CO2 combining power and outcomes in patients with acute ischaemic stroke or transient ischaemic attack

Background and purposeThe clinical significance of carbon dioxide combining power (CO2CP) in ischaemic cerebrovascular disease is not well established, and the role of CO2CP in the prognosis of acute ischaemic stroke (AIS) or transient ischaemic attack (TIA) has not been reported. The objective of the study was to investigate the associations between CO2CP and clinical outcomes in patients with AIS or TIA.MethodsData were derived from the China National Stroke Registry III. Patients were classified into five groups by quintiles of CO2CP levels and three groups according to the normal range of CO2CP (23–29 mmol/L). Multivariable Cox and logistic regressions were adopted to explore the associations of CO2CP levels with all-cause death and poor functional outcomes (modified Rankin Scale (mRS) 3–6/2–6) at 3 months and 1 year.ResultsAmong 9531 patients included in the study, the median (IQR) CO2CP was 24.9 (23.0–27.0) mmol/L. After adjustment for potential confounders, patients in the first CO2CP quintile (21.1–23.3 mmol/L) had higher risk of all-cause death and poor functional outcomes (mRS score of 3–6/2–6) (HR or OR with 95% CI 2.37 (1.32 to 4.25), 1.49 (1.20 to 1.83) and 1.21 (1.03 to 1.42), respectively) compared with those in the fourth quintile. Similar results were found for outcomes at 1 year. Furthermore, all associations were also significant when CO2CP was <23 mmol/L compared with CO2CP of 23–29 mmol/L.ConclusionsDecreased CO2CP was associated with high risk of all-cause death and poor functional outcomes in patients with AIS or TIA.

Simultaneous PET-MRI imaging of cerebral blood flow and glucose metabolism in the symptomatic unilateral internal carotid artery/middle cerebral artery steno-occlusive disease

Purpose Cerebral blood flow (CBF) and glucose metabolism are important and significant factors in ischaemic cerebrovascular disease. The objective of this study was to use quantitative hybrid PET/MR to evaluate the effects of surgery treatment on the symptomatic unilateral internal carotid artery/middle cerebral artery steno-occlusive disease. Methods Fifteen patients diagnosed with ischaemic cerebrovascular disease were evaluated using a hybrid TOF PET/MR system (Signa, GE Healthcare). The CBF value measured by arterial spin labelling (ASL) and the standardized uptake value ratio (SUVR) measured by 18F-FDG PET were obtained, except for the infarct area and its contralateral side, before and after bypass surgery. The asymmetry index (AI) was calculated from the CBF and SUVR of the ipsilateral and contralateral cerebral hemispheres, respectively. The ΔCBF and ΔSUVR were calculated as the percent changes of CBF and SUVR between before and after surgery, and paired t tests were used to determine whether a significant change occurred. Spearman’s rank correlation was also used to compare CBF with glucose metabolism in the same region. Results The analysis primarily revealed that after bypass surgery, a statistically significant increase occurred in the CBF on the affected side (P < 0.01). The postprocedural SUVR was not significantly higher than the preprocedural SUVR (P > 0.05). However, the postprocedural AI values for CBF and SUVR were significantly lower after surgery than before surgery (P < 0.01). A significant correlation was found between the AI values for preoperative CBF and SUVR on the ipsilateral hemisphere (P < 0.01). Conclusions The present study demonstrates that a combination of ASL and 18F-FDG PET could be used to simultaneously analyse changes in patients’ cerebral haemodynamic patterns and metabolism between before and after superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery. This therefore represents an essential tool for the evaluation of critical haemodynamic and metabolic status in patients with symptomatic unilateral ischaemic cerebrovascular disease.