Abstracts of the Meeting of the Austrian Stroke Society (ÖGSF) and the Swiss Stroke Society (SHG), June 14–15, 2022, Innsbruck/Austria

: On behalf of Society ÖGSF and the Swiss Stroke Society SHG, we are pleased to present the Abstracts of the Annual Meeting that was held from 14–15 June 2022 in Innsbruck/Austria. Twenty (20) abstracts were selected for presentation as oral presentations and sixteen (16) abstracts were selected as poster presentations. We congratulate all the presenters on their research work and contribution

Background:Adverse events (AEs) -healthcare caused events leading to patient harm or even death-are common in healthcare. Systematic knowledge on this phenomenon in stroke patients is limited. Aim: To determine cumulative incidence of no-harm incidents and AEs, including their severity and preventability. Method: A cohort study using trigger tool methodology for retrospective record review was designed and carried out in a German speaking stroke center. Electronic records from 150 randomly selected patient admissions for TIA or ischemic stroke, with or without acute recanalization therapy, were used. Results: Totally, 170 events (108 AEs and 62 no-harm incidents) were identified, affecting 83 patients (55.3%; 95% CI 47 to 63.4), corresponding to an event rate of 113 events/ 100 admissions or 142 events/1000 patient days. The three most frequent AEs were ischemic strokes (n = 12, 7.1%), urinary tract infections (n = 11, 6.5%) and phlebitis (n = 10, 5.9%). The most frequent no-harm incidents were medication events (n = 37, 21.8%). Preventability ranged from 12.5% for allergic reactions to 100% for medication events and pressure ulcers. Most of the events found (142; 83.5%; 95% CI 76.9 to 88.6) occurred throughout the whole stroke care. Conclusions: Trigger tool methodology allows detection of AEs and no-harm incidents, showing a frequent occurrence of both event types during stroke care. Further investigations into events' relationships with organizational systems and processes will be needed, first to achieve a better understanding of these events' underlying mechanisms and risk factors, then to determine efforts needed to improve patient safety.

Stroke in the Stroke Unit: Recognition, Treatment and Outcomes in a Single-Center Cohort
João Pedro Marto 1 , Alexander Salerno 2 , Errikos Maslias 2 , Dimitris Lambrou 2 , Ashraf Eskandari 2 , Davide Strambo 2 and Patrik Michel 2 Background and Purpose: In-hospital strokes (IHS) are associated with longer diagnosis times, treatment delays, and poorer outcomes. Strokes occurring in the stroke unit have seldom been studied. Our aim is to assess the quality of management of in-stroke unit ischemic stroke (ISUS) in our institution. Methods: Consecutive patients from the Acute Stroke Registry and Analysis of Lausanne registry, from January 2003 to June 2019, were classified as ISUS, other-IHS or communityonset stroke (COS). Baseline and stroke characteristics of patients, time-to-imaging and -to treatment, missed treatment opportunities, treatment rates and outcomes were compared using multivariate analysis. Results: Among the 3456 patients analyzed, 138 (4.0%) were ISUS, 214 (6.2%) other-IHS and 3104 (89.8%) COS. In multivariate analysis, patients with ISUS more frequently had known stroke onset-time than other-IHS (adjusted odds ratio [aOR] 2.44; 95% confidence interval [CI] 1. 39-4.35) or COS (aOR 2.56; 95% CI 1.59-4.17), had less missed treatment opportunities than other-IHS (aOR 0.22; 95% CI 0.06-0.86) and higher endovascular treatment rates than COS (aOR 3.03; 95% CI 1. 54-5.88). ISUS were associated with a favorable shift in the modified Rankin Scale at 3 months in comparison with other-IHS (aOR 1.73; 95% CI, 1.11-2.69) or COS (aOR 1.46; 95% CI, 1.00-2.12). Conclusions: ISUS more frequently had known stroke onset-time than other-IHS or COS, less missed treatment opportunities than other-IHS and a higher endovascular treatment rate than COS. This readiness to identify and treat patients in the stroke unit may explain the better longterm outcome of ISUS.

