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Dive into the research topics where Jawad Mazhar is active.

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Featured researches published by Jawad Mazhar.


International Journal of Cardiology | 2015

The effect of coronary artery plaque composition, morphology and burden on Absorb bioresorbable vascular scaffold expansion and eccentricity — A detailed analysis with optical coherence tomography

E. Shaw; U. Allahwala; James Cockburn; Thomas Hansen; Jawad Mazhar; Gemma A. Figtree; P. Hansen; Ravinay Bhindi

AIMS Suboptimal stent expansion correlates with adverse cardiac events. There is limited information regarding Absorb bioresorbable vascular scaffold (BVS) expansion characteristics. Optical coherence tomography (OCT) allows for high-resolution assessment of plaque morphology, composition and assessment of BVS expansion. This study evaluates coronary plaque composition, morphology and burden and their effect on Absorb BVS expansion using OCT. METHODS AND RESULTS Two thousand three hundred and thirty four frames totalling 462.6 mm of BVS from twenty OCT-guided BVS implantations were examined. 200 μm longitudinal cross-sections of each BVS were analysed for lumen contours and plaque characteristics. The relationship between each plaque characteristic and scaffold expansion index (SEI) or scaffold eccentricity index (SEC) was analysed by repeated measures ANOVA. Forty-four fibrous and 265 calcific plaques were identified. Lower SEI was significantly (p<0.001) associated with greater calcific plaque (CP) area (mean SEI 78.9% vs. 80.0%), thickness (78.5% vs. 80.4%) and lower CP depth (78.3% vs. 80.2%). Lower SEC was significantly (p<0.001) associated with greater fibrous plaque (FP) area (0.84 vs. 0.85), thickness (0.83 vs. 0.86), arc angle (0.84 vs. 0.85), greater CP area (0.83 vs. 0.86), CP thickness (0.83 vs. 0.86), CP angle (0.84 vs. 0.85) and lower CP depth (0.84 vs. 0.85). Greater FP area was associated with greater SEI (81.0% vs. 80.0%, p<0.001), even after adjustment for target vessel size. Greater FP angle (80.7% vs 78.3%, p<0.001) and quadrants occupied were also associated (80.0% vs 78.5%, p<0.002) with greater SEI. CONCLUSION BVS expansion and eccentricity are significantly impacted by plaque composition, morphology and burden.


Journal of the American Heart Association | 2014

Automated Quantification of Myocardial Salvage in a Rat Model of Ischemia-Reperfusion Injury Using 3D High-Resolution Magnetic Resonance Imaging (MRI)

Stuart M. Grieve; Jawad Mazhar; Fraser M. Callaghan; Cindy Kok; Sarah Tandy; Ravinay Bhindi; Gemma A. Figtree

Background Quantification of myocardial “area at risk” (AAR) and myocardial infarction (MI) zone is critical for assessing novel therapies targeting myocardial ischemia–reperfusion (IR) injury. Current “gold‐standard” methods perfuse the heart with Evans Blue and stain with triphenyl tetrazolium chloride (TTC), requiring manual slicing and analysis. We aimed to develop and validate a high‐resolution 3‐dimensional (3D) magnetic resonance imaging (MRI) method for quantifying MI and AAR. Methods and Results Forty‐eight hours after IR was induced, rats were anesthetized and gadopentetate dimeglumine was administered intravenously. After 10 minutes, the coronary artery was re‐ligated and a solution containing iron oxide microparticles and Evans Blue was infused (for comparison). Hearts were harvested and transversally sectioned for TTC staining. Ex vivo MR images of slices were acquired on a 9.4‐T magnet. T2* data allowed visualization of AAR, with microparticle‐associated signal loss in perfused regions. T1 data demonstrated gadolinium retention in infarcted zones. Close correlation (r=0.92 to 0.94; P<0.05) of MRI and Evans Blue/TTC measures for both AAR and MI was observed when the combined techniques were applied to the same heart slice. However, 3D MRI acquisition and analysis of whole heart reduced intra‐observer variability compared to assessment of isolated slices, and allowed automated segmentation and analysis, thus reducing interobserver variation. Anatomical resolution of 81 μm3 was achieved (versus ≈2 mm with manual slicing). Conclusions This novel, yet simple, MRI technique allows precise assessment of infarct and AAR zones. It removes the need for tissue slicing and provides opportunity for 3D digital analysis at high anatomical resolution in a streamlined manner accessible for all laboratories already performing IR experiments.


IJC Heart & Vasculature | 2015

Comparison of two dimensional quantitative coronary angiography (2D-QCA) with optical coherence tomography (OCT) in the assessment of coronary artery lesion dimensions

Jawad Mazhar; E. Shaw; U. Allahwala; Gemma A. Figtree; Ravinay Bhindi

Objectives There is limited data on how well 2D-QCA and OCT agree with each other for measurement of coronary artery lumen dimensions. We aimed to assess the agreement between the two modalities. Methods Patients undergoing OCT for assessment of coronary artery lesions were reviewed. Minimum luminal diameter (MLD), proximal reference diameter and distal reference diameter were measured for each lesion prior to stenting. Results OCT was performed in 64 patients and 40 lesions were suitable for analysis. There was a good correlation for proximal and distal reference diameters (r = 0.86, p < 0.0001 and r = 0.92, p < 0.0001 respectively). There was good agreement on Bland–Altman analysis; the proximal and distal reference diameters measured by QCA were on average 0.09 mm (95% CI, − 0.52 to 0.53 mm) and 0.1 mm (95% CI, − 0.59 to 0.6 mm) smaller than OCT respectively. There was a satisfactory correlation (r = 0.63, p = < 0.0001) between QCA and OCT for MLD. However, the MLD by QCA was 0.49 mm (95% CI, − 1.57 to 0.59 mm) smaller than OCT, suggesting a poor agreement for MLD. Conclusions There is a good correlation and agreement between QCA and OCT for measurement of proximal and distal reference diameters. However, the MLD was underestimated by QCA.


