Abstract TP166: Noninvasive Fractional Flow on MRA Predicts Stroke Risk of Intracranial Stenosis in SONIA/WASID

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
David S Liebeskind ◽  
Andrzej S Kosinski ◽  
Michael J Lynn ◽  
Fabien Scalzo ◽  
Albert K Fong ◽  
...  
Keyword(s):  
High Risk ◽  
Signal Intensity ◽  
Stroke Risk ◽  
Recurrent Stroke ◽  
Univariate Analysis ◽  
Intracranial Stenosis ◽  
Background Intensity ◽  
Fractional Flow ◽  
Relative Signal Intensity ◽  
Tof Mra

Background: Intracranial stenosis carries a high risk of recurrent stroke, but there is no noninvasive method to identify high-risk lesions. Fractional flow, or the pressure gradient across a stenosis, may identify hemodynamic effects and ischemic risk beyond percent stenosis of an artery. TOF-MRA signal intensity correlates with blood flow and may serve as a useful, noninvasive risk marker. We hypothesized that diminished TOF-MRA signal intensity distal to an intracranial stenosis predicts stroke risk. Methods: TOF-MRA of the intracranial circulation acquired prospectively in the SONIA-WASID trials was digitized to enable measurement of relative signal intensity immediately distal and proximal to symptomatic intracranial stenoses. The distal/proximal signal intensity ratio (SIR) was calculated from 3 mm regions of interest distal and proximal to symptomatic stenoses, correcting for background intensity and blinded to outcome. Univariate and multivariate analyses included clinical variables, SIR, and invasive angiography measures (luminal stenosis, TICI, collateral grade) to identify predictors for risk of stroke in the territory in this SONIA-WASID cohort. Results: 189 patients with site-based 50-99% symptomatic intracranial stenosis in SONIA-WASID had TOF-MRA available. In a univariate analysis, the hazard ratio (HR) for stroke in the territory of the symptomatic artery with SIR < 0.9 (i.e. SIR below median) was 5.2 (1.8, 15.3; p=0.001) as compared to SIR ≥ 0.9. In a multivariate analysis correcting for baseline blood pressure, LDL, percent stenosis, recency of symptoms, TICI and downstream collaterals, the HR for SIR < 0.9 was 10.9 (2.0, 58.9; p=0.001). Only collaterals also had a significant independent association with stroke risk, HR 13.8 (3.4, 55.5; p<0.001). In the subset of patients with < 70% stenosis, a SIR < 0.9 maintained a significant association with recurrent stroke in the territory (p=0.006), with a two year event rate of 17.3%. Conclusions: Fractional flow assessed by TOF-MRA SIR may be a useful noninvasive tool to identify high-risk intracranial lesions, even in patients with moderate (< 70%) degrees of stenosis, and may be suitable for selection of high-risk patients for clinical trials or aggressive treatments.

Abstract WP124: Signal Intensity Ratio Does Not Predict Recurrent Stroke in Patients with Symptomatic Intracranial Atherosclerotic Disease

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Owaiz Ansari ◽  
Rajbeer S Sangha ◽  
Sameer Ansari ◽  
Shyam Prabhakaran
Keyword(s):  
High Risk ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Stroke Risk ◽  
Recurrent Stroke ◽  
Signal Intensity Ratio ◽  
Single Center ◽  
Tof Mra ◽  
Intracranial Atherosclerotic Disease ◽  
Stenotic Lesions

