Endothelial inflammatory activation is related to myocardial perfusion disturbance in experimental chronic Chagas disease

Background

Microvascular myocardial perfusion defect (MPD) is frequent in chronic Chagas cardiomyopathy (CCC) and may be involved in the pathophysiologic process that leads to left ventricular systolic dysfunction (LVSD). However, there is scarcity of studies addressing the histopathological meaning of MPD in CCC and its correlation with endothelial activation.

Purpose

To investigate the correlations between MPD detected in vivo with functional and histopathological changes in the experimental model of CCC in hamsters.

Methods

24 female Sirius hamsters were investigated 8-months after intraperitoneal infection with 3.5x104 trypomastigote forms of Y-strain of T. cruzi. All animals were submitted to rest high-resolution 99mTc-Sestamibi-SPECT myocardial perfusion scintigraphy and echocardiography in vivo. The area of MPD was assessed through the calculation of polar maps by using a dedicated software (MunichHeart®) and a 13-segments model of LV. After euthanasia, we performed a histopathological study of cardiac inflammation and fibrosis and mRNA expression for TNF-α and ICAM, for assessment of inflammation and endothelial activation, respectively.

Results

Most of the animals presented MPD, n=17 (71%), its extension ranging from 1.4 to 30.3% of LV surface. We observed lower values of LVEF in animals with MPD (38.5±11.2%) when compared with animals without MPD 48.4±9.1%, p=0.04) and a trend to higher intensity of myocardial inflammation (estimated by the number of mononuclear cells) in animals with MPD (540.4±153.6 cell/mm2) vs. without MPD (409.6±130.3 cell/mm2), p=0.09. In addition, animals with MPD presented a higher ICAM (0.02±0.01) expression when compared with animals without MPD (0.01±0.01, p=0.02). There was no difference between groups regarding the extent of fibrosis. The results of the regression and correlation analysis showed that individual values of MPD area presented negative correlation with LVEF (R=−0.6, p=0.001), with echocardiographic wall motion score index (WMSi, R=0.5, p=0.007), and with the number of mononuclear cells (R=0.5, p=0.01). Moreover, an analysis based on myocardial segments (n=312), showed that segments with MPD (n=54) in comparison to those without MPD (n=258) presented higher number of mononuclear cells (608±299.9 cell/mm2 and 478.3±201.1 cell/mm, respectively, p<0.0001) and higher WMSi (1.8±0.9 and 1.2±0.4, respectively, p<0.0001.

Conclusions

MPD is a common finding in experimental model of CCC in hamsters and is correlated with inflammation, endothelial inflammatory activation, and systolic ventricular dysfunction. These results suggest that perfusion defects may be an in vivo surrogate marker for inflammation with potential translational implication for monitoring disease activity.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Fundação de Amparo à Pesquisa do Estado de São Paulo

Main results of the first Brazilian Registry of Heart Failure (BREATHE)

Background

Heart failure represents a common cause of hospitalization associated with poor short-term clinical outcomes. Little is known about the long-term prognosis of these patients in Latin America.

Methods

The rationale and design of the study were previously published (1). Briefly, BREATHE was the first nation-wide prospective observational study that included patients hospitalized due to acute heart failure in Brazil. In-hospital management as well as 12-month clinical outcomes were assessed. Patients were included during two time periods: from February 2011 to December 2012 (BREATHE I) and from June 2016 to July 2018 (BREATHE Extension). Adherence to evidence-based therapies was also evaluated.

Results

A total of 3,013 patients were included in 71 centers in Brazil. The median follow-up was 346 days. The BREATHE population included 39.3% of women, had a mean age of 65.2 (± 15.6) with a mean ejection fraction of 39.7% (± 17.5). Among the comorbidities, systemic arterial hypertension was the most common, present in almost 75% of the sample. At hospital admission, 83.8% of patients had clear signs of pulmonary congestion and the main cause of decompensation was poor adherence to heart failure medications, representing 27.8% of cases. Among patients with reduced ejection fraction, the concomitant use of renin-angiotensin-aldosterone inhibitors, beta-blocker and spironolactone at hospital discharge was 44.5% and decreased to 35.2% after 3 months (p<0.01). Mortality rate at 12 months was 28.9 for every 100 patient years with 26.2% readmission at 90 days and 46.4% at 365 days. The most common etiology of heart failure was ischemic disease (Figure 1) but the worst prognosis was associated with Chagas disease (Figure 2) including an analysis of a composite outcome encompassing death, myocardial infarction, stroke or cardiac arrest after discharge.