International Journal of Cardiology | 2013

Optical coherence tomography (OCT) as an adjunct to percutaneous coronary intervention; a single centre experience.

Jawad Mazhar; J. Murphy; Gemma A. Figtree; P. Hansen; G. I. C. Nelson; Ravinay Bhindi

Intravascular imaging of coronary arteries has become increasingly common. Optical coherence tomography (OCT) and intravascular ultrasound (IVUS) are the two most recognized modalities utilized. Unlike IVUS which uses ultrasound waves, OCT creates an image by directing an optical beam of infrared light onto the tissue and measuring the reflected intensity of light [1]. Until recently OCT has predominantly been used in the research setting, though it has been shown to be safe and feasible to use in the clinical setting [2,3]. IVUS guided percutaneous coronary intervention has been shown to reduce target lesion revascularisation in certain patient cohorts [4,5] and although no similar outcome studies currently exist with OCT, it is arguable that the indications for its use would be similar to those established for IVUS. We sought to clarify the potentially under-appreciated clinical role that OCT may play in PCI. We report a single centre experience where OCT was used to help guide management in routine clinical practice. Between November 2010 and February 2012 all cases where OCT performed for clinical indications during PCI in our centre were retrospectively analysed. The OCT acquisition was performed using the C7 DragonflyTM intracoronary imaging catheter and the ILUMIENTM PCI Optimization System (St. Jude Medical). All images were acquired using a non-occlusive technique with injection of isosmolar iodixonoal (VisipaqueTM by GE healthcare) contrast to clear the vessel of blood [3].


Heart Lung and Circulation | 2013

Impact of Multivessel Coronary Artery Disease on Serum Biochemical Markers and Clinical Outcomes Following Acute Myocardial Infarction Treated with Percutaneous Coronary Intervention

U. Allahwala; Jawad Mazhar; S. Conte; G. Nelson; Ravinay Bhindi

no disease. Future studies will investigate the underlying mechanisms of cytokines in CAD. http://dx.doi.org/10.1016/j.hlc.2013.05.102


European Heart Journal | 2013

Visualizing pericardial inflammation as the cause of acute chest pain in a patient with a congenital pericardial cyst: the incremental diagnostic value of cardiac magnetic resonance.

Jawad Mazhar; Claire M. Lawley; Anthony J. Gill; Stuart M. Grieve; Gemma A. Figtree

A 29-year-old female presented with chest pain radiating to the back and worse on inspiration. An ECG was unremarkable. d-Dimer was 0.54 µg/mL (<0.5 µg/mL). Chest X-ray showed an abnormal left heart border ( Panel A ). CT pulmonary angiogram found no evidence of pulmonary embolism, but showed a 7.5 × 5.4 × …


Journal of the American Heart Association | 2013

Selective inhibition of the master regulator transcription factor Egr-1 with catalytic oligonucleotides reduces myocardial injury and improves left ventricular systolic function in a preclinical model of myocardial infarction

Benjamin S. Rayner; Gemma A. Figtree; T. Sabaretnam; Ping Shang; Jawad Mazhar; James C. Weaver; W. Lay; Paul K. Witting; Stephen N. Hunyor; Stuart M. Grieve; Levon M. Khachigian; Ravinay Bhindi


European Biophysics Journal | 2013

Cardiac magnetic resonance imaging of rapid VCAM-1 up-regulation in myocardial ischemia–reperfusion injury

Stuart M. Grieve; Jacob Lønborg; Jawad Mazhar; Timothy C. Tan; Edwin Ho; Chia-Chi Liu; W. Lay; Anthony J. Gill; Philip W. Kuchel; Ravinay Bhindi; Gemma A. Figtree


Journal of the American College of Cardiology | 2013

SELECTIVE INHIBITION OF THE MASTER REGULATOR TRANSCRIPTION FACTOR EGR-1 USING CATALYTIC OLIGONUCLEOTIDES REDUCES MYOCARDIAL INJURY AND IMPROVES LV SYSTOLIC FUNCTION IN A PRECLINICAL MODEL OF MYOCARDIAL INFARCTION

Benjamin Rayner; Gemma A. Figtree; William Lay; Tharani Sabaretnam; Ping Shang; Jawad Mazhar; James Weaver; Stuart M. Grieve; Stephen N. Hunyor; Levon Khachigian; Ravinay Bhindi


International Journal of Cardiology | 2013

Visualizing pericardial inflammation in Dressler's syndrome with cardiac magnetic resonance imaging

Claire M. Lawley; Jawad Mazhar; Stuart M. Grieve; Gemma A. Figtree

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Ravinay Bhindi

Royal North Shore Hospital

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U. Allahwala

Royal North Shore Hospital

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E. Shaw

University of Sydney

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P. Hansen

Royal North Shore Hospital

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James Cockburn

Royal North Shore Hospital

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Thomas Hansen

Royal North Shore Hospital

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Anthony J. Gill

Kolling Institute of Medical Research

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