Long-term study finds that smoking doubles the risk of developing heart failure
Newswise – A new study by researchers at the Johns Hopkins Bloomberg School of Public Health found that people who smoked tobacco cigarettes developed heart failure twice as often as those who never smoked. This higher rate occurred in two major subtypes of heart failure and confirms that smoking is an important risk factor for both.
The study is considered one of the first to assess the association of smoking with both subtypes of heart failure: reduced ejection fraction and preserved ejection fraction.
For their study, the researchers analyzed records from a long-term study of nearly 9,500 people in four US communities. The study found that participants who quit smoking maintained a significantly increased risk of either type of heart failure for decades after quitting.
The study was published online June 6 in the Journal of the American College of Cardiology.
“These findings underscore the importance of preventing smoking in the first place, especially in children and young adults.” says the study’s lead author, Kunihiro Matsushita, MD, PhD, an associate professor in the Bloomberg School’s Department of Epidemiology. “We hope our results will encourage current smokers to quit as soon as possible, as the harms of smoking can last for up to three decades.”
Heart failure is a progressive disease in which the heart loses its ability to pump enough blood to meet the body’s needs. It’s one of the most common causes of disability and death in developed countries, with more than 6 million adults suffering from heart failure in the United States alone, according to the most recent data from the Centers for Disease Control and Prevention. Besides smoking, risk factors for heart failure include obesity, hypertension, diabetes, coronary heart disease, and advanced age.
There are two types of heart failure: reduced ejection fraction and preserved ejection fraction. In heart failure with reduced ejection fraction, the left ventricle – the heart’s main pump – does not contract enough when pumping blood out. Heart failure with reduced ejection fraction is more closely related to coronary artery disease. Treatment includes several drugs that improve the prognosis.
In heart failure with preserved ejection fraction, the left ventricle fails to relax sufficiently after contracting. The treatment of heart failure with preserved ejection fraction is very limited, which makes its prevention of crucial importance. At the same time, its risk factors are less clear. Some previous studies have linked smoking to a higher risk of preserved ejection fraction, while others have not.
Matsushita and his colleagues assessed the medical records of participants in the ARIC (Atherosclerosis Risk In Communities) study. Launched in 1987, the ARIC study includes middle-aged and older adults across the United States, with a substantial representation of black individuals. The new study’s analysis included data from four communities in Maryland, North Carolina, Minnesota and Mississippi, and focused on 9,345 ARIC participants, ages 61 to 81, who had sufficient records and no diagnosis of heart failure in early 2005.
Over a median follow-up of 13 years, there were 1,215 cases of heart failure in the study, including 492 cases of reduced ejection fraction and 555 cases of preserved ejection fraction. The researchers’ analysis showed that smokers in the group were diagnosed with both subtypes of heart failure at roughly the same high rates as non-smokers – 2.28 times higher for ejection fraction preserved and 2.16 times higher for reduced ejection fraction.
The link to smoking also showed a ‘dose-response’ relationship – more cigarettes per day and more years of smoking being associated with a higher risk of heart failure. Similarly, quitting smoking reduced the risk of heart failure, which increased over time. Overall, former smokers were 31% and 36% more likely to have preserved ejection fraction and reduced ejection fraction, respectively, compared to non-smokers.
When the researchers stratified former smokers by the number of years since quitting, they found that their overall risk of heart failure remained significantly higher than the risk of non-smokers, except for the group that did not. hadn’t smoked for 30 years or more.
“It reinforces the idea that smoking casts a shadow over heart health,” says Matsushita.
“Cigarette Smoking, Cessation, and Risk of Heart Failure With Preserved and Reduced Ejection Fraction” was co-authored by Ning Ding, Amil Shah, Michael Blaha, Patricia Chang, Wayne Rosamond, and Kunihiro Matsushita.
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