Impact of 4D-Flow CMR Parameters on Functional Evaluation of Fontan Circulation

We sought to evaluate the potential clinical role of 4D-flow cardiac magnetic resonance (CMR)-derived energetics and flow parameters in a cohort of patients' post-Fontan palliation. In patients with Fontan circulation who underwent 4D-Flow CMR, streamlines distribution was evaluated, as well a 4D-flow CMR-derived energetics parameters as kinetic energy (KE) and energy loss (EL) normalized by volume. EL/KE index as a marker of flow efficiency was also calculated. Cardiopulmonary exercise test (CPET) was also performed in a subgroup of patients. The population study included 55 patients (mean age 22 ± 11 years). The analysis of the streamlines revealed a preferential distribution of the right superior vena cava flow for the right pulmonary artery (62.5 ± 35.4%) and a mild preferential flow for the left pulmonary artery (52.3 ± 40.6%) of the inferior vena cave-pulmonary arteries (IVC-PA) conduit. Patients with heart failure (HF) presented lower IVC/PA-conduit flow (0.75 ± 0.5 vs 1.3 ± 0.5 l/min/m2, p = 0.004) and a higher mean flow-jet angle of the IVC-PA conduit (39.2 ± 22.8 vs 15.2 ± 8.9, p < 0.001) than the remaining patients. EL/KE index correlates inversely with VO2/kg/min: R: - 0.45, p = 0.01 peak, minute ventilation (VE) R: - 0.466, p < 0.01, maximal voluntary ventilation: R:0.44, p = 0.001 and positively with the physiological dead space to the tidal volume ratio (VD/VT) peak: R: 0.58, p < 0.01. From our data, lower blood flow in IVC/PA conduit and eccentric flow was associated with HF whereas higher EL/KE index was associated with reduced functional capacity and impaired lung function. Larger studies are needed to confirm our results and to further improve the prognostic role of the 4D-Flow CMR in this challenging population.

Relationships between plasma cytokine balance and cardiac magnetic resonance imaging in long-term post-COVID follow-up: a cross-sectional preliminary study

Background

COVID-19 infection can lead to a constellation of long-lasting post-infectious sequelae, including myocardial dysfunction, whose outcome is strongly affected by a fine-tuned balance between pro- and anti-inflammatory systemic immune responses. Plasma cytokines are key mediators of this immunological balance. In this preliminary study we evaluated the cross-sectional association between the circulating levels of the main pro- and anti-inflammatory cytokines and cardiac magnetic resonance (CMR) abnormalities.

Methods

71 subjects (59% female, mean age 52±14) with previous diagnosis of COVID-19 infection were enrolled at our institution for MULTICOVID protocol, comprehensive of CMR and biomarkers assessment performed &gt;3 months and &lt;1 year following the first negative swab test. CMR protocols consisted of conventional sequences (cine, T2-weighted imaging, and late gadolinium enhancement [LGE]) and quantitative mapping sequences (T1, T2, and extracellular volume [ECV] mapping). Plasma levels of cytokines TNF-α, IL-1β, IL-1α, IFN-α2, IL-6, IL-8, IL-13, IL-10, IL-17A, IL-18, IP-10, MIG and MCP-1 were quantified by Multiplex Immunoassays on the Luminex technology platform. Soluble cardiologic and biochemical biomarkers were measured by routine laboratory analysis.

Results

After a median of 9 (IQR 6–11) months following negative swab, CMR was normal in 48 subjects, while in 23 (32%) it revealed tissue characterization abnormalities (myocardial late enhancement and/or edema). By multivariate regression analysis (adjusted for age, sex, vaccination, severity degrees of the initial COVID disease, presence of comorbidities, smoke, time interval between COVID diagnosis and CMR assessment) the cytokine ratio TNF-α/(IL-10+IL-13) was independently associated (OR=2.89, 95% CI 1.19–7.04, p=0.02) with CMR abnormalities. Interestingly, the cumulative pro-/anti-inflammatory cytokine ratio (IL-1β+TNF-α+IFN-α2+IL-6+IL-17A+IL-8)/(IL-10+IL-13) showed a positive (OR=1.70, 95% CI: 1.04–2.75) and significant (p=0.03) association with CMR imaging aspects. Also, the ratio IFN-α2/(IL-10+IL-13), although without achieving a complete statistical significance (p=0.09), was associated positively with CMR findings.

