Abnormalities of the ventilatory equivalent for carbon dioxide in patients with chronic heart failure

Introduction. The relation between minute ventilation (VE) and carbon dioxide production (VCO2) can be characterised by the instantaneous ratio of ventilation to carbon dioxide production, the ventilatory equivalent for CO2 (VEqCO2). We hypothesised that the time taken to achieve the lowest VEqCO2 (time to VEqCO2 nadir) may be a prognostic marker in patients with chronic heart failure (CHF). Methods. Patients and healthy controls underwent a symptom-limited, cardiopulmonary exercise test (CPET) on a treadmill to volitional exhaustion. Results. 423 patients with CHF (mean age 63±12 years; 80% males) and 78 healthy controls (62% males; age 61±11 years) were recruited. Time to VEqCO2 nadir was shorter in patients than controls (327±204 s versus 514±187 s; P=0.0001). Univariable predictors of all-cause mortality included peak oxygen uptake (X 2 =53.0), VEqCO2 nadir (X 2 =47.9), and time to VEqCO2 nadir (X 2 =24.0). In an adjusted Cox multivariable proportional hazards model, peak oxygen uptake (X 2 =16.7) and VEqCO2 nadir (X 2 =17.9) were the most significant independent predictors of all-cause mortality. Conclusion. The time to VEqCO2 nadir was shorter in patients with CHF than in normal subjects and was a predictor of subsequent mortality. © 2012 Lee Ingle et al

Taxonomy of segmental myocardial systolic dysfunction.

The terms used to describe different states of myocardial health and disease are poorly defined. Imprecision and inconsistency in nomenclature can lead to difficulty in interpreting and applying trial outcomes to clinical practice. In particular, the terms 'viable' and 'hibernating' are commonly applied interchangeably and incorrectly to myocardium that exhibits chronic contractile dysfunction in patients with ischaemic heart disease. The range of inherent differences amongst imaging modalities used to define myocardial health and disease add further challenges to consistent definitions. The results of several large trials have led to renewed discussion about the classification of dysfunctional myocardial segments. This article aims to describe the diverse myocardial pathologies that may affect the myocardium in ischaemic heart disease and cardiomyopathy, and how they may be assessed with non-invasive imaging techniques in order to provide a taxonomy of myocardial dysfunction

Regional circulatory distribution of novel cardiac bio-markers and their relationships with haemodynamic measurements.

© 2016 Elsevier Ireland Ltd. All rights reserved.Background Regional sampling may identify sites of production or removal of novel biomarkers in the circulation; their relationship to haemodynamic measurements may clarify their association with the pathophysiology of heart failure. Methods Samples were obtained from up to eight circulatory sites from 22 patients with left ventricular dysfunction undergoing elective cardiac catheterisation. The plasma concentrations (PC) of six biomarkers [mid-regional pro-atrial natriuretic peptide (MR-proANP), C-terminal pro-endothelin-1 (CT-proET-1), mid-regional pro-adreno-medullin (MR-proADM), high sensitivity pro-calcitonin (hsPCT), copeptin and galectin-3 (Gal-3)] were measured. Results Plasma concentrations of MR-proANP were highest in the pulmonary artery (PA) and left ventricle, suggesting myocardial production. Lower concentrations of copeptin, CT-proET-1, MR-proADM and hsPCT were found in the supra-renal inferior vena cava (SRIVC) sample suggesting renal extraction. Plasma concentrations of Galectin-3 varied little by sampling site. Plasma concentrations of MR-proANP (R = 0.69, P = 0.002), MR-proADM (R = 0.51, P = 0.03), CT-proET-1 (R = 0.60, P = 0.009) and Copeptin (R = 0.47, P < 0.05) measured from PA samples correlated with PA systolic pressure. There was no relation between any measured marker and cardiac index. Conclusions Regional sampling shows variation in the plasma concentration of various novel peptides that provides clues to sites of net production and removal. Plasma concentrations of several biomarkers were positively correlated with pulmonary artery pressure

Cardiac Dysfunction, Congestion and Loop Diuretics: their Relationship to Prognosis in Heart Failure

