says. "In addition, this study appears to have demonstrated a greater importance, perhaps, with viral infections rather than bacterial infections. This may send us in a little different direction – looking more carefully at viruses than we had before."

Co-authors are Judy Gnarpe, Ph.D.; Eva Lonn, M.D.; Hakan Gnarpe, M.D., Ph.D.; Gunnar Olsson, M.D., Ph.D.; Qilong Yi, Ph.D.; Vladimir Dzavik, M.D.; Matthew McQueen, M.D., Ph.D.; and Salim Yusef, M.B.B.S., D.Phil.


Story Source:

The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.


Cite This Page:

American Heart Association. "Viral Infection Linked To Heart Attack And Stroke." ScienceDaily. ScienceDaily, 24 December 2002. <www.sciencedaily.com/releases/2002/12/021224091204.htm>.
American Heart Association. (2002, December 24). Viral Infection Linked To Heart Attack And Stroke. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2002/12/021224091204.htm
American Heart Association. "Viral Infection Linked To Heart Attack And Stroke." ScienceDaily. www.sciencedaily.com/releases/2002/12/021224091204.htm (accessed October 22, 2014).

Share This



More Health & Medicine News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins