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Featured researches published by Jayanta Roy.


Lancet Neurology | 2012

Prediction of haematoma growth and outcome in patients with intracerebral haemorrhage using the CT-angiography spot sign (PREDICT): a prospective observational study

Andrew M. Demchuk; Dar Dowlatshahi; David Rodriguez-Luna; Carlos A. Molina; Yolanda Silva Blas; Imanuel Dzialowski; Adam Kobayashi; Jean-Martin Boulanger; Cheemun Lum; Gord Gubitz; Vasantha Padma; Jayanta Roy; Carlos S. Kase; Jayme C. Kosior; Rohit Bhatia; Sarah Tymchuk; Suresh Subramaniam; David J. Gladstone; Michael D. Hill; Richard I. Aviv

BACKGROUND In patients with intracerebral haemorrhage (ICH), early haemorrhage expansion affects clinical outcome. Haemostatic treatment reduces haematoma expansion, but fails to improve clinical outcomes in many patients. Proper selection of patients at high risk for haematoma expansion seems crucial to improve outcomes. In this study, we aimed to prospectively validate the CT-angiography (CTA) spot sign for prediction of haematoma expansion. METHODS PREDICT (predicting haematoma growth and outcome in intracerebral haemorrhage using contrast bolus CT) was a multicentre prospective observational cohort study. We recruited patients aged 18 years or older, with ICH smaller than 100 mL, and presenting at less than 6 h from symptom onset. Using two independent core laboratories, one neuroradiologist determined CTA spot-sign status, whereas another neurologist masked for clinical outcomes and imaging measured haematoma volumes by computerised planimetry. The primary outcome was haematoma expansion defined as absolute growth greater than 6 mL or a relative growth of more than 33% from initial CT to follow-up CT. We reported data using standard descriptive statistics stratified by the CTA spot sign. Mortality was assessed with Kaplan-Meier survival analysis. FINDINGS We enrolled 268 patients. Median time from symptom onset to baseline CT was 135 min (range 22-470), and time from onset to CTA was 159 min (32-475). 81 (30%) patients were spot-sign positive. The primary analysis included 228 patients, who had a follow-up CT before surgery or death. Median baseline ICH volume was 19·9 mL (1·5-80·9) in spot-sign-positive patients versus 10·0 mL (0·1-102·7) in spot-sign negative patients (p<0·001). Median ICH expansion was 8·6 mL (-9·3 to 121·7) for spot-sign positive patients and 0·4 mL (-11·7 to 98·3) for spot-negative patients (p<0·001). In those with haematoma expansion, the positive predictive value for the spot sign was61% (95% CI 47–73) for the positive predictive value and 78% (71–84) for the negative predictive value, with 51% (39–63) sensitivity and 85% (78–90) specificity[corrected]. Median 3-month modified Rankin Scale (mRS) was 5 in CTA spot-sign-positive patients, and 3 in spot-sign-negative patients (p<0·001). Mortality at 3 months was 43·4% (23 of 53) in CTA spot-sign positive versus 19·6% (31 of 158) in CTA spot-sign-negative patients (HR 2·4, 95% CI 1·4-4·0, p=0·002). INTERPRETATION These findings confirm previous single-centre studies showing that the CTA spot sign is a predictor of haematoma expansion. The spot sign is recommended as an entry criterion for future trials of haemostatic therapy in patients with acute ICH. FUNDING Canadian Stroke Consortium and NovoNordisk Canada.


Annals of Neurology | 2005

Triaging transient ischemic attack and minor stroke patients using acute magnetic resonance imaging.

Shelagh B. Coutts; Jessica Simon; Michael Eliasziw; Chul-Ho Sohn; Michael D. Hill; Philip A. Barber; Vanessa Palumbo; James Kennedy; Jayanta Roy; Alexis Gagnon; James N. Scott; Alastair M. Buchan; Andrew M. Demchuk

We examined whether the presence of diffusion‐weighted imaging (DWI) lesions and vessel occlusion on acute brain magnetic resonance images of minor stroke and transient ischemic attack patients predicted the occurrence of subsequent stroke and functional outcome. 120 transient ischemic attack or minor stroke (National Institutes of Health Stroke Scale ≤ 3) patients were prospectively enrolled. All were examined within 12 hours and had a magnetic resonance scan within 24 hours. Overall, the 90‐day risk for recurrent stroke was 11.7%. Patients with a DWI lesion were at greater risk for having a subsequent stroke than patients without and risk was greatest in the presence of vessel occlusion and a DWI lesion. The 90‐day risk rates, adjusted for baseline characteristics, were 4.3% (no DWI lesion), 10.8% (DWI lesion but no vessel occlusion), and 32.6% (DWI lesion and vessel occlusion) (p = 0.02). The percentages of patients who were functionally dependent at 90 days in the three groups were 1.9%, 6.2%, and 21.0%, respectively (p = 0.04). The presence of a DWI lesion and a vessel occlusion on a magnetic resonance image among patients presenting acutely with a transient ischemic attack or minor stroke is predictive of an increased risk for future stroke and functional dependence. Ann Neurol 2005;57:848–854


International Journal of Stroke | 2008

Intracranial thrombus extent predicts clinical outcome, final infarct size and hemorrhagic transformation in ischemic stroke: the clot burden score.

Volker Puetz; Imanuel Dzialowski; Michael D. Hill; Suresh Subramaniam; P. N. Sylaja; Andrea Krol; Christine O'Reilly; Mark E. Hudon; William Hu; Shelagh B. Coutts; Philip A. Barber; Timothy Watson; Jayanta Roy; Andrew M. Demchuk

Background In ischemic stroke, functional outcomes vary depending on site of intracranial occlusion. We tested the prognostic value of a semiquantitative computed tomography angiography-based clot burden score. Methods Clot burden score allots major anterior circulation arteries 10 points for presence of contrast opacification on computed tomography angiography. Two points each are subtracted for thrombus preventing contrast opacification in the proximal M1, distal M1 or supraclinoid internal carotid artery and one point each for M2 branches, A1 and infraclinoid internal carotid artery. We retrospectively studied patients with disabling neurological deficits (National Institute of Health Stroke Scale score ≥ 5) and computed tomography angiography within 24-hours from symptom onset. We analyzed percentages independent functional outcome (modified Rankin Scale score ≤ 2), final infarct Alberta Stroke Program Early Computed Tomography Score and parenchymal hematoma rates across categorized clot burden score groups and performed multivariable analysis. Results We identified 263 patients (median age 73-years, National Institute of Health Stroke Scale score 10, onset-to-computed tomography angiography time 165 min). Clot burden score < 10 was associated with reduced odds of independent functional outcome (odds ratio 0.09 for clot burden score ≤5; odds ratio 0.22 for clot burden score 6–7; odds ratio 0.48 for clot burden score 8–9; all versus clot burden score 10; P <0.02 for all). Lower clot burden scores were associated with lower follow-up Alberta Stroke Program Early CT Scores (P <0.001) and higher parenchymal hematoma rates (P = 0.008). Inter-rater reliability for clot burden score was 0.87 (lower 95% confidence interval 0.71) and intra-rater reliability 0.96 (lower 95% confidence interval 0.92). Conclusion The quantification of intracranial thrombus extent with the clot burden score predicts functional outcome, final infarct size and parenchymal hematoma risk acutely. The score needs external validation and could be useful for patient stratification in stroke trials.


Stroke | 2007

A Prospective Community-Based Study of Stroke in Kolkata, India

Shyamal Kumar Das; Tapas Kumar Banerjee; Atanu Biswas; Trishit Roy; Deepak K. Raut; Chandra Shekhar Mukherjee; Arijit Chaudhuri; Avijit Hazra; Jayanta Roy

Background and Purpose— Information on essential stroke parameters are lacking in India. This population-based study on stroke disorder was undertaken in the city of Kolkata, India, to determine the subtypes, prevalence, incidence, and case fatality rates of stroke. Methods— This was a longitudinal descriptive study comprising 2-stage door-to-door survey of a stratified randomly selected sample of the city population, conducted twice per year for 2 successive years from March 2003 to February 2005. Results— Out of the screened population of 52 377 (27 626 men, 24 751 women), the age standardized prevalence rate of stroke to world standard population is 545.10 (95% CI, 479.86 to 617.05) per 100 000 persons. The age standardized average annual incidence rate to world standard population of first-ever-in-a-lifetime stroke is 145.30 (95% CI, 120.39 to 174.74) per 100 000 persons per year. Thirty-day case fatality rate is 41.08% (95% CI, 30.66 to 53.80). Women have higher incidence and case fatality rates. Despite divergence on socioeconomic status between the slum and nonslum dwellers, stroke parameters were not significantly different. Conclusion— The age standardized prevalence and incidence rates of stroke in this study are similar to or higher than many Western nations. The overall case fatality rate is among the highest category of stroke fatality in the world. The women have higher incidence and case fatality rates compared with men.


