Abstract The purpose of this study is to examine the association of sarcopenia as measured by psoas muscle area and outcomes in patients undergoing LVAD implantation. We retrospectively examined 333 ...consecutive patients who underwent implantation of a HeartMate II LVAD at our institution between June 2008 and August 2013. Patients were included if they had a perioperative CT that spanned the L3-L4 vertebrae. Sarcopenia was defined as having lowest tertile psoas muscle area by gender. The primary endpoint was the composite of inpatient death or prolonged length of stay of >30 days. 100 patients met inclusion criteria. The psoas muscle area cut-off values for the lowest tertiles were 12.0 cm2 for males and 6.5 cm2 for females, resulting in n=32 (32%) sarcopenic. The primary outcome of inpatient death or prolonged length of stay occurred in 81% of patients in the sarcopenic vs 60% of the non-sarcopenic group (p=0.043). There was a trend toward prolonged length of stay in sarcopenic patients but no difference in overall mortality. This demonstrates that sarcopenia as measured by psoas muscle area is associated with increased composite length of stay and mortality following LVAD implantation and may serve as correlate for frailty.
Singlet fission (SF) is the process of converting an excited singlet to a pair of excited triplets. Harvesting two charges from a single photon has the potential to increase photovoltaic device ...efficiencies. Acenes, such as tetracene and pentacene, are model molecules for studying SF. Despite SF being an endoergic process for tetracene and exoergic for pentacene, both acenes exhibit near unity SF quantum efficiencies, raising questions about how tetracene can overcome the energy barrier. Here, we use recently developed instrumentation to measure inelastic neutron scattering (INS) while optically exciting the model molecules using two different excitation energies. The spectroscopic results reveal intermolecular structural relaxation due to the presence of a triplet excited state. The structural dynamics of the combined excited state molecule and surrounding tetracene molecules are further studied using time-dependent density functional theory (TD-DFT), which shows that the singlet and triplet levels shift due to the excited state geometry, reducing the uphill energy barrier for SF to within kT.
The Fontan operation is a common end point for children born with a single functional ventricle. Fontan patients typically experience physiological deterioration leading to transplant or death in ...their third or fourth decades of life. This deterioration is partially attributable to progressive increases in pulmonary vascular resistance (PVR) and as such endothelin receptor antagonists, which are known to decrease pulmonary vascular resistance, have been proposed as potentially beneficial in this population. We conducted a single-center, randomized, double-blind, placebo-controlled, crossover study of 12 weeks of ambrisentan therapy (10 mg per day) versus placebo to test the hypothesis that endothelin receptor antagonism will improve cardiopulmonary exercise test parameters and 36-item short form (SF-36) assessed quality of life in adult Fontan patients. Twenty-eight patients entered the trial, 19 patients completed the protocol. Ambrisentan therapy improved peak oxygen consumption by 1.7 ml/kg/min in patients who achieved a respiratory exchange ratio of >0.95 (p = 0.05) and decreased the slope of the ventilatory equivalent ratio for oxygen (−2.8, p = 0.019) in all completers. It did not change SF-36 physical function score compared with placebo (p = 0.28). Ambrisentan therapy resulted in a decrease in (−1.4 g/dl, p <0.001) with no change in liver or renal function. Therapy was generally well tolerated, with no greater rate of side effects than placebo. In conclusion, ambrisentan is well tolerated and improves exercise capacity in adult Fontan patients.