Background: Diuretics are the mainstay of treatment for congestion but concerns exist that they adversely affect prognosis. We explored whether the relationship between loop diuretic use and outcome is explained by the underlying severity of congestion amongst patients referred with suspected heart failure. Method and Results: Of 1190 patients, 712 had a left ventricular ejection fraction (LVEF) ≤50 %, 267 had LVEF >50 % with raised plasma NTproBNP (>400 ng/L) and 211 had LVEF >50 % with NTproBNP ≤400 ng/L; respectively, 72 %, 68 % and 37 % of these groups were treated with loop diuretics including 28 %, 29 % and 10 % in doses ≥80 mg furosemide equivalent/day. Compared to patients with cardiac dysfunction (either LVEF ≤50 % or NT-proBNP >400 ng/L) but not taking a loop diuretic, those taking a loop diuretic were older and had more clinical evidence of congestion, renal dysfunction, anaemia and hyponatraemia. During a median follow-up of 934 (IQR: 513–1425) days, 450 patients were hospitalized for HF or died. Patients prescribed loop diuretics had a worse outcome. However, in multi-variable models, clinical, echocardiographic (inferior vena cava diameter), and biochemical (NTproBNP) measures of congestion were strongly associated with an adverse outcome but not the use, or dose, of loop diuretics. Conclusions: Prescription of loop diuretics identifies patients with more advanced features of heart failure and congestion, which may account for their worse prognosis. Further research is needed to clarify the relationship between loop diuretic agents and outcome; imaging and biochemical measures of congestion might be better guides to diuretic dose than symptoms or clinical signs

Early indication of decompensated heart failure in patients on home-telemonitoring: a comparison of prediction algorithms based on daily weight and noninvasive transthoracic bio-impedance.

Heart Failure (HF) is a common reason for hospitalization. Admissions might be prevented by early detection of and intervention for decompensation. Conventionally, changes in weight, a possible measure of fluid accumulation, have been used to detect deterioration. Transthoracic impedance may be a more sensitive and accurate measure of fluid accumulation.In this study, we review previously proposed predictive algorithms using body weight and noninvasive transthoracic bio-impedance (NITTI) to predict HF decompensations.We monitored 91 patients with chronic HF for an average of 10 months using a weight scale and a wearable bio-impedance vest. Three algorithms were tested using either simple rule-of-thumb differences (RoT), moving averages (MACD), or cumulative sums (CUSUM).Algorithms using NITTI in the 2 weeks preceding decompensation predicted events (P<.001); however, using weight alone did not. Cross-validation showed that NITTI improved sensitivity of all algorithms tested and that trend algorithms provided the best performance for either measurement (Weight-MACD: 33%, NITTI-CUSUM: 60%) in contrast to the simpler rules-of-thumb (Weight-RoT: 20%, NITTI-RoT: 33%) as proposed in HF guidelines.NITTI measurements decrease before decompensations, and combined with trend algorithms, improve the detection of HF decompensation over current guideline rules; however, many alerts are not associated with clinically overt decompensation

Outbreak of tropical rat mite (Ornithonyssus bacoti) dermatitis in a home for disabled persons

Five mentally handicapped individuals living in a home for disabled persons in Southern Germany were seen in our outpatient department with pruritic, red papules predominantly located in groups on the upper extremities, neck, upper trunk and face. Over several weeks 40 inhabitants and 5 caretakers were affected by the same rash. Inspection of their home and the sheds nearby disclosed infestation with rat populations and mites. Finally the diagnosis of tropical rat mite dermatitis was made by the identification of the arthropod Ornithonyssus bacoti or so-called tropical rat mite. The patients were treated with topical corticosteroids and antihistamines. After elimination of the rats and disinfection of the rooms by a professional exterminator no new cases of rat mite dermatitis occurred. The tropical rat mite is an external parasite occurring on rats, mice, gerbils, hamsters and various other small mammals. When the principal animal host is not available, human beings can become the victim of mite infestation. Copyright (c) 2007 S. Karger AG, Base

Should beta-blocker therapy be reduced or withdrawn after an episode of decompensated heart failure? Results from COMET.

BACKGROUND: It is unclear whether beta-blocker therapy should be reduced or withdrawn in patients who develop acute decompensated heart failure (HF). We studied the relationship between changes in beta-blocker dose and outcome in patients surviving a HF hospitalisation in COMET. METHODS: Patients hospitalised for HF were subdivided on the basis of the beta-blocker dose administered at the visit following hospitalisation, compared to that administered before. RESULTS: In COMET, 752/3029 patients (25%, 361 carvedilol and 391 metoprolol) had a non-fatal HF hospitalisation while on study treatment. Of these, 61 patients (8%) had beta-blocker treatment withdrawn, 162 (22%) had a dose reduction and 529 (70%) were maintained on the same dose. One-and two-year cumulative mortality rates were 28.7% and 44.6% for patients withdrawn from study medication, 37.4% and 51.4% for those with a reduced dosage (n.s.) and 19.1% and 32.5% for those maintained on the same dose (HR,1.59; 95%CI, 1.28-1.98; p<0.001, compared to the others). The result remained significant in a multivariable model: (HR, 1.30; 95%CI, 1.02-1.66; p=0.0318). No interaction with the beneficial effects of carvedilol, compared to metoprolol, on outcome was observed (p=0.8436). CONCLUSIONS: HF hospitalisations are associated with a high subsequent mortality. The risk of death is higher in patients who discontinue beta-blocker therapy or have their dose reduced. The increase in mortality is only partially explained by the worse prognostic profile of these patients