Volume of subclinical embolic infarct correlates to long-term cognitive changes after carotid revascularization

Abstract

OBJECTIVE Carotid intervention is safe and effective in stroke prevention in appropriately selected patients. Despite minimal neurologic complications, procedure-related subclinical microemboli are common and their cognitive effects are largely unknown. In this prospective longitudinal study, we sought to determine long-term cognitive effects of embolic infarcts. METHODS 119 patients including 46% symptomatic patients who underwent carotid revascularization were recruited. Neuropsychological testing was administered preoperatively and at 1, 6, and 12 months postoperatively. Rey Auditory Learning Test (RAVLT) was the primary cognitive measure with parallel forms to avoid practice effort. All patients also received 3T brain MRIs with a diffusion-weighted sequence (DWI) preoperatively and within 48 hours postoperatively to identify procedure-related new embolic lesions. Each DWI lesion was manually traced and input into a neuroimaging program to define volume. Embolic infarct volumes were correlated with cognitive measures. Regression models were used to identify relationships between infarct volumes and cognitive measures. RESULTS A total 587 DWI lesions were identified on 3T MRI in 81.7% of CAS and 36.4% of CEA patients with a total volume of 29327mm3. Among them, 54 DWI lesions were found in CEA patients and 533 in the CAS patients. Four patients had transient postoperative neurologic symptoms and one had a stroke. CAS was an independent predictor of embolic infarct (OR: 6.6 [2.1–20.4], p<.01) and infarct volume (P=.004). Diabetes and contralateral carotid severe stenosis/occlusion had a trend of positive association with infarct volume, while systolic blood pressure more or equal to 140mmHg had a negative association (P=.1, .09, and .1, respectively). There was a trend of improved RAVLT scores overall following carotid revascularization. Significantly higher infarct volumes were observed among those with RAVLT decline. Within the CAS cohort, infarct volume was negatively correlated with short and long-term RAVLT changes (P<0.05). CONCLUSIONS Cognitive assessment of procedure-related subclinical microemboli is challenging. Volumes of embolic infarct correlates with long-term cognitive changes, suggesting that micro-embolization should be considered as a surrogate measure for carotid disease management.

One swallow does not a summer make but many swallows do: accumulating clinical evidence for nearly-eliminated peri-procedural and 30-day complications with mesh-covered stents transforms the carotid revascularisation field

“…Selection bias-free randomisation could be considered either unethical (in the case of high-risk lesion randomisation in a study employing prior generation single-layer stent(s) now DW-MRI evidenced to be associated with cerebral embolisation significantly exceeding, in both incidence and volume, that of a mesh-covered stent system [ 5 , 60 ]), or the study would be a priori likely to be inconclusive (in case of low-risk patient lesion randomisation). Cerebral DW-MRI imaging is going to continue [ 35 , 38 , 40 , 43 , 55 , 60 , 67 ] to provide a sensitive and clinically-relevant [ 76 , 79 , 80 , 83 ] surrogate in the evaluation of novel carotid revascularisation technologies and treatment strategies.…”

“…Understanding is thus increasing today that the total burden of DW-MRI-depicted microembolisation in patients undergoing carotid revascularisation by CEA or CAS may be associated with transient cognitive decline [ 82 ]. In a proportion of patients, part of the deficit may persist months after the intervention [ 82 , 83 ]. Thus, any carotid intervention, to have a positive impact on brain function, needs to be associated with minimised cerebral embolism.…”

Can We Predict Who Will Develop Hypertension After Carotid Endarterectomy?

“…5 These "silent lesions" are relevant for their association with cognitive decline. 6 These two limitations indicate that the frequency of new cerebral events after CEA, symptomatic or not, was probably underestimated in the current study.…”

Convergence Analysis of Micro-Lesions (CAML): An approach to mapping of diffuse lesions from carotid revascularization

“…These lesions are clearly identifiable as procedure-related because they appear immediately after the procedure, are typically visible for only a few days, and have been related to particles flowing to the brain and detected on carotid ultrasound ( Bonati et al, 2010 ; Ederle et al, 2010 ; Poppert et al, 2006 ; Rapp et al, 2007 ; Skjelland et al, 2009 ; Tedesco et al, 2009 ). Clinically, endovascular procedures are effective means of preventing stroke, and whereas serious associated complications are rare ( Brott, 2010 ), there have been inconsistent studies suggesting these lesions may be linked to subtle post-procedural cognitive decline and increased vulnerability to future cognitive declines ( Aharon-Peretz et al, 2003 ; Fink et al, 2015 ; Ghogawala et al, 2008 ; Heyer et al, 1998 ; Tiemann et al, 2009 ; van Dijk and Kalkman, 2009 ; Wasser et al, 2011 ; Zhou et al, 2017 ; Zhou et al, 2012 ). For example, one large study showed changes in hand dexterity related to side of intervention ( Heyer et al, 2015 ).…”