Detecting left ventricular (LV) dysfunction at an early stage is key in addressing the heart failure epidemic. In proteome profiling experiments in mice subjected either to aortic banding or sham, ...the circulating CXCR3 ligands monokine induced by interferon-γ (MIG) and interferon-γ inducible protein 10 (IP10) were 5 to 40 fold up-regulated at eight weeks. We assessed the diagnostic value of circulating NT-pro BNP and CXCR3 ligands (MIG, IP10, Interferon-inducible T-cell alpha chemo-attractant I-TAC) in patients with hypertension (≥140/90 mm Hg) associated with subclinical (n = 19) or symptomatic (n = 16) diastolic LV dysfunction on echocardiography and healthy controls. NT-pro BNP, MIG, IP10, I-TAC all increased (p ≤ 0.014) across the categories of worsening left ventricular dysfunction. In patients with symptomatic disease, MIG, IP10, and I-TAC increased 210% (p = 0.015), 140% (p = 0.007) and 120% (p = 0.035) more than NT-pro BNP. The optimal discrimination limits, obtained by maximizing Youden's index were 246 pmol/L, 65 pg/mL, 93 pg/mL, and 24 pg/mL, respectively. The odds ratios associated with the four biomarkers were significant (p ≤ 0.010), ranging from 4.00 for IP10 to 9.69 for MIG. With adjustment for NT-pro BNP, the CXCR3 ligands retained significance (p ≤ 0.028). Adding optimized thresholds for the CXCR3 ligands to NT-pro BNP enhanced (p ≤ 0.014) the integrated discrimination improvement and the net reclassification improvement. In conclusion, congruent with the concept that inflammation plays a key role in the pathogenesis of LV dysfunction, MIG, IP10 and I-TAC add diagnostic accuracy over and beyond NT-pro BNP.
Background Stiffening and calcification of the large arteries are forerunners of cardiovascular complications. MGP (Matrix Gla protein), which requires vitamin K-dependent activation, is a potent ...locally acting inhibitor of arterial calcification. We hypothesized that the central hemodynamic properties might be associated with inactive desphospho-uncarboxylated MGP (dp-uc MGP ). Methods and Results In 835 randomly recruited Flemish individuals (mean age, 49.7 years; 45.6% women), we measured plasma dp-uc MGP , using an ELISA -based assay. We derived central pulse pressure and carotid-femoral pulse wave velocity (PWV) from applanation tonometry and calculated forward and backward pulse waves using an automated, pressure-based wave separation analysis algorithm. Aortic PWV (n=657), central pulse pressure, forward pulse wave, and backward pulse wave mean± SD values were 7.34±1.64 m/s, 45.2±15.3 mm Hg, 33.2±10.2 mm Hg, and 21.8±8.6 mm Hg, respectively. The geometric mean plasma concentration of dp-uc MGP was 4.09 μg/L. All hemodynamic indexes increased across tertiles of dp-uc MGP distribution. In multivariable-adjusted analyses, a doubling of dp-uc MGP was associated with higher PWV (0.15 m/s; 95% CI, 0.01-0.28 m/s), central pulse pressure (1.70 mm Hg; 95% CI, 0.49-2.91 mm Hg), forward pulse wave (0.93 mm Hg; 95% CI, 0.01-1.84 mm Hg), and backward pulse wave (0.71 mm Hg; 95% CI, 0.11-1.30 mm Hg). Categorization of aortic PWV by tertiles of its distribution highlighted a decreasing trend of PWV at low dp-uc MGP (<3.35 μg/L) and an increasing trend at high dp-uc MGP (≥5.31 μg/L). Conclusions In people representative for the general population, higher inactive dp-uc MGP was associated with greater PWV , central pulse pressure, forward pulse wave, and backward pulse wave. These observations highlight new avenues for preserving vascular integrity and preventing cardiovascular complications (eg, by improving a person's vitamin K status).
Active matrix Gla protein (MGP), a potent inhibitor of calcification in large arteries, protects against macrovascular complications. Recent studies suggested that active MGP helps maintaining the ...integrity of the renal and myocardial microcirculation, but its role in preserving the retinal microcirculation remains unknown. In 935 randomly recruited Flemish participants (mean age, 40.9 years; 50.3% women), we measured plasma desphospho-uncarboxylated MGP (dp-ucMGP), a marker of poor vitamin K status using an ELISA-based assay at baseline (1996-2010) and retinal microvascular diameters using IVAN software (Vasculomatic ala Nicola, version 1.1) including the central retinal arteriolar (CRAE) and venular (CRVE) equivalent and the arteriole-to-venule ratio (AVR) at follow-up (2008-2015). CRAE (P = 0.005) and AVR (P = 0.080) at follow-up decreased across tertiles of the dp-ucMGP distribution. In unadjusted models, for a doubling of dp-ucMGP at baseline, CRAE and AVR at follow-up respectively decreased by 1.40 µm (95% confidence interval CI, 0.32 to 2.48; P = 0.011) and 0.006 (CI, 0.001 to 0.011; P = 0.016). In multivariable-adjusted models accounting for sex, baseline characteristics and follow-up duration, these estimates were -1.03 µm (CI, -1.96 to -0.11; P = 0.028) and -0.007 (CI, -0.011 to -0.002; P = 0.007). Additional adjustment for changes from baseline to follow-up in major baseline characteristics yielded as estimates -0.91 µm (CI, -1.82 to -0.01; P = 0.048) and -0.006 (95% CI, -0.011 to -0.001; P = 0.014), respectively. Circulating inactive dp-ucMGP is a long-term predictor of smaller retinal arteriolar diameter in the general population. Our observations highlight the possibility that vitamin K supplementation might promote retinal health.