Background: Symptomatic intracranial atherosclerotic disease (ICAD) is associated with high risk for recurrent stroke. Identification of patients remains a challenge using clinical and radiographic markers. Recent research has identified signal intensity ratio (SIR) across stenotic lesions on time-of-flight magnetic resonance angiography (TOF-MRA) as a novel noninvasive marker of recurrent stroke risk. We sought to externally validate this approach in a single center analysis. Methods: From a prospective observational stroke registry since August 2012, we identified patients with ischemic stroke due to ICAD causing moderate-severe stenosis of the basilar, intracranial vertebral, intracranial internal carotid, or middle cerebral arteries. Using the method described previously, we calculated SIR values across the stenotic lesions corrected for background signal intensity from TOF-MRA performed within 7 days of index stroke admission. Outcomes were prospectively captured by phone interview at 1 and 3 months after stroke. Recurrent stroke was defined by new infarct in the territory of the stenotic artery or absent imaging confirmation, territory-specific clinical symptoms lasting > 24 hours. We evaluated whether baseline SIR values were different between patients with and without recurrent stroke overall and in subgroups by ICAD location. P-value < 0.05 was considered significant. Results: Among 99 consecutive patients with ICAD, 79 (80%) had interpretable MRAs at baseline (mean age 68.4 +11.2 years, 53.2% male, 53.2% black, median NIHSS score 3; 27.7% posterior circulation stenosis). Recurrent stroke occurred in 21.5% and 25.3% of patients at 1 and 3 months, respectively. Median SIR at baseline was 0.86 (interquartile range 0.56-1.04) and was not different those with vs. without recurrent stroke (1-month: 0.79 vs. 0.86, p=0.93; 3-month: 0.79 vs. 0.86, p=0.68). Results were not different by ICAD location. Discussion: In this single center prospective registry, we were unable to validate SIR on time-of-flight MRA as a marker of early recurrent stroke risk in patients with symptomatic ICAD. Further research is needed to identify novel predictors of recurrence in this high-risk cohort.

scholarly journals Fractional Flow on TOF-MRA as a Measure of Stroke Risk in Children with Intracranial Arterial Stenosis

2020 ◽  
Vol 41 (3) ◽  
pp. 535-541 ◽  
Author(s):  
A.Y. Ibrahim ◽  
A. Amirabadi ◽  
M.M. Shroff ◽  
N. Dlamini ◽  
P. Dirks ◽  
...  
Keyword(s):  
Stroke Risk ◽  
Arterial Stenosis ◽  
Intracranial Arterial Stenosis ◽  
Fractional Flow ◽  
Tof Mra

Abstract T P105: Decrease in Noninvasive Fractional Flow on MRA Is a Useful Marker of Misery Perfusion on SPECT

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Masatomo Miura ◽  
Makoto Nakajima ◽  
Masaki Watanabe ◽  
Shinya Shiraishi ◽  
Yukio Ando
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
High Risk ◽  
Cerebrovascular Reactivity ◽  
Stage I ◽  
Stage Ii ◽  
Intracranial Atherosclerosis ◽  
Fractional Flow ◽  
Tof Mra ◽  
Misery Perfusion

Background: Cerebrovascular reactivity to acetazolamide on 123I-IMP SPECT is used to detect misery perfusion due to intracranial atherosclerosis. Noninvasive fractional flow reserve (FFR) on time-of-flight magnetic resonance angiography (TOF-MRA) can provide a feasible alternative to identify high-risk intracranial atherosclerosis. We here demonstrate the association between FFR on TOF-MRA and cerebral blood flow pattern on 123I-IMP SPECT. Methods: Patients with a unilateral middle cerebral artery (MCA) stenosis who underwent both TOF-MRA and 123I-IMP SPECT with acetazolamide administration were retrospectively recruited from our radiology database. Signal intensity (SI) was measured in the background, proximal and distal to the stenotic lesion in the MCA on TOF-MRA. Adjusted FFR was calculated: FFR = [distal SI - background SI] / [proximal SI - background SI]. Mean cerebral blood flow (CBF) at rest, CBF after acetazolamide administration, and cerebrovascular reactivity (CVR) were measured in the target MCA territory. CBF patterns of MCA were divided into three: Stage II, CBF at rest of < 80% in that of normal subject and CVR below 10%; Stage 0, CVR over 30% regardless of CBF at rest, and Stage I, any other CBF patterns. We sought the optimum cut-off point for FFR to identify MCA territories with Stage II CBF on 123I-IMP SPECT. Results: A total of 41 sets of diagnostic imaging in 23 patients (mean age 57 y; 14 men, 9 women) was assessed. Four (9.8%) MCA territories demonstrated Stage II, 21 (51.2%) stage I, and 16 (39.0%) stage 0. Mean FFR of MCA with Stage II pattern was 0.59 (IQR 0.38 - 0.69), Stage I was 0.78 (IQR 0.70- 0.92), and Stage 0 was 0.90 (IQR 0.81 - 0.93). The optimal cut-off point for FFR to predict Stage II was ≤ 0.7 (sensitivity 100%; specificity 86%). Conclusion: In patients with unilateral MCA lesions, an FFR decrease was correlated with misery perfusion on 123I-IMP SPECT with acetazolamide, which may be a more feasible predictor of high-risk intracranial stenosis.

