Association of aortic flow propagation velocity with ankle-brachial blood pressure index in patients with hypertension: an observational study

Objective: Endothelial dysfunction is considered the first stage in the development of atherosclerosis and assessed by flow-mediated dilatation (FMD) and aortic flow velocity propagation (AVP). Ankle-brachial index (ABI) is used to assess peripheral arterial disease and is associated with FMD but the relationship between ABI and AVP is unknown. In this study, we aimed to search the association between AVP, and ABI in patients with newly diagnosed hypertension. Methods: Sixty-eight patients with newly diagnosed hypertension and 34 healthy subjects were enrolled in the crosssectional observational study. The maximum ankle arterial pressures were divided by the maximum of the brachial arterial pressures to calculate the ABI. AVP was calculated from dividing the distance between points corresponding to the beginning and end of the propagation slope, to the duration between corresponding time points proximally descending aorta. Statistical analysis was performed using Student t-test, Chi-square test, Pearson correlation and linear regression analyses. Results: Age and gender of both groups were similar. Compared to control group E deceleration time of early diastolic flow velocity (184.0±32.2 vs. 217.1±38.6, p 0.001), isovolumic relaxation time (95.5±19.4 vs. 105.7±18.1, p 0.001) and body mass index (25.6±5.1 vs. 27.5±3.8, p=0.044) values were significantly higher, while ABI (1.08±0.07 vs. 1.14±0.07, p=0.001) and AVP (54.97±9.3 vs. 69.17±10.8 cm/sec, p=0.001) values were significantly lower in hypertensive patients. There was a significant correlation between AVP and ABI (r=0.279, p=0.005). Both ABI and AVP were independent predictors of hypertension (OR - 0.353, 95%CI 0.151-0.826, p=0.02 and OR - 0.133, 95%CI 0.0502-0.35, p=0.001, respectively). Conclusion: Our data indicate that in patients with isolated hypertension AVP and ABI decrease. We also conclude that AVP is directly associated with ABI.