Women who are even light-to-moderate cigarette smokers may be significantly more likely than nonsmokers to suffer sudden cardiac death, according to data from the Nurses Health Study.
Long-term smokers may be at even greater risk, according to the findings, but quitting can reduce and eliminate the risk over time.
“Cigarette smoking is a known risk factor for sudden cardiac death, but until now, we didnt know how the quantity and duration of smoking affected the risk among apparently healthy women, nor did we have long-term follow-up,” Roopinder K. Sandhu, MD, MPH, the studys lead author and a cardiac electrophysiologist at the University of Albertas Mazankowski Heart Institute in Canada, said in a news release.
Researchers examined the incidence of sudden cardiac death among more than 101,000 healthy women in the Nurses Health Study, which has collected biannual health questionnaires from female nurses nationwide since 1976. They included records dating back to 1980 with 30 years of follow-up. Most of the participants were white, and all were between ages 30 and 55 at the start of the study. On average, those who smoked reported starting in their late teens.
During the study, 351 participants died of sudden cardiac death. Light-to-moderate smokers, defined in the study as those who smoked one to 14 cigarettes daily, had nearly twice the risk of sudden cardiac death as their nonsmoking counterparts.
Women with no history of heart disease, cancer or stroke who smoked had almost 2 1/2 times the risk of sudden cardiac death compared with healthy women who never smoked.
For every five years of continued smoking, the risk climbed by 8%. But among women with heart disease, the risk of sudden cardiac death dropped to that of a nonsmoker within 15 to 20 years after smoking cessation. In the absence of heart disease, there was a reduction in sudden cardiac death risk in fewer than five years.
Sudden cardiac death accounts for 300,000 to 400,000 deaths in the United States each year and “is often the first sign of heart disease among women, so lifestyle changes that reduce that risk are particularly important,” said Sandhu, who also is a visiting scientist at Brigham and Womens Hospital in Boston. “Our study shows that cigarette smoking is an important modifiable risk factor for sudden cardiac death among all women. Quitting smoking before heart disease develops is critical.”
The study appeared Dec. 11 on the website of Circulation: Arrhythmia and Electrophysiology, and American Heart Association journal. The study abstract is available at http://circep.ahajournals.org/content/early/2012/11/16/CIRCEP.112.975219.abstract.