Conclusions

In this large national prospective registry of patients hospitalized with acute heart failure, mortality and readmission were higher than what have been reported globally. Poor adherence to evidence-based therapies was a common both at hospital discharge and 1-year of follow-up.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Brazilian Society of Cardiology

The role of process mining tools in STEMI networks: where should we build a new primary PCI centre?

Background

In ST-segment elevation myocardial infarction (STEMI), time delay between symptom onset and treatment is critical to improve outcome. The expected transport delay between patient location and percutaneous coronary intervention (PCI) centre is paramount for choosing the adequate reperfusion therapy. The “Centre” region of Portugal has heterogeneity in PCI assess due to geographical reasons.

Purpose

We aimed to explore time delays between regions using process mining (PM) tools.

Methods

We retrospectively assessed the Portuguese Registry of Acute Coronary Syndromes for patients with STEMI from October 2010 to September 2019, collecting information on geographical area of symptom onset, reperfusion option, and in-hospital mortality. We used a PM toolkit (PM4H – PMApp Version) to build two models (one national and one regional) that represent the flow of patients in a healthcare system, enhancing time differences between groups. One-way analysis of variance was employed for the global comparison of study variables between groups and post hoc analysis with Bonferroni correction was used for multiple comparisons.

Results

Overall, 8956 patients (75% male, 48% from 51 to 70 years) were included in the national model (Fig. 1A), in which primary PCI was the treatment of choice (73%), with the median time between admission and primary PCI <120 minutes in every region; “Lisboa” and “Centro” had the longest delays, (orange arrows). Fibrinolysis was performed in 4.5%, with a median time delay <1 hour in every region. In-hospital mortality was 5%, significantly higher for those without reperfusion therapy compared to PCI and fibrinolysis (10% vs. 4% vs. 4%, P<0.001). In the regional model (Fig. 1B) corresponding to the “Centre” region of Portugal divided by districts (n=773, 74% male, 47% from 51 to 70 years), only 61% had primary PCI, with “Guarda” (05:04) and “Castelo Branco” (06:50) showing significant longer delays between diagnosis and reperfusion treatment (orange and red arrows, respectively) than “Coimbra” (01:19) (green arrow); only 15% of patients from “Castelo Branco” had primary PCI. Fibrinolysis was chosen in 10% of patients, mostly in “Castelo Branco” (53%), followed by “Guarda” (30%), with a median time delay of 39 and 48 minutes, respectively. Regarding mortality, PCI and fibrinolysis groups had similar death rates while those patients without reperfusion had higher mortality (5% vs. 3% vs. 13%, P=0.001).

Conclusion

Process mining tools help to understand referencing networks visually, easily highlighting inefficiencies and potential needs for improvement. The “Centre” region of Portugal has lower rates and longer delay to primary PCI partially due to the geographical reasons, with worse outcomes in remote regions. The implementation of a new PCI centre in one of these districts, is critical to offer timely first-line treatment to their population.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Presence and clinical significance of myocardial ischemia during aerobic exercise training in patients with ischemic burden

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiovascular rehabilitation is efficient and safe for patients with coronary artery disease (CAD). Exercises are usually prescribed below the clinic and electrocardiographic ischemic threshold. Training above this threshold remains controversial, given the potential risks compared to the additional benefits. However, clinic and electrocardiographic detection of ischemia has lower accuracy than myocardial perfusion scintigraphy (MPS). Therefore, MPS during physical training can better assess ischemia. Moreover, serial maximum MPS can document the benefits of exercise that can be correlated with ischemia during training.

Purpose

To investigate the presence and clinical significance of scintigraphic myocardial ischemia during aerobic exercise in patients with CAD and ischemic burden.

Methods

Thirty-three patients with stable CAD were evaluated at maximum effort (M1) and at rest (R1) using MPS. Twelve patients were excluded; 3 did not complete the intervention, and 9 did not exhibit ischemia. The remaining 21 patients with ischemic burden were included. The intervention consisted of a 12-week training program of moderate-intensity aerobic exercises, below the clinical and electrocardiographic ischemic threshold. During weeks 1 (T1) and 12 (T2), patients underwent MPS during the exercises. After 12 weeks, patients underwent another MPS at maximum effort (M2). All images were quantitatively analyzed, and the presence, extent, and intensity of ischemia were determined.  The Wilcoxon test was used to compare 2 variables, and the Friedman test to compare 3 variables, followed by the post hoc Dunn’s test. Correlations were analyzed using Spearman’s test. The level of significance was set at 5% (p < 0.05).