Conclusions

The preliminary results of this cross-sectional study suggest that the systemic inflammatory environment, long-lasting unbalanced towards a prevalent cytokine-driven pro-inflammatory condition following COVID infection, could affect the development of CMR-detectable myocardial edema and fibrosis in long-term post-COVID subjects.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Tuscany Region

Prevalence and risk factors for venous thromboembolic events in critically ill patients with SARS-CoV-2 infection: a prospective observational study

BACKGROUND

The majority of prevalence studies on deep vein thrombosis (DVT) in severe COVID-19 patients are retrospective with DVT assessment based on clinical suspicion. Our aim was to prospectively and systematically estimate the occurrence of DVT in critically-ill mechanically-ventilated patients, and to identify potential risk factors for DVT occurrence and mortality.

METHODS

All patients with COVID-19 admitted to our 45 beds in the Intensive Care Unit (ICU) between March 6, 2020, and April 18, 2020, requiring invasive ventilatory support were daily screened for DVT with lower extremities and jugular veins ultrasonography. Univariate and multivariable logistic regression models were performed in order to identify predictors of DVT and mortality.

RESULTS

Seventy-six patients were included in the final analysis (56 men, mean age 67 years, median SOFA=7 points, median SAPS II=41 points, median PaO<inf>2</inf>/Fi0<inf>2</inf>=10.8 kPa). The period prevalence of DVT was 40.8%. Thirty-one DVTs were diagnosed. Twenty-five DVTs (80.6% of total DVTs) were catheter-related, mainly in the jugular veins. Twenty-six DVTs (83.9%) occurred in patients receiving enhanced antithrombotic prophylaxis. No independent variable was predictive of DVT occurrence. Twenty-eight patients (36.8%) died during the ICU stay. Age and SOFA score were independently associated with mortality.

CONCLUSIONS

A high number of critically-ill mechanically-ventilated COVID-19 patients developed a DVT. The majority of DVTs were catheter-related and occurred under intensive prophylactic anticoagulation. Routine ultrasound of the jugular veins should be suggested in this patient population, and in particular in presence of a central venous catheter.

Collapsibility of caval vessels and right ventricular afterload: decoupling of stroke volume variation from preload during mechanical ventilation

Collapsibility of caval vessels and stroke volume and pulse pressure variations (SVV, PPV) are used as indicators of volume responsiveness. Their behavior under increasing airway pressures and changing right ventricular afterload is incompletely understood. If the phenomena of SVV and PPV augmentation are manifestations of decreasing preload, they should be accompanied by decreasing transmural right atrial pressures. Eight healthy pigs equipped with ultrasonic flow probes on the pulmonary artery were exposed to positive end-expiratory pressure of 5 and 10 cmH₂O and three volume states (Euvolemia, defined as SVV < 10%, Bleeding, and Retransfusion). SVV and PPV were calculated for the right and PPV for the left side of the circulation at increasing inspiratory airway pressures (15, 20, and 25 cmH₂O). Right ventricular afterload was assessed by surrogate flow profile parameters. Transmural pressures in the right atrium and the inferior and superior caval vessels (IVC and SVC) were determined. Increasing airway pressure led to increases in ultrasonic surrogate parameters of right ventricular afterload, increasing transmural pressures in the right atrium and SVC, and a drop in transmural IVC pressure. SVV and PPV increased with increasing airway pressure, despite the increase in right atrial transmural pressure. Right ventricular stroke volume variation correlated with indicators of right ventricular afterload. This behavior was observed in both PEEP levels and all volume states. Stroke volume variation may reflect changes in right ventricular afterload rather than changes in preload.NEW & NOTEWORTHY Stroke volume variation and pulse pressure variation are used as indicators of preload or volume responsiveness of the heart. Our study shows that these variations are influenced by changes in right ventricular afterload and may therefore reflect right ventricular failure rather than pure volume responsiveness. A zone of collapse detaches the superior vena cava and its diameter variation from the right atrium.