Stroke | 2007

Incidence of radiocontrast nephropathy in patients undergoing acute stroke computed tomography angiography

Andrea Krol; Imanuel Dzialowski; Jayanta Roy; Volker Puetz; Suresh Subramaniam; Shelagh B. Coutts; Andrew M. Demchuk

Background and Purpose— Minimal research has evaluated the renal safety of emergent computed tomography angiography (CTA) procedures, consecutive contrast medium application, and the long-term outcome in acute stroke patients. We investigated the incidence of contrast-induced renal impairment in these populations. Methods— We retrospectively reviewed patients with acute stroke syndrome who received a CTA of the brain with or without the neck within 24 hours from onset of symptoms. All creatinine results and additional conventional angiography findings were recorded. With a positive history of renal disease, contrast administration was delayed until creatinine results were available. Radiocontrast nephropathy (RCN) was defined as a ≥25% increase in serum creatinine from the baseline value up to 5 days after CTA. Results— Four hundred eighty-one patients were reviewed, and 224 met the inclusion criteria. There were 7 of 224 (3%) who fulfilled the criteria for RCN. A number of patients underwent emergent CTA without knowledge of their creatinine value; 2 of 93 (2%) developed RCN. There were 36 patients who received an additional digital subtraction angiogram, and none of these developed subsequent RCN. No patients required dialysis, and 9 of 68 (13%) had a >25% increase in their creatinine levels at a late (>30 days) follow-up. Conclusions— Overall, these results illustrate that there is a low incidence of RCN in acute stroke patients undergoing emergency CTA.


Stroke | 2013

Spot Sign Number Is the Most Important Spot Sign Characteristic for Predicting Hematoma Expansion Using First-Pass Computed Tomography Angiography: Analysis From the PREDICT Study

Thien J. Huynh; Andrew M. Demchuk; Dar Dowlatshahi; David J. Gladstone; Özlem Krischek; Alex Kiss; Michael D. Hill; Carlos A. Molina; David Rodriguez-Luna; Imanuel Dzialowski; Yolanda Silva; Anna Członkowska; Cheemun Lum; Jean-Martin Boulanger; Gord Gubitz; Rohit Bhatia; Vasantha Padma; Jayanta Roy; Carlos S. Kase; Richard I. Aviv

Background and Purpose— The spot sign score (SSS) provides risk stratification for hematoma expansion in acute intracerebral hemorrhage; however, external validation is needed. We sought to validate the SSS and assess prognostic performance of individual spot characteristics associated with hematoma expansion from a prospective multicenter intracerebral hemorrhage study. Methods— Two hundred twenty-eight intracerebral hemorrhage patients within 6 hours after ictus were enrolled in the Predicting Hematoma Growth and Outcome in Intracerebral Hemorrhage Using Contrast Bolus CT (PREDICT) study, a multicenter prospective intracerebral hemorrhage cohort study. Patients were evaluated with baseline noncontrast computerized tomography, computerized tomography angiography, and 24-hour follow-up computerized tomography. Primary outcome was significant hematoma expansion (>6 mL or >33%) and secondary outcome was absolute and relative expansion. Blinded computerized tomography angiography spot sign characterization and SSS calculation were independently performed by 2 neuroradiologists and a radiology resident. Diagnostic performance of the SSS and individual spot characteristics were examined with multivariable regression, receiver operating characteristic analysis, and tests for trend. Results— SSS and spot number independently predicted significant, absolute, and relative hematoma expansion (P<0.05 each) and demonstrated near perfect interobserver agreement (&kgr;=0.82 and &kgr;=0.85, respectively). Incremental risk of hematoma expansion among spot-positive patients was not identified for SSS (P trend=0.720) but was demonstrated for spot number (P trend=0.050). Spot number and SSS demonstrated similar area under the curve (0.69 versus 0.68; P=0.306) for hematoma expansion. Conclusions— Multicenter external validation of the SSS demonstrates that the spot number alone provides similar prediction but improved risk stratification of hematoma expansion compared with the SSS.


