Longitudinal Monitoring of Microstructural Alterations in Cerebral Ischemia with in Vivo Diffusion-weighted MR Spectroscopy.

Background The time course of cellular damage after acute ischemic stroke (IS) is currently not well known, and specific noninvasive markers of microstructural alterations linked to inflammation are lacking, which hinders the monitoring of anti-inflammatory treatment. Purpose To evaluate the temporal pattern of neuronal and glial microstructural changes after stroke using in vivo single-voxel diffusion-weighted MR spectroscopy. Materials and Methods In this prospective longitudinal study, participants with IS and healthy volunteers (HVs) underwent MRI at 3.0 T. In participants with IS, apparent diffusion coefficients (ADCs) and concentrations of total N-acetyl-aspartate (tNAA), total creatine (tCr), and total choline (tCho) were measured in volumes of interest (VOIs), including the lesion VOI (VOIles) and the contralateral VOI (VOIcl) at 2 weeks, 1 month, and 3 months after IS. HVs were examined once, with VOIs located in the same brain regions as participants with IS. Within- and between-group differences and longitudinal changes were examined using linear mixed-effects models. Results Twenty participants with IS (mean age, 61 years ± 13 [SD]; 12 women) and 20 HVs (mean age, 59 years ± 13; 12 women) were evaluated. No differences in ADCs or concentrations were observed in VOIcl between HVs and participants with IS. In participants with IS, the ADC of tCr was higher in VOIles than in VOIcl at 1 month (+14.4%, P = .004) and 3 months after IS (+19.0%, P < .001), while the ADC of tCho was higher only at 1 month (+16.7%, P = .001). No difference in the ADC of tNAA was observed between the two VOIs at any time point. tNAA and tCr concentrations were lower in VOIles than in VOIcl and were stable over time (approximately -50% and -30%, respectively; P < .001). Conclusion High diffusivity of choline-containing compounds and total creatine (tCr) in the ischemic lesion 1 month after ischemic stroke (IS) indicates glial morphologic changes, suggesting that active inflammation is still ongoing at this time point. High tCr diffusivity up to 3 months after IS likely reflects the presence of astrogliosis at the chronic stage of cerebral ischemia. Clinical trial registration no. NCT02833961 © RSNA, 2022 Online supplemental material is available for this article.

Factor seven activating protease (FSAP) predicts response to intravenous thrombolysis in acute ischemic stroke.

BACKGROUND: Prediction of recanalization after intravenous thrombolysis could be important to direct secondary reperfusion techniques. Factor seven activating protease (FSAP) has been described to have a relevant pathophysiological role in stroke. AIM: The aim is to determine whether plasma FSAP levels are associated with recanalization after tissue plasminogen activator in acute stroke. METHODS: FSAP antigen, activity, and FSAP-inhibitor complexes were measured in 120 acute stroke patients admitted to Hospital Vall d'Hebron with arterial occlusions, before intravenous thrombolysis. Recanalization was assessed by transcranial Doppler 2 h after thrombolysis. Predictors of recanalization were determined by logistic regression analysis and the additional predictive value of FSAP over them was determined by integrated discrimination improvement index. RESULTS: Complete recanalization was achieved in 31 patients. FSAP antigen levels were lower in patients achieving recanalization (8.2 (6.3-11.7) µg/mL vs. 9.8 (7.6-12.8) µg/mL; p = 0.046). After adjustment by age, sex, and National Institutes of Health Stroke Scale, Oxfordshire Community Stroke Project (odds ratio = 0.33 (0.13-0.82), p = 0.017) and FSAP antigen (odds ratio = 3.22 (1.22-8.47), p = 0.018) were independently associated with recanalization, and the addition of FSAP improved the model discrimination (integrated discrimination improvement = 5.5% (1.4-9.7), p = 0.009). CONCLUSIONS: Our study showed that lower FSAP antigen plasma levels were associated with a higher chance of arterial recanalization after tissue plasminogen activator treatment, suggesting an involvement of FSAP in tissue plasminogen activator-induced clot lysis. FSAP antigen determination might be useful in predicting tissue plasminogen activator response in stroke patients.

Admission troponin-I predicts subsequent cardiac complications and mortality in acute stroke patients.

PURPOSE: The importance of troponin elevation at stroke presentation remains uncertain. We aimed to assess whether baseline ultrasensitive Troponin I (hs-TnI) predicts cardiac complications and outcome in acute stroke patients. METHOD: Stroke patients admitted within 6 h were consecutively enrolled from May 2013 to March 2014. Blood samples were taken at admission to determine hs-TnI by chemiluminescent microparticle immunoassay. hs-TnI > 34.2 pg/ml (male) and >15.6 pg/ml (female) were considered elevated. Complications during in-hospital stay and outcome at 90 days were prospectively recorded. Independent predictors of cardiac complications (heart failure and acute coronary syndrome) and mortality were determined by logistic regression. The additional predictive value of hs-TnI was evaluated by integrated discrimination improvement index. A subanalysis was performed after excluding patients with previous cardiac diseases. FINDINGS: From 174 patients, 39(22%) had elevated hs-TnI, having these patients higher incidence of cardiac complications (57% versus 19%, p = 0.004). hs-TnI was an independent predictor of cardiac complications (OR = 16.1 (1.7-150.3)) together with diastolic blood pressure (OR = 0.92 (0.86-0.99)). Addition of hs-TnI to clinical variables significantly improved discrimination (IDI = 15.2% (7.8-22.7)). Subanalysis in patients without previous cardiac diseases showed similar results. Elevated hs-TnI was independently associated with 90 days mortality (OR = 3.6 (1.3-9.4)), but addition of hs-TnI to clinical data did not result in an increased discrimination. DISCUSSION: The present study confers hs-TnI a 2b level of evidence as a diagnostic tool to predict cardiac complications in stroke. Absence of serial hs-TnI measurements and limited sample size are the main weaknesses of the study. CONCLUSION: Patients with elevated baseline hs-TnI showed a higher frequency of cardiac complications and a higher mortality. Measurement of hs-TnI in acute stroke might be useful to identify patients at a high risk of cardiac complications and death.