Manuela Kisiel
Department of Neurology, St. John's Hospital, Vienna, Austria Background: Many patients show motor deficits in the early phase after a stroke. They are dependent in their daily living (ADL's) and restricted in their walking abilities. Mental imagery is a method where patients can work independently on their walking skills. Objective: The aim of this pilot study is to verify the feasibility of mental imagery in the early phase after stroke. Additionally, the effects of mental imagery on the motor functions of the lower extremities and in particular on the recovery of the ability to walk shall be tested. Methods: This single-center randomized pilot study included eight study participants. Mental imagery training was applied to the intervention group (n = 4) for 15 min five times a week for four weeks additionally to the standard physiotherapy (30 min). The control group (n = 4) had 45 min of regular physiotherapy five times a week. The primary outcome variable was the Functional Ambulation Category (FAC) to assess the functional walking ability. To measure the postural control and the ability of mental imagery, the Berg Balance Scale (BBS) and the Kinesthetic and Visual Imagery Questionnaire (KVIQ-10) were applied as secondary outcome measures. Results: The feasibility of mental imagery training for a larger randomized controlled trial is confirmed. It has a positive effect on the recovery of the walking abilities, but due to the small study population, no statistically significant statement can be made. Conclusions: Mental imagery training is a low-cost, fast, and easy method to integrate in the everyday practice. It requires further investigation in order to make statistically relevant statements.
Introduction: During the COVID-19 pandemic, most of outpatient services were suspended, disturbing the continuum of care in the rehabilitation process for neurological patients. Tech-enhanced neurorehabilitation can provide a suitable and feasible solution for clinicians to increase patient rehabilitation time on task and provide appropriate monitoring. Methods: MindMotion™ GO is a versatile medical device that accounts 26 activities designed for motor neurorehabilitation of upper limb, lower limb, trunk and hand. Devices uses Kinect camera and Leap Motion system to quantify the patients motion. 3 patients (2 stroke, 1 multiple sclerosis) were given the device to continue performing rehabilitation at home over a 4-week period during the COVID-19 pandemic. Therapists used an online platform to prescribe rehabilitation programs and monitor the patient progress. Patient and Ttherapist usage, and structured feedback was assessed. Results: The three patients used the device on average (mean) 14h07 during the 4 weeks, and 32 min per day, applying 4 activities per session. The average (mean) adherence was 72%. The structured feedback questionnaire showed that all three patients found the device easy to install and use. The three therapists also perceived a clinical value in adding remote therapy in the practice.
Background: Data on the safety and effectiveness of once-daily (QD) versus twice-daily (BID) direct oral anticoagulants (DOAC) in comparison to vitamin K antagonists (VKA) and to one another in patients with atrial fibrillation (AF) and recent stroke are scarce. Patients and Methods: Based on prospectively obtained data from the observational registry Novel-Oral-Anticoagulants-in-Ischemic-Stroke-Patients(NOACISP)-LONGTERM (NCT03826927) from Basel, Switzerland, we compared the occurrence of the primary outcome-the composite of recurrent ischemic stroke, major bleeding and all-cause deathamong consecutive AF patients treated with either VKA, QD DOAC or BID DOAC following a recent stroke using Cox proportional hazards regression including adjustment for potential confounders. . Secondary analyses focusing on the individual components of the composite outcome revealed no clear differences in the risk-benefit profile of QD versus BID DOAC. Discussion and Conclusions: The overall benefit of DOAC over VKA seems to apply to both QD and BID DOAC in AF patients with a recent stroke, without evidence that one DOAC dosing regimen is more advantageous than the other.

Mechanical Thrombectomy in Acute Stroke Patients with Moderate to Severe Pre-Stroke Disability
Background and Purpose: There are limited data on mechanical thrombectomy (MT) in acute ischemic stroke (AIS) patients with preexisting disability. We aimed to compare functional and safety outcomes of AIS patients with pre-stroke disability treated with MT compared to those receiving best medical treatment. Methods: From the Austrian Stroke Unit registry and the ASTRAL registry, we included all consecutive acute ischemic stroke patients with pre-stroke disability, defined as modified Rankin Score (mRS) ≥3, and acute intracranial large vessel occlusion (LVO). Patients undergoing MT were compared to those receiving best medical treatment (BMT) by means of univariate and multivariate logistic regression analysis. Results: We included in the study 462 AIS patients with pre-stroke mRS ≥3 and LVO. Among them, 175 underwent MT and 287 received BMT. Patients with MT were younger, had more severe strokes and lower pre-stroke mRS, but similar proportion of treatment with intravenous thrombolysis. On multivariate analysis, MT was associated with a higher probability of returning to baseline mRS at 3 months (aOR 2.5, CI 1.4-4.5) and early neurological improvement ≥8 NIHSS points (aOR 2.6, CI 1.4-4.9), as well as to a lower probability of 3-month poor outcome (aOR 0.4, CI 0.2-0.7) and mortality (aOR 0.3, CI 0.2-0.5). Conclusions: Patients with pre-stroke mRS ≥3 treated with mechanical thrombectomy had better short-term and 3-month outcomes. This suggests that pre-stroke disability alone should not be a reason to withhold MT, but that individual case-by-case decisions may be more appropriate.

