Sudden Cardiac Death, Heart Disease Surprise More Women Than Men

Circulation, a peer-reviewed journal of the American Heart Association, just released its fourth annual Go Red for Women issue, in which researchers from the Smidt Heart Institute at Cedars-Sinai note the stark disparities in how heart disease manifests in women and men. Among women, sudden cardiac death (SCD), which is “the result of defective electrical activity of the heart,” is often the first sign they even have heart disease, and its rate is on the rise, compared with men with known heart disease in whom a similar increase occurred.

The Cedars-Sinai team used data from the ongoing community-based Oregon Sudden Unexpected Death Study, or SUDS, for adults 18 years or older from February 1, 2004, to January 31, 2016, who lived in Multnomah County, Oregon, on the increasing rates of SCD among women and men to investigate this disturbing trend. Thirty-seven percent of the study population was women, and their mean (SD) age was 70 (16) years versus 65 (15) for the men. There was a total of 2938 SCDs during the study.

They stratified their data into three 4-year intervals—2004 to 2007, 2008 to 2011, and 2012 to 2015—and by each year, as well as looked at how SCD correlated with both known and unknown previous heart disease. This recent uptick in SCD follows a 7-year period of decline.

Overall, SCD declined in 2007, 2008, and from 2010 through 2012; however, for the years with higher rates, 2013 and 2015 had “significantly higher” rates of SCD versus 2011. Here is the breakdown for the periods, per 100,000 individuals:

• Between the first and second 4-year periods: Women: 30% decline, from 34 (95% CI, 31-38) to 24 (95% CI, 21-27; P = .001) SCDs Men: 21% decline, from 63 (95% CI, 59-68) to 50 (95% CI, 46-54; P = .001) SCDs
• Between the second and third 4-year periods: Women: 27% increase, to 30 (95% CI, 27-33; P = .002) SCDs Men: 17% increase, to 58 (95% CI, 54-62; P = .006) SCDs

Women whose heart disease made itself known with their SCD accounted for 58% of the rise in SCD incidence between the second and third periods. There was no change among the women with known heart disease. Among the men, however, 55% with known heart disease contributed to the SCD rate increase.

“Reasons for the rebound in SCD incidence and its sex-specific characteristics are likely complex,” the authors noted. However, they went on to explain that this difference is most likely due to left ventricular hypertrophy by ECG criteria compared with ischemic causes in men.

“The study validates the need for the discovery of novel risk factors and diagnostics to reduce the risk of sudden cardiac arrest among women,” stated Kyndaron Reinier, PhD, MPH, research scientist and associate director of Epidemiology at the Center for Cardiac Arrest Prevention, and first author on the study. “And, because more than 40% of both men and women had known heart disease before their sudden cardiac arrest, prevention and treatment of heart disease remain critically important.”

Reference

Reinier K, Stecker EC, Uy-Evanado A, et al. Sudden cardiac death as first manifestation of heart disease in women. Circulation. 2020;141(7):606-608. doi: 10.1161/CIRCULATIONAHA.119.044169.