Relation of Elevated Resting Heart Rate in Mid-Life to Cognitive Decline Over 20 Years (from the Atherosclerosis Risk in Communities [ARIC] Study)

Resting heart rate (RHR) is independently associated with cardiovascular disease (CVD) risk. We determined whether RHR, measured in mid-life, is also associated with cognitive decline. We studied 13,720 middle-aged white and black ARIC participants without a history of stroke or atrial fibrillation. RHR was obtained from a 12-lead resting electrocardiogram at the baseline visit (1990 to 1992) and categorized into groups as <60 (reference), 60 to 69, 70 to 79 and ≥80 beats/min. Cognitive scores were obtained at baseline and at up to 2 additional visits (1996 to 1998 and 2011 to 2013). The primary outcome was a global composite cognitive score (Z-score) derived from 3 tests: delayed word recall, digit symbol substitution, and word fluency. The associations of RHR with cognitive decline and incident dementia were examined using linear mixed-effects and Cox hazard models, respectively, adjusting for sociodemographics, CVD risk factors, and AV-nodal blockade use. Multiple imputation methods were used to account for attrition over follow-up. Participants had mean ± SD age of 58 ± 6 years; 56% were women, 24% black. Average RHR was 66 ± 10 beats/min. Over a mean follow-up of 20 years, those with RHR ≥80 beats/min had greater global cognitive decline (average adjusted Z-score difference −0.12 [95% confidence interval −0.21, −0.03]) and increased risk for incident dementia (hazard ratio 1.28 (1.04, 1.57), compared with those with RHR <60 beats/min. In conclusion, elevated RHR is independently associated with greater cognitive decline and incident dementia over 20 years. Further studies are needed to determine whether the associations are causal or secondary to another underlying process, and whether modification of RHR can affect cognitive decline.