Incomplete Recanalization and Complications Related to Early Vs. Late Endovascular Treatment in Ischemic Stroke: Frequency, Predictors and Clinical Implications
Introduction: Endovascular treatment (EVT) in acute ischemic stroke (AIS) is now performed more frequently in the late window in radiologically selected patients. Little is known whether incomplete recanalization, cerebrovascular and technical (procedural) complications differ in the early vs. late window in the real world, on their predictors and clinical impact. Methods: We retrospectively reviewed all patients with AIS receiving EVT <24 h from 2015-2019 from the Acute STroke Registry and Analysis of Lausanne (ASTRAL). We compared all the EVT complications in the early (<6 h) vs. late (6-24 h) windows, identified their predictors and correlated them with short and long-term clinical outcome. Results: Among 682 AIS patients receiving EVT, 144 (21.1%) had at least one complication. Frequency of incomplete recanalization was similar in early and late EVT (7.5% vs 9.3%, padj = 0.26), as was the frequency of technical (procedural) complications (16.2% vs. 16.3%, padj = 0.90) and cerebrovascular complications (16.9% vs 20.5%, padj = 0.36). We identified groin puncture during the night shift (OR = 2.24), treatment of two arterial sites (OR = 2.71) and active smoking (OR = 1.93) as the most powerful predictors of procedural complications. Although complications lead to worse short-term outcome in late EVT (delta-NIHSS-24h = -2.5 vs 2, Padj = 0.01), 3-months mRS-values were similar (3 vs 3, p = 0.69).

Conclusions:
The frequency of incomplete recanalization and EVT complications seems similar in early and well-selected late EVT patients. Late EVT seemed to have worse 24 h outcome, but the long-term outcome did not differ. Our results confirm the safety of well-selected late EVT on AIS patients. Background and purpose: It is unclear whether intravenous thrombolysis (IVT) outperforms early dual antiplatelet therapy (DAPT) in the setting of mild ischemic stroke. The aim of this study was to compare early safety and efficacy of IVT as compared to DAPT. Methods: Data of mild non-cardioembolic stroke patients with admission NIHSS ≤3 who received IVT or early DAPT in the period 2018-2021 were extracted from a nationwide, prospective stroke unit registry. Study endpoints included symptomatic intracerebral haemorrhage (sICH) according to ECASS3 criteria, early neurological deterioration ≥4 NIHSS points (END) and 3-months functional outcome by modified Rankin Score (mRS).

Intravenous Thrombolysis Versus Early Dual Antiplatelet Therapy in Patients with
Results: 1195 stroke patients treated with IVT and 2625 treated with DAPT were included. IVT patients were younger (68.1 vs 70.8 years), had less hypertension (72.8% versus 83.5%), diabetes (19% versus 28.8%) and history of myocardial infarction (7.6% versus 9.2%) and slightly higher admission NIHSS scores (median 2 versus median 1) as compared to DAPT patients. After propensity score matching, IVT was associated with sICH (4 (1.2%) vs 0), END (aOR 2.8, CI 1.1-7.5), and mRS 0-1 at 3 months (aOR 1.3, CI 0.7-2.6). Conclusions: This large non-randomized comparison may indicate that IVT is not superior to DAPT in the setting of mild non-cardioembolic stroke and may eventually be associated with harm. Further research focusing acute therapy of mild stroke seems to be highly warranted. however, data about its effectiveness and safety is limited. We retrospectively analyzed the outcome of CRAO patients treated with IVT from nine European stroke centers. Methods: From the multicenter IVT database ThRombolysis for Ischemic Stroke Patients (TRISP), we compared assessed Visual acuity (VA) at baseline and within 3 months. Outcomes were any visual improvement, favorable VA (>0.2 in decimal) and safety (symp-tomatic intracranial hemorrhage (sICH) according to ECASS II criteria, asymptomatic intracranial hemorrhage (ICH) and major extracranial bleeding). Results: We identified 56 IVT and 141 non-IVT patients with CRAO. We excluded 106 patients with missing information about VA. Median IVT symptom-to-needle time was 235 min (25th/75th percentile: 216, 306). At baseline, IVT patients had more severely impaired VA. At follow up, VA improved in 27/48 (56%) IVT patients and in 17/43 (39%) non-IVT patients. Rates of favourable VA recovery were 12/48 (25%) in IVT and 21/43 (48%) in non-IVT patients. We observed no sICH, two asymptomatic ICH (4%) and one major extracranial bleeding (2%) after IVT and none in non-IVT patients. Conclusion: Our study provides real-life data from a large European cohort of IVT treated RAO patients. IVT seems safe and may improve VA in RAO patients. However, rates of satisfactory visual outcomes remain low. To facilitate further studies, outcome assessment in RAO patients should be standardised.

