Heart Failure Re-Admission: Measuring the Ever Shortening Gap between Repeat Heart Failure Hospitalizations

Many quality-of-care and risk prediction metrics rely on time to first rehospitalization even though heart failure (HF) patients may undergo several repeat hospitalizations. The aim of this study is to compare repeat hospitalization models. Using a population-based cohort of 40,667 patients, we examined both HF and all cause re-hospitalizations using up to five years of follow-up. Two models were examined: the gap-time model which estimates the adjusted time between hospitalizations and a multistate model which considered patients to be in one of four states; community-dwelling, in hospital for HF, in hospital for any reason, or dead. The transition probabilities and times were then modeled using patient characteristics and number of repeat hospitalizations. We found that during the five years of follow-up roughly half of the patients returned for a subsequent hospitalization for each repeat hospitalization. Additionally, we noted that the unadjusted time between hospitalizations was reduced ∼40% between each successive hospitalization. After adjustment each additional hospitalization was associated with a 28 day (95% CI: 22-35) reduction in time spent out of hospital. A similar pattern was seen when considering the four state model. A large proportion of patients had multiple repeat hospitalizations. Extending the gap between hospitalizations should be an important goal of treatment evaluation.     

The Prognostic Importance of Changes in Renal Function during Treatment for Acute Heart Failure Depends on Admission Renal Function

Background

Worsening and improving renal function during acute heart failure have been associated with adverse outcomes but few studies have considered the admission level of renal function upon which these changes are superimposed.

Objectives

The objective of this study was to evaluate definitions that incorporate both admission renal function and change in renal function.

Methods

696 patients with acute heart failure with calculable eGFR were classified by admission renal function (Reduced [R, eGFR<45 ml/min] or Preserved [P, eGFR≥45 ml/min]) and change over hospital admission (worsening [WRF]: eGFR ≥20% decline; stable [SRF]; and improving [IRF]: eGFR ≥20% increase). The primary outcome was all-cause mortality. The prevalence of Pres and Red renal function was 47.8% and 52.2%. The frequency of R-WRF, R-SRF, and R-IRF was 11.4%, 28.7%, and 12.1%, respectively; the incidence of P-WRF, P-SRF, and P-IRF was 5.7%, 35.3%, and 6.8%, respectively. Survival was shorter for patients with R-WRF compared to R-IRF (median survival times 13.9 months (95%CI 7.7–24.9) and 32.5 months (95%CI 18.8–56.1), respectively), resulting in an acceleration factor of 2.3 (p = 0.016). Thus, an increase compared with a decrease in renal function was associated with greater than two times longer survival among patients with Reduced renal function.     

Gas-phase purification enables accurate, multiplexed proteome quantification with isobaric tagging

We describe a mass spectrometry method, QuantMode, which improves accuracy of isobaric tag-based quantification by alleviating the pervasive problem of precursor interference, simultaneous isolation and fragmentation of impurities, through gas-phase purification. QuantMode analysis of a yeast sample 'contaminated' with interfering human peptides showed substantially improved quantitative accuracy compared to a standard scan, with a small loss of spectral identifications. This technique enables large-scale, multiplexed quantitative proteomics using isobaric tagging.     

Preferential integration of adeno-associated virus type 2 into a polypyrimidine/polypurine-rich region within AAVS1

Adeno-associated virus type 2 (AAV2) preferentially integrates its genome into the AAVS1 locus on human chromosome 19. Preferential integration requires the AAV2 Rep68 or Rep78 protein (Rep68/78), a Rep68/78 binding site (RBS), and a nicking site within AAVS1 and may also require an RBS within the virus genome. To obtain further information that might help to elucidate the mechanism and preferred substrate configurations of preferential integration, we amplified junctions between AAV2 DNA and AAVS1 from AAV2-infected HeLaJW cells and cells with defective Artemis or xeroderma pigmentosum group A genes. We sequenced 61 distinct junctions. The integration junction sequences show the three classical types of nonhomologous-end-joining joints: microhomology at junctions (57%), insertion of sequences that are not normally contiguous with either the AAV2 or the AAVS1 sequences at the junction (31%), and direct joining (11%). These junctions were spread over 750 bases and were all downstream of the Rep68/78 nicking site within AAVS1. Two-thirds of the junctions map to 350 bases of AAVS1 that are rich in polypyrimidine tracts on the nicked strand. The majority of AAV2 breakpoints were within the inverted terminal repeat (ITR) sequences, which contain RBSs. We never detected a complete ITR at a junction. Residual ITRs at junctions never contained more than one RBS, suggesting that the hairpin form, rather than the linear ITR, is the more frequent integration substrate. Our data are consistent with a model in which a cellular protein other than Artemis cleaves AAV2 hairpins to produce free ends for integration.     

Case management for blood pressure and lipid level control after minor stroke: PREVENTION randomized controlled trial

Background:

Optimization of systolic blood pressure and lipid levels are essential for secondary prevention after ischemic stroke, but there are substantial gaps in care, which could be addressed by nurse- or pharmacist-led care. We compared 2 types of case management (active prescribing by pharmacists or nurse-led screening and feedback to primary care physicians) in addition to usual care.

Methods:

We performed a prospective randomized controlled trial involving adults with recent minor ischemic stroke or transient ischemic attack whose systolic blood pressure or lipid levels were above guideline targets. Participants in both groups had a monthly visit for 6 months with either a nurse or pharmacist. Nurses measured cardiovascular risk factors, counselled patients and faxed results to primary care physicians (active control). Pharmacists did all of the above as well as prescribed according to treatment algorithms (intervention).

