Denervated Myocardium Is Preferentially Associated With Sudden Cardiac Arrest in Ischemic Cardiomyopathy: A Pilot Competing Risks Analysis of Cause-Specific Mortality.

BACKGROUND: Previous studies have identified multiple risk factors that are associated with total cardiac mortality. Nevertheless, identifying specific factors that distinguish patients at risk of arrhythmic death versus heart failure could better target patients likely to benefit from implantable cardiac defibrillators, which have no impact on nonsudden cardiac death. METHODS AND RESULTS: We performed a pilot competing risks analysis of the National Institutes of Health-sponsored PAREPET trial (Prediction of Arrhythmic Events with Positron Emission Tomography). Death from cardiac causes was ascertained in subjects with ischemic cardiomyopathy (n=204) eligible for an implantable cardiac defibrillator for the primary prevention of sudden cardiac arrest after baseline clinical evaluation and imaging at enrollment (positron emission tomography and 2-dimensional echo). Mean age was 67±11 years with an ejection fraction of 27±9%, and 90% were men. During 4.1 years of follow-up, there were 33 sudden cardiac arrests (arrhythmic death or implantable cardiac defibrillator discharge for ventricular fibrillation or ventricular tachycardia >240 bpm) and 36 nonsudden cardiac deaths. Sudden cardiac arrest was correlated with a greater volume of denervated myocardium (defect of the positron emission tomography norepinephrine analog 11C-hydroxyephedrine), lack of angiotensin inhibition therapy, elevated B-type natriuretic peptide, and larger left ventricular end-diastolic volume index. In contrast, nonsudden cardiac death was associated with a higher resting heart rate, older age, elevated creatinine, larger left atrial volume index, and larger left ventricular end-diastolic volume index. CONCLUSIONS: Distinct clinical, laboratory, and imaging variables are associated with cause-specific cardiac mortality in primary-prevention candidates with ischemic cardiomyopathy. If prospectively validated, these multivariable associations may help target specific therapies to those at the greatest risk of sudden and nonsudden cardiac death. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT01400334.

Evidence for improved survival in postsymptomatic stem cell-transplanted patients with Krabbe's disease.

Krabbe's disease (KD) is a severe neurodegenerative disorder affecting white matter in the brain and peripheral nerves. Transplantation of hematopoietic stem cells (HSCT), although not curative, has been shown to extend survival and alleviate neurodevelopmental symptoms when treatment precedes the onset of symptoms. Existing evidence, although not tested statistically, seems clearly to show that postsymptomatic transplantation does not improve neurodevelopmental outcomes. The impact of postsymptomatic HSCT treatment on survival, however, is an open question. This study uses a KD registry to examine the effect of HSCT on survival of symptomatic KD patients. Sixteen transplanted patients were matched by age of onset to 68 nontransplanted patients. The potential confounding effect of age of onset was, therefore, avoided. To quantify the effect of HSCT over time, we used Cox regression analysis, and we observed a sustained and nearly 2.2-fold risk of death from KD in patients who were not transplanted relative to those who were transplanted (one-tailed P = 0.0365; 95% lower bound = 1.07). The improvement of survival resulting from HSCT did not appear to depend on the age of symptom onset. Thus, these results establish a long-term, quantitative benefit of HSCT even in patients who are already experiencing symptoms. They also provide a benchmark for improved survival that can be used for potential new treatments for KD. © 2016 Wiley Periodicals, Inc.

Synthesis of nanoparticle-cored dendrimers by convergent dendritic functionalization of monolayer-protected nanoparticles.

This article presents a synthesis method for nanoparticle-cored dendrimers (NCDs), which have dendritic architectures around a monolayer-protected gold nanoparticle. The synthesis method is based on a strategy in which the synthesis of monolayer-protected nanoparticles is followed by adding dendrons on functionalized nanoparticles by a single coupling reaction. NMR spectroscopy, IR spectroscopy, and thermogravimetric analysis (TGA) characterizations confirmed the successful coupling reaction between dendrons with different generations ([G1], [G2], and [G3]) and COOH-functionalized nanoparticles ( approximately Au201L71). The dendrimer wedge density also could be controlled by reacting nanoparticles having different loading of COOH groups ( approximately 60 and approximately 10% COOH of the 71 ligands per gold nanoparticle) with functionalized dendrons. Transmission electron microscope results showed that this synthesis strategy maintains the average size of the nanoparticle core during dendron coupling reactions. This control over the composition and core size makes the systematic study of NCDs with different generations possible. The chemical stability of NCDs was found to be affected by dendron generation around the nanoparticle core. The current-potential response of NCD films on microelectrode arrays exhibited better electrical conductivity for NCDs with lower dendron generation.