Background: Four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) allows quantification of left ventricular (LV) blood flow. We aimed to 1) establish reference ranges for 4D flow... Show moreBackground: Four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) allows quantification of left ventricular (LV) blood flow. We aimed to 1) establish reference ranges for 4D flow CMR-derived LV relative flow components and kinetic energy parameters indexed to end-diastolic volume (KEiEDV) among healthy Asian subjects, 2) assess effects of age and sex on these parameters, and 3) compare these parameters between Asian and Caucasian subjects.Methods: 74 healthy Asian subjects underwent cine and 4D flow CMR. Relative flow components (direct flow, retained inflow, delayed ejection flow, residual volume) and multiple phasic KEiEDV (LV global, peak systolic, systolic, diastolic, peak E-wave, peak A-wave) were analyzed. Sex-and age-specific reference ranges were reported.Results: Relative flow components and systolic phase KEiEDV did not vary with age. Women had higher retained inflow and peak E-wave KEiEDV, lower residual volume, peak systolic and systolic KEiEDV than men. Peak A-wave KEiEDV increased significantly (r = 0.474) whereas peak E-wave KEiEDV (r = -0.458) and E-wave/A-wave ratio (r = -0.528) decreased with age. A sub-population (n = 44) was compared with 44 sex-and age-matched Caucasian subjects: no significant group differences were observed for all 4D flow CMR parameters.Conclusion: Asian sex-and age-specific 4D flow CMR reference ranges were established. Sex differences in retained inflow, residual volume, peak systolic, systolic KEiEDV and peak E-wave KEiEDV were observed. Ageing influenced diastolic KEiEDV but not systolic phase KEiEDV or relative flow components. All studied parameters were similar between sex-and age-matched Asian and Caucasian subjects, implying generalizability of the ranges. (C) 2021 Elsevier B.V. All rights reserved. Show less
Aims Hypertensive left ventricular hypertrophy (LVH) is associated with increased cardiovascular events. We previously developed the remodelling index (RI) that incorporated left ventricular (LV)... Show moreAims Hypertensive left ventricular hypertrophy (LVH) is associated with increased cardiovascular events. We previously developed the remodelling index (RI) that incorporated left ventricular (LV) volume and wall-thickness in a single measure of advanced hypertrophy in hypertensive patients. This study examined the prognostic potential of the RI in reference to contemporary LVH classifications.Methods and results Cardiovascular magnetic resonance was performed in 400 asymptomatic hypertensive patients. The newly derived RI ((3)root EDV/t, where EDV is LV end-diastolic volume and t is the maximal wall thickness across 16 myocardial segments) stratified hypertensive patients: no LVH, LVH with normal RI (LVHNormal-RI), and LVH with low RI (LVHLow-RI). The primary outcome was a composite of all-cause mortality, acute coronary syndromes, strokes, and decompensated heart failure. LVHLow-RI was associated with increased LV mass index, fibrosis burden, impaired myocardial function and elevated biochemical markers of myocardial injury (high-sensitive cardiac troponin I), and wall stress. Over 18.3 +/- 7.0 months (601.3 patient-years), 14 adverse events occurred (2.2 events/100 patient-years). Patients with LVHLow-RI had more than a five-fold increase in adverse events compared to those with LVHNormal-RI (11.6 events/100 patient-years vs. 2.0 events/100 patient-years, respectively; log-rank P < 0.001). The RI provided incremental prognostic value over and above a model consisting of clinical variables, LVH and concentricity; and predicted adverse events independent of clinical variables, LVH, and other prognostic markers. Concentric and eccentric LVH were associated with adverse prognosis (log-rank P = 0.62) that was similar to the natural history of hypertensive LVH (5.1 events/100 patient-years).Conclusion The RI provides prognostic value that improves risk stratification of hypertensive LVH. Show less
Croom, S.M.; Owers, M.S.; Scott, N.; Poetrodjojo, H.; Groves, B.; Sande, J. van de; ... ; Vaughan, S.P. 2021
Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a... Show moreYellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV-GP1 and -GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and -GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF proteins and LASV GP antigens in infected cells. YF17D/LASV-GP1 and -GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1 and -GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. (C) 2010 Elsevier Ltd. All rights reserved. Show less
Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a... Show moreYellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV-GP1 and -GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and -GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF proteins and LASV GP antigens in infected cells. YF17D/LASV-GP1 and -GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1 and -GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. Show less