Results:

Most of the 279 study participants (mean age 67.6 yr, mean systolic blood pressure 134 mm Hg, mean low-density lipoprotein [LDL] cholesterol 3.23 mmol/L) were already receiving treatment at baseline (antihypertensives: 78.1%; statins: 84.6%), but none met guideline targets (systolic blood pressure ≤ 140 mm Hg, fasting LDL cholesterol ≤ 2.0 mmol/L). Substantial improvements were observed in both groups after 6 months: 43.4% of participants in the pharmacist case manager group met both systolic blood pressure and LDL guideline targets compared with 30.9% in the nurse-led group (12.5% absolute difference; number needed to treat = 8, p = 0.03).

Interpretation:

Compared with nurse-led case management (risk factor evaluation, counselling and feedback to primary care providers), active case management by pharmacists substantially improved risk factor control at 6 months among patients who had experienced a stroke. Trial registration: ClinicalTrials.gov, no. {"type":"clinical-trial","attrs":{"text":"NCT00931788","term_id":"NCT00931788"}}NCT00931788The risk of cardiovascular events is high for patients who survive a stroke or transient ischemic attack.^1,2 Treatment of hypertension and dyslipidemia can substantially reduce this risk.^3–7 However, vascular risk factors are often suboptimally managed after stroke or transient ischemic attack, even among patients admitted to hospital or seen in specialized stroke prevention clinics.^8–10Multiple barriers are responsible for the suboptimal control of risk factors, and traditional means of educating practitioners and patients have limited effectiveness.¹¹ Although it has been suggested that “case managers” may be able to improve the management of risk factors, evidence is sparse and inconsistent between studies.^12–16 The most recent Cochrane review on this topic concluded that “nurse- or pharmacist-led care may be a promising way forward … but these interventions require further evaluation.”¹⁶ Thus, we designed this trial to evaluate whether a pharmacist case manager could improve risk factors among survivors of stroke or transient ischemic attack.¹⁷ Because we have previously shown that hypertension control can be improved by monthly evaluation by nurses (with patient counselling and faxing of blood pressure measurements with guideline recommendations to primary care physicians),¹⁸ and this is an alternate method of case management implemented in many health organizations, we used this approach as the active control group for this study. Thus, our study represents a controlled comparison of 2 modes of case management: active prescribing (pharmacist-led case management) versus screening and delegating to primary care physicians (nurse-led case management).     

Completing the structural family portrait of the human EphB tyrosine kinase domains

The EphB receptors have key roles in cell morphology, adhesion, migration and invasion, and their aberrant action has been linked with the development and progression of many different tumor types. Their conflicting expression patterns in cancer tissues, combined with their high sequence and structural identity, present interesting challenges to those seeking to develop selective therapeutic molecules targeting this large receptor family. Here, we present the first structure of the EphB1 tyrosine kinase domain determined by X‐ray crystallography to 2.5Å. Our comparative crystalisation analysis of the human EphB family kinases has also yielded new crystal forms of the human EphB2 and EphB4 catalytic domains. Unable to crystallize the wild‐type EphB3 kinase domain, we used rational engineering (based on our new structures of EphB1, EphB2, and EphB4) to identify a single point mutation which facilitated its crystallization and structure determination to 2.2 Å. This mutation also improved the soluble recombinant yield of this kinase within Escherichia coli, and increased both its intrinsic stability and catalytic turnover, without affecting its ligand‐binding profile. The partial ordering of the activation loop in the EphB3 structure alludes to a potential cis‐phosphorylation mechanism for the EphB kinases. With the kinase domain structures of all four catalytically competent human EphB receptors now determined, a picture begins to emerge of possible opportunities to produce EphB isozyme‐selective kinase inhibitors for mechanistic studies and therapeutic applications.     

Relationships among Egg Size, Composition, and Energy: A Comparative Study of Geminate Sea Urchins

Egg size is one of the fundamental parameters in the life histories of marine organisms. However, few studies have examined the relationships among egg size, composition, and energetic content in a phylogenetically controlled context. We investigated the associations among egg size, composition, and energy using a comparative system, geminate species formed by the closure of the Central American Seaway. We examined western Atlantic (WA) and eastern Pacific (EP) species in three echinoid genera, Echinometra, Eucidaris, and Diadema. In the genus with the largest difference in egg size between geminates (Echinometra), the eggs of WA species were larger, lipid rich and protein poor compared to the smaller eggs of their EP geminate. In addition, the larger WA eggs had significantly greater total egg energy and summed biochemical constituents yet significantly lower egg energy density (energy-per-unit-volume). However, the genera with smaller (Eucidaris) or no (Diadema) differences in egg size were not significantly different in summed biochemical constituents, total egg energy, or energy density. Theoretical models generally assume a strong tradeoff between egg size and fecundity that limits energetic investment and constrains life history evolution. We show that even among closely-related taxa, large eggs cannot be assumed to be scaled-up small eggs either in terms of energy or composition. Although our data comes exclusively from echinoid echinoderms, this pattern may be generalizable to other marine invertebrate taxa. Because egg composition and egg size do not necessarily evolve in lockstep, selective factors such as sperm limitation could act on egg volume without necessarily affecting maternal or larval energetics.