Prediction Model for Medical Rescue Treatment Strategies in Patients with Incomplete Reperfusion
Adnan Mujanovic 1 , Noel Jungi 1,2 , Christoph C. Kurmann 1,3 , Tomas Dobrocky 1 , Thomas R. Meinel 2 , Lorenz Grunder 1,3 , Morin Beyeler 2 , Matthias F. Lang 1 , Simon Jung 2 , Tomas Klail 1 , Angelika Hoffmann 1,4 , David J. Seiffge 2 , Mirjam R. Heldner 2 , Sara Pilgram-Pastor 1 , Pasquale Mordasini 1 , Marcel Arnold 2 , Eike I. Piechowiak 1 , Jan Gralla 1 , Urs Fischer 2,5 and Johannes Kaesmacher 1 Background: After successful reperfusion is achieved (extended Thrombolysis in Cerebral Infarction (eTICI) ≥ 2b50), decision on pursuing additional treatment strategies in order to achieve complete reperfusion (eTICI = 2c/3), is multifactorial and depends on patient's clinical and imaging characteristics. We have developed and validated a clinical decision tool to provide individualized predictions on achieving delayed reperfusion based on individual patient data. Methods: Single-center registry analysis for all consecutive patients admitted between February 2015-December 2020. Primary variable of interest was perfusion imaging outcome in patients with incomplete reperfusion (eTICI 2a-2c), evaluated on the 24-h follow-up imaging. This variable was dichotomized into delayed reperfusion, in case of non-observable perfusion deficit, and persistent perfusion deficit, in case of perfusion deficit captured on the final angiography imaging. Final model variable selection was performed via bootstrapped (n = 200) stepwise backwards regression. Model was split into a training and testing set (80:20 ratio), with 10-fold cross validation resampling. Results: 372 patients (50.8% female, mean age 74) were included, with 228 (61.2%) of them having delayed reperfusion. Final model identified seven variables of importance including: age, sex, atrial fibrillation, Intervention-to-Follow-Up time, maneuver count, eTICI and collateral status. Model's discriminative ability for predicting delayed reperfusion was adequate (AUC 0.83, 95% CI 0.74-0.92), with an overall adjusted calibration (Brier score 0.17, 95% CI 0.15-0.18). Conclusions: Current model presents a tool that may aid clinical decision-making process in selection of patients for pursuing additional treatment strategies after incomplete reperfusion has been achieved. This is an important next step towards personalized treatment of stroke patients undergoing mechanical thrombectomy.