The ability to investigate the microvascular structure and function is important in improving our understanding of pathophysiological processes in hypertension and related cardiovascular disease. A ...range of techniques are available or emerging for investigating different aspects of the microcirculation in animals and humans. Techniques such as experimental intravital microscopy and clinical intravital microscopy (e.g. orthogonal polarization spectral imaging) allow visualization at the level of single microvessels. Venous occlusion plethysmography can be used to measure blood flow in organs, and laser Doppler flowmetry to measure red cell flux in small areas of tissue. Positron emission tomography, myocardial contrast echocardiography, and magnetic resonance imaging provide three-dimensional imaging of local blood flow. The current and potential clinical usefulness of these different techniques is evaluated. The technical quality and availability for clinical use of some of the techniques should improve dramatically during the next few years. ‘Molecular imaging’—the combination of these techniques with genetic, molecular, and computational approaches—offers great potential for use in research and in diagnosis and the monitoring of disease progression or the results of therapy. Closer attention to the microcirculation will ultimately improve the treatment and prevention of many of the most important forms of cardiovascular disease.
Background Prematurity disrupts the perinatal maturation of the microvasculature and macrovasculature and confers high risk of vascular dysfunction later in life. No previous studies have ...investigated the crosstalk between the microvasculature and macrovasculature in childhood. Methods and Results In a case-control study, we enrolled 55 children aged 11 years weighing <1000 g at birth and 71 matched controls (October 2014-November 2015). We derived central blood pressure (BP) wave by applanation tonometry and calculated the forward/backward pulse waves by an automated pressure-based wave separation algorithm. We measured the renal resistive index by pulsed wave Doppler and the central retinal arteriolar equivalent by computer-assisted program software. Compared with controls, patients had higher central systolic BP (101.5 versus 95.2 mm Hg,
<0.001) and backward wave amplitude (15.5 versus 14.2 mm Hg,
=0.029), and smaller central retinal arteriolar equivalent (163.2 versus 175.4 µm,
<0.001). In multivariable analyses, central retinal arteriolar equivalent was smaller with higher values (+1 SD) of central systolic BP (-2.94 µm; 95% CI, -5.18 to -0.70 µm
=0.011) and forward (-2.57 µm; CI, -4.81 to -0.32 µm
=0.026) and backward (-3.20 µm; CI, -5.47 to -0.94 µm
=0.006) wave amplitudes. Greater renal resistive index was associated with higher backward wave amplitude (0.92 mm Hg,
=0.036). Conclusions In childhood, prematurity compared with term birth is associated with higher central systolic BP and forward/backward wave amplitudes. Higher renal resistive index likely moves reflection points closer to the heart, thereby explaining the inverse association of central retinal arteriolar equivalent with central systolic BP and backward wave amplitude. These observations highlight the crosstalk between the microcirculation and macrocirculation in children. Registration URL: http://www.clinicaltrials.gov. Unique Identifier: NCT02147457.
Abstract
BACKGROUND
Retinal microvascular traits predict adverse health outcomes. The Singapore I Vessel Assessment (SIVA) software improved automated postprocessing of retinal photographs. In ...addition to microvessel caliber, it generates measures of arteriolar and venular geometry. Few studies addressed the reproducibility of SIVA measurements across a wide age range.
METHODS
In the current study, 2 blinded graders read images obtained by nonmydriatic retinal photography twice in 20 11-year-old children, born prematurely (n = 10) or at term (n = 10) and in 60 adults (age range, 18.9–86.1 years).
RESULTS
Former preterm compared with term children had lower microvessel diameter and disorganized vessel geometry with no differences in intraobserver and interobserver variability. Among adults, microvessel caliber decreased with age and blood pressure and arteriolar geometry was inversely correlated with female sex and age. Intraobserver differences estimated by the Bland–Altman method did not reach significance for any measurement. Across measurements, median reproducibility (RM) expressed as percent of the average trait value was 8.8% in children (median intraclass correlation coefficient ICC, 0.94) and 8.0% (0.97) in adults. Likewise, interobserver differences did not reach significance with RM (ICC) of 10.6% (0.85) in children and 10.4% (0.93) in adults. Reproducibility was best for microvessel caliber (intraobserver/interobserver RM, 4.7%/6.0%; ICC, 0.98/0.96), worst for venular geometry (17.0%/18.8%; 0.93/0.84), and intermediate for arteriolar geometry (10.9%/14.9%; 0.95/0.86).
CONCLUSIONS
SIVA produces repeatable measures of the retinal microvasculature in former preterm and term children and in adults, thereby proving its usability from childhood to old age.
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