Cerebral Hyperperfusion Syndrome After Carotid Revascularization; Predictors and Complications.

Objectives: Cerebral hyperperfusion syndrome (CHS) is a rare but serious complication following carotid artery revascularization. Considering the varying rates observed among carotid endarterectomy (CEA), Transfemoral Carotid Artery Stenting (TFCAS), and Transcarotid Artery Revascularization (TCAR), identifying the predictors and complications of CHS is essential for improving patient outcomes. This study utilizes a national database to investigate the predictors and complications of CHS following carotid revascularizations.

Methods: We conducted a retrospective analysis of all patients undergoing CEA, TFCAS, and TCAR for carotid artery stenosis in the VQI database from 2020 to 2023. Multivariate logistic regression was applied to identify CHS predictors, which were used to develop a risk score calculator. Moreover, we compared the stroke and mortality rates following CHS among the three revascularization techniques.

Results: The final cohort in our study included 59,130 (53%) CEA, 14,064 (13%) TFCAS, and 37,565 (34%) TCAR. There were 281 cases of CHS (0.25%), and TFCAS was associated with the highest rate of CHS (0.78% vs. 0.22% vs. 0.15%; p < 0.001). After adjusting for potential confounders, TFCAS was associated with almost three-fold higher risk compared to CEA (aOR=2.87[ 95%CI:1.65-4.9] P<0.001). On the other hand, TCAR was comparable to CEA. Other predictors of CHS included uncontrolled hypertension, insulin-dependent diabetes, symptomatic status, prior carotid procedure, urgent intervention, and postoperative blood pressure medication. These predictors were used to develop an interactive CHS risk calculator (C-statistic = 0.8). Among patients who developed CHS, TFCAS was associated with a 70% higher risk of in-hospital stroke (aOR[adjusted odds ratio]=1.7[ 95%CI:1.4-2] P<0.001) and almost triple the risk of in-hospital death (aOR=2.9[ 95%CI:2.3-3.8] P<0.001). TCAR and CEA were comparable except for a slight risk of in-hospital stroke after TCAR (aOR=1.2[ 95%CI:1-1.3] P=0.03).

Conclusion: In this multi-institutional national study, we have demonstrated that the type of carotid revascularization significantly influences the risk of CHS and subsequent stroke and mortality, with TFCAS associated with the highest risk. Uncontrolled hypertension was associated with a two-fold increased risk of CHS, underscoring the importance of tight blood pressure control. We were able to provide a prediction model for CHS based on preoperative factors. Prospective use of this risk calculator might benefit in postoperative monitoring.