Associations among antimicrobial use, calf management practices, and antimicrobial resistance in Escherichia coli from a pooled fecal sample in calves on Canadian dairy farms: a cross-sectional study

The objective of this cross-sectional study was to determine associations between calf management practices, the number of antimicrobial treatments, and antimicrobial resistance in pre-weaned heifers on Canadian dairy farms. A composite of 5 fecal samples from pre-weaned calves was collected from 142 dairy farms in 5 provinces and analyzed for phenotypic antimicrobial susceptibility with the microbroth dilution method. Questionnaires were used to capture herd characteristics and calf management practices used on the farm. Calf treatment records were collected during the farm visits. Escherichia coli was isolated from all 142 fecal samples with the highest resistance to tetracycline (41%), followed by sulfisoxazole (36%), streptomycin (32%), chloramphenicol (28%), ampicillin (16%), trimethoprim-sulfamethoxazole (15%), ceftriaxone (4.2%), cefoxitin (2.8%), amoxicillin-clavulanic acid (2.1%), ciprofloxacin (2.1%), nalidixic acid (2.1%), azithromycin (1.4%), and gentamicin (1.4%). Multidrug resistance was observed in 37% of E. coli isolates. Three-quarters of farms used fresh colostrum as the most common type of colostrum fed to calves. Colostrum quality was checked on 49% of farms, but the transfer of passive immunity was only checked on 32% of farms in the last 12 mo. Almost 70% of farms used straw or hay or a combination as the bedding material for calves. Among the 142 farms, a complete set of calf records were collected from 71 farms. In a multivariable logistic regression model, farms with ≥1.99 - 32.57 antimicrobial treatments/calf-year were 3.2 times more likely to have multidrug resistant E. coli in calf feces compared farms with <1.99 antimicrobial treatments/calf-year. Farms using hay or straw beddings were 5.1 times less likely to have multidrug resistant E. coli compared with those with other bedding materials including shavings or sawdust. Bedding management practices on farms may need to be investigated to reduce the potential impact on disseminating multidrug resistant bacteria.

Epidemiology of mastitis and interactions of environmental factors on udder health in the compost barn system

ABSTRACT This study aimed to describe the epidemiological indexes of mastitis, milk quality and udder hygiene in the Compost Barn system, as well as to search for associations between isolated pathogens from milk with compost characteristics. Three dairy herds participated in the study, and the samples were collected during different periods on each farm. Individual milk samples were collected in duplicate for SCC analysis and microbiological culture. Environmental pathogens caused most cases of clinical mastitis on farm 2, and contagious pathogens caused the most cases on farm 1. Bed moisture was not associated with the incidence of environmental pathogens. Most of the animals remained in good udder hygiene during the study. Poor udder hygiene contributed to the increased incidence of environmental pathogens in one of the farms. A higher number of animals with a hygiene score of ≥ 2 were observed during the warmer and rainfall periods. There was no association between hygiene scores and somatic cell counts. The results suggest that pathogens isolated from milk in animals confined in Compost Barn under tropical climate are like other confinement systems adopted elsewhere. The year period influenced the udder hygiene score, reinforcing the importance of bed management throughout the year.

Investigation of the protective suitability of a dental fluorinated varnish by means of X Ray fluorescence and Raman spectroscopy

BACKGROUND AND AIM

Evaluating the protective effect in human enamel of a fluorinated varnish after enduring a citric acid erosive challenge.

METHODS

An in vitro model was developed considering the intraoral environment, human saliva and acid erosive procedures. The evaluation of the enamel specimens was undertaken through the direct analysis of enamel by means of Raman spectroscopy and Energy Dispersive X Ray Fluorescence (EDXRF). Ten tooth specimens per group were analysed during three stages: 1- before treatment; 2- After varnish (treatment group) or toothpaste (control) application; 3- After citric acid cycle. Additionally, Particle Induced Gamma Ray emission (PIGE) was used to gauge the fluorine uptake by enamel after the application of the varnish (stage 2). Results were presented as mean and standard deviation with ANOVA and Tukey post hoc performed considering a significance level of 0.05.

RESULTS

A significant (p < 0.05) higher Ca levels were detected in treatment group at stage 2 (37.4 ± 0.4 w/w%) and 3 (37.1 ± 0.1) when compared to the control group. After varnish application in treatment group, depolarization ratios were significant lower (p < 0.05) and anisotropy were significant higher (p < 0.05), however no differences were detected in FWHM.

CONCLUSIONS

The use of a fluorinated dental varnish suggests a protective effect for human enamel against dental erosion demineralization process which was detectable in an in vitro model.

Maternal diabetes promotes offspring lung dysfunction and inflammation in a sex-dependent manner

Exposure to maternal diabetes is increasingly recognized as a risk factor for chronic respiratory disease in children. It is currently unclear, however, whether maternal diabetes affects the lung health of male and female offspring equally. This study characterizes the sex-specific impact of a murine model of diet-induced gestational diabetes (GDM) on offspring lung function and airway inflammation. Female adult mice are fed a high-fat (45% kcal) diet for 6-weeks prior to mating. Control offspring are from mothers fed a low fat (10% kcal) diet. Offspring were weaned and fed a chow diet until 10-weeks of age, at which point lung function was measured and lung lavage was collected. Male, but not female offspring exposed to GDM had increased lung compliance and reduced lung resistance at baseline. Female offspring exposed to GDM displayed increased methacholine reactivity and elevated levels of pro-inflammatory cytokines (e.g. interleukin (IL)-1β, IL-5, and CXCL1) in lung lavage. Female GDM offspring also displayed elevated abundance of matrix metalloproteinases (MMP) within their airways, namely MMP-3 and MMP-8. These results indicate disparate effects of maternal diabetes on lung health and airway inflammation of male and female offspring exposed to GDM. Female mice may be at greater risk of inflammatory lung conditions, such as asthma, while male offspring display changes that more closely align with models of chronic obstructive pulmonary disease. In conclusion, there are important sex-based differences in the impact of maternal diabetes on offspring lung health that could signal differences in future disease risk.

STEMI with mid-range ejection fraction: a group of intermediate risk not to be forgotten

Background

Reduced left ventricular ejection fraction (LVEF) &lt;40% is an important negative prognostic factor in the setting of ST-elevation acute myocardial infarction (STEMI). On the other hand, data concerning mid-range LVEF (mrEF) post-STEMI are scarce. Consequently, recommendations regarding reassessment of LVEF or administration of neurohormonal medication in this group of patients (pts) are also lacking.

Purpose

To assess the current treatment and prognosis of STEMI with mrEF.

Methods

Retrospective study including all consecutive pts hospitalized for STEMI and submitted to primary percutaneous coronary intervention in a Cardiology centre in 2018. Pts were divided into 3 groups according to LVEF assessed before hospital discharge: preserved EF (pEF: LVEF ≥50%), mid-range EF (mrEF: LVEF 40–49%) and reduced EF (rEF: LVEF &lt;40%). We analysed clinical characteristics, treatment, evolution of LVEF post-STEMI and clinical outcomes - death, myocardial infarction (MI) and hospitalization for heart failure (HF) – of the mrEF group and compared it with pEF.

Results

188 pts with a mean age of 61 years were admitted for STEMI in 2018. The majority (58%, n=109) had pEF; 29% (n=55) had mrEF and 13% (n=24) were in the rEF group. Pts in the mrEF group had similar baseline characteristics to the others. However, compared with pEF, culprit-lesion was more often located in left main or left anterior descending arteries (80% vs 35%, p&lt;0.001) and NT-proBNP levels were higher in mrEF pts (2270 vs 881 pg/mL, p&lt;0.001).

At discharge, all mrEF patients were medicated with a renin-angiotensin-aldosterone blocker and 91% with a beta-blocker.

After a median of 8 months, LVEF improved a mean of 4% (± 9%) in the mrEF group. However, in 12.5% LVEF worsened to &lt;40% (vs 0 in the pEF group, p=0.006).

At a median follow-up of 2.6 years, there was an increase in mortality according to the EF group (pEF 4% vs mrEF 13% vs rEF 48%, log-rank: p&lt;0.001 – fig. 1) with a hazard ratio (adjusted for age) of 3.75 (95% CI 1.1–12.8, p=0.035) for mrEF vs pEF. There was also a non-significant tendency to higher rates of the composite endpoint of MI and hospitalization for HF in the mrEF group vs pEF (8.2% vs 2.9%, p=0.213).