Abstract Acute decompensated heart failure (ADHF) is a major reason for repeated hospitalizations. Identifying those patients with ADHF at risk for readmission is critical so that preventive ...interventions can be implemented. Biomarkers such as B-type Natriuretic Peptide (BNP), high-sensitivity troponin I (Hs-cTnI), and galectin-3 (Gal-3) assessed at discharge may be useful, though their role in predicting short-term readmission is not well defined in the literature. We enrolled and had follow up data for 101 participants admitted to our facility between 4/2013 and 3/2015 with a primary diagnosis of ADHF. Gal-3, Hs-cTnI, and BNP were obtained within 48 hours prior to hospital discharge after management of ADHF. Gal-3 was assessed using two commercially available assays. We compared subjects who were and were not readmitted. Discharge BNP was found to be a significant predictor of 30 and 60 day readmission AUC 0.69 (p=0.046), AUC 0.7 (p=0.005) respectively. The addition of Gal-3 to discharge BNP provided significantly improved prediction of 60 day re-admission. Gal-3 alone was found to be a significant predictor of 60 day re-admission in patients with preserved ejection fraction (AUC 0.85, p<0.001. The net reclassification improvement (NRI) was 55.2 (p=0.037). Using multivariate analysis, for every 100 pg/L BNP increase, the probability of re-admission increased by approximately 10%, and for every 1 ng/mL Gal-3 increase, the probability further increased 8%. A statistically significant NRI was not found upon examination of 30 day readmission. In conclusion, measurement of both Gal-3 and BNP at hospital discharge provides significant prediction of hospital re-admission within 60 days. When combined, the prediction of re-admission is significantly improved.
Frail patients are more prone to adverse events after cardiac surgery, particularly after implantation of left ventricular assist devices. Thus, frailty assessment may help identify patients unlikely ...to benefit from left ventricular assist device therapy. The purpose was to establish a suitable measure of frailty in adults with end-stage heart failure. In a prospective cohort of 75 patients (age 58 ± 12 years) with end-stage heart failure, we assessed the association between frailty (5-component Fried criteria) and the composite primary outcome of inpatient mortality or prolonged length of stay, as well as extubation status, time on ventilator, discharge status, and long-term mortality. Fried frailty criteria were met in 44 (59%) patients, but there was no association with the primary outcome (p = 0.10). However, an abridged set of 3 criteria (exhaustion, inactivity, and grip strength) was predictive of the primary outcome (odds ratio 2.9, 95% confidence interval 1.1 to 7.4), and of time to extubation and time to discharge. In patients with advanced heart failure, the 5-component Fried criteria may not be optimally sensitive to clinical differences. In conclusion, an abridged set of 3 frailty criteria was predictive of the primary outcome and several secondary outcomes, and may therefore be a clinically useful tool in this population.
Solid state materials possessing the ability for fast ionic diffusion of hydrogen have immense appeal for a wide range of energy-related applications. Ionic hydrogen transport research is dominated ...by proton conductors, but recently a few examples of hydride ion conductors have been observed as well. Barium hydride, BaH
, undergoes a structural phase transition around 775 K that leads to an order of magnitude increase in the ionic conductivity. This material provides a prototypical system to understand hydride ion diffusion and how the altered structure produced by the phase transition can have an enormous impact on the diffusion. We employ quasielastic and inelastic neutron scattering to probe the atomic scale diffusion mechanism and vibrational dynamics of hydride ions in both the low- and high-temperature phases. Jump lengths, residence times, diffusion coefficients, and activation energies are extracted and compared to the crystal structure to uncover the diffusion pathways. We find that the hydrogen jump distances, residence times, and energy barriers become reduced following the phase transition, allowing for the efficient conduction of hydride ions through a series of hydrogen jumps of length L = 3.1 Å.
Racial disparities exist in the treatment of many cardiovascular diseases. Aortic valve replacement (AVR) is the only treatment for aortic stenosis (AS) that improves patient symptoms and survival. ...To date, no studies have compared the rate of AVR among different races. The records of patients with an aortic valve area <1 cm2 by echocardiography diagnosed between January 2004 and May 2010 at Barnes-Jewish Hospital were reviewed retrospectively. Patients were stratified by race. Of the 880 patients analyzed, 10% were African American (AA), and 90% were European American (EA). AA more frequently had hypertension (82% vs 67%, p <0.01), diabetes mellitus (45% vs 32%, p = 0.02), chronic kidney disease (28% vs 17%, p = 0.01), and end stage renal disease (18% vs 2%, p <0.001). AA underwent AVR less frequently than EA (39% vs 53%, p = 0.02) and refused intervention more often (33% vs 20%, p = 0.04). When treated, AA and EA had similar 3-year survival (49% 38 to 60 vs 50% 45 to 54, p = 0.31). Identification of the factors associated with treatment refusal would further our ability to counsel patients on the decision to pursue AVR.
