Postmenopausal women with existing cardiovascular conditions are at an increased risk for sudden cardiac death, study shows

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Researchers from the University of Pennsylvania found that post-menopausal women with coronary artery disease and other risk factors are at an increased risk for sudden cardiac death.

“Until now, there has been very little data about sudden cardiac risk in women with existing cardiovascular conditions. Our research has revealed an important subset of women who are at an increased risk for sudden cardiac death,” said Rajat Deo, assistant professor of medicine, Cardiovascular Division, Perelman School of Medicine, University of Pennsylvania, USA, and lead author of the study. “We have identified a series of clinical risk factors that may eventually help clinicians better counsel women on how to manage their overall health to avoid sudden cardiac death.”


The researchers analysed data from the HERS (Heart and estrogen/progestin replacement study), which originally evaluated the effects of hormone replacement therapy on cardiovascular events among 2,763 postmenopausal women with coronary artery disease. The new analysis reveals that sudden cardiac death made up 54% of the cardiac-related deaths in these patients and over a quarter of all deaths in the entire study.


“Coronary artery disease is common among both men and women in the United States. The finding that sudden cardiac death comprised the majority of cardiovascular deaths and over a quarter of all deaths in this group of women with coronary artery disease is remarkable and higher than we would have expected,” said Deo. “In addition, most of these women would not have been identified as high risk using current methods for sudden cardiac risk stratification.”


Currently, the only established predictor for sudden cardiac death is to evaluate the heart’s pumping capacity in the left ventricle by measuring the ejection fraction. However, recent studies have shown that less than one-third of people who experience sudden cardiac death would have been identified by this clinical test.


Deo and colleagues also analysed a series of baseline characteristics in the HERS cohort to evaluate potential risk factors for sudden cardiac death. They determined that previous heart attack, heart failure, atrial fibrillation, physical inactivity, diabetes, and reduced kidney function were all closely associated with the sudden cardiac deaths in the HERS cohort. Women with at least three of the risk factors were at a ten-fold greater risk of sudden cardiac death than women with none of the risk factors.


“Our findings show that a simple assessment of clinical risk factors has a better predictive value for sudden cardiac death than currently available clinical measurements alone,” said Deo. “Using the two methods together provided the most complete picture of sudden cardiac death in the patients we studied.”


The researchers conclude that taken together, the results of their current research may help clinicians better counsel their patients on the modifiable risk factors, such as controlling diabetes and participating in regular exercise. They suggest that future research is needed in a larger cohort of patients to validate the use of the risk factors and help understand how they can best be used in clinical practice.


The research was supported, in part, by grants from the National Institutes of Health and a Kynett-FOCUS Junior Faculty Investigator Award for Research in Women’s Cardiovascular Health funded by the Edna G Kynett Memorial Foundation at the Perelman School of Medicine at the University of Pennsylvania.


The research is published on the online first edition of the Archives of Internal Medicine.