Chronic kidney disease and poor outcomes in ischemic stroke: is impaired cerebral autoregulation the missing link?

Pedro Castro,Farzaneh Sorond,Isabel Rocha,Elsa Azevedo,Jorge M Serrador

doi:10.1186/s12883-018-1025-4

Abstract

BackgroundChronic kidney disease increases stroke incidence and severity but the mechanisms behind this cerebro-renal interaction are mostly unexplored. Since both vascular beds share similar features, microvascular dysfunction could be the possible missing link. Therefore, we examined the relationship between renal function and cerebral autoregulation in the early hours post ischemia and its impact on outcome.MethodsWe enrolled 46 ischemic strokes (middle cerebral artery). Dynamic cerebral autoregulation was assessed by transfer function (coherence, phase and gain) of spontaneous blood pressure oscillations to blood flow velocity within 6 h from symptom-onset. Estimated glomerular filtration rate (eGFR) was calculated. Hemorrhagic transformation (HT) and white matter lesions (WML) were collected from computed tomography performed at presentation and 24 h. Outcome was evaluated with modified Rankin Scale at 3 months.ResultsHigh gain (less effective autoregulation) was correlated with lower eGFR irrespective of infarct side (p < 0.05). Both lower eGFR and higher gain correlated with WML grade (p < 0.05). Lower eGFR and increased gain, alone and in combination, progressively reduced the odds of a good functional outcome [ipsilateral OR = 4.39 (CI95% 3.15–25.6), p = 0.019; contralateral OR = 8.15 (CI95% 4.15–15.6), p = 0.002] and increased risk of HT [ipsilateral OR = 3.48 (CI95% 0.60–24.0), p = 0.132; contralateral OR = 6.43 (CI95% 1.40–32.1), p = 0.034].ConclusionsLower renal function correlates with less effective dynamic cerebral autoregulation in acute ischemic stroke, both predicting a bad outcome. The evaluation of serum biomarkers of renal dysfunction could have interest in the future for assessing cerebral microvascular risk and relationship with stroke complications.

Highlights

Chronic kidney disease increases stroke incidence and severity but the mechanisms behind this cerebrorenal interaction are mostly unexplored
Dynamic cerebral autoregulation (CA) is rapidly and noninvasively assessed at the patient bedside by transfer function analysis (TFA) using spontaneous oscillations in article blood pressure (ABP) and cerebral blood flow velocity (CBFV) [14, 19,20,21,22] which is known to be impaired in acute ischemic stroke [23]
We examined the relationship between renal function and CA, assessed from TFA measured within 6 h of symptom-onset and its impact on longterm outcome

Summary

Introduction

Chronic kidney disease increases stroke incidence and severity but the mechanisms behind this cerebrorenal interaction are mostly unexplored. Since both vascular beds share similar features, microvascular dysfunction could be the possible missing link. A possible explanation may involve the similar features of kidney and brain microvascular beds Both vascular beds are low resistance arterial beds that rely on continuous blood flow that ismaintained at relatively constant levels by a fine-tuned myogenic regulatory system. This confers protection to both the brain and kidney from arterial. Dynamic cerebral autoregulation (CA) is rapidly and noninvasively assessed at the patient bedside by transfer function analysis (TFA) using spontaneous oscillations in ABP and cerebral blood flow velocity (CBFV) [14, 19,20,21,22] which is known to be impaired in acute ischemic stroke [23]

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