73 Type of atrial fibrillation and its effect on endothelial function

Background Atrial fibrillation (AF) is associated with increased morbidity including stroke, heart failure, thromboembolic complications and high mortality. Beat to beat variation in blood flow dynamics during AF has been related to presence of endothelial dysfunction. Endothelial function can be assessed using flow mediated dilatation. Impaired FMD is associated with cardiovascular risk factors. FMD measurement using a high-resolution ultrasound has become a reliable and reproducible technique for assessment of endothelial dysfunction. Purpose To investigate whether type of AF leads to differences in endothelial function using FMD. Design: In a cross-sectional comparison, we studied two patient groups: permanent AF (n = 30) and paroxysmal AF (n = 31). Each participant underwent baseline blood tests, blood pressure check, electrocardiogram (ECG) and an echocardiogram. High-resolution ultrasound was used to measure brachial artery diameter at rest and during reactive hyperaemia (endothelium-dependent FMD). Results Participants in the two groups were well matched for age, sex, clinical characteristics including body mass index (BMI), mean blood pressure, HBA1c, creatinine clearance and left ventricular systolic function. There was a significant difference in FMD between permanent AF and paroxysmal AF groups (3.1, 95% CI [2.3 – 4.8] vs 5.9, 95% CI [4.0 – 8.1]; p = 0.02). Ischaemic heart disease was identified as an independent predictor of FMD on univariate analysis (p = 0.03) but there were no independent predictors of FMD on multivariate analysis. Conclusions Endothelium-dependent FMD is impaired in patients with AF. The duration and frequency of AF (paroxysmal AF to permanent AF) leads to worsening endothelial function. Conflict of Interest None