[The regions' contribution to assessment of work-related stress: an operative guide]

In order to formulate indications for work-related stress assessment established by Italian health and safety regulation (D.Lgs. 81/2008), the interregional technical committee has instituted a working group to define an operative guide. The guide indicates the elements that must be considered in the evaluation, criteria and methods for the assessment, the minimum requirements for the evaluation instruments, and the specific contents of the risk assessment document.The medical surveillance and the role of health and safety local authorities are also considered. The risk assessment must examine work organization indicators and the direct or indirect effects of work-related stress, like morbility, frequent accidents, changing job requests, legal actions, etc. Detecting subjective factors is a second step of the assessment, which must be carried out if the work organization indicators show considerable work-related stress problems, and only in the companies which employ more then ten workers.

[The activity of the Service for Prevention and Safety in Workplaces of the Health Local Agency of Rome C towards the "competent physicians" in the enterprises of the territory]

In the past seven years the Service for Prevention and Safety in Workplaces of the Health Local Agency of Rome C set out some activities towards the occupational physicians (so-called "competent physicians") of three different kinds: control and surveillance, institutional activities on demand and activities for quality improvement. In the first ambit we conducted some investigations on the procedures of the workers' medical surveillance and the role of competent physicians in the risk evaluation inside three different intervention projects (monitoring the enforcement of the D.Lgs. 626/94; intervention on the chemical risk, intervention in the car repair shops). In the second ambit we analysed 92 notifications of occupational diseases and we dealt with 27 appeals against the judgement of the fitness to work. In the third ambit we made 19 meetings on various subjects: correct procedures in medical surveillance, quality in diagnostic examinations, the enforcement of new regulations. We report the results of these interventions which let us identify the most common criticalities in the activity of the competent physicians, but also to face them with a new approach based more on peer review instead of control and surveillance.

[Technical quality control of chest x-rays for the health surveillance of workers exposed to the risk of pneumoconiosis: proposal for a qualitative screening method]

BACKGROUND

The necessity of a qualitative screening has arisen from the fact that good technical quality is of fundamental importance for evaluating initial pneumoconiosis, for reducing inter- and intra-reader variability, for effective secondary prevention and for forensic medicine purposes.

OBJECTIVES

The authors report experience in use of a method to evaluate the quality of chest radiographs performed in health surveillance programs for workers at risk for development of pneumoconiosis.

METHODS

747 postero-anterior chest radiographs concerning employees of 21 ceramic factories in the Province of Viterbo were examined. A standardized pattern was created for this evaluation. The pattern considers the main factors that can influence the quality of chest radiographs and assigns points for each of them. That factors are: 1) reproduced image of the lung's vascular structure, chiefly in the peripheral portions; 2) reproduced image of heart border, aorta, diaphragm; 3) deep inspiration; 4) symmetric image of the chest; 5) position of the scapulae; 6) visualization of the costal-phrenic angles; 7) technical impairments.

RESULTS

The application of the method revealed that half of the chest radiographs examined had poor image quality for a suitable reading, in conformity with the ILO 1980 guidelines. The critical points are poor visualization of the lung's vascular structure due to overexposure or underexposure, technical impairments, non-correct scapulae position.

CONCLUSIONS

The authors believe that the suggested method can be a useful instrument for self-testing the quality of chest radiographs performed in radiology centers and for the National Health Service to test the quality of chest radiographs performed in health surveillance programs.

