Smoking, Alcohol increase lifetime risk of AF : BMJ

The overall lifetime risk of atrial fibrillation (AF) in individuals aged 55 years or older, was 37 percent and was influenced by the burden of risk factors including smoking, obesity, and drinking, according to a new study published in the journal The BMJ.

The study was conducted by Ludovic Trinquart, assistant professor of biostatistics at Boston University School of Public Health (BUSPH), and colleagues, to examine the association between risk factor burdens—categorized as optimal, borderline, or elevated—and the lifetime risk of AF.

Advancing age is a prominent risk factor for atrial fibrillation or irregular heartbeat. In addition to increasing age, other established risk factors for developing AF within 10 years include hypertension, obesity, smoking, drinking, heart failure and myocardial infarction. Modifiable risk factors could be associated with increased risk of the disease even if they were previously considered borderline- for example, overweight and high systolic blood pressure. The elevation of one risk factor rarely occurs in isolation, because many people often have a mixture of borderline or elevated levels of risk factors.

Lifetime risk is a useful method for quantification of atrial fibrillation risk over a person's lifetime. However, there is a dearth of data with respect to the lifetime risk of atrial fibrillation in the presence of one or multiple risk factors such as obesity and smoking.

"We examined the lifetime risk of atrial fibrillation, which measures the cumulative risk of developing a disease during the remainder of an individual's life," says co-author Trinquart. "It is essential to look at lifetime risks in addition to short-term risks, because it may enable early identification of individuals at higher long-term risk and facilitate lifestyle change counselling."

"By contrast with the relative risk of AF, the lifetime risk is an easy way for clinicians to communicate the future risk of atrial fibrillation to individuals," the authors wrote. "Estimating the lifetime risk of atrial fibrillation in various subgroups with one or multiple elevated or borderline-elevated risk factors might also help to design preventive strategies."

For carrying out the study, the researchers assessed 5,338 participants from the Framingham Heart Study who did not have AF at one or more of the index ages of 55, 65, and 75 years. They identified smoking, alcohol consumption, body mass index, blood pressure, diabetes, and history of myocardial infarction or heart failure at an index age as risk factors. Then, they categorized risk factor burdens as optimal (all risk factors were optimal), elevated (at least one risk factor elevated), and borderline, and compared the lifetime risk estimates according to those levels of risk factor burden.

Risk factors present at index age 55 years considerably influenced lifetime risk. An optimal risk factor profile was associated with a lifetime risk of atrial fibrillation of 23 percent. Lifetime risk rose to about 34 percent in individuals borderline risk profile, and to 38 percent in individuals with an elevated risk factor.

"Studying atrial fibrillation is important because it is emerging as a global epidemic; it also imposes a considerable socioeconomic burden. Atrial fibrillation hospitalizations follow an exponential increase and have surpassed heart failure admissions," Trinquart says. "Moreover, atrial fibrillation is associated with increased risks of stroke, dementia, myocardial infarction, heart failure, and premature death. Primary prevention remains largely untapped for improving AF management."

Based on the study, the authors concluded that regardless of index ages at 55, 65, or 75 years, an optimal risk factor profile was associated with a lifetime risk of atrial fibrillation of about one in five; this risk rose to more than one in three a third in individuals with at least one elevated risk factor.

For further information click on the link: https://doi.org/10.1136/bmj.k1453