Midregional proatrial naturetic peptide (MRproANP) and copeptin (COPAVP) as predictors of all-cause mortality in recently diagnosed mild to moderate COPD-results from COSYCONET.

BACKGROUND: MRproANP and COPAVP are prognostic markers for mortality in chronic obstructive pulmonary disease (COPD). Furthermore, these biomarkers predict mortality due to cardiovascular diseases, which are important prognostically determining comorbidities in patients with COPD. However, less is known about these biomarkers in recently diagnosed mild to moderate COPD. Therefore, we analyzed these biomarkers as potential predictors of mortality in recently diagnosed mild to moderate COPD. METHODS: The blood biomarkers considered were copeptin (COPAVP), midregional adrenomedullin (MRproADM), midregional proatrial naturetic peptide (MRproANP), and fibrinogen. Analyses were performed in patients with stable "recently diagnosed mild to moderate COPD" defined by GOLD grades 0-2 and diagnosis of COPD ≤ 5 years prior to inclusion into the COSYCONET cohort (COPD and Systemic Consequences-Comorbidities Network), using Cox regression analysis with stepwise adjustment for multiple COPD characteristics, comorbidities, troponin and NT-proBNP. RESULTS: 655 patients with recently diagnosed mild to moderate COPD were included. In the initial regression model, 43 of 655 patients died during the 6-year follow-up, in the final model 27 of 487. Regression analyses with adjustment for confounders identified COPAVP and MRproANP as statistically robust biomarkers (p < 0.05 each) of all-cause mortality, while MRproADM and fibrinogen were not. The fourth quartile of MRproANP (97 pmol/L) was associated with a hazard ratio of 4.5 (95%CI: 1.6; 12.8), and the fourth quartile of COPAVP (9.2 pmol/L) with 3.0 (1.1; 8.0). The results for MRproANP were confirmed in the total cohort of grade 0-4 (n = 1470 finally). CONCLUSION: In patients with recently diagnosed mild to moderate COPD, elevated values of COPVP and in particular MRproANP were robust, independent biomarkers for all-cause mortality risk after adjustment for multiple other factors. This suggests that these markers might be considered in the risk assessment of early COPD.

Statins did not reduce the frequency of exacerbations in individuals with COPD and cardiovascular comorbidities in the COSYCONET cohort.

BACKGROUND: The evidence regarding effects of statins on exacerbation risk in COPD remains controversial. Previous studies often excluded patients with cardiovascular comorbidities despite their high prevalence in COPD and role for exacerbations. Based on the cardioprotective properties of statins, we hypothesised that statins may reduce the risk of exacerbations especially in patients with cardiovascular comorbidities. METHODS: One thousand eight hundred eighty seven patients of the German COPD cohort COSYCONET (COPD and Systemic Consequences Comorbidities Network) of GOLD grades 1-4 (37.8% female, mean age 64.78 ± 8.3) were examined at baseline and over a period of 4.5 years for the occurrence of at least one exacerbation or severe exacerbation per year in cross-sectional and longitudinal analyses adjusted for age, gender, BMI, GOLD grade and pack-years. Due to their collinearity, various cardiovascular diseases were tested in separate analyses, whereby the potential effect of statins in the presence of a specific comorbidity was tested as interaction between statins and comorbidity. We also identified patients who never took statins, always took statins, or initiated statin intake during the follow-up. RESULTS: One thousand three hundred six patients never took statins, 31.6% were statin user, and 12.9% initiated statins during the follow-up. Most cardiovascular diseases were significantly (p < 0.05)may associated with an increased risk of COPD exacerbations, but in none of them the intake of statins was a significant attenuating factor, neither overall nor in modulating the increased risk linked to the specific comorbidities. The results of the cross-sectional and longitudinal analyses were consistent with each other, also those regarding at least 1 exacerbation or at least 1 severe exacerbation per year. CONCLUSION: These findings complement the existing literature and may suggest that even in patients with COPD, cardiovascular comorbidities and a statin therapy that targets these comorbidities, the effects of statins on exacerbation risk are either negligible or more subtle than a reduction in exacerbation frequency. TRIAL REGISTRATION: Trial registration ClinicalTrials.gov, Identifier: NCT01245933. Other Study ID (BMBF grant): 01GI0881, registered 18 November 2010, study start 2010-11, primary completion 2013-12, study completion 2023-09. https://clinicaltrials.gov/study/NCT01245933?cond=COPD&term=COSYCONET&rank=3.

The impact of COPD on polyneuropathy: results from the German COPD cohort COSYCONET.

BACKGROUND: Peripheral neuropathy is a common comorbidity in COPD. We aimed to investigate associations between alterations commonly found in COPD and peripheral neuropathy, with particular emphasize on the distinction between direct and indirect effects. METHODS: We used visit 4 data of the COPD cohort COSYCONET, which included indicators of polyneuropathy (repeated tuning fork and monofilament testing), excluding patients with diabetes a/o increased HbA1c. These indicators were analysed for the association with COPD characteristics, including lung function, blood gases, 6-min walk distance (6-MWD), timed-up-and-go-test (TUG), exacerbation risk according to GOLD, C-reactive protein (CRP), and ankle-brachial index (ABI). Based on the results of conventional regression analyses adjusted for age, BMI, packyears and gender, we utilized structural equation modelling (SEM) to quantify the network of direct and indirect relationships between parameters. RESULTS: 606 patients were eligible for analysis. The indices of polyneuropathy were highly correlated with each other and related to base excess (BE), ABI and TUG. ABI was linked to neuropathy and 6-MWD, exacerbations depended on FEV1, 6-MWD and CRP. The associations could be summarized into a SEM comprising polyneuropathy as a latent variable (PNP) with three measured indicator variables. Importantly, PNP was directly dependent on ABI and particularly on BE. When also including patients with diabetes and/or elevated values of HbA1c (n = 742) the SEM remained virtually the same. CONCLUSION: We identified BE and ABI as major determinants of peripheral neuropathy in patients with COPD. All other associations, particularly those with lung function and physical capacity, were indirect. These findings underline the importance of alterations of the micromilieu in COPD, in particular the degree of metabolic compensation and vascular status.

Treatment options in myocarditis and inflammatory cardiomyopathy : Focus on i. v. immunoglobulins.

For myocarditis and inflammatory cardiomyopathy, an etiologically driven treatment is today the best option beyond heart failure therapy. Prerequisites for this are noninvasive and invasive biomarkers including endomyocardial biopsy and polymerase chain reaction on cardiotropic agents. Imaging by Doppler echocardiography and cardiac magnetic resonance imaging as well as cardiac biomarkers such as C­reactive protein, N­terminal pro-B-type natriuretic peptide , and troponins can contribute to the clinical work-up of the syndrome but not toward elucidating the underlying cause or pathogenetic process. This review summarizes the phases and clinical features of myocarditis and gives an up-to-date short overview of the current treatment options starting with heart failure and antiarrhythmic therapy. Although inflammation in myocardial disease can resolve spontaneously, often specific treatment directed against the causative agent is required. For fulminant, acute, and chronic autoreactive myocarditis, immunosuppressive treatment has proven to be beneficial in the TIMIC and ESETCID trials; for viral cardiomyopathy and myocarditis, intravenous immunoglobulin IgG subtype and polyvalent intravenous immunoglobulins IgG, IgA, and IgM can frequently resolve inflammation. However, despite the elimination of inflammation, the eradication of parvovirus B19 and human herpesvirus-6 is still a challenge, for which ivIg treatment can become a future key player.

Characteristics and outcomes of patients hospitalized for infection with influenza, SARS-CoV-2 or respiratory syncytial virus in the season 2022/2023 in a large German primary care centre.

BACKGROUND: In 2022/2023, Influenza A and Respiratory Syncytial Virus (RSV) reappeared in hospitalized patients, which was in parallel to ongoing SARS-CoV-2 infections. The aim of our study was to compare the characteristics and outcomes of these infections during the same time. METHODS: We included patients of all ages with a positive polymerase chain reaction (PCR) test for Influenza A/B, RSV, or SARS-CoV-2 virus hospitalized in the neurological, internal or paediatric units of the RoMed Hospital Rosenheim, Germany, between October 1st 2022 and February 28th 2023. RESULTS: A total of 906 patients were included (45.6% female; median age 68.0 years; 21.9% Influenza A, 48.2% SARS-CoV-2, 28.3% RSV). Influenza B (0.2%) and co-infections (1.5%) played a minor role. In patients aged ≥ 18 years (n = 637, 71%), Influenza A, SARS-CoV-2 and RSV groups differed in age (median 72, 79, 76 years, respectively; p < 0.001). Comorbidities, particularly asthma and COPD, were most prevalent for RSV. 103 patients were admitted to the intensive care unit (ICU) (16.3% Influenza A, 15.3% SARS-CoV-2, 19.2% RSV; p = 0.649), 56 died (6.8% Influenza A, 9% SARS-CoV-2, 11.1% RSV; p = 0.496). RSV showed the highest frequencies of low-flow oxygen supplementation for admission and stay. Differences in the length of stay were minor (median 7 days). Conversely, in patients aged < 18 years (n = 261, 28,8%), 19.5%, 17.6% and 60.2% were in the Influenza A, SARS-CoV-2 and RSV groups, respectively; 0.4% showed Influenza B and 2.3% co-infections. 17 patients were admitted to ICU (3.9% Influenza A, 9.6% RSV, 0% SARS-CoV-2); none died. RSV showed the highest frequencies of high- and low-flow oxygen supplementation, SARS-CoV-2 the lowest. CONCLUSION: When comparing infections with Influenza, SARS-CoV-2 and RSV in the winter 2022/2023 in hospitalized adult patients, rates of ICU admission and mortality were similar. RSV showed the highest frequencies of obstructive airway diseases, and of oxygen supplementation. The latter was also true in children/adolescents, in whom RSV dominated. Thus, in the situation of declining importance of SARS-CoV-2, RSV showed a disease burden that was relatively higher than that from Influenza and SARS-CoV-2 across ages, and this might be relevant for the seasons coming.

Diabetic cardiomyopathy--fact or fiction?

Epidemiologic as well as clinical studies confirm the close link between diabetes mellitus and heart failure. Diabetic cardiomyopathy (DCM) is still a poorly understood "entity", however, with several contributing pathogenetic factors which lead in different stages of diabetes to characteristic clinical phenotypes. Hyperglycemia with a shift from glucose metabolism to increased beta-oxidation and consecutive free fatty acid damage (lipotoxicity) to the myocardium, insulin resistance, renin-angiotensin-aldosterone system (RAAS) activation, altered calcium homeostasis and structural changes from the natural collagen network to a stiffer matrix due to advanced glycation endproduct (AGE) formation, hypertrophy and fibrosis contribute to the respective clinical phenotypes of DCM. We propose the following classification of cardiomyopathy in diabetic patients: a) Diastolic heart failure with normal ejection fraction (HFNEF) in diabetic patients often associated with hypertrophy without relevant hypertension. Relevant coronary artery disease (CAD), valvular disease and uncontrolled hypertension are not present. This is referred to as stage 1 DCM. b) Systolic and diastolic heart failure with dilatation and reduced ejection (HFREF) in diabetic patients excluding relevant CAD, valvular disease and uncontrolled hypertension as stage 2 DCM. c) Systolic and/or diastolic heart failure in diabetic patients with small vessel disease (microvascular disease) and/or microbial infection and/or inflammation and/or hypertension but without CAD as stage 3 DCM. d) If heart failure may also be attributed to infarction or ischemia and remodeling in addition to stage 3 DCM the term should be heart failure in diabetes or stage 4 DCM. These clinical phenotypes of diabetic cardiomyopathy can be separated by biomarkers, non-invasive (echocardiography, cardiac magnetic resonance imaging) and invasive imaging methods (levocardiography, coronary angiography) and further analysed by endomyocardial biopsy for concomitant viral infection. The role of specific diabetic drivers to the clinical phenotypes, to macro- and microangiopathy as well as accompanying risk factors or confounders, e.g. hypertension, autoimmune factors or inflammation with or without viral persistence, need to be identified in each individual patient separately. Thus hyperglycemia, hyperinsulinemia and insulin resistance as well as lipotoxicity by free fatty acids (FFAs) are the factors responsible for diabetic cardiomyopathy. In stage 1 and 2 DCM diabetic cardiomyopathy is clearly a fact. However, precise determination of to what degree the various underlying pathogenetic processes are responsible for the overall heart failure phenotype remains a fiction.

Intrapericardial procedures for cardiac regeneration by stem cells: need for minimal invasive access (AttachLifter) to the normal pericardial cavity.

In view of the only modest functional and anatomical improvements achieved by bone marrow-derived cell transplantation in patients with heart disease, the question was addressed whether the intracoronary, transcoronary-venous, and intramyocardial delivery routes are adequate. It is hypothesized that an intrapericardial delivery of stem cells or activators of resident cardiac stem cells increases therapeutic benefits. From such an intrapericardial depot, cells or modulating factors, such as thymosin ß4 or Ac-SDKP, are expected to reach the myocardium with sustained kinetics. Novel tools which provide access to the pericardial space even in the absence of pericardial effusion are, therefore, described. When the pericardium becomes attached to the suction head (monitored by an increase in negative pressure), the pericardium is lifted from the epicardium ("AttachLifter"). The opening of the suction head ("Attacher") is narrowed by flexible clamps which grab the tissue and improve the vacuum seal in the case of uneven tissue. A ridge, i.e.,"needle guidance", on the suction head excludes injury to the epicardium, whereby the pericardium is punctured by a needle which resides outside the suction head. A fiberscope can be used to inspect the pericardium prior to puncture. Based on these procedures, the role of the pericardial space and the presence of pericardial effusion in cardiac regeneration can be assessed.

Associations of oxygenated hemoglobin with disease burden and prognosis in stable COPD: Results from COSYCONET.

We studied whether in patients with stable COPD blood gases (BG), especially oxygenated hemoglobin (OxyHem) as a novel biomarker confer information on disease burden and prognosis and how this adds to the information provided by the comorbidity pattern and systemic inflammation. Data from 2137 patients (GOLD grades 1-4) of the baseline dataset of the COSYCONET COPD cohort were used. The associations with dyspnea, exacerbation history, BODE-Index (cut-off ≤2) and all-cause mortality over 3 years of follow-up were determined by logistic and Cox regression analyses, with sex, age, BMI and pack years as covariates. Predictive values were evaluated by ROC curves. Capillary blood gases included SaO2, PaO2, PaCO2, pH, BE and the concentration of OxyHem [haemoglobin (Hb) x fractional SaO2, g/dL] as a simple-to-measure correlate of oxygen content. Inflammatory markers were WBC, CRP, IL-6 and -8, TNF-alpha and fibrinogen, and comorbidities comprised a broad panel including cardiac and metabolic disorders. Among BG, OxyHem was associated with dyspnoea, exacerbation history, BODE-Index and mortality. Among inflammatory markers and comorbidities, only WBC and heart failure were consistently related to all outcomes. ROC analyses indicated that OxyHem provided information of a magnitude comparable to that of WBC, with optimal cut-off values of 12.5 g/dL and 8000/µL, respectively. Regarding mortality, OxyHem also carried independent, additional information, showing a hazard ratio of 2.77 (95% CI: 1.85-4.15, p < 0.0001) for values <12.5 g/dL. For comparison, the hazard ratio for WBC > 8000/µL was 2.33 (95% CI: 1.60-3.39, p < 0.0001). In stable COPD, the concentration of oxygenated hemoglobin provided additional information on disease state, especially mortality risk. OxyHem can be calculated from hemoglobin concentration and oxygen saturation without the need for the measurement of PaO2. It thus appears well suited for clinical use with minimal equipment, especially for GPs.

Combined effects of lung function, blood gases and kidney function on the exacerbation risk in stable COPD: Results from the COSYCONET cohort.

RATIONALE: Alterations of acid-base metabolism are an important outcome predictor in acute exacerbations of COPD, whereas sufficient metabolic compensation and adequate renal function are associated with decreased mortality. In stable COPD there is, however, only limited information on the combined role of acid-base balance, blood gases, renal and respiratory function on exacerbation risk grading. METHODS: We used baseline data of the COPD cohort COSYCONET, applying linear and logistic regression analyses, the results of which were implemented into a comprehensive structural equation model. As most informative parameters it comprised the estimated glomerular filtration rate (eGFR), lung function defined via forced expiratory volume in 1 s (FEV1), intrathoracic gas volume (ITGV) and (diffusing capacity for carbon monoxide (DLCO), moreover arterial oxygen content (CaO2), partial pressure of oxygen (PaCO2), base exess (BE) and exacerbation risk according to GOLD criteria. All measures were adjusted for age, gender, body-mass index, the current smoking status and pack years. RESULTS: 1506 patients with stable COPD (GOLD grade 1-4; mean age 64.5 ±â€¯8.1 y; mean FEV1 54 ±â€¯18 %predicted, mean eGFR 82.3 ±â€¯16.9 mL/min/1.73 m2) were included. BE was linked to eGFR, lung function and PaCO2 and played a role as indirect predictor of exacerbation risk via these measures; moreover, eGFR was directly linked to exacerbation risk. These associations remained significant after taking into account medication (diuretics, oral and inhaled corticosteroids), whereby corticosteroids had effects on exacerbation risk and lung function, diuretics on eGFR, BE and lung function. CONCLUSION: Even in stable COPD acid-base metabolism plays a key integrative role in COPD risk assessment despite rather small deviations from normality. It partially mediates the effects of impairments in kidney function, which are also directly linked to exacerbation risk.

Apoptosis in myocarditis and dilated cardiomyopathy: does enterovirus genome persistence protect from apoptosis? An endomyocardial biopsy study.

UNLABELLED: The purpose of this study was to examine the role of apoptosis in myocarditis and dilated cardiomyopathy. Apoptosis is an active energy-consuming mechanism of cell death in several cardiac diseases in different quality and quantity. METHODS: Endomyocardial biopsies from 81 patients with active (1) and chronic myocarditis (10), dilated cardiomyopathy with inflammation (DCMi; 10) and without inflammation (DCM; 20), with borderline myocarditis and positive PCR for cytomegalovirus-DNA (6), adenovirus-DNA, or enterovirus-RNA (7), and controls (17) were analysed. Apoptosis was detected by using the TUNEL method. The highest rate of apoptotic cardiocytes was found in active and chronic myocarditis. One patient with severe active myocarditis demonstrated 6.15% of apoptotic cardiocytes. Mean percentage of apoptotic cardiocytes in chronic myocarditis was significantly increased (0.61+/-1.25%) when compared to controls (0.01+/-0.04%, P<.05). Particularly, patients with cytomegalovirus-DNA persistence in borderline myocarditis had an elevated rate of apoptosis (0.34+/-0.68%, P<.05). Increased rates of apoptosis were found in borderline myocarditis with adenovirus-DNA persistence (0.20+/-0.57%) and in DCM (0.06+/-0.15%). Only a nonsignificant increase of apoptotic cardiocytes was found in DCMi (0.03+/-0.08%). No apoptosis was found in patients with enteroviral genome persistence in borderline myocarditis. CONCLUSIONS: Apoptosis of cardiac cells is increased in myocarditis and dilated cardiomyopathy, being highest in severe active myocarditis. Apoptosis thus contributes to cell death in active myocarditis and may play a role not to be neglected in dilated cardiomyopathy. Enteroviruses seem to have anti-apoptotic effects, because no apoptosis at all was found in the myocardium.

Comparison of geometry-based and CT voxel-based finite element modelling and experimental validation.

The objectives of the paper presented here is the comparison of a geometry-based and voxel-based finite element (FE) method preprocessor of the human femur. The models were experimentally validated by strain gauge measurements (principal stress). The correlation coefficients (r) between the three methods (geometry-based FEM, voxel-based FEM, strain gauge measurements) were found to be in the range 0.91-0.94 (r2: 0.84-0.88). The relationships between the samples are highly significant (P = 0.001), where the strain gauge results are the independent variables. These results suggest that the validity with respect to the principal stress of a voxel-based modelling is similar to the validity of geometry-based modelling. In summary, therefore, we conclude that voxel-based meshing allows a straightforward interfacing with computerized tomography (CT) scans and might contribute to a clinically applicable FEM technology.

Angiography, CT and MR imaging of a high vena cava inferior interruption in a patient with Hirschsprung disease.

We report on a high vena cava inferior interruption immediately at the insertion to the right atrium in a patient with Hirschsprung disease assessed by angiography, CT, and MRI. Hirschsprung disease is frequently associated with Down, Undine, Waardenburg, Bardet-Biedl, Smith-Lemli-Opitz and Goldberg-Sphrintzen syndromes. We suggest that the association of these two malformations are most likely interrelated and should be considered as a new syndrome.

[Fully automated generation of hip prosthesis voxel models of the femur for finite element analysis. Comparison of direct and subsequent prosthesis implantation]. / Die vollautomatische Erstellung implantatbestückter Voxelmodelle des Femurs zur FE-Analyse, Vergleich von direkter und nachträglicher Prothesenimplantation.

Two means of generating implant-bearing FE voxel models of the human femur are described and compared. The first method consists in the fully automatic production of a femur model from CT data and subsequent implantation of a prosthesis stem on the basis of a redefinition of existing voxel elements using geometrical data control. The second method processes the CT data of a femur already bearing a prosthesis. Here, the prosthesis elements are generated separately from the surrounding bony elements on the basis of the differing CT density thresholds. Although the two implantation algorithms produce comparable results, they have different fields of application. The method of numerical stress analysis involving automatic generation of voxel models can be applied to implant-bearing femurs. Clinical follow-up observations of patients with prostheses made of titanium can be supported by FE calculations.

[Use of voxel-oriented femur models for stress analysis. Generation, calculation and validation of CT-based FEM models]. / Die Anwendung voxelorientierter Femurmodelle zur Spannungsanalyse. Generierung, Berechnung und Validierung CT-basierter FEM-Modelle.

A means of interfacing computed tomography with the finite element method for the analysis of stress distribution in human femurs is described. With the aid of data transfer and image processing programs, three-dimensional voxel models of four macerated and a fresh-frozen cadaveric femur were generated from CT data sets. The underlying basic principle is direct generation of model elements from one or more adjacent CT-voxels, which are characterised by their coordinates and local absorption coefficients. A new algorithm was used for smoothing the edges of the model. All the models were analysed with respect to their stress distribution under different load situations, and the results were compared with the data of a parallel study utilizing the strain-gauge technique. Using the method of linear regression, a high correlation (coefficient of determination r2: 0.80-0.91) was found between the calculated and experimentally measured principal stresses at the surface of the bones.

Inverse shift in serum polyunsaturated and monounsaturated fatty acids is associated with adverse dilatation of the heart.

BACKGROUND: Cardiac dilatation is associated with impaired pump function, progression of heart failure and electrical instability. Risk of sudden death is associated with a low blood level of n-3 polyunsaturated fatty acids. OBJECTIVE: The hypothesis was, therefore, addressed that left ventricular dilatation as assessed by echocardiography is associated with a reduced serum polyunsaturated fatty acid level. METHODS: Fatty acids were determined with gas chromatography/mass spectrometry in serum of 308 patients with dilative heart failure unrelated to myocardial infarction (age 48 (SD12) years, NYHA class 2.2 (0.6), ejection fraction 31% (10%)). RESULTS: The extent of left ventricular dilatation as assessed by left ventricular end-diastolic diameter was associated with a reduction of both n-3 and n-6 polyunsaturated fatty acids. The n-3 docosahexaenoic acid (1.0% (0.5%) vs 1.3% (0.6%), p<0.001) and the n-6 arachidonic acid (4.6% (1.8%) vs 5.2% (1.9%), p<0.01) were reduced in patients with left ventricular dilatation (end-diastolic diameter, 68-90 mm, upper tertile vs 48-61 mm, lower tertile). By contrast, monounsaturated fatty acids were increased (the n-9 oleic acid 26.1% (4.8%) vs 23.9% (4.8%), p<0.01). A low docosahexaenoic acid (0.01-0.9%, lower tertile vs 1.4-3.1%, upper tertile) was associated with greater left ventricular dilatation (end-diastolic diameter, 67 (8) vs 63 (7) mm, p<0.001). The cut-off for the absence of severe dilatation (end-diastolic diameter >70 mm) was set at >1.24% docosahexaenoic acid. In our sample, the negative-predictive value for severe dilatation was 91% and sensitivity was 84%. CONCLUSIONS: Docosahexaenoic acid provides a new sensitive biomarker for monitoring and detecting severe left ventricular dilatation in heart failure patients.

A new method to assess ventricular wall stress in patients with heart failure and its relation to heart rate variability.

INTRODUCTION: Heart failure is characterized by an increase in cardiac load, wall stress and autonomic dysfunction. The neurohumoral imbalance arising from adrenergic activation and parasympathetic withdrawal is associated with worse prognosis. We addressed the hypothesis that an increased left ventricular (LV) wall stress as assessed by cardiac magnetic resonance imaging (CMR) in patients with heart failure is related to a depression of heart rate variability (HRV). METHODS: Cardiac function and mass were measured in 37 individuals with suspected cardiomyopathy using CMR imaging. A thick-walled sphere model was used to calculate ventricular wall stress. Time domain analysis of HRV was obtained by long-term Holter ECG. RESULTS: Standard deviation of both normal-to-normal (NN) intervals (SDNN) and average NN intervals over 5 minutes (SDANN-i) were negatively correlated with LV enddiastolic wall stress (r = 0.42, P < 0.01). SDNN and SDANN-i were severely decreased (P < 0.01) in patients with increased enddiastolic LV wall stress > 12 kPa (vs. normal range: < 4 kPa). CONCLUSION: A relation between increased cardiac wall stress and depressed heart rate variability was observed in patients with heart failure. CMR-based measurement of LV volume and mass is appropriate to calculate LV wall stress which should be considered not only as a potential prognostic determinant but also as therapeutic target.

A new methodological approach to assess cardiac work by pressure-volume and stress-length relations in patients with aortic valve stenosis and dilated cardiomyopathy.

In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.