EFFECT OF BLOOD PRESSURE OPTIMISATION ON ENDOTHELIAL FUNCTION IN PATIENTS WITH ATRIAL FIBRILLATION AND HYPERTENSION

Objective: Hypertension accounts for more cases of atrial fibrillation (AF) than any other risk factors. AF and hypertension commonly co-exist and both are associated with endothelial dysfunction. FMD measurement using a high-resolution ultrasound has become a reliable and reproducible technique for assessment of endothelial dysfunction. To investigate whether optimising of blood pressure (BP) in patients with hypertension and AF leads to improvement in FMD. Design and method: In a longitudinal comparison, we recruited 30 participants with hypertension and permanent AF. Each participant had 3 serial BP readings and an echocardiogram. Their drug history was noted. High-resolution ultrasound was used to measure brachial artery diameter at rest and during reactive hyperaemia (endothelium-dependent FMD). Participant's BP medication was optimised according to their BP. Participants were then followed them up after 8 weeks for repeat FMD measurements. Data analysis was carried out using paired t-test on SPSS. Results: Following optimisation of BP medication, patients with permanent AF and hypertension were followed up after 8 weeks and FMD repeated. There was significant improvement in mean heart rate (77 ± 18 (baseline) vs 72 ± 17 (follow up), p = 0.01), systolic BP (140 mmHg [128 – 148] (baseline) vs 131 mmHg [122 – 146] (follow up), p = 0.03), diastolic BP (81 mmHg ± 13 (baseline) vs 77 mmHg ± 12 (follow up), p = 0.02) and mean arterial pressure (MAP) (100 mmHg ± 9 (baseline) vs 97 mmHg ± 13 (follow up), p = 0.01). Both groups had a similar baseline brachial artery diameter (p = 0.34). Endothelium-dependent FMD response was better following 8 weeks of BP optimisation but this was not significant (3.1%, 95% CI [2.3 – 4.8] (baseline) vs 5.2%, 95% CI [3.9 – 6.5] (follow up), p = 0.09). No variables were identified on univariate or multivariate analysis as independent predictors of FMD. Conclusions: Endothelial dysfunction can be improved following optimisation of BP medication suggesting modulation of endothelial function is possible in patients with permanent AF and hypertension. Longer-term improvement in FMD may have a prognostic implication.