Hypertension Exacerbates Endothelial Dysfunction in Patients With Atrial Fibrillation

Atrial fibrillation (AF) and hypertension (HT) often coincide and both are independently associated with endothelial dysfunction. We tested the hypothesis that brachial artery flow-mediated dilation (FMD), an indicator of endothelial health, will be poorer in AF patients with HT (AF + HT) than AF without concurrent HT. In a cross-sectional design study, AF (n = 29; mean 70 years; 9 females) and AF + HT (n = 33; 68 years (p = 0.302); 14 females) patients underwent Duplex-Doppler ultrasound imaging of brachial artery diameter and flow velocity during baseline (2 min), distal tourniquet cuff inflation (5 min), and following cuff deflation (3 min). The peak increase in artery diameter following cuff deflation was taken as FMD and analyzed as absolute, percentage change, FMD and shear-rate area-under-the-curve (SR_AUC; FMD-to-SR_AUC) ratio, and using SR_AUC as a covariate (FMD_SRAUC). Body mass index (BMI) was used as an additional covariate for between-group comparisons of vascular data. Mean arterial pressure was higher in the AF + HT versus the AF group (median [interquartile range] 93 [85-99] vs. 84 [80-90] mm Hg, respectively; p < 0.05). Baseline brachial artery diameters were similar (p > 0.05). FMD was lower in AF + HT than AF patients (3.36 [1.69-5.21] vs. 4.98 [2.96-7.11] %, respectively; p < 0.05). Similar group differences were observed in absolute FMD, FMD-to-SR_AUC ratio and FMD_SRAUC (p < 0.05). AF patients with concurrent HT exhibit poorer endothelium-dependent vasodilation compared to AF patients, indicating that the presence of comorbid HT exacerbates endothelial dysfunction in AF patients.