Results

The prevalence of scintigraphic ischemia during exercise training was 81% at T1 and 71% at T2. The median number (and interquartile range) of ischemic segments at T1 was 3 (2–5), which was significantly different (p = 0.003) from that observed at M1 [5 (3–8)]. The median values of the myocardial uptake in the ischemic segments at R1, T1, and M1 were 59.1% (53.1–68.5), 51.5% (45.3–60.3), and 40.8% (37.3–53.3), respectively, with significant differences between T1 and R1 (p < 0.05) and between T1 and M1 (p < 0.01). After 12 weeks, the extent and intensity of ischemia at maximum effort decreased. The median number of ischemic segments significantly decreased from 5 (3–8) at M1 to 4 (2–6) at M2 (p = 0.005). This reduction in the extent of ischemia after training was significantly correlated with the number of ischemic segments at M1 (r = 0.60; p = 0.004) and at T1 (r = 0.64; p = 0.002), such that patients with more extensive ischemia experienced greater benefits from training.

Conclusions

Scintigraphic ischemia was highly prevalent during moderate-intensity aerobic training in patients with CAD and ischemic burden. There was a correlation between the ischemic stimulus during training and the documented benefits at maximum effort.

Abstract Figure. Polar maps at rest, training and maximum

Process mining tools: where should we build another PCI centre to reduce STEMI mortality?

Introduction

The expected delay of transport between patient location and percutaneous coronary intervention (PCI) centre is paramount for choosing the adequate reperfusion therapy in ST-segment elevation myocardial infarction (STEMI). The central region of Portugal has heterogeneity in PCI assess due to geographical reasons. However, this data is usually presented numerically without providing a visual distribution of patients.

Purpose

We aimed to analyse the impact of distance to PCI centres on mortality in patients with STEMI through visual maps of patients' flow by using an experimental process mining tool, integrated in EIT Health's project PATHWAYS.

Methods

Using the Portuguese Registry of Acute Coronary Syndromes (ProACS), we retrospectively assessed patients with an established diagnosis of STEMI, geographical presentation specified, reperfusion option identified (PCI, fibrinolysis or no reperfusion), short-term outcomes defined as discharge or in-hospital death. With the 2 317 patients that fulfilled the criteria, we used a process mining tool to build national and regional models that represent the flow of patients in a healthcare system, enhancing differences between groups.

Results

Colour gradient in nodes and arrows changes from green to red, with green representing a lower number of patients as opposed to red. In the national model, most patients from all regions had PCI. Mortality was similar between PCI and fibrinolysis groups (4%) but higher in those without reperfusion (9%). In the central region model, one third of the patients were more than 120 minutes away from a PCI centre. Despite that, almost one third of these patients had PCI instead of fibrinolysis. In this model, fibrinolytic therapy had higher in-hospital survival rate than PCI (98% vs. 94%). Overall mortality was higher in the central model compared with the national model (6.92% vs. 5%). Central region had less PCI (53% vs. 73%), more fibrinolysis (15% vs. 7%) and more patients with no reperfusion (32% vs. 20%).

Conclusion

In the ProACS registry, mortality was higher in the central region compared with national data. Even though global interpretation of these findings is limited by underrepresentation from certain central areas, process mining offers an easily understandable view of patients flow. With its statistical upgrade and continuous development, this tool will facilitate the analysis of big data and comparison between groups.

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): EIT Health

P1284 The role of three-dimensional echocardiography in the evaluation of geometry and function of the left ventricle in patients with chronic chagas cardiomyopathy

BACKGROUND

A hallmark of chronic Chagas" cardiomyopathy (CCC) is the early appearance of regional wall motion abnormalities of the left ventricle (LV), especially in the lateral and apical regions. The morphological and functional assessment of LV by two-dimensional (2D) echocardiography, besides depending on geometric assumptions, may not include the most affected segments. The three-dimensional (3D) method offers advantage for the quantification of chamber volumes, but its role in the assessment of patients with CCC is not well established. PURPOSE: The aim of this study is to evaluate the concordance between 3D and 2D methods in the quantification of left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) in patients with CCC. METHODS: 44 patients with CCC were selected. Seven subjects were excluded from the analysis (3 for atrial fibrillation, 1 for frequent ventricular extrasystoles, 3 for inadequate acoustic window), resulting in 37 patients. Subjects were submitted to 2D and 3D transthoracic echocardiography by a single experienced examiner following the recommendations from the chamber quantification guidelines. The concordance between the methods was evaluated using the Lin concordance correlation coefficient (CCI) and the Bland-Altman graph analysis. Descriptive analyses of the percentage of individuals reclassified as to altered or to non altered-LVEDV and LVEF values were performed using normal values of 3D as a reference. RESULTS: Age = 58 ± 12 years, 54% men. LVEF-2D = 47 ± 9% and LVEDV- 2D = 73 ± 18 ml / m². The CCI for the measurements of LVEDV and FEVE by both methods was 0.861 and 0.833, respectively. The mean difference found was 3 mL for LVEDV and 3% for LVEF. The 95% agreement limits found were (-14, 20 ml) for LVEDV and (-5; 11%) for LVEF. When assessed with 2D, 27% of individuals previously classified as having LV enlargement were reclassified as having normal LV volumes using the 3D method. Conversely, regarding LVEF, 16% of individuals considered normal by 2D were reclassified as having reduced LVEF with the 3D method. CONCLUSION: In individuals with CCC measurements of LVEDV and LVEF by 3D and 2D methods show high agreement. However, 3D evaluation allows the reclassification of 27% and 16% of the individuals regarding the presence of LV dilatation and LV systolic dysfunction, respectively.