Effect of Symptomatic and Asymptomatic COVID-19 on Safety and Outcome of Acute Ischemic Stroke Treatments
Davide Strambo 1, † , João Pedro Marto 2, † , George Ntaios 3 , Thanh N. Nguyen 4 , Roman Herzig 5 , Anna Członkowksa 6 , Jelle Demeestere 7 , Ossama Yassin Mansour 8 , Georgios Georgiopoulos 9,10 , Raul Nogueira 11 and Patrik Michel 1 on behalf of the Global COVID-19 Stroke Registry Background and aims: COVID-19 related inflammation, endothelial dysfunction and coagulopathy may increase the bleeding risk and lower the efficacy of revascularization treatments in patients with ischemic stroke (IS). The effect of these pathophysiological processes is possibly related to the disease severity. We aimed to evaluate the safety and outcomes of revascularization treatments in patients with IS and asymptomatic or symptomatic COVID-19. Methods: Retrospective multicenter cohort study of consecutive IS patients receiving intravenous thrombolysis (IVT) and/or endovascular treatment (EVT) between March-2020 and June-2021, tested for SARS-CoV-2 infection, with or without COVID-19-compatible symptoms. By multivariate logistic regression analysis, we assessed the association of asymptomatic and symptomatic COVID-19 with bleeding complications and clinical outcomes. Study protocol was registered in ClinicalTrials.gov (NCT04895462). Results: Among 15128 revascularized patients from 105 centers, 853 (5.6%) were diagnosed with COVID-19, of whom 395 (46%) were asymptomatic and 454 (54%) symptomatic. 5848 (38.7%) patients received IVT only, and 9280 (61.3%) EVT (+/− IVT). As shown in Figure, the hemorrhagic complications similarly increased in both asymptomatic and symptomatic COVID-19 patients, while 24-h and 3-month mortality was significant increased only in symptomatic ones. Compared to COVID-negative controls, 3-month disability was significantly worse in COVID-19 patients regardless the symptoms of the disease, but it was affected to a larger extent in symptomatic patients. Conclusions: Ischemic stroke patients with asymptomatic or symptomatic COVID-19 showed higher rates of intracranial bleeding complications and worse clinical outcomes after acute revascularization treatments than contemporaneous non-COVID-19 treated patients.

Diagnostic Yield of a Systematic Vascular Health Screening Approach in Adolescents at Schools
Purpose: A significant proportion of non-communicable diseases in adults has its roots in adolescence and this is particularly true for cardiovascular disease and stroke. Detection of vascular and metabolic risk factors at young ages may aid disease prevention. Methods: In 2088 adolescents sampled from the general population of Tyrol, Austria and South Tyrol, Italy, we systematically assessed the frequency of yet unknown vascular and metabolic risk conditions that require further diagnostic work-up or intervention (life-style counselling or pharmacotherapy). The health screening included medical history taking, fasting blood analysis, and blood pressure and body measurements, and was performed at schools. To recruit a representative sample of adolescents, equal proportions (about 67%) of schools were invited per school type and region.  , 35.0-39.8] percent in girls, p < 0.001). The most prevalent were elevated blood pressure and hypertension, metabolic syndrome, hypercholesterolemia, hypertriglyceridemia, hyperuricemia, and subclinical hypothyroidism. Detection of risk conditions did not depend on socioeconomic status but increased with age and body-mass index. Conclusions: Vascular health screening in adolescence at schools has a high diagnostic yield and may aid guideline-recommended prevention in the young. Implementation should carefully consider national differences in health-care systems, resources, and existing programs.

Association of Patient and Intracranial Aneurysm Characteristics with the Risk of Subarachnoid Hemorrhage: An International Pooled-Analysis
Objective: Intracranial aneurysms (IAs) are usually asymptomatic with a low risk of rupture, but consequences of aneurysmal subarachnoid hemorrhage (aSAH) are severe. Identifying IAs at risk of rupture has important clinical and socio-economic consequences. The goal of this study was to identify patient-and IA-characteristics associated with IA rupture. Methods: Patients with saccular IA were recruited at 21 international centers in the context of genetic studies on IA. Patient-characteristics included basis of recruitment, sex, positive family history of IA/aSAH, hypertension, smoking, age at time of IA rupture and IA multiplicity. IA-characteristics were rupture status, maximum diameter at rupture, and location. We performed a cross-sectional analysis of patient-and IA-characteristics associated with IA rupture using multivariate analyses. Results: 8560 patients were included. In the final cohort of 7992 participants, 31% had ruptured IAs. Multivariate analysis demonstrated that: (1) IA rupture was associated with IA location, awareness of hypertension, and former smoking; (2) IA size and age at rupture were associated with IA location; (3) IA in smokers ruptured at larger sizes and younger age; (4) Former smokers had a lower risk of rupture than current smokers; (5) IAs in female ruptured at smaller sizes and older age; (6) IA size at rupture correlated with patient age at rupture. Conclusions: We extend the current IA disease model showing that IA location and size are the strongest factors associated with rupture, followed by active smoking and hypertension awareness. Female sex and IA multiplicity are not associated with rupture. Background: Increased middle cerebral artery (MCA) flow velocities on transcranial duplex sonography (TCD) were observed in individual patients after stroke thrombectomy and associated with intracranial hemorrhage and poor outcome. However, the retrospective study design did not allow elucidation of the underlying pathomechanism, and the relationship between TCD and parenchymal perfusion abnormalities remains to be determined. Methods: Successfully recanalized anterior circulation stroke thrombectomy patients were prospectively investigated with TCD and MRI including contrast-enhanced perfusion sequences within 48 h post-intervention. Increased MCA flow on TCD was defined as >30% mean blood flow velocity in the treated compared to the contralateral MCA. MRI blood flow maps served to assess hyperperfusion rated by neuroradiologists blinded to TCD. Results: All included 226 thrombectomy patients underwent postinterventional TCD and 92 patients additionally had perfusion MRI (41%). 85 patients (38%) showed increased postinverventional MCA flow on TCD. Of those, 10 patients (12%) had an underlying focal stenosis or vasospasm. Increased TCD blood flow in the recanalized MCA was associated with intracranial hemorrhage, larger infarct size and poor 90-day outcome (p < 0.001, multivariable adjustment). In the subgroup that had both TCD and perfusion MRI available (n = 92), 29 patients had increased ipsilateral MCA flow velocities on TCD (31%). Of those, 25 patients also showed parenchymal hyperperfusion on MRI (86%, p < 0.001; diagnostic accuracy: 77%). Hyperperfusion severity on MRI correlated with MCA flow velocities on TCD (r = 0.457, p < 0.001) Conclusions: TCD is a reliable tool to identify post-reperfusion hyperperfusion, correlates well with perfusion MRI, and indicates bleeding complications and poor outcome after stroke thrombectomy.

