Diabetes mellitus does not alter mortality or hospitalisation risk in patients with newly diagnosed heart failure with preserved ejection fraction: Time to rethink pathophysiological models of disease progression

INTRODUCTION

Type 2 diabetes is a common and adverse prognostic co-morbidity for patients with heart failure with reduced ejection fraction (HFrEF). The effect of diabetes on long-term outcomes for heart failure with preserved ejection fraction (HFpEF) is less established.

METHODS

Prospective cohort study of patients referred to a regional HF clinic with newly diagnosed with HFrEF and HFpEF according to the 2016 European Society of Cardiology guidelines. The association between diabetes, all-cause mortality and hospitalisation was quantified using Kaplan-Meier or Cox regression analysis.

RESULTS

Between 1st May 2012 and 1st May 2013, of 960 unselected consecutive patients referred with suspected HF, 464 and 314 patients met the criteria for HFpEF and HFrEF respectively. Within HFpEF and HFrEF groups, patients with diabetes were more frequently male and in both groups patients with diabetes were more likely to be treated with β-adrenoceptor antagonists and angiotensin converting enzyme inhibitors. After adjustment for age, sex, medical therapy and co-morbidities, diabetes was associated with increased mortality in individuals with HFrEF (HR 1.46 95% CI: 1.05-2.02; p = .023), but not in those with HFpEF (HR 1.26 95% CI 0.92-1.72; p = .146).

CONCLUSION

In unselected patients with newly diagnosed HF, diabetes is not an adverse prognostic marker in patients with HFpEF, but is in HFrEF.

Guideline-directed medical therapy is similarly effective in heart failure with mildly reduced ejection fraction

AIMS

Current guidelines recommend that disease-modifying pharmacological therapies may be considered for patients who have heart failure with mildly reduced ejection fraction (HFmrEF). We aimed to describe the characteristics, outcomes, provision of pharmacological therapies and dose-related associations with mortality risk in HFmrEF.

METHODS AND RESULTS

We explored data from two prospective observational studies, which permitted the examination of the effects of pharmacological therapies across a broad spectrum of left ventricular ejection fraction (LVEF). The combined dataset consisted of 2388 unique patients, with a mean age of 73.7 ± 13.2 years of whom 1525 (63.9%) were male. LVEF ranged from 5 to 71% (mean 37.2 ± 12.8%) and 1504 (63.0%) were categorised as having reduced ejection fraction (HFrEF), 421 (17.6%) as HFmrEF and 463 (19.4%) as preserved ejection fraction (HFpEF). Patients with HFmrEF more closely resembled HFrEF than HFpEF. Adjusted all-cause mortality risk was lower in HFmrEF (hazard ratio [HR] 0.86 (95% confidence interval [CI] 0.74-0.99); p = 0.040) and in HFpEF (HR 0.61 (95% CI 0.52-0.71); p < 0.001) compared to HFrEF. Adjusted all-cause mortality risk was lower in patients with HFrEF and HFmrEF who received the highest doses of beta-blockers or renin-angiotensin inhibitors. These associations were not evident in HFpEF. Once adjusted for relevant confounders, each mg equivalent of bisoprolol (HR 0.95 [95% CI 0.91-1.00]; p = 0.047) and ramipril (HR 0.95 [95%CI 0.90-1.00]; p = 0.044) was associated with incremental reductions in mortality risk in patients with HFmrEF.

CONCLUSIONS

Pharmacological therapies were associated with lower mortality risk in HFmrEF, supporting guideline recommendations which extend the indications of these agents to all patients with LVEF < 50%. HFmrEF more closely resembles HFrEF in terms of clinical characteristics and outcomes. Pharmacological therapies are associated with lower mortality risk in HFmrEF and HFrEF, but not in HFpEF.

Left ventricular dysfunction, heart failure, and mortality risk factors in de novo pacemaker recipients and those requiring pacemaker generator replacement

Background

Pacing the right ventricle (RV) can lead to adverse remodelling of the left ventricle (LV), LV dysfunction, increased risk of heart failure hospitalisation (HFH) and mortality. Despite RV pacing avoidance programming becoming commonplace, pacemaker patients remain at risk of pacing-induced cardiomyopathy. New pacing strategies and cardiac resynchronisation therapy are available therapeutic options, but it is unclear which patients should be targeted, and when.

