Studies describe heart disease following vaccination.

2003 DEC 10 - (NewsRx.com & NewsRx.net) -- Heart-related complications can occur after the smallpox vaccine, but symptoms are usually mild, according to three studies presented at the American Heart Association's Scientific Sessions 2003 in Orlando, Florida.

The rate of adverse cardiac events was about 58 per 100,000 vaccinations in data collected between January and May 2003, said Richard Schieber, MD, of the Smallpox Vaccine Adverse Events Monitoring and Response Activity, National Immunization Program at the U.S. Centers for Disease Control and Prevention (CDC).

Twenty-four cases of pericarditis, myocarditis, dilated cardiomyopathy or acute coronary syndromes (heart attack or chest pain known as angina) were identified among 37,876 U.S. civilian health care workers vaccinated as part of the nation's bioterrorism readiness program. Twenty-two patients had pericarditis or myocarditis.

Pericarditis is inflammation of the pericardium, the thin sac (membrane) that surrounds the heart and the roots of the great blood vessels. Chest pain is one of the first signs.

Myocarditis is inflammation of the heart muscle caused by conditions such as infection, rheumatic fever, diphtheria, tuberculosis or toxic drug poisoning.

The average interval from vaccination to illness was about 12 days. Most patients with myocarditis had a mild form of the disease, but two of eight patients with acute coronary syndromes died suddenly within 3 weeks after vaccination. Five of the eight had three or more risk factors for, or a history of, coronary artery disease before vaccination.

In a large population in the same age range, some acute coronary events will occur over several weeks even in the absence of any identifiable cause, Schieber said.