O19 Trends of Functional Outcome in Acute Stroke Patients Treated with Intravenous Thrombolysis
Background and aims: Frequencies of rtPA-treatment for acute stroke have been increasing over time. We aimed to investigate trends in frequencies of good functional outcome in rtPA-treated patients and to assess the influence of clinical variables on functional outcome. Methods: We analyzed patient data in the Austrian Stroke Unit Registry from 2006 to 2019. Frequencies of favorable outcome, defined as modified Rankin Scale (mRS) 0-2, were assessed for the overall population and prespecified subgroups. Logistic regression analysis was performed to evaluate associations of baseline characteristics, including relevant interaction terms, with functional outcome. Results: Overall, 4865/9409 rtPA-treated patients (51.7%) achieved favorable outcome at 3 months. Frequencies of favorable outcome increased from 45.9% in 2006 to 56.8% in 2019. In logistic regression analysis, year of treatment (OR 1.08, 95%CI 1.01-1.15) was associated with favorable outcome. Stroke severity (NIHSS, OR 0.86, 95%CI 0.85-0.87), age (61-70 years: OR 0.67, 95%CI 0.55-0.80, 71-80 years: OR 0.42, 95%CI 0.35-0.50, >80 years: OR 0.16, 95%CI 0.13-0.20), female sex (OR 0.53, 95%CI 0.89-0.99), and cardiovascular comorbidities were negatively associated. Including interaction terms into the model we observed an association of favorable outcome with interactions between stroke severity and year of treatment (OR 1.01, 95%CI 1.0-1.02), and stroke severity and endovascular treatment (EVT, OR 1.02, 95%CI 1.01-1.03). Conclusions: Frequencies of favorable outcome in rtPA-treated patients have been increasing over time, likely driven by improved outcome in more severely affected patients receiving EVT. However,

Head-/Neck Pain Characteristics after Spontaneous Cervical Artery Dissection in The Acute Phase and on aLong-Run
Lukas Mayer-Suess 1 , Florian Frank 1 , Thomas Toell 1 , Christian Boehme 1 , clinically inapparent liver fibrosis is related to atrial fibrillation and other stroke etiologies in a cohort of consecutive acute ischemic stroke patients. Methods: We analyzed data from a prospective single-center study investigating all ischemic stroke patients admitted to our stroke over a one-year-period. All patients received thorough etiological work-up including extended cardiac rhythm monitoring. For evaluation of liver fibrosis, we calculated the FIB-4 index, a well-established non-invasive liver fibrosis test based on simple clinical and laboratory parameters (cut-off ≥ 2.67). Laboratory results were analyzed from a uniform blood sample, which was taken within 24 h of stroke unit admission. Results: Of 418 included patients (mean age 70.3 years, 57.2% male), FIB-4 indicated advanced liver fibrosis in 92 (22.0%). Atrial fibrillation as the underlying stroke mechanism was present in 24.6% (large vessel disease: 25.6%, small vessel disease: 11.2%, cryptogenic: 32.8%). Atrial fibrillation was strongly related to liver fibrosis (Odds Ratio 4.41, 95% confidence interval 2.70-7.19, p < 0.001). This association remained significant after correction for relevant co-morbidities (hypertension, diabetes, dyslipidemia, coronary heart disease) and age (p = 0.001). Conclusions: Clinically inapparent liver fibrosis evaluated by a simple noninvasive test is independently associated with atrial fibrillation in acute ischemic stroke patients. Further studies should evaluate whether adding liver fibrosis to atrial fibrillation risk scores will increase their precision.