Purpose

This study examined the effects of RV pacing on LV function, the risk of heart failure requiring hospitalisation and all-cause mortality in patients during the first 12 months of pacemaker therapy, compared to those at pacemaker generator replacement (PGR).

Methods

Data were obtained from a cohort of patients who underwent de novo pacemaker implantation between 2014 and 2017, and patients requiring PGR between 2008 and 2011 at a single tertiary UK hospital, with follow-up from 12 months. Clinical, echocardiographic, and pacemaker variables, medication, and past medical history data were collected. Predictors of a combined endpoint of all-cause mortality or HFH were assessed using cox-regression analysis, with predictors of impaired LV function analysed using multivariable regression analysis.

Results

514 newly implanted (NI) patients (mean age, 75 years; 66% male) were recruited, and 491 patients (mean age, 76 years; 56% male) requiring PGR. After a mean follow up of 887 days, 79 NI patients (16%) were deceased (n=27) or had been hospitalised for HF (n=52), whereas after a mean follow up of 668 days, 56 patients after PGR (12%) were deceased (n=34) or had been hospitalised (n=22) for HF. After 12 months of pacemaker therapy, 182 (35%) NI patients had a LV ejection fraction (LVEF) &lt;50%, which had a higher incidence at PGR of 197 (40%). Age was the only significant predictor of mortality or HFH for both NI and PGR (hazard ratio (HR), 1.068; 95% confidence interval (CI), 1.039 to 1.098; p&lt;0.001 vs 1.035; 95% CI, 1.007 to 1.064; p=0.014), respectively). Univariate analysis revealed baseline LVEF (2.439; 95 percent CI, 1.279 to 4.659; p=0.007), RV pacing burden, medication and blood chemistry were significant predictors of the combined outcome at PGR but not at NI (Table 2). Multivariable analysis of predictors of LV impairment (&lt;50% LVEF) showed history of MI (odds ratio (OR), 0.47; 95% CI, 0.29 to 0.78; p=0.003), RV pacing burden (1.01; 95% CI, 1.01 to 1.02; p&lt;0.001) and creatinine (1.06; 95% CI, 1.02 to 1.10; p=0.004) were independently associated in both cohorts.

Conclusions

Our data suggest that there remains a similar subgroup of people from initial implantation to PGR at risk of LV impairment that might benefit from medication optimisation or novel pacing strategies. Further research is required to better identifying these people to direct more complex therapies to those with the most to gain.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The research is supported by a National Institute for Health Research (NIHR) clinician scientist fellowship (NIHRCS-2012-032). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. This research was supported by the NIHR Leeds Clinical Research Facility.

Atrial fibrillation and risk of progressive heart failure in patients with preserved ejection fraction heart failure

AIMS

Understanding of the pathophysiology of progressive heart failure (HF) in patients with heart failure with preserved ejection fraction (HFpEF) is incomplete. We sought to identify factors differentially associated with risk of progressive HF death and hospitalization in patients with HFpEF compared with patients with HF and reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Prospective cohort study of patients newly referred to secondary care with suspicion of HF, based on symptoms and signs of HF and elevated natriuretic peptides (NP), followed up for a minimum of 6 years. HFpEF and HFrEF were diagnosed according to the 2016 European Society of Cardiology guidelines. Of 960 patients referred, 467 had HFpEF (49%), 311 had HFrEF (32%), and 182 (19%) had neither. Atrial fibrillation (AF) was found in 37% of patients with HFpEF and 34% with HFrEF. During 6 years follow-up, 19% of HFrEF and 14% of HFpEF patients were hospitalized or died due to progressive HF, hazard ratio (HR) 0.67 (95% CI: 0.47-0.96; P = 0.028). AF was the only marker that was differentially associated with progressive HF death or hospitalization in patients with HFpEF HR 2.58 (95% CI: 1.59-4.21; P < 0.001) versus HFrEF HR 1.11 (95% CI: 0.65-1.89; P = 0.7).