Stroke | 2015

Intracerebral Hematoma Morphologic Appearance on Noncontrast Computed Tomography Predicts Significant Hematoma Expansion

Dylan Blacquiere; Andrew M. Demchuk; Mohammed Alhazzaa; Anirudda Deshpande; William Petrcich; Richard I. Aviv; David Rodriguez-Luna; Carlos A. Molina; Yolanda Silva Blas; Imanuel Dzialowski; Anna Członkowska; Jean-Martin Boulanger; Cheemun Lum; Gord Gubitz; Vasantha Padma; Jayanta Roy; Carlos S. Kase; Rohit Bhatia; Michael D. Hill; Dar Dowlatshahi

Background and Purpose— Hematoma expansion in intracerebral hemorrhage is associated with higher morbidity and mortality. The computed tomography (CT) angiographic spot sign is highly predictive of expansion, but other morphological features of intracerebral hemorrhage such as fluid levels, density heterogeneity, and margin irregularity may also predict expansion, particularly in centres where CT angiography is not readily available. Methods— Baseline noncontrast CT scans from patients enrolled in the Predicting Hematoma Growth and Outcome in Intracerebral Hemorrhage Using Contrast Bolus CT (PREDICT) study were assessed for the presence of fluid levels and degree of density heterogeneity and margin irregularity using previously validated scales. Presence and grade of these metrics were correlated with the presence of hematoma expansion as defined by the PREDICT study on 24-hour follow-up scan. Results— Three hundred eleven patients were included in the analysis. The presence of fluid levels and increasing heterogeneity and irregularity were associated with 24-hour hematoma expansion (P=0.021, 0.003 and 0.049, respectively) as well as increases in absolute hematoma size. Fluid levels had the highest positive predictive value (50%; 28%–71%), whereas margin irregularity had the highest negative predictive value (78%; 71%–85). Noncontrast metrics had comparable predictive values as spot sign for expansion when controlled for vitamin K, antiplatelet use, and baseline National Institutes of Health Stroke Scale, although in a combined area under the receiver-operating characteristic curve model, spot sign remained the most predictive. Conclusions— Fluid levels, density heterogeneity, and margin irregularity on noncontrast CT are associated with hematoma expansion at 24 hours. These markers may assist in prediction of outcomes in scenarios where CT angiography is not readily available and may be of future help in refining the predictive value of the CT angiography spot sign.


Stroke | 2014

Venous Phase of Computed Tomography Angiography Increases Spot Sign Detection, but Intracerebral Hemorrhage Expansion Is Greater in Spot Signs Detected in Arterial Phase

David Rodriguez-Luna; Dar Dowlatshahi; Richard I. Aviv; Carlos A. Molina; Yolanda Silva; Imanuel Dzialowski; Cheemun Lum; Anna Członkowska; Jean-Martin Boulanger; Carlos S. Kase; Gord Gubitz; Rohit Bhatia; Vasantha Padma; Jayanta Roy; Teri Stewart; Thien J. Huynh; Michael D. Hill; Andrew M. Demchuk

Background and Purpose— Variability in computed tomography angiography (CTA) acquisitions may be one explanation for the modest accuracy of the spot sign for predicting intracerebral hemorrhage expansion detected in the multicenter Predicting Hematoma Growth and Outcome in Intracerebral Hemorrhage Using Contrast Bolus CT (PREDICT) study. This study aimed to determine the frequency of the spot sign in intracerebral hemorrhage and its relationship with hematoma expansion depending on the phase of image acquisition. Methods— PREDICT study was a prospective observational cohort study of patients with intracerebral hemorrhage presenting within 6 hours from onset. A post hoc analysis of the Hounsfield units of an artery and venous structure were measured on CTA source images of the entire PREDICT cohort in a core laboratory. Each CTA study was classified into arterial or venous phase and into 1 of 5 specific image acquisition phases. Significant hematoma expansion and total hematoma enlargement were recorded at 24 hours. Results— Overall (n=371), 77.9% of CTA were acquired in arterial phase. The spot sign, present in 29.9% of patients, was more frequently seen in venous phase as compared with arterial phase (39% versus 27.3%; P=0.041) and the later the phase of image acquisition (P=0.095). Significant hematoma expansion (P=0.253) and higher total hematoma enlargement (P=0.019) were observed more frequently among spot sign–positive patients with earlier phases of image acquisition. Conclusions— Later image acquisition of CTA improves the frequency of spot sign detection. However, spot signs identified in earlier phases may be associated with greater absolute enlargement. A multiphase CTA including arterial and venous acquisitions could be optimal in patients with intracerebral hemorrhage.