[Quality control of spirometric tests used in health surveillance for occupational exposure risk, in the province of Viterbo]

A quality control survey on spirometry assessments carried out in a number of factories in the province of Viterbo (Lazio Region) was made by the Local Health Unit in Viterbo, as required by law 626/94 on the promotion of workers health. The survey concerned 734 measurements concerning the same number of employees from 29 different factories. Each spirometry assessment was repeated in this study according to the quality standards defined in the literature and our own results were compared with the values which had been obtained over one year during the health surveillance program (ASP). A few main functional parameters were considered according to the following criteria: percentage of agreement (tolerance +/- 5%) between the two FVC, FEV1 and FEF25-75 measures or degree of discrepancy; for FEV1/FVC ratio, the occurrence of < 70 (suggestive of an obstructive lesion) and > 90 values (reflecting poor reliability in the measurement of the lung volumes) in the two sets of data. Further criteria concerned the comparison of the height of the individuals (tolerance range +/- 1 cm), and the comparison of the overall spirometry rating expressed as the number of tests rated normal or abnormal (during the first assessment as compared to the second). The results show poor agreement (11.4%) for FVC with as many as 85.8% underestimated values; 30.1% agreement and 64.2% underestimate for FEV1; 17% agreement and 53.5% overestimate for FEF25-75. There were 6.5% fewer < 70 FEV1/FVC ratios, and 18.3% more > 90 ratios in the tests carried out in the factories as compared to our own. There was 32.9% agreement on the height, with overestimation in 63.7% of the cases. There were 12.3% "false abnormal" and 2.6% "false normal" results in the overall rating of the spirometry (as carried out by the factories compared to our own). In conclusion, the survey revealed a trend in the measurements carried out by the factories to underestimate the volumes, overestimate the flows, improperly select the theoretical reference values because of a mistake in measuring the height, to overestimate restrictive abnormalities, and underestimate the obstructive ones.

[Evaluation of the absorption of polycyclic aromatic hydrocarbons by analysing 1-hydroxypyrene in the urine of the workers in a factory of graphite electrodes]

A group of 288 workers of a graphite electrode manufacturing plant (33 of whom were not classified as either exposed or non-exposed) participated in a biological monitoring programme of exposure to PAHs via determination of 1-hydroxypyrene in end-of-shift urine. A highly significant difference (p < 0.000001) was observed in the mean urinary values of the metabolite in the 132 subjects classified as exposed compared to the 123 not exposed, which was not influenced by by confounding factors. The maintenance workers group showed mean urinary levels of 1-hydroxypyrene similar to the production department workers who were exposed to pitch. Among the exposed the use of a mask with filters for organic fumes reduced absorption of PAHs and significantly reduced urinary excretion of 1-hydroxypyrene (p < 0.005). The test also proved to be sensitive in discriminating the subjects exposed to low doses of PAHs, as the results obtained in laboratory workers showed. After comparing their data with the proposals for Biological Limit Values for 1-hydroxypyrene, the authors stress the usefulness of this biological monitoring tool in exposure to PAHs for the assessment of cancer risk, as provided for by Law No. 626/94.

Effect of long-term GH administration on pituitary-thyroid function in idiopathic hypopituitarism

Twenty-four euthyroid children with idiopathic pituitary dwarfism were studied. The euthyroid state for seven of these patients was determined by negative physical examinations, normal plasma T4 assays and normal 131I uptakes. For the other children, thyroid function was evaluated with T3 and T4 assays and on the basis of the TRH test. Each of the children was treated with HGH in one of three different ways. The first group (five cases) was given a HGH dose, ranging from 12.4 to 17.2 IU/m2//week. The second and third groups (nine and ten cases, respectively) were treated with 10 and 20 IU/m2/week, respectively. Treatment was carried out for periods ranging from 6 months to 6 years. After no less than 6 months of treatment, and at intervals of 6 months (or some multiple of 6 months) plasma T3 and T4 assays, as well as a TRH test were performed in each patient. In some patients one of the indices was once beyond the upper or lower limit of the normal range (none of the children presented simultaneous abnormal levels of more than one index during the controls). This value, however, returned to within normal limits at the following control. There was no correlation between T3, T4 and TSH with the duration of HGH therapy. There was no significant difference between the groups of children treated with the different HGH doses. These data seem to demonstrate that the risk of inducing an alteration in thyroid function in hypopituitary patients during HGH treatment is very slight, and that the irregularly abnormal thyroid indices observed in some of the children during one of the controls might be an expression of their metabolic status at that moment.