18 research outputs found
Collagen Organization in Canine Myxomatous Mitral Valve Disease: An X-Ray Diffraction Study
Collagen fibrils, a major component of mitral valve leaflets, play an important role in defining shape and providing mechanical strength and flexibility. Histopathological studies show that collagen fibrils undergo dramatic changes in the course of myxomatous mitral valve disease in both dogs and humans. However, little is known about the detailed organization of collagen in this disease. This study was designed to analyze and compare collagen fibril organization in healthy and lesional areas of myxomatous mitral valves of dogs, using synchrotron small-angle x-ray diffraction. The orientation, density, and alignment of collagen fibrils were mapped across six different valves. The findings reveal a preferred collagen alignment in the main body of the leaflets between two commissures. Qualitative and quantitative analysis of the data showed significant differences between affected and lesion-free areas in terms of collagen content, fibril alignment, and total tissue volume. Regression analysis of the amount of collagen compared to the total tissue content at each point revealed a significant relationship between these two parameters in lesion-free but not in affected areas. This is the first time this technique has been used to map collagen fibrils in cardiac tissue; the findings have important applications to human cardiology
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Kidney Function and Outcomes in Patients Hospitalized With Heart Failure
BackgroundFew contemporary data exist evaluating care patterns and outcomes in heart failure (HF) across the spectrum of kidney function.ObjectivesThis study sought to characterize differences in quality of care and outcomes in patients hospitalized for HF by degree of kidney dysfunction.MethodsGuideline-directed medical therapies were evaluated among patients hospitalized with HF at 418 sites in the GWTG-HF (Get With The Guidelines-Heart Failure) registry from 2014 to 2019 by discharge CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration)-derived estimated glomerular filtration rate (eGFR). We additionally evaluated the risk-adjusted association of admission eGFR with in-hospital mortality.ResultsAmong 365,494 hospitalizations (age 72 ± 15 years, left ventricular ejection fraction [EF]: 43 ± 17%), median discharge eGFR was 51 ml/min/1.73 m2 (interquartile range: 34 to 72 ml/min/1.73 m2), 234,332 (64%) had eGFR <60 ml/min/1.73 m2, and 18,869 (5%) were on dialysis. eGFR distribution remained stable from 2014 to 2019. Among 157,439 patients with HF with reduced EF (≤40%), discharge guideline-directed medical therapies, including beta-blockers, were lowest in discharge eGFR <30 mL/min/1.73 m2 or dialysis (p < 0.001). "Triple therapy" with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitor + beta-blocker + mineralocorticoid receptor antagonist was used in 38%, 33%, 25%, 15%, 5%, and 3% for eGFR ≥90, 60 to 89, 45 to 59, 30 to 44, <30 ml/min/1.73 m2, and dialysis, respectively; p < 0.001. Mortality was higher in a graded fashion at lower admission eGFR groups (1.1%, 1.5%, 2.0%, 3.0%, 5.0%, and 4.2%, respectively; p < 0.001). Steep covariate-adjusted associations between admission eGFR and mortality were observed across EF subgroups, but was slightly stronger for HF with reduced EF compared with HF with mid-range or preserved EF (pinteraction = 0.045).ConclusionsDespite facing elevated risks of mortality, patients with comorbid HF with reduced EF and kidney disease are not optimally treated with evidence-based medical therapies, even at levels of eGFR where such therapies would not be contraindicated by kidney dysfunction. Further efforts are required to mitigate risk in comorbid HF and kidney disease