Magnetic resonance imaging of the aortic wall as a risk index for acute ischemic stroke in patients with resistant arterial hypertension

Abstract

Abstract Aim To value the possible relationship between the intensity of neoangiogenesis in the aortic wall in patients with resistant arterial hypertension and the subsequent development of ischemic cerebral disorders in them over a three-year follow-up. Materials and methods This study comprised 36 patients with resistant hypertension, in whom the renal denervation was carried out. MRI of the brain and also with contrast enhancement of the aorta and kidneys were examined. MRI studies included T2 and T1 spin-echo MRI, and also coronal slices, with suppression of the signal from adipose tissue (TR=150 ms, TE = 4 ms), before and in 12–15 minutes after contrast-enhanced. The diameter and thickness of the wall of the descending aorta were measured. Index of the enhancement of the aortic wall was calculated as the ratio of intensities of the wall after, and before contrast-enhanced. 9 according to MRI data - developed an acute ischemic stroke during this period, and 27 had no cerebral circulation disorders. The control group consisted of individuals without hypertension (n=12). Results After renal denervation, the systolic blood pressure significantly decreased in all patients for more than 15 mm Hg. In groups of patients with ischemic stroke, and without it, the diameter of the aortic lumen at the level above the renal arteries was 22,1±2,4 mm and 22,8±2,7 mm, respectively; the aortic wall thickness was 3,9±0,7 mm and 3,7±0,8 mm. In control subjects without hypertension, the wall thickness was less than 2,7 mm (on average 2,2±0,4 mm), with an aortic diameter of 21,3±0,9. As to the index of enhancement (as a marker of neoangiogenesis intensity) in the control group, in everybody, the IE was <1,12. In patients with stroke within 3 years after renal denervation, IE = 2,12±0,31, and in patients without stroke IE = 1,66±0,19. The value of IE = 1,82 was the best for separating groups with and without stroke in the three years endpoint, as from the ROC analysis. Conclusion Contrast enhancement of the aortic wall in MRI is associated with the risk of brain ischemic stroke in patients with resistant arterial hypertension, even when blood pressure control is achieved by renal denervation. This makes it possible to predict the risk of stroke in these patients more reliably and encourages the inclusion of agents that reduce the activity of inflammation and pathological neoangiogenesis in the aortic wall, to the spectrum of antihypertensive therapy. Funding Acknowledgement Type of funding sources: None. Brain MRI T2WIMRI of the kidneys and aorta, T1WI