Although periodic cardiac stress testing is commonly used to screen patients on the waiting list for kidney transplantation for ischemic heart disease, there is little evidence to support this ...practice. We hypothesized that cardiac stress testing in the 18 months prior to kidney transplantation would not reduce postoperative death, total myocardial infarction (MI) or fatal MI.
Using the United States Renal Data System, we identified ESRD patients ≥40 years old with primary Medicare insurance who received their first kidney transplant between 7/1/2006 and 11/31/2013. Propensity matching created a 1:1 matched sample of patients with and without stress testing in the 18 months prior to kidney transplantation. The outcomes of interest were death, total (fatal and nonfatal) MI or fatal MI within 30 days of kidney transplantation.
In the propensity-matched cohort of 17,304 patients, death within 30 days occurred in 72 of 8,652 (0.83%) patients who underwent stress testing and in 65 of 8,652 (0.75%) patients who did not (OR 1.07; 95% CI: 0.79-1.45; P = 0.66). MI within 30 days occurred in 339 (3.9%) patients who had a stress test and in 333 (3.8%) patients who did not (OR 1.03; 95% CI: 0.89-1.21; P = 0.68). Fatal MI occurred in 17 (0.20%) patients who underwent stress testing and 15 (0.17%) patients who did not (OR 0.97; 95% CI: 0.71-1.32; P = 0.84).
Stress testing in the 18 months prior to kidney transplantation is not associated with a reduction in death, total MI or fatal MI within 30 days of kidney transplantation.
Abstract Objective The purpose of this study was to determine the incidence and clinical significance of postoperative delirium (PD) in patients with aortic stenosis undergoing surgical aortic valve ...replacement (SAVR) or transcatheter aortic valve replacement (TAVR). Method Between 2010 and 2013, 427 patients underwent TAVR (n = 168) or SAVR (n = 259) and were screened for PD using the Confusion Assessment Method for the Intensive Care Unit. The incidence of PD in both treatment groups was determined and its association with morbidity and mortality was retrospectively compared. Results PD occurred in 135 patients (32%) with a similar incidence between SAVR (33% 86 out of 259) and TAVR (29% 49 out of 168) ( P = .40). TAVR by transfemoral approach had the lowest incidence of PD compared with SAVR (18% vs 33%; P = .025) or TAVR when performed by alternative access techniques (18% vs 35%; P = .02). Delirium was associated with longer initial intensive care unit stay (70 vs 27 hours), intensive care unit readmission (10% 14 out of 135 vs 2% 6 out of 292), and longer hospital stay (8 vs 6 days) ( P < .001 for all). PD was associated with increased mortality at 30 days (7% vs 1%; P < .001) and 1 year (21% vs 8%; P < .001). After multivariable adjustment, PD remained associated with increased 1-year mortality (hazard ratio, 3.02; 95% confidence interval, 1.75-5.23; P < .001). There was no interaction between PD and aortic valve replacement approach with respect to 1-year mortality ( P = .12). Among propensity-matched patients (n = 170), SAVR-treated patients had a higher incidence of PD than TAVR-treated patients (51% vs 29%; P = .004). Conclusions PD occurs commonly after SAVR and TAVR and is associated with increased morbidity and mortality. Given the high incidence of PD and its associated adverse outcomes, further studies are needed to minimize PD and potentially improve patient outcomes.
PDF
