Cuff-Based Oscillometric Measurements of Central Hemodynamics: Factors Influencing Central Augmentation Pressure in Normotensive Japanese Individuals

Relation between Oscillometric Measurement of Central Hemodynamics and Left Ventricular Hypertrophy in Hypertensive Patients

Introduction

The augmentation index (AIx) or central systolic blood pressure (SBP), measured by radial applanation tonometry, has been reported to be independently associated with left ventricular hypertrophy (LVH) in Japanese hypertensive patients. Cuff-based oscillometric measurement of the AIx using Mobil-O-Graph® showed a low or moderate agreement with the AIx measurement with other devices.

Methods

The AIx measured using the Mobil-O-Graph was validated against the tonometric measurements of the radial AIx measured using HEM-9000AI in 110 normotensive healthy individuals (age, 21-76 years; 50 men). We investigated the relationship between the central hemodynamics assessed using the Mobil-O-Graph and LVH in 100 hypertensive patients (age, 54-75 years; 48 men), presenting a wall thickness of ≥11 mm and ≥10 mm in men and women, respectively.

Results

Although the Mobil-O-Graph-measured central AIx showed no negative values, it correlated moderately with the HEM-9000AI-measured radial AIx (r = 0.602, p < 0.001) in the normotensive individuals. The hypertensive patients did not show a significant difference in the central SBP between the sexes, but the central AIx was lower in men than in women. The independent determinants influencing left ventricle (LV) mass index (LVMI) (R² = 0.362; adjusted R² = 0.329, p < 0.001) were heart rate (β = -0.568 ± 0.149, p < 0.001), central SBP (β = 0.290 ± 0.100, p = 0.005), and aortic root diameter (β = 1.355 ± 0.344, p = 0.001). Age (β = -0.025 ± 0.124, p = 0.841) and the central AIx (β = 0.120 ± 0.131, p = 0.361) were not independently associated with the LVMI. The area under the receiver operator characteristic curve to evaluate the diagnostic performance of the central AIx for the presence of LVH (LVMI >118 g/m² in men or >108 g/m² in women) was statistically significant in men (0.875, p < 0.001) but not in women (0.622, p = 0.132). In men, a central AIx of 28.06% had a sensitivity of 83.3% and specificity of 80.0% for detecting LVH.

Conclusions

AIx measurement in men provided useful prognostic information for the presence of LVH. Pulse-wave analysis assessed using the Mobil-O-Graph may be a valuable tool for detecting LVH in hypertensive patients.

Total vascular resistance, augmentation index, and augmentation pressure increase in patients with peripheral artery disease

Peripheral arterial disease (PAD) is one of major vascular diseases which frequently coexists with coronary arterial disease and cerebrovascular disease. The patients with PAD have a poor prognosis when it progresses. A new blood pressure testing device enables to simultaneously measure brachial blood pressure (BP), central BP, and several vascular parameters, with easy and non-invasive, in a short time. Here, we aimed to evaluate these arterial stiffness parameters in patients with PAD.In this study, 243 consecutive patients who were suspected of having PAD and referred to our hospital from September 2016 to June 2019, were registered. Several parameters, such as brachial BP, central BP, aortic pulse wave velocity (aPWV), total vascular resistance (TVR), augmentation index (AI) and augmentation pressure (AP), were determined by Mobil-O-Graph. Ankle-brachial pressure index (ABI) was used to define PAD (ABI ≤ 0.9 as PAD). The relationship between PAD and central BP, aPWV, TVR, AI, or AP were investigated.One hundred sixty-two patients (67%) were categorized as the PAD group and 81 patients (33%) as the non-PAD group. In the PAD group, the systolic brachial BP and central systolic BP were significantly higher than those in the non-PAD group (138 ± 24 mmHg vs 131 ± 19 mmHg, P < .05, 125 ± 22 mmHg vs 119 ± 18 mmHg, P < .05, respectively). TVR, AI, and AP were significantly higher in the PAD group (1785 ± 379 dyn s/cm5 vs 1661 ± 317 dyn s/cm5, P < .05, 26.2 ± 13.0% vs 22.2 ± 13.3%, P < .05, 13.5 ± 9.4 mmHg vs 10.7 ± 7.2 mmHg, P < .05, respectively). No significant differences in diastolic BP, central diastolic BP, and aPWV were found between the groups. Multivariate logistic regression analysis revealed that PAD was significantly associated with TVR, AI, and AP (P < .05, respectively).TVR/AP/AI were significantly higher in the PAD group than in the non-PAD group.