Risk Factors Associated With Outcomes of Non-cardioembolic Ischemic Stroke In Patients Stratified By Essen Stroke Risk Score

2020 ◽  
Author(s):  
Yanting Ping Ping ◽  
Qianqian Yang Yang ◽  
Yuwen Huang Huang ◽  
Huimin Xu Xu ◽  
Haibin Dai
Keyword(s):  
Risk Factors ◽  
Ischemic Stroke ◽  
Risk Score ◽  
Protective Factor ◽  
Stroke Risk ◽  
Recurrent Stroke ◽  
Univariate Analysis ◽  
Tertiary Care ◽  
Vascular Events ◽  
Stroke Outcomes

Abstract Background: Identifying risk factors of cardiovascular events is crucial for stroke prevention and they can be used as predictive factors of stroke outcomes.In this study, it is to evaluate the risk factors that predict outcomes of acute non-cardioembolic ischemic stroke in patients stratified by Essen Stroke Risk Score (ESRS). Methods: A retrospective study was carried out in acute non-cardioembolic ischemic stroke patients in a Chinese tertiary-care teaching hospital. ESRS stratification and factors that might influence the outcomes of stroke, as indicated by fatal or non-fatal combined vascular events of recurrent stroke, myocardial infarction, or primary intracranial hemorrhage, were documented. Univariate analysis and multivariable regression analysis was used to identify independent predictors of stroke outcomes. Results: A total of 878 patients with acute non-cardioembolic ischemic stroke who completed a mean follow-up of 5.2 years were enrolled, and 163 patients experienced at least one component of the combined vascular event. In patients with an ESRS ≤ 3, age ≥ 65 years (OR , 2.935; 95% CI 1.625-5.301, P < 0.001) and clopidogrel treatment (OR , 1.685 ; 95% CI , 1.026-2.768; P = 0.041) were significantly associated with stroke outcomes. In patients with an ESRS > 3, age ≥ 65 years (OR , 2.107, 95% CI , 1.208-3.673 ; P = 0.008) and history of diabetes (OR , 1.465 ; 95% CI , 1.041–2.062 ; P = 0.027) were risk factors for stroke outcomes , whereas clopidogrel treatment (OR , 0.542; 95% CI , 0.356–0.824; P = 0.003) was a protective factor for stroke outcomes. Conclusions: According to this study, clopidogrel treatment, blood pressure control, and glycemic control are protective factors for stroke outcomes in high-risk patients (ESRS>3).

scholarly journals Noninvasive Fractional Flow on MRA Predicts Stroke Risk of Intracranial Stenosis

2014 ◽  
Vol 25 (1) ◽  
pp. 87-91 ◽  
Author(s):  
David S. Liebeskind ◽  
Andrzej S. Kosinski ◽  
Michael J. Lynn ◽  
Fabien Scalzo ◽  
Albert K. Fong ◽  
...  
Keyword(s):  
Stroke Risk ◽  
Intracranial Stenosis ◽  
Fractional Flow

Abstract 137: Noninvasive Fractional Flow on MRA and Recurrent Stroke: SPS3 Trial

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Makoto Nakajima ◽  
Nobuyuki Ohara ◽  
Lesly A Pearce ◽  
Edward Feldmann ◽  
Carlos Bazan ◽  
...  
Keyword(s):  
Proportional Hazards ◽  
Recurrent Stroke ◽  
Cox Proportional Hazards ◽  
Blood Pressure Target ◽  
Lacunar Stroke ◽  
Vascular Territory ◽  
Fractional Flow ◽  
Stroke Patients ◽  
Tof Mra ◽  
Flow Reserve

