Carlo Cereda

Etiology of first‐ever ischaemic stroke in European young adults: the 15 cities young stroke study

Risk factors for IS in young adults differ between genders and evolve with age, but data on the age‐ and gender‐specific differences by stroke etiology are scare. These features were compared based on individual patient data from 15 European stroke centers.

Demographic and geographic vascular risk factor differences in european young adults with ischemic stroke: The 15 cities young stroke study

Background and Purpose— We compared among young patients with ischemic stroke the distribution of vascular risk factors among sex, age groups, and 3 distinct geographic regions in Europe. Methods— We included patients with first-ever ischemic stroke aged 15 to 49 years from existing hospital- or population-based prospective or consecutive young stroke registries involving 15 cities in 12 countries. Geographic regions were defined as northern (Finland, Norway), central (Austria, Belgium, France, Germany, Hungary, The Netherlands, Switzerland), and southern (Greece, Italy, Turkey) Europe. Hierarchical regression models were used for comparisons. Results— In the study cohort (n=3944), the 3 most frequent risk factors were current smoking (48.7%), dyslipidemia (45.8%), and hypertension (35.9%). Compared with central (n=1868; median age, 43 years) and northern (n=1330; median age, 44 years) European patients, southern Europeans (n=746; median age, 41 years) were younger. No sex difference emerged between the regions, male:female ratio being 0.7 in those aged <34 years and reaching 1.7 in those aged 45 to 49 years. After accounting for confounders, no risk-factor differences emerged at the region level. Compared with females, males were older and they more frequently had dyslipidemia or coronary heart disease, or were smokers, irrespective of region. In both sexes, prevalence of family history of stroke, dyslipidemia, smoking, hypertension, diabetes mellitus, coronary heart disease, peripheral arterial disease, and atrial fibrillation positively correlated with age across all regions. Conclusions— Primary preventive strategies for ischemic stroke in young adults—having high rate of modifiable risk factors—should be targeted according to sex and age at continental level.

Response to endovascular reperfusion is not time-dependent in patients with salvageable tissue

Objective: To evaluate whether time to treatment modifies the effect of endovascular reperfusion in stroke patients with evidence of salvageable tissue on MRI. Methods: Patients from the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution 2 (DEFUSE 2) cohort study with a perfusion-diffusion target mismatch were included. Reperfusion was defined as a decrease in the perfusion lesion volume of at least 50% between baseline and early follow-up. Good functional outcome was defined as a modified Rankin Scale score ≤2 at day 90. Lesion growth was defined as the difference between the baseline and the early follow-up diffusion-weighted imaging lesion volumes. Results: Among 78 patients with the target mismatch profile (mean age 66 ± 16 years, 54% women), reperfusion was associated with increased odds of good functional outcome (adjusted odds ratio 3.7, 95% confidence interval 1.2–12, p = 0.03) and attenuation of lesion growth (p = 0.02). Time to treatment did not modify these effects (p value for the time × reperfusion interaction is 0.6 for good functional outcome and 0.3 for lesion growth). Similarly, in the subgroup of patients with reperfusion (n = 46), time to treatment was not associated with good functional outcome (p = 0.2). Conclusion: The association between endovascular reperfusion and improved functional and radiologic outcomes is not time-dependent in patients with a perfusion-diffusion mismatch. Proof that patients with mismatch benefit from endovascular therapy in the late time window should come from a randomized placebo-controlled trial.

A benchmarking tool to evaluate computer tomography perfusion infarct core predictions against a DWI standard

Differences in research methodology have hampered the optimization of Computer Tomography Perfusion (CTP) for identification of the ischemic core. We aim to optimize CTP core identification using a novel benchmarking tool. The benchmarking tool consists of an imaging library and a statistical analysis algorithm to evaluate the performance of CTP. The tool was used to optimize and evaluate an in-house developed CTP-software algorithm. Imaging data of 103 acute stroke patients were included in the benchmarking tool. Median time from stroke onset to CT was 185 min (IQR 180-238), and the median time between completion of CT and start of MRI was 36 min (IQR 25-79). Volumetric accuracy of the CTP-ROIs was optimal at an rCBF threshold of <38%; at this threshold, the mean difference was 0.3 ml (SD 19.8 ml), the mean absolute difference was 14.3 (SD 13.7) ml, and CTP was 67% sensitive and 87% specific for identification of DWI positive tissue voxels. The benchmarking tool can play an important role in optimizing CTP software as it provides investigators with a novel method to directly compare the performance of alternative CTP software packages.