CONCLUSIONS

De novo patients diagnosed with HFrEF have greater risk of death or hospitalization due to progressive HF than patients with HFpEF. AF is associated with increased risk of progressive HF death or hospitalization in HFpEF but not HFrEF, raising the intriguing possibility that this may be a novel therapeutic target in this growing population.

Personalised reprogramming to prevent progressive pacemaker-related left ventricular dysfunction: A phase II randomised, controlled clinical trial

BACKGROUND

Pacemakers are widely utilised to treat bradycardia, but right ventricular (RV) pacing is associated with heightened risk of left ventricular (LV) systolic dysfunction and heart failure. We aimed to compare personalised pacemaker reprogramming to avoid RV pacing with usual care on echocardiographic and patient-orientated outcomes.

METHODS

A prospective phase II randomised, double-blind, parallel-group trial in 100 patients with a pacemaker implanted for indications other than third degree heart block for ≥2 years. Personalised pacemaker reprogramming was guided by a published protocol. Primary outcome was change in LV ejection fraction on echocardiography after 6 months. Secondary outcomes included LV remodeling, quality of life, and battery longevity.

RESULTS

Clinical and pacemaker variables were similar between groups. The mean age (SD) of participants was 76 (+/-9) years and 71% were male. Nine patients withdrew due to concurrent illness, leaving 91 patients in the intention-to-treat analysis. At 6 months, personalised programming compared to usual care, reduced RV pacing (-6.5±1.8% versus -0.21±1.7%; p<0.01), improved LV function (LV ejection fraction +3.09% [95% confidence interval (CI) 0.48 to 5.70%; p = 0.02]) and LV dimensions (LV end systolic volume indexed to body surface area -2.99mL/m2 [95% CI -5.69 to -0.29; p = 0.03]). Intervention also preserved battery longevity by approximately 5 months (+0.38 years [95% CI 0.14 to 0.62; p<0.01)) with no evidence of an effect on quality of life (+0.19, [95% CI -0.25 to 0.62; p = 0.402]).

CONCLUSIONS

Personalised programming in patients with pacemakers for bradycardia can improve LV function and size, extend battery longevity, and is safe and acceptable to patients.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03627585.

Impact of QRS duration on left ventricular remodelling and survival in patients with heart failure

AIMS

In patients with chronic heart failure, QRS duration is a consistent predictor of poor outcomes. It has been suggested that for indicated patients, cardiac resynchronization therapy (CRT) could come sooner in the treatment algorithm, perhaps in parallel with the attainment of optimal guideline-directed medical therapy (GDMT). We aimed to investigate differences in left ventricular (LV) remodelling in those with narrow QRS (NQRS) compared with wide QRS (WQRS) in the absence of CRT, whether an early CRT strategy resulted in unnecessary implants and the effect of early CRT on outcomes.

METHODS

Our cohort consisted of 214 consecutive patients with LV ejection fraction (LVEF) of 35% or less who underwent repeat echocardiography 1 year after enrolment. Of these, 116 patients had NQRS, and 98 had WQRS of whom 40 received CRT within 1 year and 58 did not.

RESULTS

In the absence of CRT, patients with WQRS had less LV reverse remodelling compared with those with NQRS, with differences in ΔLVEF (+2 vs. +9%, P < 0.001) ΔLV end-diastolic diameter (-1 vs. -2 mm, P = 0.095), ΔLV end-systolic diameter (-2 vs. -4.5 mm, P = 0.038), LV end-systolic volume (-12.6 vs. -25.0 ml, P = 0.054) and LV end-diastolic volume (-7.3 vs. -12.2 ml, P = 0.071). LVEF was more likely to improve by at least 10% if patients had NQRS or received CRT (P = 0.08). Thirteen (24%) patients with WQRS achieved an LVEF greater than 35% in the absence of CRT; however, none achieved greater than 50%.

CONCLUSION

A strictly linear approach to heart failure therapy might lead to delays to optimal treatment in those patients with the most to gain from CRT and the least to gain from GDMT.

Effect of disease-modifying agents and their association with mortality in multi-morbid patients with heart failure with reduced ejection fraction

Aims

An increasing proportion of patients with heart failure with reduced ejection fraction (HFrEF) have co‐morbidities. The effect of these co‐morbidities on modes of death and the effect of disease‐modifying agents in multi‐morbid patients is unknown.