Background and Purpose: Noninvasive fractional flow reserve (FFR) on time-of-flight magnetic resonance angiography (TOF-MRA) may be used to identify high-risk intracranial lesions. We tested whether FFR was associated with vascular territory of the qualifying lacunar stroke in participants of the Secondary Prevention of Small Subcortical Strokes (SPS3) trial and the utility of FFR for predicting recurrent stroke during the trial. Methods: SPS3 was a randomized trial investigating optimal blood pressure target and antiplatelet regimen in patients with recent, symptomatic, MRI-confirmed lacunar stroke patients TOF-MRA proximate to study entry was adequate and available for 2169 of 3020 study patients. Signal intensity (SI) was measured in the background, and proximal and distal aspects of 7 intracranial arteries (internal carotid, middle cerebral, basilar, and vertebral). Adjusted FFR was then calculated in each artery: FFR = [distal SI - background SI] / [proximal SI - background SI] and divided into quartiles by artery. Associations between the vascular territory of the qualifying infarct and the FFR quartile of the relevant artery were investigated using contingency tables and chi-square tests. Risks for recurrent stroke associated with FFR quartiles were evaluated using Cox Proportional Hazards models (model adjusted for assigned treatment groups). Results: Mean age of the 2169 patients included was 63 yr with 63% male; hypertension, diabetes, and prior lacunar stroke were present in 75%, 36%, and 10% respectively. Median FFRs varied by artery with the lowest in the basilar (0.793) and highest in the middle cerebral arteries (left 1.154; right 1.176). A recurrent stroke occurred in 195 patients during a mean follow-up of 3.5 years (annualized rate 2.5% per patient-year).No significant association was found between the FFR tertiles and the vascular territory of the qualifying infarct. Quartiles of adjusted FFR in any of the 7 arteries were not found to be predictive of recurrent stroke. Conclusion: In this large well-characterized cohort of lacunar stroke patients, FFR was not associated with the location of the qualifying subcortical infarct and did not predict the risk of recurrent stroke.

scholarly journals Fractional Flow Assessment for the Evaluation of Intracranial Atherosclerosis: A Feasibility Study

2016 ◽  
Vol 5 (1-2) ◽  
pp. 65-75 ◽  
Author(s):  
ZhongRong Miao ◽  
David S. Liebeskind ◽  
WaiTing Lo ◽  
LiPing Liu ◽  
YueHua Pu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Pressure Gradient ◽  
Feasibility Study ◽  
Stroke Risk ◽  
Intracranial Stenosis ◽  
Intracranial Atherosclerosis ◽  
Fractional Flow ◽  
Flow Measurements ◽  
Luminal Stenosis ◽  
Ischemic Stroke Risk

Purpose: Current studies on endovascular intervention for intracranial atherosclerosis select patients based on luminal stenosis. Coronary studies demonstrated that fractional flow measurements assess ischemia better than anatomical stenosis and can guide patient selection for intervention. We similarly postulated that fractional flow can be used to assess ischemic stroke risk. Methods: This was a feasibility study to assess the technical use and safety of applying a pressure guidewire to measure fractional flow across intracranial stenoses. Twenty patients with severe intracranial stenosis were recruited. The percentage of luminal stenosis, distal to proximal pressure ratios (fractional flow) and the fractional flow gradients across the stenosis were measured. Procedural success rate and safety outcomes were documented. Results: All 20 patients had successful crossing of stenosis by the pressure guidewire. Ten patients underwent angioplasty, and 5 had stenting performed. There was one perforator stroke, but not related to the use of the pressure wire. For the 13 patients with complete pre- and postintervention data, the mean preintervention stenosis, fractional flow and translesional pressure gradient were 76.2%, 0.66 and 29.9 mm Hg, whilst the corresponding postintervention measurements were 24.7%, 0.88 and 10.9 mm Hg, respectively. Fractional flow (r = -0.530, p = 0.001) and the translesional pressure gradient (r = 0.501, p = 0.002) only had a modest correlation with the luminal stenosis. Conclusion: Fractional flow measurement by floating a pressure guidewire across the intracranial stenosis was technically feasible and safe in this study. Further studies are needed to validate its use for ischemic stroke risk assessment.