Neurology | 2016

Ultraearly hematoma growth in active intracerebral hemorrhage

David Rodriguez-Luna; Pilar Coscojuela; Marta Rubiera; Michael D. Hill; Dar Dowlatshahi; Richard I. Aviv; Yolanda Silva; Imanuel Dzialowski; Cheemun Lum; Anna Członkowska; Jean-Martin Boulanger; Carlos S. Kase; Gord Gubitz; Rohit Bhatia; Vasantha Padma; Jayanta Roy; Alejandro Tomasello; Andrew M. Demchuk; Carlos A. Molina

Objective: To determine the association of ultraearly hematoma growth (uHG) with the CT angiography (CTA) spot sign, hematoma expansion, and clinical outcomes in patients with acute intracerebral hemorrhage (ICH). Methods: We analyzed data from 231 patients enrolled in the multicenter Predicting Haematoma Growth and Outcome in Intracerebral Haemorrhage Using Contrast Bolus CT study. uHG was defined as baseline ICH volume/onset-to-CT time (mL/h). The spot sign was used as marker of active hemorrhage. Outcome parameters included significant hematoma expansion (>33% or >6 mL, primary outcome), rate of hematoma expansion, early neurologic deterioration, 90-day mortality, and poor outcome. Results: uHG was higher in spot sign patients (p < 0.001) and in patients scanned earlier (p < 0.001). Both uHG >4.7 mL/h (p = 0.002) and the CTA spot sign (p = 0.030) showed effects on rate of hematoma expansion but not its interaction (2-way analysis of variance, p = 0.477). uHG >4.7 mL/h improved the sensitivity of the spot sign in the prediction of significant hematoma expansion (73.9% vs 46.4%), early neurologic deterioration (67.6% vs 35.3%), 90-day mortality (81.6% vs 44.9%), and poor outcome (72.8% vs 29.8%), respectively. uHG was independently related to significant hematoma expansion (odds ratio 1.06, 95% confidence interval 1.03–1.10) and clinical outcomes. Conclusions: uHG is a useful predictor of hematoma expansion and poor clinical outcomes in patients with acute ICH. The combination of high uHG and the spot sign is associated with a higher rate of hematoma expansion, highlighting the need for very fast treatment in ICH patients.


Stroke | 2015

Validation of the 9-Point and 24-Point Hematoma Expansion Prediction Scores and Derivation of the PREDICT A/B Scores

Thien J. Huynh; Richard I. Aviv; Dar Dowlatshahi; David J. Gladstone; Andreas Laupacis; Alex Kiss; Michael D. Hill; Carlos A. Molina; David Rodriguez-Luna; Imanuel Dzialowski; Yolanda Silva; Adam Kobayashi; Cheemun Lum; Jean-Martin Boulanger; Gord Gubitz; Rohit Bhatia; Vasantha Padma; Jayanta Roy; Carlos S. Kase; Sean P. Symons; Andrew M. Demchuk

Background and Purpose— Nine- and 24-point prediction scores have recently been published to predict hematoma expansion (HE) in acute intracerebral hemorrhage. We sought to validate these scores and perform an independent analysis of HE predictors. Methods— We retrospectively studied 301 primary or anticoagulation-associated intracerebral hemorrhage patients presenting <6 hours post ictus prospectively enrolled in the Predicting Hematoma Growth and Outcome in Intracerebral Hemorrhage Using Contrast Bolus Computed Tomography (PREDICT) study. Patients underwent baseline computed tomography angiography and 24-hour noncontrast computed tomography follow-up for HE analysis. Discrimination and calibration of the 9- and 24-point scores was assessed. Independent predictors of HE were identified using multivariable regression and incorporated into the PREDICT A/B scores, which were then compared with existing scores. Results— The 9- and 24-point HE scores demonstrated acceptable discrimination for HE>6 mL or 33% and >6 mL, respectively (area under the curve of 0.706 and 0.755, respectively). The 24-point score demonstrated appropriate calibration in the PREDICT cohort (&khgr;2 statistic, 11.5; P=0.175), whereas the 9-point score demonstrated poor calibration (&khgr;2 statistic, 34.3; P<0.001). Independent HE predictors included spot sign number, time from onset, warfarin use or international normalized ratio >1.5, Glasgow Coma Scale, and National Institutes of Health Stroke Scale and were included in PREDICT A/B scores. PREDICT A showed improved discrimination compared with both existing scores, whereas performance of PREDICT B varied by definition of expansion. Conclusions— The 9- and 24-point expansion scores demonstrate acceptable discrimination in an independent multicenter cohort; however, calibration was suboptimal for the 9-point score. The PREDICT A score showed improved discrimination for HE prediction but requires independent validation.

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Imanuel Dzialowski

Dresden University of Technology

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Richard I. Aviv

Sunnybrook Health Sciences Centre

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Carlos A. Molina

Autonomous University of Barcelona

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Vasantha Padma

All India Institute of Medical Sciences

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Dar Dowlatshahi

Ottawa Hospital Research Institute

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