Low deceleration capacity is associated with higher stroke risk in patients with paroxysmal atrial fibrillation

Background: Deceleration capacity (DC) is a non-invasive marker for cardiac autonomic dysfunction; however, few studies have shown that the influence factors of cardiac autonomic dysfunction and the correlations between DC and stroke risk in paroxysmal atrial fibrillation (AF). We aimed to explore the influencing factors of abnormal DC and the relationships between DC and stroke risk in patients with paroxysmal AF.Methods: The study included hospitalized paroxysmal AF patients with DC measurements derived from 24-h Holter electrocardiography recordings taken between August 2015 and June 2016. Multivariable regression analysis was performed to evaluate the associations between correlated variables and abnormal DC values. The relationship between DC and ischemic stroke risk scores in patients with paroxysmal AF was analyzed.Results: We studied 259 hospitalized patients with paroxysmal AF (143 [55.2%] male, mean age 66.4 ± 12.0 years); 38 patients of them showed abnormal DC values. In the univariate analysis, age, hypertension, heart failure, and previous stroke/transient ischemic attack (TIA) were significantly associated with abnormal DC values. Among these factors, a history of previous stroke/TIA (odds ratio = 2.861, 95% confidence interval: 1.356–6.039) were independently associated with abnormal DC values in patients with paroxysmal AF. The abnormal DC group showed a higher stroke risk with the score of congestive heart failure, hypertension, age >75 years, diabetes mellitus, previous stroke and TIA (CHADS2) (2.25 ± 1.48vs. 1.40 ± 1.34,t = -4.907,P = 0.001) and CHA2DS2-vascular disease, age 65–74 years and female category (VASc) (3.76 ± 1.95vs. 2.71 ± 1.87,t = -4.847,P = 0.001) scores. Correlation analysis showed that DC was negatively correlated with CHADS2 scores (r = -0.290,P < 0.001) and CHA2DS2-VASc scores (r = -0.263,P > 0.001).Conclusions: Lower DC is closely associated with previous stroke/TIA, and is also correlated negatively with higher stroke risk scores in patients with paroxysmal AF. It could be a potential indicator of stroke risk in paroxysmal AF patients.