Kandil Heba, Soliman Ahmed, Alghamdi Norah Saleh, Jennings J Richard, El-Baz Ayman
Bioengineering Department, University of Louisville, Louisville, KY 40292, USA.
Information Technology Department, Faculty of Computers and Informatics, Mansoura University, Mansoura 35516, Egypt.
Biomedicines. 2023 Mar 10;11(3):849. doi: 10.3390/biomedicines11030849.
Hypertension is a severe and highly prevalent disease. It is considered a leading contributor to mortality worldwide. Diagnosis guidelines for hypertension use systolic and diastolic blood pressure (BP) together. Mean arterial pressure (MAP), which refers to the average of the arterial blood pressure through a single cardiac cycle, can be an alternative index that may capture the overall exposure of the person to a heightened pressure. A clinical hypothesis, however, suggests that in patients over 50 years old in age, systolic BP may be more predictive of adverse events, while in patients under 50 years old, diastolic BP may be slightly more predictive. In this study, we investigated the correlation between cerebrovascular changes, (impacted by hypertension), and MAP, systolic BP, and diastolic BP separately. Several experiments were conducted using real and synthetic magnetic resonance angiography (MRA) data, along with corresponding BP measurements. Each experiment employs the following methodology: First, MRA data were processed to remove noise, bias, or inhomogeneity. Second, the cerebrovasculature was delineated for MRA subjects using a 3D adaptive region growing connected components algorithm. Third, vascular features (changes in blood vessel's diameters and tortuosity) that describe cerebrovascular alterations that occur prior to and during the development of hypertension were extracted. Finally, feature vectors were constructed, and data were classified using different classifiers, such as SVM, KNN, linear discriminant, and logistic regression, into either normotensives or hypertensives according to the cerebral vascular alterations and the BP measurements. The initial results showed that MAP would be more beneficial and accurate in identifying the cerebrovascular impact of hypertension (accuracy up to 95.2%) than just using either systolic BP (accuracy up to 89.3%) or diastolic BP (accuracy up to 88.9%). This result emphasizes the pathophysiological significance of MAP and supports prior views that this simple measure may be a superior index for the definition of hypertension and research on hypertension.
高血压是一种严重且高度流行的疾病。它被认为是全球死亡率的主要促成因素。高血压的诊断指南同时使用收缩压和舒张压(BP)。平均动脉压(MAP)指的是通过单个心动周期的动脉血压平均值,它可以作为一个替代指标,可能反映个体承受更高压力的总体情况。然而,一个临床假设表明,在50岁以上的患者中,收缩压可能更能预测不良事件,而在50岁以下的患者中,舒张压可能更具预测性。在本研究中,我们分别研究了(受高血压影响的)脑血管变化与MAP、收缩压和舒张压之间的相关性。使用真实和合成的磁共振血管造影(MRA)数据以及相应的血压测量进行了多项实验。每个实验采用以下方法:首先,对MRA数据进行处理以去除噪声、偏差或不均匀性。其次,使用三维自适应区域生长连通分量算法为MRA受试者描绘脑血管系统。第三,提取描述高血压发生之前和期间出现的脑血管改变的血管特征(血管直径和曲折度的变化)。最后,构建特征向量,并使用不同的分类器(如支持向量机、K近邻、线性判别和逻辑回归)根据脑血管改变和血压测量将数据分类为正常血压者或高血压患者。初步结果表明,与仅使用收缩压(准确率高达89.3%)或舒张压(准确率高达88.9%)相比,MAP在识别高血压对脑血管的影响方面更有益且准确(准确率高达95.2%)。这一结果强调了MAP的病理生理学意义,并支持了先前的观点,即这个简单的测量指标可能是定义高血压和研究高血压的一个更优指标。