Methods and results

We performed a prospective cohort study of ambulatory patients with HFrEF to assess predictors of outcomes. We identified four key co‐morbidities—ischaemic aetiology of heart failure, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and chronic kidney disease (CKD)—that were highly prevalent and associated with an increased risk of all‐cause mortality. We used these data to explore modes of death and the utilization of disease‐modifying agents in patients with and without these co‐morbidities. The cohort included 1789 consecutively recruited patients who had an average age of 69.6 ± 12.5 years, and 1307 (73%) were male. Ischaemic aetiology of heart failure was the most common co‐morbidity, occurring in 1061 (59%) patients; 503 (28%) patients had diabetes mellitus, 283 (16%) had COPD, and 140 (8%) had CKD stage IV/V. During mean follow‐up of 3.8 ± 1.6 years, 737 (41.5%) patients died, classified as progressive heart failure (n = 227, 32%), sudden (n = 112, 16%), and non‐cardiovascular deaths (n = 314, 44%). Multi‐morbid patients were older (P < 0.001), more likely to be male (P < 0.001), and had higher New York Heart Association class (P < 0.001), despite having higher left ventricular (LV) ejection fraction (P = 0.001) and lower LV end‐diastolic diameter (P = 0.001). Multi‐morbid patients were prescribed lower doses of disease‐modifying agents, especially patients with COPD who received lower doses of beta‐adrenoceptor antagonists (2.7 ± 3.0 vs. 4.1 ± 3.4 mg, P < 0.001) and were less likely to be implanted with internal cardioverter defibrillators (7% vs. 13%, P < 0.001). In multivariate analysis, COPD and diabetes mellitus conferred a >2.5‐fold and 1.5‐fold increased risk of sudden death, whilst higher doses of beta‐adrenoceptor antagonists were protective (hazard ratio per milligram 0.92, 95% confidence interval 0.86–0.98, P = 0.009). Each milligram of bisoprolol‐equivalent beta‐adrenoceptor antagonist was associated with 9% (P = 0.001) and 11% (P = 0.023) reduction of sudden deaths in patients with <2 and ≥2 co‐morbidities, respectively.

Conclusions

Higher doses of beta‐adrenoceptor antagonist are associated with greater protection from sudden death, most evident in multi‐morbid patients. Patients with COPD who appear to be at the highest risk of sudden death are prescribed the lowest doses and less likely to be implanted with implantable cardioverter defibrillators, which might represent a missed opportunity to optimize safe and proven therapies for these patients.

Personalized Rate-Response Programming Improves Exercise Tolerance After 6 Months in People With Cardiac Implantable Electronic Devices and Heart Failure

Background:

Heart failure with reduced ejection fraction (HFrEF) is characterized by blunting of the positive relationship between heart rate and left ventricular (LV) contractility known as the force-frequency relationship (FFR). We have previously described that tailoring the rate-response programming of cardiac implantable electronic devices in patients with HFrEF on the basis of individual noninvasive FFR data acutely improves exercise capacity. We aimed to examine whether using FFR data to tailor heart rate response in patients with HFrEF with cardiac implantable electronic devices favorably influences exercise capacity and LV function 6 months later.

Methods:

We conducted a single-center, double-blind, randomized, parallel-group trial in patients with stable symptomatic HFrEF taking optimal guideline-directed medical therapy and with a cardiac implantable electronic device (cardiac resynchronization therapy or implantable cardioverter-defibrillator). Participants were randomized on a 1:1 basis between tailored rate-response programming on the basis of individual FFR data and conventional age-guided rate-response programming. The primary outcome measure was change in walk time on a treadmill walk test. Secondary outcomes included changes in LV systolic function, peak oxygen consumption, and quality of life.

Results:

We randomized 83 patients with a mean±SD age 74.6±8.7 years and LV ejection fraction 35.2±10.5. Mean change in exercise time at 6 months was 75.4 (95% CI, 23.4 to 127.5) seconds for FFR-guided rate-adaptive pacing and 3.1 (95% CI, −44.1 to 50.3) seconds for conventional settings (analysis of covariance; P =0.044 between groups) despite lower peak mean±SD heart rates (98.6±19.4 versus 112.0±20.3 beats per minute). FFR-guided heart rate settings had no adverse effect on LV structure or function, whereas conventional settings were associated with a reduction in LV ejection fraction.

