31 research outputs found

    Accurate and reproducible reconstruction of coronary arteries and endothelial shear stress calculation using 3D OCT: Comparative study to 3D IVUS and 3D QCA

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    Background: Geometrically-correct 3D OCT is a new imaging modality with the potential to investigate the association of local hemodynamic microenvironment with OCT-derived high-risk features. We aimed to describe the methodology of 3D OCT and investigate the accuracy, inter- and intra-observer agreement of 3D OCT in reconstructing coronary arteries and calculating ESS, using 3D IVUS and 3D QCA as references. Methods-Results: 35 coronary artery segments derived from 30 patients were reconstructed in 3D space using 3D OCT. 3D OCT was validated against 3D IVUS and 3D QCA. The agreement in artery reconstruction among 3D OCT, 3D IVUS and 3D QCA was assessed in 3-mm-long subsegments using lumen morphometry and ESS parameters. The inter- and intra-observer agreement of 3D OCT, 3D IVUS and 3D QCA were assessed in a representative sample of 61 subsegments (n ¼ 5 arteries). The data processing times for each reconstruction methodology were also calculated. There was a very high agreement between 3D OCT vs. 3D IVUS and 3D OCT vs. 3D QCA in terms of total reconstructed artery length and volume, as well as in terms of segmental morphometric and ESS metrics with mean differences close to zero and narrow limits of agreement (BlandeAltman analysis). 3D OCT exhibited excellent inter- and intra-observer agreement. The analysis time with 3D OCT was significantly lower compared to 3D IVUS. Conclusions: Geometrically-correct 3D OCT is a feasible, accurate and reproducible 3D reconstruction technique that can perform reliable ESS calculations in coronary arteries

    Does presence of left ventricular contractile reserve improve response to cardiac resynchronization therapy? An updated meta-analysis

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    Background: Up to a third of patients undergoing cardiac resynchronization therapy (CRT) do not have a clinical or echocardiographic response. It is also unclear, whether contractile reserve (CR) could predict CRT response. This meta-analysis examines whether the presence of CR improves response to CRT and whether this is modulated by other clinical factors. Methods: Search of PubMed/EMBASE/Cochrane databases for articles examining response to CRT stratified by the presence or not of CR. End-point classified as clinical or echocardiographic response. The analysis compared response to CRT (echocardiographic or clinical) between patients with or without CR. Results: 824 patients in 12 studies were included. The presence of left ventricular CR was associated with a significant reduction in echocardiographic non-responders to CRT compared to patients without CR (OR: 0.16, 95% CI 0.08-0.33, p < 0.00001). The presence of left ventricular CR was associated with a significant reduction in clinical non-responders to CRT compared to patients without CR (OR: 023, 95% CI 0.14-0.37, p < 0.00001). Sensitivity analysis showed no difference in response when pooling studies using left ventricular ejection fraction (LVEF) or non-LVEF markers of CR. Meta-regression showed that CR was associated with lower rates of non-responders and this was more pronounced in patients with a narrower mean QRS complex. Conclusions: Identification of CR is associated with improved response to CRT. Importantly, QRS width is a potential moderator variable which can explain part of the heterogeneity in echo response. The combination of CR and QRS width may modulate the response to CRT. (C) 2017 Elsevier B.V. All rights reserved

    Predictive Role of BNP/NT-proBNP in Non-Heart Failure Patients Undergoing Catheter Ablation for Atrial Fibrillation: An Updated Systematic Review

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    Atrial Fibrillation (AF) is a growing public health issue, associated with significant morbidity and mortality. In addition to pharmacological therapy, catheter ablation is an effective strategy in restoring and maintaining sinus rhythm. However, ablation is not without risk, and AF recurs in a significant proportion of patients. Non-invasive, easily accessible markers or indices that could stratify patients depending on the likelihood of a successful outcome following ablation would allow us to select the most appropriate patients for the procedure, reducing the AF recurrence rate and exposure to potentially life-threatening risks. There has been much attention paid to Brain Natriuretic Peptide (BNP) and N-Terminal prohormone of Brain Natriuretic Peptide (NT-proBNP) as possible predictive markers of successful ablation. Several studies have demonstrated an association between higher pre-ablation levels of these peptides, and a greater likelihood of AF recurrence. Therefore, there may be a role for measuring brain natriuretic peptides levels when selecting patients for catheter ablation

    Vascular Abnormalities, Paraoxonase Activity, and Dysfunctional HDL in Primary Antiphospholipid Syndrome

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    Context Accelerated atherosclerosis has been described in antiphospholipid syndrome, but the vascular abnormalities and the underlying mechanisms remain unclear. Objectives To compare vascular structure and function in patients with positive antiphospholipid antibodies (aPL) with controls and to assess their relationship with paraoxonase activity. Design, Setting, and Participants A cross-sectional study of 77 women with positive antiphospholipid antibodies from a lupus outpatient clinic in London, England (90% of the eligible population) and 77 controls matched on frequency basis for age and cardiovascular risk factors between June 2006 and April 2009. Carotid intima media thickness (CIMT), flow-mediated dilatation, pulse wave velocity, and paraoxonase activity were measured in all patients. Anti-inflammatory and antioxidant properties of high-density lipoprotein (HDL) were examined. Main Outcome Measures CIMT, pulse wave velocity, flow-mediated dilatation, and paraoxonase. Results Women with aPL had greater CIMT and pulse wave velocity compared with controls (mean [SD], 0.75 [0.16] vs 0.64 [0.09] mm; 95% confidence interval [CI],-0.14 to-0.06; P<.001; and 9.2 [1.6] vs 8.5 [1.8] m/s; 95% CI,-1.14 to-0.06; P=.04) and lower flow-mediated dilatation (6.2% [4.1%] vs 9.6% [4.2%]; 95% CI, 2.02%-4.69%; P<.001). Paraoxonase activity was lower in women with aPL vs controls (median [interquartile range], 91.2 [64.3-105.1] vs 103.0 [80.5-111.5] mu mol p-nitrophenol/L/serum/min; 95% CI, 0.004-0.007; P=.005) and was inversely associated with CIMT and pulse wave velocity in women with aPL (standardized beta coefficient=-0.4 and-0.3, respectively; P<.05 for both), but not in the control group. High-density lipoprotein from women with aPL inhibited endothelial nitric oxide production in human aortic endothelial cells, in contrast with controls. The beneficial effects of HDL from women with aPL on vascular cell adhesion molecule 1 expression, superoxide production, and monocyte adhesion following activation of human aortic endothelial cells were largely blunted. Conclusions Compared with controls, women with aPL had greater functional and structural arterial abnormalities, which were associated with lower activity of paraoxonase. In patients with aPL, HDL reduced nitric oxide bioavailability and had impaired anti-inflammatory and antioxidant properties. JAMA. 2009; 302(11): 1210-121
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