Abstract WP227: Noninvasive Blood Flow Measures in Atherosclerosis of the Posterior Circulation: Quantitative MRA Bests TOF Signal Intensity Ratio in VERiTAS

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
David S Liebeskind ◽  
Shyam Prabhakaran ◽  
Edward Feldmann ◽  
Xinjian Du ◽  
Linda Rose-Finnell ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Intensity Ratio ◽  
Atherosclerotic Lesion ◽  
Posterior Circulation ◽  
Anatomical Landmarks ◽  
Signal Intensity Ratio ◽  
Fractional Flow ◽  
Stenotic Lesion ◽  
Tof Mra ◽  
Clinical Events

Background: Fractional flow across an atherosclerotic lesion measured with TOF-MRA signal intensity ratio (SIR) may be used to gauge hemodynamic severity and to predict subsequent stroke. The degree of flow impairment may also be ascertained by quantitative MRA (QMRA). We analyzed performance of these noninvasive imaging parameters to estimate risk of subsequent posterior circulation events in VERiTAS. Methods: TOF-MRA data and QMRA were simultaneously acquired in VERiTAS. SIR were derived from TOF source images and normalized for analysis with volume flow ratios (VFR) on QMRA at standard anatomical landmarks and across the maximal stenosis. Statistics analyzed the correlation between SIR and VFR, and the ability of each to predict clinical events. Results: 72 subjects (mean age 65.6±10.3 years, 32 (44%) women) with posterior circulation atherosclerosis were enrolled in VERiTAS. Posterior communicating artery (PCOMM) flow to the posterior circulation was detected in 85% on the right, in 86% on the left, with bilateral PCOMM flow in 78%. Fractional flow measures or SIR across the maximal stenotic lesion evident on TOF MRA was reduced in 43%, increased in 16%, with no change in 40%. SIR from the proximal to distal basilar artery segments increased in 62%, was unchanged in 33% and decreased in 4% of cases. SI and VFR exhibited limited correlation at corresponding arterial segments. QMRA VFR indicative of low distal flow status predicted subsequent clinical events, unlike SIR. Conclusions: Evaluation of hemodynamics in posterior circulation atherosclerosis reveals superiority of QMRA to SIR in prospectively predicting recurrent ischemia. Collateral circulation, tandem disease and unique aspects of vertebrobasilar atherosclerosis likely influence the utility of SIR on TOF MRA.

Recurrent Stroke Risk in Pilots with Atrial Fibrillation

2020 ◽  
Vol 91 (4) ◽  
pp. 352-357
Author(s):  
Jessica Tedford ◽  
Valerie Skaggs ◽  
Ann Norris ◽  
Farhad Sahiar ◽  
Charles Mathers
Keyword(s):  
Atrial Fibrillation ◽  
General Population ◽  
Recurrent Events ◽  
Stroke Risk ◽  
Event Rate ◽  
Recurrent Stroke ◽  
Previous History ◽  
Recurrent Event ◽  
Recurrence Rates ◽  
Medical Certification

INTRODUCTION: Atrial fibrillation (AF) is one of the most common cardiac arrhythmias in the general population and is considered disqualifying aeromedically. This study is a unique examination of significant outcomes in aviators with previous history of both AF and stroke.METHODS: Pilots examined by the FAA between 2002 and 2012 who had had AF at some point during his or her medical history were reviewed, and those with an initial stroke or transient ischemic attack (TIA) during that time period were included in this study. All records were individually reviewed to determine stroke and AF history, medical certification history, and recurrent events. Variables collected included medical and behavior history, stroke type, gender, BMI, medication use, and any cardiovascular or neurological outcomes of interest. Major recurrent events included stroke, TIA, cerebrovascular accident, death, or other major events. These factors were used to calculate CHA2DS2-VASc scores.RESULTS: Of the 141 pilots selected for the study, 17.7% experienced a recurrent event. At 6 mo, the recurrent event rate was 5.0%; at 1 yr, 5.8%; at 3 yr 6.9%; and at 5 yr the recurrent event rate was 17.3%. No statistical difference between CHA2DS2-VASc scores was found as it pertained to number of recurrent events.DISCUSSION: We found no significant factors predicting risk of recurrent event and lower recurrence rates in pilots than the general population. This suggests CHA2DS2-VASc scores are not appropriate risk stratification tools in an aviation population and more research is necessary to determine risk of recurrent events in aviators with atrial fibrillation.Tedford J, Skaggs V, Norris A, Sahiar F, Mathers C. Recurrent stroke risk in pilots with atrial fibrillation. Aerosp Med Hum Perform. 2020; 91(4):352–357.

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