Cognitive Function After Carotid Endarterectomy: Early Decline and Later Recovery

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Easily Screenable Characteristics Associated with Cognitive Improvement and Dysfunction After Carotid Endarterectomy

BACKGROUND

Carotid endarterectomy (CEA) is an effective treatment for the prevention of stroke in patients with carotid artery stenosis. We aimed to clarify the incidence and risk factors for early cognitive dysfunction (eCD) and early cognitive improvement (eCI), defined as change in cognitive performance ≤24 hours after surgery, using a battery of neuropsychometric tests.

METHODS

In total, 585 patients undergoing CEA were tested with neuropsychometric tests before and after surgery; 155 patients undergoing "simple" spine surgery were the reference group. Patient performance for each test was evaluated by z scores. Cognitive change was defined as eCD (or eCI) if: 1) patients had a z score ≤-2 (or ≥2) in ≥2 cognitive domains or 2) patients had mean z scores across all domains ≤-1.5 (or ≥1.5). Associations between the categorical cognitive outcomes and variables of interest were modeled using the proportional odds model.

RESULTS

Of the 585 subjects, 24% had eCD, 6% had eCI, and 70% had "no change." Patients who had eCD were more likely to be statin naïve (odds ratio [OR] 1.23 [1.03-1.48], P = 0.02) or women (OR 1.27 [1.06-1.53], P = 0.02). Those with eCI were less likely to have less formal education (OR 0.95 [0.90-1.00], P = 0.04) and less likely to have diabetes mellitus (OR 0.8 [0.65-0.99], P = 0.04).

CONCLUSIONS

Patients having CEA may develop eCD or eCI postoperatively. Medications likely to be associated with less eCD are statins and aspirin, which correlate most strongly in asymptomatic patients. In addition to confirming previous findings, we found that women were more likely than men to develop eCD. More sex-specific studies and analysis are needed to better explore these findings.