Clinical Utility of Cardiovascular Magnetic Resonance Imaging for Diagnosis of Acute Myocarditis

A 49 year-old patient with past medical history significant for arterial hypertension (treated with telmisartan 80 mg daily), presented to the emergency department with 18-hour gastric discomfort and fatigue. Five days prior to this presentation the patient had an episode of febrile gastroenteritis. The evening prior to presentation the patient had blood chemistries performed at an outside institution, where an increase of myocardial enzymes (troponin and CPK-MB) were noted. On presentation the patient was uncomfortable due to abdominal pain, but the clinical examination was almost normal. Blood pressure was 150/80 mmHg and heart rate was 60 beats/min. Cardiac S1 and S2 sounds where audible, without additional cardiac tones, murmurs, pericardial or pleural friction. There was no jugular venous distention, rales or peripheral edema present. Admission 12-lead electrocardiogram (ECG) demonstrated normal sinus rhythm with a rate of 60 beats/min, and early repolarization pattern with a slight J-point elevation in the lateral leads (I, aVL, V5, V6)

Clinical Utility of Cardiovascular Magnetic Resonance Imaging for Diagnosis of Acute Myocarditis

Cardiac magnetic resonance imaging (CMR) is a novel imaging technique that may help differentiate between myocarditis and acute coronary syndrome and compares favorably to other imaging techniques because it also provides information on tissue consistency and characteristics. We herein present a case, whereby CMR was most useful in providing such a differential diagnosis

Age-Related Differences in Ocular Features of a Naturalistic Free-Ranging Population of Rhesus Macaques

This is the final version. Available on open access from the Association for Research in Vision and Ophthalmology via the DOI in this recordPURPOSE: Rhesus macaques (Macaca mulatta) are the premier nonhuman primate model for studying human health and disease. We investigated if age was associated with clinically relevant ocular features in a large cohort of free-ranging rhesus macaques from Cayo Santiago, Puerto Rico. METHODS: We evaluated 120 rhesus macaques (73 males, 47 females) from 0 to 29 years old (mean ± SD: 12.6 ± 6.4) from September to December 2021. The ophthalmic evaluation included intraocular pressure (IOP) assessment, corneal pachymetry, biomicroscopy, A-scan biometry, automated refraction, and fundus photography after pupil dilation. The associations of age with the outcomes were investigated through multilevel mixed-effects models adjusted for sex and weight. RESULTS: On average, IOP, pachymetry, axial length, and automated refraction spherical equivalent were 18.37 ± 4.68 mmHg, 474.43 ± 32.21 µm, 19.49 ± 1.24 mm, and 0.30 ± 1.70 diopters (D), respectively. Age was significantly associated with pachymetry (β coefficient = -1.20; 95% confidence interval [CI], -2.27 to -0.14; P = 0.026), axial length (β coefficient = 0.03; 95% CI, 0.01 to 0.05; P = 0.002), and spherical equivalent (β coefficient = -0.12; 95% CI, -0.22 to -0.02; P = 0.015). No association was detected between age and IOP. The prevalence of cataracts in either eye was 10.83% (95% CI, 6.34-17.89) and was significantly associated with age (odds ratio [OR] = 1.20; 95% CI, 1.06-1.36; P = 0.004). Retinal drusen in either eye was observed in 15.00% (95% CI, 9.60-22.68) of animals, which was also significantly associated with age (OR = 1.14; 95% CI, 1.02-1.27; P = 0.020). CONCLUSIONS: Rhesus macaques exhibit age-related ocular associations similar to those observed in human aging, including decreased corneal thickness, increased axial length, myopic shift, and higher prevalence of cataract and retinal drusen.New Frontiers in Research FoundationNatural Sciences and Engineering Research CouncilCanada Research Chairs ProgramNational Aging InstituteBrightFocus FoundationNational Institutes of Health (NIH)University of Calgar

A study to assess changes in myocardial perfusion after treatment with spinal cord stimulation and percutaneous myocardial laser revascularisation; data from a randomised trial

<p>Abstract</p> <p>Background</p> <p>Spinal cord stimulation (SCS) and percutaneous myocardial laser revascularisation (PMR) are treatment modalities used to treat refractory angina pectoris, with the major aim of such treatment being the relief of disabling symptoms. This study compared the change in myocardial perfusion following SCS and PMR treatment.</p> <p>Methods</p> <p>Subjects with Canadian Cardiovascular Society class 3/4 angina and reversible perfusion defects as assessed by single-photon emission computed tomographic myocardial perfusion scintigraphy were randomised to SCS (34) or PMR (34). 28 subjects in each group underwent repeat myocardial perfusion imaging 12 months post intervention. Visual scoring of perfusion images was performed using a 20-segment model and a scale of 0 to 4.</p> <p>Results</p> <p>The mean (standard deviation) baseline summed rest score (SRS) and stress scores (SSS) were 4.6 (5.7) and 13.6 (9.0) in the PMR group and 6.1 (7.4) and 16.8 (11.6) in the SCS group. At 12 months, SRS was 5.5 (6.0) and SSS 15.3 (11.3) in the PMR group and 6.9 (8.2) and 15.1 (10.9) in the SCS group. There was no significant difference between the two treatment groups adjusted for baseline (p = 1.0 for SRS, p = 0.29 for SSS).</p> <p>Conclusion</p> <p>There was no significant difference in myocardial perfusion one year post treatment with SCS or PMR.</p

