Causes of Sudden Cardiac Death in Women Differ From That for Men

The number of women in their 30s and 40s who experience sudden cardiac death is increasing much faster than the number of men of the same age who experience sudden cardiac death. But a study led by an Oregon Health & Sciences University cardiac researcher has found men and women are not dying from the same causes. Sudden cardiac death in men is usually caused by coronary heart disease or other specific causes. However, researchers did not find a specific cause of sudden cardiac death for 50 percent of the women they studied. The study was published this month in the American Heart Journal.

“This was an unexpected finding. However, the study underscores the need to focus on what is causing these younger women to die unexpectedly because the number of deaths continues to increase,” said Sumeet Chugh, M.D., associate professor of medicine (cardiology) in the OHSU School of Medicine.

Chugh and his colleagues compared 27 women between the ages of 35 and 44 years and 45 men of the same age group. All died of a sudden cardiac death between 1984 and 1996 in the same geographic community. The analysis included a review of available clinical information, autopsy findings and detailed pathologic assessment of the heart. The research was conducted in collaboration with the Jesse E. Edwards Cardiovascular Registry in St. Paul, Minn., where all the patients were referred.

A year ago a study by the Centers for Disease Control and Prevention found the rate of sudden cardiac deaths increasing in women between 35 and 44 years of age more than the rate among men in that age range. Chugh and his team wanted to find out why and theorized that it might be a difference in men and women. Their study found the difference was in the causes of death, which were undetermined in 50 percent of the women.

“The chances are that in younger women sudden cardiac deaths are more complicated than in young men. We need to hone in on novel, unorthodox causes,” said Chugh.

Chugh has a study under way that is already doing that. The Oregon Sudden Unexplained Death Study, or SUDS, focuses on the discovery of novel mechanisms of sudden cardiac arrest in patients who do not have coronary heart disease or other known cardiac disorders. In the process, these investigators identify and study all instances of sudden cardiac arrest in Multnomah County, thereby gathering critical community-based data. So far, the SUDS project has collected one and a half years of such information, and the study is ongoing.

Sudden cardiac death is a significant health threat in Oregon. The CDC reports that more than 70 percent of cardiac deaths in Oregon are sudden, one of the highest percentages in the country. The overwhelming majority of these patients have associated coronary heart disease.

This study was funded in part by the American Heart Association.