P04
Background: Atrial fibrillation (AF) is a major risk factor for ischemic stroke. Gapless electrocardiogram (ECG) monitoring without any interruption of monitoring time via an implantable loop recorder (ILR) might increase the detection rates of AF after ischemic stroke. Methods: Patients with acute ischemic stroke or transient ischemic attack without known AF were included in this prospective multicenter study. Participants received gapless ECG monitoring via telemetry followed by implantation of an ILR during stroke-unit admission, avoiding any interruption in monitoring time. Patients acted as their own controls and also received standard Holter ECG-monitoring. The primary outcome parameter was new-onset AF within six months of follow-up. Results: A total of 80 patients were included. Of these, 65 (81.3%) patients had an embolic stroke of unknown source, 6 (9.2%) patients were included with large-artery disease and 9 (11.3%) participants had small-vessel disease. AF was newly detected in 15 (18.8%) patients via ILR monitoring compared to one patient (1.3%) via Holter-ECG monitoring (p = 0.001).
The median time to the first AF episode was 19 days [Interquartile range (IQR): 9-43] with a median duration of the detected AF episodes of 3.1 [IQR: 0.25-4.78] hours. Patients with a CHA2DS2-VASc Score ≥ 5 had a significantly higher risk of new onset AF compared to patients with a CHA2DS2-VASc Score < 5 (Figure 1, p = 0.008). Oral anticoagulation was established in all patients with new-onset AF. Conclusions: Gapless ECG monitoring with an ILR is a feasible and highly effective approach to significantly increase the detection rates of AF after acute ischemic stroke.

The Smoker's Paradox in Stroke: No Evidence for Smoking-Induced Preconditioning in Large Vessel Occlusion Stroke
Background: Smoking is a well-known risk factor for stroke. However, several studies have reported a better outcome after stroke for patients who smoke. We aimed to investigate this "Smoker's Paradox", which may originate from a preconditioning-like protection due to better collaterals in smokers.

Methods:
In this retrospective study, we analysed data of patients with acute ischemic stroke due to middle cerebral artery M1 segment occlusion treated with mechanical thrombectomy at the University Hospital Zurich between 2014 and 2018. We assessed angiography and CT perfusion imaging along with clinical characteristics. Patients were grouped into current, former and never smokers. We compared the association of smoking to stroke severity on admission (NIHSS), functional disability after 3-6 months (mRS), collateral status, infarct core volume and recanalisation success using unadjusted and adjusted analyses. Results: Out of 402 patients with M1 occlusion, we included 320. 19.7% (n = 63) were current, 18.8% (n = 60) were former, and 61.6% (n = 197) never smokers. Admission NIHSS and mRS after 6 months were similar in all groups. Current smokers were younger, more often male and significantly less likely to have atrial fibrillation. Neither current nor former smoker status were associated with good collateral status, smaller infarct cores or better recanalization success.