Reperfusion of Very Low Cerebral Blood Volume Lesion Predicts Parenchymal Hematoma After Endovascular Therapy

Background and Purpose— Ischemic stroke patients with regional very low cerebral blood volume (VLCBV) on baseline imaging have increased risk of parenchymal hemorrhage (PH) after intravenous alteplase–induced reperfusion. We developed a method for automated detection of VLCBV and examined whether patients with reperfused-VLCBV are at increased risk of PH after endovascular reperfusion therapy. Methods— Receiver operating characteristic analysis was performed to optimize a relative CBV threshold associated with PH in patients from the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution 2 (DEFUSE 2) study. Regional reperfused-VLCBV was defined as regions with low relative CBV on baseline imaging that demonstrated normal perfusion (Tmax <6 s) on coregistered early follow-up magnetic resonance imaging. The association between VLCBV, regional reperfused-VLCBV and PH was assessed in univariate and multivariate analyses. Results— In 91 patients, the greatest area under the curve for predicting PH occurred at an relative CBV threshold of <0.42 (area under the curve, 0.77). At this threshold, VLCBV lesion volume ≥3.55 mL optimally predicted PH with 94% sensitivity and 63% specificity. Reperfused-VLCBV lesion volume was more specific (0.74) and equally sensitive (0.94). In total, 18 patients developed PH, of whom 17 presented with VLCBV (39% versus 2%; P=0.001), all of them had regional reperfusion (47% versus 0%; P=0.01), and 71% received intravenous alteplase. VLCBV lesion (odds ratio, 33) and bridging with intravenous alteplase (odds ratio, 3.8) were independently associated with PH. In a separate model, reperfused-VLCBV remained the single independent predictor of PH (odds ratio, 53). Conclusions— These results suggest that VLCBV can be used for risk stratification of patients scheduled to undergo endovascular therapy in trials and routine clinical practice.

Endothelial Dysfunction and Arterial Stiffness in Ischemic Stroke The Role of Sleep-Disordered Breathing

Background and Purpose— Sleep-disordered breathing (SDB) represents a risk factor for cardiovascular morbidity after a cerebral ischemic event (acute ischemic event, ischemic stroke, or transient ischemic attack). In the present study, endothelial function and arterial stiffness were analyzed in patients who experienced a postacute ischemic event with relation to SDB, sleep disruption, and nocturnal oxygenation parameters. Methods— SDB was assessed by full polysomnography in patients with acute ischemic event 3 months after the admission at our stroke unit. Moderate-severe SDB was defined according to the apnea-hypopnea index as apnea-hypopnea index ≥20. Endothelial function and arterial stiffness were assessed by peripheral arterial tonometry using Endo-PAT 2000. Results— Thirty-seven patients were included. The augmentation index was significantly different between patients with apnea-hypopnea index <20 and apnea-hypopnea index ≥20 (22.4±15.6% versus 34.6±21.6%; P=0.042), whereas reactive hyperemia index level was not (2.02±0.65 versus 2.31±0.61; P=0.127). Patients with apnea-hypopnea index ≥20 showed an increased risk for arterial stiffness (odds ratio, 5.98 [95% CI, 1.11–41.72]) even when controlling for age, sex, body mass index, hypertension, and diabetes mellitus. The augmentation index was correlated with the arousal index (P=0.010) and with mean O2 saturation (P=0.043). Conclusions— Poststroke patients with moderate-severe SDB were more prone to have increased arterial stiffness, although we did not find significant differences in endothelial function. Arterial stiffness also correlated with sleep disruption (arousal index) and mean O2 saturation.

Sleep-disordered breathing in acute ischemic stroke and transient ischemic attack: effects on short- and long-term outcome and efficacy of treatment with continuous positive airways pressure--rationale and design of the SAS CARE study.

Objectives Sleep-disordered breathing represents a risk factor for cardiovascular morbidity and mortality and negatively affects short-term and long-term outcome after an ischemic stroke or transient ischemic attack. The effect of continuous positive airways pressure in patients with sleep-disordered breathing and acute cerebrovascular event is poorly known. The SAS CARE 1 study assesses the effects of sleep-disordered breathing on clinical evolution, vascular functions, and markers within the first three-months after an acute cerebrovascular event. The SAS CARE 2 assesses the effect of continuous positive airways pressure on clinical evolution, cardiovascular events, and mortality as well as vascular functions and markers at 12 and 24 months after acute cerebrovascular event. Methods SAS CARE 1 is an open, observational multicenter study in patients with acute cerebrovascular event acutely admitted in a stroke unit: a sample of 200 acute cerebrovascular event patients will be included. Vascular functions and markers (blood pressure, heart rate variability, endothelial function by peripheral arterial tonometry and specific humoral factors) will be assessed in the acute phase and at three-months follow-up. SAS CARE 2 will include a sample of patients with acute cerebrovascular event in the previous 60–90 days. After baseline assessments, the patients will be classified according to their apnea hypopnea index in four arms: non-sleep-disordered breathing patients (apnea hypopnea index <10), patients with central sleep-disordered breathing, sleepy patients with obstructive apnea hypopnea index ≥20, which will receive continuous positive airways pressure treatment, nonsleepy patients with obstructive sleep-disordered breathing (apnea hypopnea index ≥20), which will be randomized to receive continuous positive airways pressure treatment or not. Conclusions The SAS CARE study will improve our understanding of the clinical sleep-disordered breathing in patients with acute cerebrovascular event and the feasibility/efficacy of continuous positive airways pressure treatment in selected patients with acute cerebrovascular event and sleep-disordered breathing.

