Is there a correlation between atrial fibrillation and heart attack?

This study examined the extent to which atrial fibrillation is a risk factor for heart attack. 

Atrial fibrillation (AF), an abnormal rhythm of the heart where the atria (heart chambers that receive blood into the heart and drive it to the heart’s pumping chambers) quiver instead of beat is increasing in prevalence and is strongly associated with the risk of morbidity (having a disease) and mortality (death).

Heart attack is an established risk factor for atrial fibrillation, with atrial fibrillation occurring in 6% to 21% of patients suffering from a heart attack. Recently, some findings suggest that atrial fibrillation may also be an independent risk factor for heart attack and not simply the result of the condition. Studies to support these reports are lacking.

23,928 participants were included in the trial. At the beginning of the study, AF was present in 1,631 participants (6.8%). During an average follow-up of 4.5 years, 648 heart attacks were recorded (2.7% of entire group). In order for analysis to be as accurate as possible, adjustments for factors known to be associated with heart attacks such as high total cholesterol levels, smoking, high blood pressure, different drug use, obesity, diabetes and kidney disease were performed.

Following analysis researchers concluded that atrial fibrillation is significantly associated with increased risk of heart attack independent of common coronary artery disease risk factors. After adjusting results for risk factors, participants suffering from atrial fibrillation showed a 70% increase in risk of heart attack compared to participants with no atrial fibrillation.

Furthermore, significant differences were observed in sex and race subgroup analysis. In women (2.16 times the risk) and in black participants (2.53 times the risk) the risk of heart attack associated with atrial fibrillation was significantly higher compared with men (39% increase in risk) or white (26% increase in risk) participants.

This study concluded that atrial fibrillation is an independent risk factor for heart attack.

This study included only white and black participants; hence, results may not be applicable to other racial or ethnic groups.