Measuring the levels of sex hormones in patients’ blood may identify patients likely to suffer cardiac arrest, a heart rhythm disorder that is fatal in 95 percent of patients.
A new study, published online by the peer-reviewed journal Heart Rhythm, shows that lower levels of testosterone, the predominant male sex hormone, were found in men who had a sudden cardiac arrest. Higher levels of estradiol, the major female sex hormone, were strongly associated with greater chances of having a sudden cardiac arrest in both men and women.
Unlike heart attacks, which are typically caused by clogged coronary arteries reducing blood flow to the heart muscle, sudden cardiac arrest is the result of defective electrical impulses. Patients may have little or no warning, and the disorder usually causes nearly instantaneous death.
Every year, 250,000 to 300,000 people in the U.S. and up to five million worldwide die from sudden cardiac arrest.
The sex hormone findings are a result of the Oregon Sudden Unexpected Death Study, a comprehensive, 16-hospital, multi-year assessment of cardiac deaths in the one-million population Portland, Oregon metropolitan area.
“This is the first time it has been reported that there is an association between sex hormone levels and sudden cardiac arrest,” said Sumeet Chugh, MD, director of the Heart Rhythm Center in the Cedars-Sinai Heart Institute. “While these findings need to be confirmed by other studies, they suggest that higher testosterone levels in men may offer protection from sudden cardiac arrest and lower levels of estrogen my protect both men and women.”