Background: Atrial fibrillation (AF) is associated with cognitive decline. Whether left atrial enlargement (LAE), a critical substrate for AF, is also associated is less well established. Therefore, we assessed the association of LAE and AF with cognitive decline in the ARIC-NCS (Atherosclerosis Risk in Communities Neurocognitive Study). Methods and Results: Participants (n=3391; mean age, 75±5 years; 59% women) underwent cognitive tests and 2-dimensional echocardiograms at visit 5 (2011–2013) and follow-up cognitive tests at visit 6 (2016–2017). LAE was defined as left atrium volume index ≥34 mL/m2. AF was ascertained using study ECGs and hospitalization discharge codes. We assessed the association of AF and LAE with (a) cognitive domain scores at visit 5 and (b) cognitive domain score changes between visit 5 and visit 6. At visit 5, compared with the reference group (without AF, normal left atrium), participants with LAE and AF had significantly lower global cognition (Z score, −0.24; 95% CI, −0.38 to −0.10), whereas participants with AF and without LAE and participants with LAE and without AF did not have lower global cognition. In longitudinal analysis, compared with the reference group, participants with AF but without LAE had significantly greater decline in global cognition (Z score, −0.13; 95% CI, −0.21 to −0.06). However, LAE, with or without AF, was not associated with greater cognitive decline. Conclusion: Although LAE with AF was significantly associated with lower cognitive function in cross-sectional analysis, LAE, with or without AF, was not associated with greater cognitive decline over 5 years, highlighting the importance of evaluating longitudinal cognitive function. Future studies should have longer follow-up and evaluate left atrium function.
Bibliographical noteFunding Information:
Dr Alonso is supported by American Heart Association grant 16EIA26410001. Dr Chen is supported by National Institutes of Health (NIH) grants R01HL126637 and R01HL141288. Dr Shah is supported by NIH grants K08HL116792, R01HL135008, and R01HL143224. The ARIC (Atherosclerosis Risk in Communities) study is performed as a collaborative study, supported by National Heart, Lung, and Blood Institute (NHLBI) contracts (HHSN268201700001I, HHSN268201700002I, HHSN268201700003I, HHSN268201700005I, and HHSN268201700004I). Neurocognitive data are collected by 2U01HL096812, 2U01HL096814, 2U01HL096899, 2U01HL096902, and 2U01HL096917 from the NIH (NHLBI, National Institute of Neurological Disorders and Stroke, National Institute on Aging, and National Institute on Deafness and Other Communication Disorders), and with previous brain magnetic resonance imaging examinations funded by R01‐HL70825 from the NHLBI. Funding for laboratory testing and biospecimen collection at ARIC visit 6 was supported by grant R01DK089174 from the National Institutes of Diabetes and Digestive and Kidney Diseases of the NIH. The views expressed in this article are those of the authors and do not necessarily represent the views of the NHLBI, the NIH, or the US Department of Health and Human Services.
© 2019 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.
- atrial fibrillation
- left atrial volume index
- longitudinal cohort study