Conclusions:

In this phase II study, FFR-guided rate-response programming determined using a reproducible, noninvasive method appears to improve exercise time and limit changes to LV function in people with HFrEF and cardiac implantable electronic devices. Work is ongoing to confirm our findings in a multicenter setting and on longer-term clinical outcomes.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02964650.

Ischemic Heart Disease Modifies the Association of Atrial Fibrillation With Mortality in Heart Failure With Reduced Ejection Fraction

Background

The CASTLE‐AF (Catheter Ablation versus Standard Conventional Therapy in Patients With Left Ventricular Dysfunction and Atrial Fibrillation) trial recently reported that catheter ablation of atrial fibrillation (AF) improves survival in heart failure (HF) with reduced ejection fraction (HFrEF). However, established AF was not associated with mortality in trials of contemporary HFrEF pharmacotherapies. We investigated whether HFrEF pathogenesis may influence the conclusions of studies evaluating the prognostic impact of AF.

Methods and Results

Using a prospective cohort study of 791 patients with HFrEF, with AF determined using 24‐hour ambulatory ECG monitoring, univariable and multivariable Cox regression analyses were used to define the association between AF and mode‐specific mortality (mean follow‐up of 5.4 years). One‐year HF‐related hospitalization was assessed with binary logistic regression analysis. One‐year cardiac remodeling was assessed in a subgroup (n=378) using echocardiography. AF was present in 28.2% of patients, with 9.4% of these being paroxysmal. While AF was associated with increased risk of all‐cause mortality (hazard ratio, 1.27; 95% confidence interval 1.03–1.57), with diverging survival curves after 1 year of follow‐up, this association was lost in age‐sex–adjusted analyses. However, AF was associated with increased risk of age‐sex–adjusted all‐cause mortality in people with ischemic pathogenesis, with a statistically significant interaction between pathogenesis and AF. This was predominantly attributed to progressive HF deaths. After 1 year, HF hospitalization and cardiac remodeling were not associated with AF, even in people with ischemic pathogenesis.

Conclusions

AF is associated with increased risk of death in HFrEF of ischemic pathogenesis, predominantly due to progressive HF deaths during long‐term follow‐up. HFrEF pathogenesis should be considered in trial design and interpretation.

Optimising pacemaker therapy and medical therapy in pacemaker patients for heart failure: protocol for the OPT-PACE randomised controlled trial

INTRODUCTION

Permanent artificial pacemaker implantation is a safe and effective treatment for bradycardia and is associated with extended longevity and improved quality of life. However, the most common long-term complication of standard pacemaker therapy is pacemaker-associated heart failure. Pacemaker follow-up is potentially an opportunity to screen for heart failure to assess and optimise patient devices and medical therapy.

METHODS AND ANALYSIS

The study is a multicentre, phase-3 randomised trial. The 1200 participants will be people who have a permanent pacemaker for bradycardia for at least 12 months, randomly assigned to undergo a transthoracic echocardiogram with their pacemaker check, thereby tailoring their management directed by left ventricular function or the pacemaker check alone, continuing with routine follow-up. The primary outcome measure is time to all-cause mortality or heart failure hospitalisation. Secondary outcomes include external validation of our risk stratification model to predict onset of heart failure and quality of life assessment.

ETHICS AND DISSEMINATION

The trial design and protocol have received national ethical approval (12/YH/0487). The results of this randomised trial will be published in international peer-reviewed journals, communicated to healthcare professionals and patient involvement groups and highlighted using social media campaigns.

TRIAL REGISTRATION NUMBER

NCT01819662.

Prospective evaluation and long-term follow-up of patients referred to secondary care based upon natriuretic peptide levels in primary care

AIMS

The UK National Institute for Health and Care Excellence (UK-NICE) and European Society of Cardiology (ESC) guidelines advise natriuretic peptide (NP) assessment in patients presenting to primary care with symptoms possibly due to chronic heart failure (HF), to determine need for specialist involvement. This prospective service evaluation aimed to describe the diagnostic and prognostic utility of these guidelines.