Vascular function assessed with cardiovascular magnetic resonance predicts survival in patients with advanced chronic kidney disease

<p>Abstract</p> <p>Background</p> <p>Increased arterial stiffness is associated with mortality in patients with chronic kidney disease. Cardiovascular magnetic resonance (CMR) permits assessment of the central arteries to measure aortic function.</p> <p>Methods</p> <p>We studied the relationship between central haemodynamics and outcome using CMR in 144 chronic kidney disease patients with estimated glomerular filtration rate <15 ml/min (110 on dialysis). Aortic distensibilty and volumetric arterial strain were calculated from cross sectional aortic volume and pulse pressure measured during the scan.</p> <p>Results</p> <p>Median follow up after the scan was 24 months. There were no significant differences in aortic distensibilty or aortic volumetric arterial strain between pre-dialysis and dialysis patients. Aortic distensibilty and volumetric arterial strain negatively correlated with age. Aortic distensibilty and volumetric arterial strain were lower in diabetics, patients with ischaemic heart disease and peripheral vascular disease. During follow up there were 20 deaths. Patients who died had lower aortic distensibilty than survivors. In a survival analysis, diabetes, systolic blood pressure and aortic distensibilty were independent predictors of mortality. There were 12 non-fatal cardiovascular events during follow up. Analysing the combined end point of death or a vascular event, diabetes, aortic distensibilty and volumetric arterial strain were predictors of events.</p> <p>Conclusion</p> <p>Deranged vascular function measured with CMR correlates with cardiovascular risk factors and predicts outcome. CMR measures of vascular function are potential targets for interventions to reduce cardiovascular risk.</p

Combined magnetic resonance coronary artery imaging, myocardial perfusion and late gadolinium enhancement in patients with suspected coronary artery disease

<p>Abstract</p> <p>Background</p> <p>Cardiovascular Magnetic Resonance (CMR) imaging offers methods for the detection of ischemia and myocardial infarction as well as visualization of the coronary arteries (MRCA). However, a direct comparison of adenosine perfusion (PERF), late gadolinium enhancement (LGE) and MRCA or the results of their combination has not been performed. Aim of the study was to evaluate the feasibility/diagnostic performance of rest/stress perfusion, late gadolinium enhancement and MRCA and their combination in patients with suspected coronary artery disease (CAD) in comparison to invasive angiography.</p> <p>Methods</p> <p>Fifty-four patients (60 ± 10 years, 35 men, CAD 48%) underwent CMR including MRCA (steady state free precession, navigator whole heart approach, spatial resolution 0.7 × 0.7 × .0.9 mm, trigger delay and temporal resolution adjusted individually), stress PERF (adenosine 140 μg/min/kg), rest PERF (SSFP, 3 short axis, 1 saturation prepulse per slice) and LGE (3D inversion recovery technique) using Gd-BOPTA. Images were analyzed visually. Stenosis >50% in invasive angiography was considered significant.</p> <p>Results</p> <p>Mean study time was 68 ± 11 minutes. Sensitivity for PERF, LGE, MRCA and the combination of PERF/LGE and PERF/LGE/MRCA was 87%, 50%, 91%, 88% and 92%, respectively and specificity 88%, 96%, 46%, 88% and 56%, respectively. If image quality of MRCA was excellent (n = 18) the combination of MRCA/PERF/LGE yield a sensitivity of 86% and specificity of 91%. However, no test or combination improved diagnostic performance significantly compared to PERF alone.</p> <p>Conclusion</p> <p>In patients with CAD, the combination of stress PERF, LGE and MRCA is feasible. When compared to invasive angiography, adenosine stress perfusion outperforms CMR coronary angiography in direct comparison and yields the best results with non-significant improvement in combination with LGE and significant deterioration in combination with MRCA. MRCA may be of additional value only in a minority of patients with excellent image quality.</p

CXCR3 Antagonism of SDF-1(5-67) Restores Trabecular Function and Prevents Retinal Neurodegeneration in a Rat Model of Ocular Hypertension

Glaucoma, the most common cause of irreversible blindness, is a neuropathy commonly initiated by pathological ocular hypertension due to unknown mechanisms of trabecular meshwork degeneration. Current antiglaucoma therapy does not target the causal trabecular pathology, which may explain why treatment failure is often observed. Here we show that the chemokine CXCL12, its truncated form SDF-1(5-67), and the receptors CXCR4 and CXCR3 are expressed in human glaucomatous trabecular tissue and a human trabecular cell line. SDF-1(5-67) is produced under the control of matrix metallo-proteinases, TNF-α, and TGF-β2, factors known to be involved in glaucoma. CXCL12 protects in vitro trabecular cells from apoptotic death via CXCR4 whereas SDF-1(5-67) induces apoptosis through CXCR3 and caspase activation. Ocular administration of SDF-1(5-67) in the rat increases intraocular pressure. In contrast, administration of a selective CXCR3 antagonist in a rat model of ocular hypertension decreases intraocular pressure, prevents retinal neurodegeneration, and preserves visual function. The protective effect of CXCR3 antagonism is related to restoration of the trabecular function. These data demonstrate that proteolytic cleavage of CXCL12 is involved in trabecular pathophysiology, and that local administration of a selective CXCR3 antagonist may be a beneficial therapeutic strategy for treating ocular hypertension and subsequent retinal degeneration

Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms.

Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings