Abstract Cardiorenal syndrome (CRS) is defined as an interaction of cardiac disease with renal dysfunction that leads to diuretic resistance and renal function worsening, mainly with heart failure ...(HF) exacerbation. Hemodynamic variables linking heart and kidney are renal blood flow (cardiac output) and perfusion pressure, i.e., the aortic – renal venous pressure gradient. CRS has traditionally been interpreted as related to defective renal perfusion and arterial underfilling and, more recently, to elevation in central venous pressure transmitted back to renal veins. Our suggestion is that in a setting where aortic pressure is generally low, due to heart dysfunction and to vasodrepressive therapy, the elevated central venous pressure (CVP) contributes to lower the renal perfusion pressure below the threshold of kidney autoregulation (≤ 80 mm Hg) and causes renal perfusion to become directly pressure dependent. This condition is associated with high neurohumoral activation and preglomerular vasoconstriction that may preserve pressure, but may decrease filtration fraction and glomerular filtration rate and enhance proximal tubular sodium absorption. Thus, congestion worsens and drives the vicious cycle of further sodium retention and HF exacerbation. Lowering CVP by targeting the lung–right heart interaction that sustains elevated CVP seems to be a more rational approach rather than reducing intravascular volume. This interaction is crucial and consists of a cascade with stepwise development of pulmonary post-capillary hypertension, precapillary arteriolar hypertone, right ventricular overload and enlargement with tricuspid incompetence and interference with left ventricular filling (interdependence). The resultant CVP rise is transmitted to the renal veins, eventually drives CRS and leads to a positive feedback loop evolving towards HF refractoriness.
Periodic repetition of right heart catheterization (RHC) in pulmonary arterial hypertension (PAH) can be challenging. We evaluated the correlation between RHC and cardiopulmonary exercise test (CPET) ...aiming at CPET use as a potential noninvasive tool for hemodynamic burden evaluation. One hundred and forty‐four retrospective PAH patients who had performed CPET and RHC within 2 months were enrolled. The following analyses were performed: (a) CPET parameters in hemodynamic variables tertiles; (b) position of hemodynamic parameters in the peak end‐tidal carbon dioxide pressure (PETCO2) versus ventilation/carbon dioxide output (VE/VCO2) slope scatterplot, which is a specific hallmark of exercise respiratory abnormalities in PAH; (c) association between CPET and a hemodynamic burden score developed including mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index, and right atrial pressure. VE/VCO2 slope and peak PETCO2 significantly varied in mPAP and PVR tertiles, while peak oxygen uptake (peak VO2) and O2 pulse varied in the tertiles of all hemodynamic parameters. PETCO2 versus VE/VCO2 slope showed a strong hyperbolic relationship (R2 = 0.7627). Patients with peak PETCO2 > median (26 mmHg) and VE/VCO2 slope < median (44) presented lower mPAP and PVR (p < 0.005) than patients with peak PETCO2 < median and VE/VCO2 slope > median. Multivariate analysis individuated peak VO2 (p = 0.0158) and peak PETCO2 (p = 0.0089) as hemodynamic score independent predictors; the formula 11.584 − 0.0925 × peak VO2 − 0.0811 × peak PETCO2 best predicts the hemodynamic score value from CPET data. A significant correlation was found between estimated and calculated scores (p < 0.0001), with a precise match for patients with mild‐to‐moderate hemodynamic burden (76% of cases). The results of the present study suggest that CPET could allow to estimate the hemodynamic burden in PAH patients.
The erosion of the fine fraction of granular soils due to seepage is a possible cause of the settlements of shallow foundations. Here the problem is tackled with reference to deep pumping wells to be ...installed in an urban area. First, the results of laboratory tests on reconstituted soil samples are illustrated that provide the quantity of eroded particles during time depending on the imposed hydraulic gradient. Based on the experimental data, an incremental erosion law is proposed that has been implemented in a finite-element code for erosion-transport analysis. After describing the steps of the numerical solution procedure, the results of two- and three-dimensional finite-element calculations are discussed. They provide an estimation of the quantity of eroded material in the vicinity of the pumping wells and of the possible consequent settlements of nearby buildings.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
Background
β-blockers are one of the four recommended disease-modifying classes of drugs for the treatment of heart failure with reduced ejection fraction (HFrEF). Although their efficacy ...and prognostic role is unquestionable in the general population of HFrEF patients, the differences in their effect in relation to sex have not been yet investigated in detail. The present study analyzed a large, real-world, Italian population of HFrEF patients aiming to highlight any prognostic difference between males and females in relation to dose and β-selectivity of the ongoing β-blocker treatment.
Methods
Out of the 7900 HFrEF patients included in the MECKI score registry, we retrospectively analyzed those treated with β-blockers. We investigated the prognostic role of β-selectivity, dividing the population in assuming β1/β2-receptor blockers (carvedilol) vs. β1-selective blockers (bisoprolol, nebivolol or metoprolol), according to sex, and the prognostic role of daily carvedilol-equivalent β-blocker dose in relation to sex. The primary outcome of the study was the composite of all cause mortality, urgent heart transplant and LVAD implant analyzed at 5 years, both as raw data and after correction of potential confounders.
Results
6784 HFrEF patients treated with β-blockers were analyzed (1215 females, 5569 males). Patients median follow-up was 4.05 years 1.72-7.47: 4.37 1.6-8.13 for females and 3.99 1.75-7.3 for males (p=ns). According to β-selectivity no prognostic differences were found in the general population, as in female or males (Fig. 1 right panel). Stratification of patients according to β-blockers equivalent dose showed significant difference among groups: mortality decreases with increasing β-blockers dose in both males and females (Fig. 1, left panel), both at baseline and after adjustment for the main confounders (LVEF, age, peakVO2, systolic pressure, hemoglobin, rest heart rate; VE/VCO2 slope, etiology. ICD, MDRD).
Conclusions
In a large, real-life population of chronic HFrEF patients analyzed according to sex, no prognostic differences were found between stratifying for β-selectivity. A better outcome was observed in subjects receiving a high daily dose, independently from sex.Fig 1Table 1
Abstract
Introduction
exertional dyspnea is a symptom present in several diseases, identifying the origin is of fundamental diagnostic and therapeutic importance. Cardiorespiratory exercise testing ...(CPET) is a valuable tool not only to assess functional capacity but also for diagnostic and prognostic purposes.
Clinical case
55–year–old patient with a history of episode of acute pulmonary edema. Echocardiogram showed FE 35% with diffuse left ventricular (LV) hypokinesis and mild–to–moderate mitral insufficiency (MI). Diagnostic coronarography showed lesion–free coronary tree. An interrupted CPET at 140W showed peak O2 consumption of 23.6 mL/kg/min that excluded indication for cardiac transplantation. An echocardiogram from us confirmed dilated cardiomyopathy (CMPD) with FE=32%, diffuse VS hypokinesia and mild–to–moderate functional MI. CPET was repeated, maximal for respiratory quotient (1.42) interrupted due to muscle exhaustion, indicative of moderate reduction in functional capacity with peak VO2 at 64% of predicted, preserved anaerobic threshold at 51% of VO2 max and reduced VO2/W and Pulse Oxygen Ratio (VO2/HR) values from cardiogenic limitation. Also evident drop in VO2/HR during the final stages of the test and associated change in slope of the VO2/Work relationship a sign of decline in stroke volume and cardiogenic efficiency. Absent signs of ventilatory limitation, pulmonary vascular (Ve/VCO2=20.8 in normal range), or exercise desaturation. In the final phase of the test increase in VCO2 and Ve/VCO2 and Ve/VO2 equivalents. In order to find the explanation to the data collected by CPET, exercise echocardiogram was performed, which revealed the development of severe mitral valvular insufficiency and subsequent pulmonary hypertension justifying the behavior of the parameters collected by CPET.