METHODS AND RESULTS

We prospectively collected clinical, echocardiography and outcomes data (minimum 5 years) from all patients referred to the Leeds HF Service for 12 months of following the initiation of the NP-guideline-directed pathway. Between 1 May 2012 and 1 August 2013, 1020 people with symptoms possibly due to HF attended either with a raised NT-pro-BNP or a previous myocardial infarction (MI) with an overall rate of left ventricular systolic dysfunction (LVSD) of 33%. Of these, 991 satisfied the ESC criteria (NT-pro-BNP ≥125 pg/mL) in whom the rate of LVSD was 32%, and 821 the UK-NICE criteria in whom the rate of LVSD was 49% in those with a previous MI, 25% in those with NT-pro-BNP concentration 400-2000 pg/mL, and 54% in those with NT-pro-BNP concentration of >2000 pg/mL. An NT-pro-BNP concentration 125-400 pg/mL had a 12% risk of LVSD. Specificity was poor in women >70 years, who made up the largest proportion of attendees. Elevated NT-pro-BNP levels were associated with lower survival even in the absence of LVSD.

CONCLUSION

In people referred through the ESC and UK-NICE guidelines, elevated NT-pro-BNP is a marker of increased mortality risk, but there is wide variation in specificity for LVSD. Age- and sex-adjusted criteria might improve performance.

Prognostic Significance of Incidental Nonsustained Ventricular Tachycardia Detected on Pacemaker Interrogation

Symptomatic sustained ventricular tachycardia is a life threatening arrhythmia requiring prompt treatment. However, the risk associated with asymptomatic nonsustained ventricular tachycardia (NSVT) detected on routine permanent pacemaker (PPM) interrogation in patients with known cardiac conduction disease is unknown. Our aim is to determine if asymptomatic NSVT detected on PPM interrogation is associated with increased mortality. As part of a prospective observational cohort study, 582 patients with long-term pacemakers were recruited at a tertiary cardiac centre, and followed for 4 ± 1.96 years (mean ± standard deviation). At each subsequent pacemaker check, any symptoms and ventricular high-rate episodes were recorded. We excluded 17 patients due to incomplete data. In the remaining 565 patients (57% male, age 74.5 ± 19.2 years, left ventricular ejection fraction 50.0 ± 11.3%), NSVT was found in 125 (22.1%) patients with a higher prevalence in males (65% vs 54%; p = 0.033). Those with NSVT were more likely to have had coronary artery disease (p = 0) or previous myocardial infarction (p = 0.015). After correction for baseline variables, NSVT had no impact on survival (n = 52 [42%] vs n = 162 [37%]; log-rank p = 0.331, hazard ratio: 0.927, 95% confidence interval: 0.678 to 1.268, p = 0.697). In conclusion, asymptomatic NSVT identified on PPM interrogation does not appear to be associated with increased mortality, thus whether treatment to suppress this arrhythmia is of benefit remains unproven.

Therapeutic options for functional mitral regurgitation in chronic heart failure

INTRODUCTION

Mitral regurgitation is a common finding in patients with chronic heart failure and is associated with a progressive worsening of symptoms, reduced survival and increased cost of care. However, the use of mitral valve surgery for these patients remains controversial and has not been shown to improve survival. Consequently, research has been increasingly directed towards the nonsurgical management of this important co-morbidity of heart failure.

AREAS COVERED

The present review will describe the relevance of mitral regurgitation in people with chronic heart failure, the current options for percutaneous treatment and the evidence base for each of these.

EXPERT COMMENTARY

Although at present there are few solid data to guide heart teams in deciding what degree of mitral regurgitation to treat, in which patients, and with what, this situation is likely to change over the next two years with the release of the first large randomised trials of percutaneous interventions.

Effects of Vitamin D on Cardiac Function in Patients With Chronic HF: The VINDICATE Study

Background

Patients with chronic heart failure (HF) secondary to left ventricular systolic dysfunction (LVSD) are frequently deficient in vitamin D. Low vitamin D levels are associated with a worse prognosis.

Objectives

The VINDICATE (VitamIN D treatIng patients with Chronic heArT failurE) study was undertaken to establish safety and efficacy of high-dose 25 (OH) vitamin D₃ (cholecalciferol) supplementation in patients with chronic HF due to LVSD.

