Healthy lifestyle led to low risk for sudden death in women

Chiuve S. JAMA. 2011;306:62-69.

Issue: August 2011

In a cohort of more than 80,000 female nurses, adherence to a low-risk lifestyle, including regular exercise and abstaining from smoking, resulted in a low risk for sudden cardiac death, according to data published in the Journal of the American Medical Association.

“The primary prevention of sudden cardiac death (SCD) remains a major public health challenge because most SCD occurs among individuals not identified as high risk,” the researchers wrote. “In this cohort of female nurses, adherence to an overall healthy lifestyle was associated with a lower risk of SCD and may be an effective strategy for the prevention of SCD.”

The prospective study involved US women (n=81,722) in the Nurses’ Health Study from 1984 to 2010. The participants were sent questionnaires every 2 to 4 years that evaluated lifestyle factors, including physical activity, smoking and menopausal status, weight, use of medications and physician diagnosis of disease. Researchers defined a low-risk lifestyle using the following four low-risk factors: BMI less than 25; abstaining from smoking; exercise duration of at least 30 minutes per day; and being in the top 40% of the alternate Mediterranean diet score, which stressed the consumption of vegetables, fish, fruits, nuts, legumes, whole grains and moderate alcohol intake.

Overall, 321 SCDs occurred among participants during the 26 years of follow-up. Each of the four low-risk factors was significantly and independently linked to a lower risk for SCD. Absolute risk for SCD per 100,000 person-years was 22 cases for women with no low-risk factors, 17 cases for women with one low-risk factor, 18 cases for participants with two low-risk factors, 13 cases for those with three low-risk factors and 16 cases for those with all four low-risk factors.

Additionally, multivariable RR for SCD, when compared with women with no low-risk factors, was 0.54 (95% CI, 0.34-0.86) for women with one low-risk factor, 0.41 (95% CI, 0.25-0.65) for two low-risk factors, 0.33 (95% CI, 0.20-0.54) for three low-risk factors and 0.08 (95% CI, 0.03-0.23) for four low-risk factors.

Because SCD accounts for more than 50% of CHD mortality, “widespread adoption of a healthy lifestyle in the population may make a substantial impact on reaching the American Heart Association’s 2020 Impact Goal of further lowering CVD mortality,” the researchers concluded.

Nanette Wenger

These data from the Nurses' Health Study are striking. Whereas associations do not prove causation, the implementation of lifestyle preventive interventions, a most economical approach, offers the potential to reduce sudden cardiac death among women. The majority of women who incur sudden cardiac death had not had a clinical manifestation or prior diagnosis of CVD, hence the focus on risk factors is highly appropriate. The interventions identified are concordant with the recently released recommendations of the American Heart Association 2011 Update on the Prevention of Cardiovascular Disease in Women and deserve widespread communication both to women and to their healthcare providers. The population-based strategies of nonsmoking or smoking cessation, routine modest intensity physical activity (exercise of at least 30 minutes daily), reducing weight in those who are overweight (to a body mass index of less than 25), and adoption of the Mediterranean Diet have the potential to substantially reduce the occurrence of sudden cardiac death in women.

My own personal belief is that these are items that need to be taught to girls during the school years when many lifelong habits are formed, i.e., to emphasize not initiating smoking, regular exercise, maintaining an optimal body weight and adherence to a heart-healthy diet.

Nanette Wenger, MD
Cardiology Today Editorial Board member

Disclosures: Dr. Wenger is an author of the AHA's 2011 Prevention Guidelines for Women.

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