Discussion
The oxygen pulse represents a metabolic surrogate for stroke volume. Normally during the active phases of exertion there is a progressive increase followed by a plateau. The evident flattening of the VO2/Work curve during the final phases of exercise and the concomitant decrease in oxygen pulse denote inadequate cardiac performance relative to the increased energy demands during exercise.
Conclusions
CPET proves to be a valuable clinical tool to guide the diagnostic–therapeutic pathway, particularly in the presence of complex heart disease (CMPD or IM).
We evaluated the prognostic meaning of the simple presence or absence of identifiable anaerobic threshold (AT) and respiratory compensation point (RCP) at cardiopulmonary exercise tests (CPETs) ...performed with a maximal incremental exercise protocol.
In the present multicenter study, we retrospectively analyzed data in 1,995 patients with heart failure with reduced ejection fraction (HFrEF). All underwent clinical and laboratory evaluation, echocardiography, and maximal CPET at baseline. The analysis was performed according to absence of identified AT and RCP (group 1: n = 292; 15%), presence of AT but absence of identified RCP (group 2: n = 920; 46%), and presence of both AT and RCP (group 3: n = 783; 39%). The study end point was the composite of cardiovascular mortality, urgent heart transplant, and left ventricular assist device implantation.
Median follow-up was 2.97 years (interquartile range, 1.50-5.35 years). Eighty-seven (30%), 169 (18%), and 111 (14%) events were observed in groups 1, 2, and 3, respectively (P = .025). Compared with results in group 3 (patients with the best survival), the likelihood of reaching the study end point increased 2.7 times when neither AT nor RCP were identified (hazard ratio, 2.74) and 1.4 times when only AT was identified (hazard ratio, 1.4). Moreover, adding the presence or absence of identified AT and RCP improved the prognostic power of peak oxygen uptake because a significant reclassification was obtained.
AT and RCP identification has a potential role in the prognostic stratification of HFrEF.
Abstract
Background
Heart failure (HF) in women often assumes extremely peculiar characteristics. The risk stratification and prognostic evaluation of HF in women is a challenge for clinicians. The ...actual prognostic scores are, in fact, lacking a specific sex-oriented assessment. In HF women show better survival despite a comparatively low peak oxygen consumption (VO2) at cardiopulmonary exercise testing: this raises doubt about the accuracy of risk assessment in women. Previous studies on MECKI score database have demonstrated that female prognostic advantage is lost when sex-specific differences are correctly considered.
Purpose
The present analysis has the aim to identify parameters which could be differently associated to prognosis in men and women and to re-calibrate the MECKI score according to these differences.
Methods
The new weights of the MECKI score variables according to gender, were calculated using the means of the 200 repetitions obtained to cross-validation procedure. The primary outcome of the study was the composite of all-cause mortality, urgent heart transplant and LVAD implant. The difference in predictive ability between the native and gender re-calibrated MECKI was calculated with the ROC curve at 2 years follow-up and calibration plot.
Results
We retrospectively analyzed 7900 HF patients with reduced ejection fraction included in the MECKI score registry (61±13 years, 6456 M/ 1444 F, LVEF 33±10%, VO2 /kg 14.9±4.9 mL/min Kg). Patients follow up was: 4.05 years 1.72-7.47. Table 1 presents the weights of the individual MECKI variables for males and females. The main differences have been detected for the intercept value, hemoglobin and Na+. We used these variables to recalibrate the algorithm of MECKI score. We obtained higher AUC for MECKI re-calibrated by gender than for Native MECKI (0.7893 vs. 0.7799, p = 0.0194, Fig. 1 left panel). Moreover, the gender MECKI was better calibrated (Fig. 1, right panels).
Conclusions
The calibration of MECKI Score according to gender specific differences improves the prognostic power and accuracy of mortality prediction at two years follow up.Fig 1Table 1
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