Methods

We enrolled 229 patients (179 men) with chronic HF due to LVSD and vitamin D deficiency (cholecalciferol <50 nmol/l [<20 ng/ml]). Participants were allocated to 1 year of vitamin D₃ supplementation (4,000 IU [100 μg] daily) or matching non−calcium-based placebo. The primary endpoint was change in 6-minute walk distance between baseline and 12 months. Secondary endpoints included change in LV ejection fraction at 1 year, and safety measures of renal function and serum calcium concentration assessed every 3 months.

Results

One year of high-dose vitamin D₃ supplementation did not improve 6-min walk distance at 1 year, but was associated with a significant improvement in cardiac function (LV ejection fraction +6.07% [95% confidence interval (CI): 3.20 to 8.95; p < 0.0001]); and a reversal of LV remodeling (LV end diastolic diameter -2.49 mm [95% CI: -4.09 to -0.90; p = 0.002] and LV end systolic diameter -2.09 mm [95% CI: -4.11 to -0.06 p = 0.043]).

Conclusions

One year of 100 μg daily vitamin D₃ supplementation does not improve 6-min walk distance but has beneficial effects on LV structure and function in patients on contemporary optimal medical therapy. Further studies are necessary to determine whether these translate to improvements in outcomes. (VitamIN D Treating patIents With Chronic heArT failurE [VINDICATE]; NCT01619891)

Sonographic evaluation of urinary bladder wall thickness in normal dogs

Urinary bladder wall thickness was evaluated by ultrasonography in 16 normal dogs. Sterile saline solution was administered via urinary catheters to control the degree of bladder distention. Bladder wall thickness was measured on static ultrasound images in 4 locations and at 3 degrees of bladder distention (minimal, mild, and moderate). Four randomized distention sequences with 3 distentions per sequence were performed on each dog and the data were analyzed using Williams' balanced Latin square. Mean bladder wall thickness was 2.3 mm in minimally distended bladders (0.5 ml/kg saline), 1.6 mm in mildly distended bladders (2 ml/kg saline) and 1.4 mm in moderately distended bladders (4 ml/kg saline). Mean bladder wall thickness increased significantly with increasing body weight and with decreasing bladder distention. The caudoventral measurement location produced a statistically significant smaller measurement, with a difference of 0.3 mm. Sex did not affect bladder wall thickness. Distention sequence and repetition of distentions did not affect bladder wall thickness.

Clinical and immunohistochemical characterization of thymic lymphosarcoma in a heifer

A 2-year-old Holstein heifer with a swollen brisket, jugular vein distention, muffled heart sounds, tachycardia, and free gas bloat was examined. Thymic lymphosarcoma was suspected based on a negative agar gel immunodiffusion test for bovine leukemia virus, presence of atypical lymphocytes in pleural fluid, and detection of a mass in the thoracic inlet. Right-sided cardiac catheterization was performed, and markedly increased jugular venous pressures (41 mm Hg) with a pressure gradient of 29 mm Hg immediately cranial to the heart indicated constriction of the cranial vena cava. Immunohistochemical staining of formalin fixed, paraffin-embedded tissue sections of the tumor using a rabbit antihuman T cell, CD3 polyclonal antibody confirmed that the neoplastic lymphocytes were of thymic origin.

Comparison of radiologic imaging techniques for diagnosis of fragmented medial coronoid process of the cubital joint in dogs

Thirty cubital joints from 16 dogs suspected of having a fragmented medial coronoid process were examined. Four breeds accounted for 87.5% of the cases: German Shepherd Dog (25%), Labrador Retriever (25%), Rottweiler (18.75%), and Golden Retriever (18.75%). Seventy-five percent of the dogs were male. Mean age of affected dogs was 13.6 months. Plain-film radiography, xeroradiography, linear tomography, arthrography, and computed tomography were performed on each cubital joint prior to surgical exploration of the joint. Three reviewers evaluated each diagnostic study and independently determined whether a fragment from the medial coronoid process could be seen. The consensus opinion was compared with the finding at surgery. Abnormalities of the medial coronoid process were detected in 25 of 30 joints at surgery. Fragmented coronoid process was found in 17 of 30 joints, and wear lesions were observed in 8 of 30 joints. Computed tomography had the highest accuracy (86.7%), sensitivity (88.2%), and negative-predictive value (84.6%) of the 5 imaging modalities evaluated (P < 0.05). Specificity and positive-predictive value of all imaging techniques were high. There was no significant difference between the diagnostic ability of plain-film radiography, xeroradiography, or linear tomography of the cubital joint. The combination of plain-film radiography and linear tomography provided an improvement in accuracy, approaching that of computed tomography.