Conclusions:
We could not confirm the smoking paradox. Neither stroke severity nor imaging parameters were suggestive of a preconditioning effect provided by smoking. On the contrary; smoking causes atherosclerotic stroke at a younger age, highlighting the role of smoking as a an avoidable vascular risk factor.
Background and aims: Lipoprotein(a) (Lp(a)) serum levels are genetically determined and contribute to atherogenesis. High Lp(a) levels are associated with an increased cardiovascular morbidity. Recently, serum Lp(a) levels have been associated with large artery atherosclerosis stroke (LAAS) aetiology. We aimed to validate this association in an independent cohort. Methods: We included acute ischemic stroke patients from a prospective cohort study from the University Hospital Bern (Inselspital), Switzerland. Lp(a) serum levels were measured in serum, drawn within 24 h after symptom onset. We assessed the association of Lp(a) with LAAS in univariate and multivariate analysis, adjusting for traditional LAAS risk factors. Results: Overall, 746 patients were included, of which 105 had a LAA stroke (14%). Lp(a) was higher in patients with LAAS compared to patients with non-LAAS (23.0 nmol/l [IQR:9.8-80.0] versus 16.3 nmol/l [IQR:5.8-57.0], p = 0.01). In univariate analysis, patients with LAAS were significantly more often men, suffered more often from Dyslipidaemia, Arterial Hypertension, Diabetes and had a higher BMI than patients with non-LAAS (Table 1). In a multivariable logistic regression model, elevated Log10(Lp(a)) was associated with LAAS with a OR of 1.50 (95%CI 1.02-2.21) ( Table 2). Conclusions: Among ischemic stroke patients, we could validate the independent association of higher Lp(a) levels with LAAS aetiology, also after adjusting for traditional cardiovascular risk factors. Independent validation of biomarkers, especially with the aim to guide secondary prevention, is essential. These findings are relevant in view of randomised clinical trials investigating the effect of specific Lp(a) lowering agents in reducing major adverse cardiovascular events.   Background and Purpose: Platelet and fibrin-rich composition of retrieved thrombi in patients with acute ischemic stroke (AIS) are associated both with active malignancy and the lack of susceptibility vessel sign (SVS) on MRI. This study analyzed the association between SVS status and the presence of active malignancy in AIS patients that underwent mechanical thrombectomy (MT). Methods: Single-centered, retrospective and cross-sectional study including consecutive patients with admission MRI treated for AIS with MT between January 2010 and December 2018. SVS was evaluated on susceptibility weighted imaging (SWI). Patients with active malignancy were identified via the clinical information system. Odds ratio (OR) and adjusted OR (aOR) were calculated to determine the association between SVS negativity and active malignancy. Performance of predictive models with and without SVS status were assessed by calculating the areas under the Receiver Operating Characteristics curve (auROC). Results: Of the 577 AIS patients with assessable SVS status, 40 (6.9%) had a documented active malignancy and 72 patients (12.5%) showed no SVS. The lack of SVS was strongly associated with active malignancy (OR 5.07, 95% CI 2.52-10.18, p < 0.001), even after adjusting for other common malignancy-biomarkers (aOR 4,85, 95% CI 1.94-12.11, p = 0.001). The auROC of predictive models including demographics and common malignancy-biomarkers decreased from 0.85 to 0.81 when SVS status was excluded.

Conclusions:
The lack of SVS on baseline MRI is associated with active malignancy in patients with AIS eligible for MT. Considering SVS status may increase the chances of detecting occult malignancy in patients with AIS.

Machine Learning Analysis to Develop Outcome Prediction Scores for Posterior Circulation Occlusions: Internal Validation of the Posterior Circulation Clot Burden Score (Pc-CBS)
Stenosis of the internal carotid artery is a common cause of ischemic stroke. Current treatment recommendations focus on stenosis degree and include medical treatment, endovascular stenting as well as surgical carotid endarterectomy. Ultrasound is the method of choice to establish stenosis degree, but it is limited with respect to characterization of the plaque or vessel wall morphology. However, there is increasing evidence that plaque composition critically determines risk of rupture. Multi-spectral optoacoustic tomography (MSOT) is an emerging non-invasive approach based on acoustic echoes emitted by biological tissues when illuminated with short pulses of light. MSOT has the unique potential to acquire disease-specific molecular biomarkers in addition to morphological/flow assessment by conventional ultrasound methods. For carotid imaging, assessment of lipid content and oxygenation state are of particular interest, as lipid accumulation and plaque vascularization are key indicators of plaque formation, progression towards instability and stroke risk. We aimed at establishing a link between the lipid-and oxy/deoxyhemoglobin signals of the carotid artery/plaque and the superficial temporal artery (STA) and the type (atherosclero-sis versus inflammation) and severity of cardiovascular disease. To this end, the in vivo data was acquired from carotid arteries of eight patients with cerebrovascular disease and from temporal arteries in three patients with suspicion of giant cell arteritis (GCA), a large vessel vasculitis. Data were co-registered to ultrasound findings. Lipid signal was detected mainly on the vessel wall in patients with cerebrovascular disease. More patients will be included and data presented at the conference.

Stenting in Internal Carotid Artery Dissection-A single center Cohort Analysis
Cornelia Brunner 1 , Walter Struhal 1 and Christian Nasel 2