Risk factors, aetiology and outcome of ischaemic stroke in young adults: the Swiss Young Stroke Study (SYSS).

Barbara Goeggel Simonetti • Marie-Luise Mono • Uyen Huynh-Do • Patrik Michel • Celine Odier • Roman Sztajzel • Philippe Lyrer • Stefan T. Engelter • Leo Bonati • Henrik Gensicke • Christopher Traenka • Barbara Tettenborn • Bruno Weder • Urs Fischer • Aekaterini Galimanis • Simon Jung • Rudolf Luedi • Gian Marco De Marchis • Anja Weck • Carlo W. Cereda • Ralf Baumgartner • Claudio L. Bassetti • Heinrich P. Mattle • Krassen Nedeltchev • Marcel Arnold

Magnetic resonance imaging-based endovascular versus medical stroke treatment for symptom onset up to 12 h

Background Recent trials have shown a clear benefit of endovascular therapy for stroke patients presenting within 6 h after stroke onset. Imaging-based selection may identify a cohort with a favorable response to endovascular therapy, in an even later time window. Aims We performed an indirect comparison between outcomes seen in DEFUSE 2, a prospective cohort study of patients who received a baseline MRI before endovascular therapy, and a control group from AXIS 2 receiving standard medical care up to 12 h after symptom onset. Methods Patients from AXIS 2 with a confirmed large vessel occlusion were selected as a control group for DEFUSE 2-patients. The primary endpoint was good functional outcome at day 90 (Modified Rankin Score 0–2). We performed a stratified analysis based on the presence of the target mismatch for both studies and reperfusion status in DEFUSE 2. Results We compared good functional outcome in 108 patients from AXIS 2 and 99 patients from DEFUSE 2. In DEFUSE 2-patients with the target mismatch profile in whom reperfusion was achieved, the rate of good functional outcome was increased compared to target mismatch patients in AXIS 2, 54% versus 29% (OR 3.2, 95% CI 1.1–9.4). In target mismatch patients treated between 6 and 12 h after stroke onset, this association between study and good functional outcome remained present (OR 9.0, 95% CI 1.1–75.8). Conclusions This indirect comparison suggests that endovascular treatment resulting in substantial reperfusion is associated with improved outcome in target mismatch patients even beyond 6 h after stroke onset. Confirmation is needed from future clinical trials that randomize patients beyond the 6 h time window.

MR perfusion lesions after TIA or minor stroke are associated with new infarction at 7 days

Objective: To investigate the relationship between acute perfusion-weighted imaging (PWI) lesions occurring within the first hours after a TIA or a minor brain infarction (BI) and the incidence of new BI detected on a systematic MRI at 1 week. Methods: Consecutive patients who experienced a TIA or BI with a neurologic deficit that lasted <24 hours, did not receive any revascularization therapy (thrombolysis/thrombectomy), and underwent DWI/PWI at baseline and fluid-attenuated inversion recovery (FLAIR)/DWI 1 week after symptom onset were enrolled. Investigators blinded to clinical information independently assessed the presence of acute ischemic lesions on baseline DWI/PWI and follow-up DWI and FLAIR. Baseline and follow-up MRIs were then compared to determine the occurrence and location of new infarctions. Results: Sixty-four patients met the inclusion criteria. Median (IQR) ABCD2 score was 4 (3–5). Median delay from onset to baseline and follow-up MRI was 5 (2–10) hours and 6 (5–7) days, respectively. MRI revealed an acute ischemic lesion on DWI and/or PWI in 38 patients. Nine patients (14%) had a new infarction on follow-up MRI. Each had a PWI and 4 had a DWI lesion on baseline MRI. All new BIs except one were asymptomatic and in the same location as the acute PWI lesion. Conclusions: Our results showed that 30% of the acute focal PWI lesions detected after a TIA are associated with a new BI at 1 week. Those new BIs may result from the progression of the initial ischemic injury.