Abstract P1284 Figure. Bland-Altman plot - LVEF

Suppression of tumor-derived Semaphorin 7A and genetic ablation of host-derived Semaphorin 7A impairs tumor progression in a murine model of advanced breast carcinoma

Solid tumors can generate a plethora of neurogenesis-related molecules that enhance their growth and metastasis. Among them, we have identified axonal guidance molecule Semaphorin 7A (SEMA7A) in breast cancer. The goal of this study was to determine the therapeutic effect of suppressing SEMA7A levels in the 4T1 murine model of advanced breast carcinoma. We used anti-SEMA7A short hairpin RNA (shRNA) to gene silence SEMA7A in 4T1 mammary tumor cells. When implanted into the mammary fat pads of syngeneic mice, SEMA7A shRNA-expressing 4T1 tumors exhibited decreased growth rates, deferred metastasis and reduced mortality. In vitro, SEMA7A shRNA-expressing 4T1 cells had weakened proliferative, migratory and invasive abilities, and decreased levels of mesenchymal factors. Atomic force microscopy studies showed that SEMA7A shRNA-expressing 4T1 cells had an increase in cell stiffness that corresponded with their decreased malignant potential. Genetic ablation of host-derived SEMA7A further enhanced the antitumor effects of SEMA7A shRNA gene silencing in 4T1 cells. Our preclinical findings demonstrate a critical role for SEMA7A in mediating mammary tumor progression.

Biofouling control using microparticles carrying a biocide

This study presents a new technological approach to minimize the use of antimicrobial (AMB) agents and their deleterious effects, based on the principle of drug-delivery systems whereby the AMB chemicals are transported on microparticles. The efficacy of microparticles carrying the quaternary ammonium compound (QAC), benzyldimethyldodecyl ammonium chloride (BDMDAC), was assessed against Pseudomonas fluorescens in both the planktonic and the biofilm state. The microparticles were prepared using a layer-by-layer (LBL) self-assembly technique. Oppositely charged molecules of polyethyleneimine (PEI), sodium polystyrene sulfonate (PSS), and BDMDAC were assembled on polystyrene (PS) cores. BDMDAC-coated particles were observed by CryoSEM and their composition analyzed by X-ray microanalysis. Zeta potential measurements indicated that changes in surface charge were compatible with a BDMDAC/particle interaction. This biocidal carrier structure had significant stability, verified by the release of only 15% of the BDMDAC when immersed in water for 18 months. Biocidal carrier activity was evaluated by determining the survival ratio of P. fluorescens planktonic and biofilm cells after different exposure periods to BDMDAC-coated particles. Tests with biofilm cells were also performed with the free QAC. An efficient AMB effect (minimum bactericidal concentration) against suspended cells was found for a concentration of 9.2 mg l(-1) of BDMDAC on coated particles after incubation for 30 min and 6.5 mg l(-1) of BDMDAC on coated particles after 60 min. Exposure of biofilms to PS-PEI/PSS/BDMDAC (0.87 mg l(-1)) resulted in a decrease in viability of 60.5% and 66.5% of the total biofilm population for 30 and 60 min exposure times, respectively. Exposure for 60 min to 6.33 mg l(-1) and 11.75 mg l(-1) of BDMDAC in PS-PEI/PSS/BDMDAC particles promoted inactivation of 80.6% and 87.2% of the total population, respectively. The AMB effects obtained with the application of free BDMDAC were statistically similar to those promoted by the application of BDMDAC coated particles. The overall results indicate that this novel AMB strategy has potential for the control of microbial growth of planktonic cells and biofouling. Moreover, the technique allows the reuse of AMB molecules and consequently reduces the environmental risks associated with excessive use of AMB agents, thereby providing real benefits to public health.