Radiographic anatomy and technique for arthrography of the cubital joint in clinically normal dogs

A technique for arthrography of the cubital joint in clinically normal large-breed dogs was developed with the objective of improving visualization of the articular margin of the medial coronoid process. A lateral approach to the cubital joint for injection of contrast medium was selected. Arthrography of 24 cubital joints was performed by using 14 dogs. Twelve combinations of iodinated contrast medium, consisting of various concentrations (3) and volumes (4), were used. Two sets of arthrograms for each of the 12 combinations of contrast medium were obtained. Five radiographic views were used for each set. All arthrograms were examined by 3 evaluators, and each articular surface received a numerical rating for how well it could be seen in each view. Results of the evaluation indicated that low volumes of contrast medium were preferable to high volumes, with 2 ml providing the best visualization. Concentration of iodine seemed less important than did volume. The numerical ratings also indicated that the articular margin of the coronoid process was clearly observed a maximum of only 24% of the time on a slightly supinated mediolateral projection. The articular margins of the head of the radius, trochlea humeri, and trochlear notch were well visualized > 90% of the time. Arthrography of the cubital joint was technically easy to perform, and complications were not encountered, but arthrographic anatomy of the cubital joint is complex. Potential uses for arthrography of the cubital joint include diagnosis of osteochondrosis, intraarticular fragments, and joint capsule ruptures.

Quantity, analysis, and lethality of European and Africanized honey bee venoms

Venom from Africanized honey bees (derived mainly from Apis mellifera scutellata) was compared with venom from domestic, European bees by study of lethality, immunological cross-reactivity, venom yield, isoelectric focusing (IEF) patterns, and melittin titers. The LD50s of European and Africanized bee venom by iv injection in mice were similar. In venom neutralization experiments, Africanized bee venom was mixed with antibodies from a beekeeper exposed only to European bees and used to challenge mice. Survival times of mice given these mixtures were significantly prolonged, indicating that human serum antibodies to European bee venom neutralized the lethal effects of Africanized bee venom. Reservoirs from Africanized bees contained less venom than European bees (94 and 147 micrograms venom/bee, respectively) and Africanized bee venom had a lower melittin content. The IEF patterns of venom from individual European bees varied considerably, as did IEF patterns of individual Africanized bees. Pools of venom from 1,000 bees of each population of A. mellifera showed noticeable but less obvious electrophoretic differences. The findings suggest that multiple stinging, and not increased venom potency or delivery, is the cause of serious reactions from Africanized bee attacks.

New spiroplasmas from insects and flowers: isolation, ecology, and host association

Eight spiroplasma strains from insects and one from spring flowers failed to react with antisera specific for any of the 11 described spiroplasma groups, with sera directed against spiroplasma Group I subgroups, or with sera directed against two unnumbered groups previously reported to occur in tabanid flies. Strains, all from Maryland, were isolated from the hemolymph of the spotted cucumber beetle Diabrotica undecimpunctata and the lampyrid beetle Ellychnia corrusca, and the guts of the cantharid beetles Cantharis bilineatus and C. carolinus. Other strains were obtained from a tabanid fly, Tabanus gladiator and from the firefly Photuris pennsylvanica in Maryland and from the mosquito Culex tritaeniorhynchus in Taiwan. An isolate from pooled Cicadulina bipunctella leafhoppers in Syria apparently represented a unique group. A single isolate from spring flowers in Oklahoma also appeared to be unrelated to existing groups or subgroups. One-way deformation tests using sera prepared against known beetle and tabanid spiroplasmas showed each of the above strains to be unique. Although these results strongly indicate that the nine strains studied are representatives of unique new spiroplasma groups, the formal designation of new groups awaits fulfillment of recently proposed criteria.