The Relationship Between Renal Resistive Index, Arterial Stiffness, and Atherosclerotic Burden: The Link Between Macrocirculation and Microcirculation

Introduction: The relationship of renal haemodynamics with cardiac and aortic hameodynamics is still unclear. Hypothesis: We evaluated the relationship of increased renal resistive index (RRI) with Augmentation index (AIx) and cardiac haemodynamics by means of mitral annular early diastolic velocity (E/Ea) in untreated patients with essential hypertension. Methods: 76 newly diagnosed untreated non diabetic patients with stage I-II essential hypertension [35 males, aged 50 years, office blood pressure (BP) = 143/ 91 mm Hg], underwent ABPM, complete echocardiographic study for determination of E/Ea and blood sampling for assessment of metabolic profile. Moreover, data on renal resistive index (RRI), obtained by Doppler ultrasound sampling of the intrarenal arteries, as well as augmentation index (AIx), were retrospectively analyzed. Results: Based on the mean value of RRI (0.60), hypertensives were classified into those with high and low RRI. Hypertensives with high RRI values compared to those with low values were older (55.6±9.8 vs 44.4±11.6 years, p < 0.001), had lower 24-hour diastolic BP (77.5±7.7 vs 84.3±6.7 mmHg, p < 0.001), lower 24-hour HR (71.2±10.3 vs 76.2±9.2 bpm, p < 0.05), higher levels of AIx (27.2±8.2 vs 17.8±14.8 %, p < 0.01), and higher values of E/Ea (lateral) (7.7±1.8 vs 6.2±2.3, p < 0.05). In the total population, RRI was negatively related to 24-hour diastolic BP (r = -0.523, p < 0.001) and 24-hour HR (r = -0.281, p < 0.05), while it was positively associated with CRP (r = 0.335, p < 0.05), TChol (r = 0.296, p < 0.01), age (r = 0.443, r < 0.001), AIx (r = 0.413, p = 0.001) and E/Ea(lateral) (r = 0.465, p < 0.05). Multiple regression analysis revealed that 24-hour diastolic BP and E/Ea (lateral) were independent associated with RRI (R2 = 0.434, p < 0.05). Conclusions: Increased vascular resistance of intrarenal arteries is associated with impaired aortic and cardiac haemodynamics, as reflected by increased AIx and E/Ea (lateral) values. RRI may be considered a useful surrogate of haemodynamics in essential hypertension.

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Abstract P358: Association of Kidney Function and Cerebral Arterial Stiffness

Stroke ◽

10.1161/str.52.suppl_1.p358 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Eung-Joon Lee ◽

Hae Bong Jeong ◽

Ki-woong Nam ◽

Kipyoung Jeon ◽

Jeonghoon Bae ◽

...

Keyword(s):

Renal Function ◽

Arterial Stiffness ◽

Renal Dysfunction ◽

Doppler Ultrasound ◽

Resistive Index ◽

Retrospective Chart Review ◽

Transcranial Doppler Ultrasound ◽

Lacunar Infarction ◽

Renal Resistive Index ◽

Proportional Relationship

Background and Purpose: Chronic kidney disease (CKD) is known to have affected the systemic vasculature and its remodeling, which eventually led to the systemic arterial stiffness. However, the relationship between cerebral circulation and impaired renal function is poorly understood. To evaluate the effect of renal dysfunction to increase systemic and intracranial arterial stiffness, we assessed the relation between renal resistive index (RRI) and pulsatility index (PI) of the middle cerebral artery (MCA). Methods: We included patients with acute lacunar infarction. Demographic and clinical data were collected by retrospective chart review. Bilateral transcranial Doppler ultrasound (TCD) examination of the MCAs was performed using the ST3 Ultrasound system (Spencer Technologies) and PI were calculated. RRI was obtained through kidney Doppler sonography. Subjects with occlusion or significant stenosis of MCA, atrial fibrillation, bilaterally absent transtemporal sonographic windows were excluded. Results: Of the 283 included subjects (mean age 67.8 ± 10.2), 74 patients had renal dysfunction (glomerular filtration rate < 60ml/min/1.73m2 at admission) and 49 patients underwent kidney Doppler ultrasound within 1 year since their acute stroke. Renal dysfunction was significantly associated with higher arterial stiffness (median PI 1.12, IQR 0.85 to 1.57 vs. controls PI 0.84, IQR 0.54 to 1.22 [p<0.0001]). There was a proportional relationship between the degree of renal dysfunction and the distal vascular resistance. In multivariate adjusted regression analysis, renal function was related to high PI (p<0.001). Furthermore, there is strong correlation between RRI and PI ( r =0.65, p <0.001). Conclusions: In patients with lacunar infarction, renal impairment is an independent determinant of increased arterial stiffness in cerebral circulations. In addition, PI is significantly associated with RRI.

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