Radial fluctuations and nonisotropic disclinations in nematic liquid crystals

The aim of this paper is to study the role of the radial symmetry in the profile of anisotropic disclinations of the nematic liquid crystals. It will be shown that when radial fluctuations are allowed a macroscopic term appears. This term preserves the known topology of these disclinations but changes their angular structure and the distribution of elastic energy. Furthermore, it is shown that one of the isotropiclike disclinations predicted by the usual approach is forbidden by the radial fluctuations.

Molecular epidemiology of a nosocomial outbreak due to Enterobacter cloacae and Enterobacter agglomerans in Campinas, São Paulo, Brazil

A total of 73 isolates (57 Enterobacter cloacae and 16 Enterobacter agglomerans), recovered during an outbreak of bacteremia in the Campinas area, São Paulo, Brazil, were studied. Of these isolates, 61 were from parenteral nutrition solutions, 9 from blood cultures, 2 from a sealed bottle of parenteral nutrition solution, and one was of unknown origin. Of the 57 E. cloacae isolates, 54 were biotype 26, two were biotype 66 and one was non-typable. Of 39 E. cloacae isolates submitted to ribotyping, 87.2% showed the same banding pattern after cleavage with EcoRI and BamHI. No important differences were observed in the antimicrobial susceptibility patterns among E. cloacae isolates exhibiting the same biotype, serotype and ribotype. All E. agglomerans isolates, irrespective of their origin, showed same patterns when cleaved with EcoRI and BamHI. The results of this investigation suggest an intrinsic contamination of parenteral nutrition solutions and incriminate these products as a vehicle of infection in this outbreak.

Haemagglutinating properties of Pasteurella multocida type A strains isolated from rabbits and poultry

Thirty-one type A strains of Pasteurella multocida isolated from rabbits and poultry were able to agglutinate red blood cells (RBC) from human group O donors. Except for human RBC from group B which were also agglutinated by 3 strains, neither group A nor RBC from sheep and rabbits were agglutinated. Haemagglutination was mannose-resistant, and the two techniques used detected unrelated activities. One as tested by a slide haemagglutination (MRSH) test was common to most (31 out of 34 strains) capsulated strains, though non-mucoid ones obtained by growth on hyaluronidase-containing medium showed also this property. This haemagglutination activity was destroyed at 100 degrees C for 15 min but not at 56 degrees C for 30 min, was dependent upon an optimal pH range (7.4-7.5) and did not seem to be influenced by different enriched media. The other activity was assayed by the microhaemagglutination (MRMH) test. Only part (19 out of 34 strains) of the strains presented this activity, which was also destroyed by boiling for 15 min and was dependent on the addition of 0.5 of polyvinilpirrolidone to phosphate buffered saline, used to suspend RBC. A correlation between haemagglutination activities of P. multocida type A and the possibility of this microorganism harbouring fimbriate organelles is discussed.

[Social psychiatry of migrant workers (author's transl)]

A review of literature about psychic illness in migrant workers (with special reference to the situation in Europe) is presented, including the problems of incidence and prevalence, course of the illness, typical syndromes and treatment. Results concerning incidence and prevalence of psychic disease in migrant workers are contradictory and partly--for methodological reasons--of questionable quality. It cannot be take for granted, that migrant workers suffer more often from psychiatric disturbances than either of the two possible control groups: the populations of the emigration or immigration countries respectively. There are two high risk periods for migrants: shortly after the migration and after a longer period in the guest country. Differences between the migrant's culture and that of the immigration context (language, mythical beliefs, illness behavior) influence the manifestations of psychiatric syndromes. The following syndromes are typical for migrant workers: paranoid reactions, hypochondric-depressive syndromes, psychosomatic conditions and sexual neurosis. Special attention requests the treatment of migrant workers with psychiatric problems; the aspects of psychotherapy, accompanying social measures and the return as therapeutic measure are discussed. In the second part, a general frame of reference for the sociological analysis of the problem of migrant workers is presented. Reasons for the mass immigration of foreign workers to the industrialized countries of central Europe were the demand of labor force and the large gap in socio-economic development between the countries. In the immigration context, the foreign workers find themselves in the lowest social strata and numerous problems accumulate there. Empirical evidence for different sociological explanations of mental illnes of migrant workers ist presented: hypotheses of social selection vs. social causation (low socio-economic status, goal-striving-stress, culture-shock theory, theory of culture change and isolation hypothesis).