Tuesday, January 09, 2018

Excessive supraventricular ectopy in the elderly associated with lower cognition, and only partly explained by stroke incidence


Introduction: Supraventricular ectopic beats (SVE) are common and considered benign. However, excessive supraventricular ectopy activity (ESVEA) has been associated with incident atrial fibrillation (AF) and stroke. While AF has been associated with lower cognitive function independent of stroke, the association between ESVEA and cognitive function has not yet been characterized.

Hypothesis: ESVEA would be cross-sectionally associated with lower cognitive test scores.

Methods: We included N=1,116 ARIC study participants [age mean±SD 80±5 years, 55% female, 23% non-white race] who underwent cognitive testing and wore a leadless, ambulatory ECG-monitoring device (Zio®Patch by iRhythm Technologies Inc) for greater than or equal to 2 days between 6/2016-2/2017. Cognitive domain-specific factor scores for memory, executive function and language were estimated using standardized z-scores. SVE burden was calculated as mean number per day and ESVEA was defined as greater than or equal to 75th percentile of mean number per day. Multiple linear regression was used to evaluate the association between ESVEA and cognitive test scores.

Results: During a mean recording time of 12.8±2.4 days, 95% of participants had greater than or equal to 1 SVE, and a median 205 SVE/day (IQR=66-823). ESVEA was associated with lower executive function z-scores by 0.19 (95% CI: -0.37, -0.02) after adjustment for demographics (Table). After multivariable adjustment, this association was slightly attenuated [-0.16 (-0.33, 0.01)]. ESVEA was not associated with memory or language scores. In sensitivity analysis, the ESVEA-executive function association was weakened but followed a similar pattern after excluding those with AF and/or stroke [Model 1: -0.17 (-0.35, 0.01); Model 2: -0.13 (-0.31, 0.04)].

Conclusions: In this elderly population, ESVEA was associated with lower executive function and this association was only partly explained by AF or stroke prevalence.

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