Afib Risk Not Affected by Borderline ABI in Peripheral Artery Disease
Researchers believe that the association between afib and PAD may most likely be explained by traditional atherosclerotic risk factors.
According to a study published in the Journal of the American Heart Association, peripheral artery disease (PAD) with an ankle-brachial index (ABI) of <1.0 or >1.4 or >0.9 to <1.0 (eg, borderline ABI) was not associated with an increased risk for atrial fibrillation (AF).
The population-based prospective Atherosclerosis Risk in Communities study included 14,794 participants who were free of prevalent AF and had baseline ABI data (1987-1989) available for analysis. Investigators identified AF using hospital discharge diagnosis records, study visit electrocardiograms, and death certificates during a median follow-up period of 23.3 years.
During follow-up, a total of 2288 cases of AF were identified. Participants with an ABI <1 had a higher AF risk vs those with ABI 1.0 to1.1 following adjustment for age, sex, and race (hazard ratio [HR], 1.35; 95% CI, 1.21-1.51). Of the individuals with an ABI <1.0, the HR for AF was 1.13 (95% CI, 1.01-1.27) compared with individuals with an ABI of 1.0 to 1.4.
Individuals with an ABI >1.4 did not demonstrate an increased risk for AF. In addition, an ABI ≤0.9 as well as an ABI >0.9 to <1.0 were associated with a higher AF risk vs those with ABI 1.0 to 1.4. Following adjustment for cardiovascular risk factors, there was no significant association of ABI ≤0.9 (HR, 1.10; 95% CI, 0.90-1.34) and borderline ABI (HR, 1.14; 95% CI, 1.00-1.30) with AF. There was no significant association between ABI >1.4 and an increased risk for AF.
It is possible that an underestimation of PAD prevalence occurred in this study, considering PAD is often unilateral and ankle blood pressure was measured in only 1 leg of the study participants.
Based on these findings, the investigators believe that the association between “PAD and AF appears to be mostly explained by traditional atherosclerotic risk factors.”
Bekwelem W, Norby FL, Agarwal SK, et al. Association of peripheral artery disease with incident atrial fibrillation: the ARIC (Atherosclerosis Risk in Communities) study. J Am Heart Assoc. 2018;7:e007452.