Conclusions

This study confirms previous reports of the worse prognosis of STEMI with mrEF and suggests the existence of a continuum of risk of adverse clinical outcomes according to LVEF. Therefore, this group of intermediate risk might also benefit from neurohormonal medication, which is only specifically recommended for rEF in current STEMI guidelines. It also highlights the importance of a closer follow-up (with reassessment of LVEF) of mrEF pts since a non negligeable proportion ultimately progress to rEF and may require additional medical treatment or even an implantable cardioverter defibrillator. Further research with larger samples is required to identify predictors of worsening LVEF and assess the impact of neurohormonal modulation in this population.

Funding Acknowledgement

Type of funding sources: None. Kaplan-Meier Survival Analysis

Aortic plaques in patients with atrial fibrillation: an often-forgotten risk factor for thromboembolism

Background

CHA2DS2-VASc risk score is the main determinant for maintaining anticoagulation after atrial fibrillation (AF) ablation, irrespective of the procedure outcome. The presence of aortic plaques is included in the score, but isn't regularly assessed previously to AF ablation. This way, risk factors for coronary artery disease (CAD) other than arterial hypertension and diabetes mellitus may influence stroke risk in patients with AF, albeit not being included in the CHA2DS2-VASc score.

Purpose

We sought to evaluate the prevalence of aortic plaques diagnosed during transesophageal echocardiography (TOE) in patients submitted to AF ablation and to assess its determinants and clinical impact on the CHA2DS2-VASc score.

Methods

Retrospective study of patients submitted to AF ablation that performed TOE prior to the procedure, with assessment of aortic plaques. CHA2DS2-VASc risk score was evaluated in the pre-ablation patient evaluation and reassessed after TOE. Demographic, clinical and echocardiographic data, including cardiovascular risk factors, were analyzed. We assessed AF recurrence rate, cerebrovascular events and death during follow-up.

Results

120 patients were submitted to TOE prior to AF ablation from November 2015 to December 2020, mean age 66.6 (±9.55) years, 48% male. In 30 (25%) patients aortic plaques were identified in TOE. Mean CHA2DS2-VASc was 2.2 (±1.47) in pre-ablation evaluation and 2.5 (±1.69) post-TOE, increasing in all patients with aortic plaques and prompting beginning of oral anticoagulation in 5 patients. AF was paroxysmal in 74% and persistent in 26% of patients, mean duration of 6.28 (±3.76) years. Arterial hypertension was present in 79 (66%) of patients, type 2 diabetes mellitus in 24 (20%) and dyslipidemia in 67 (56%). 17 (14%) patients had a prior stroke. During a mean follow-up of 30 (±18.3) months, 32 (27%) patients had AF recurrence and 10 (8%) were submitted to redo procedures. 107 (89%) patients remained under oral anticoagulation, stroke occurred in 1 patient and 2 patients died.

In univariate analysis, age, type 2 diabetes mellitus and dyslipidemia predicted an increase in CHA2DS2-VASc score after TOE (respectively, OR 1.113, 95% CI 1.041–1.190, p-value 0.002; OR 2.907, 95% CI 1.145–7.379, p-value 0.025; and OR 2.442, 95% CI 1.016–5.868, p-value 0.046).

In multivariate analysis, age is the only independent predictor of increased CHA2DS2-VASc score after TOE (OR 1.095, 95% CI 1.013–1.185, p-value 0.023). No risk factor for CAD was independently associated with the presence of aortic plaques (Table 1).

Conclusion

In this population, single CAD risk factors were not independent predictors of aortic plaques. If TOE had not been performed prior to AF ablation, 25% of patients would have had an underestimated CHA2DS2-VASc score and would be off anticoagulation after the procedure, unprotected from thromboembolic events.

Funding Acknowledgement

Type of funding sources: None. Table 1

Left atrial stiffness measured by echocardiography is a stronger predictor of atrial fibrillation recurrence after radiofrequency catheter ablation than left atrial volume

Introduction

Left atrial volume (LAV) is an accepted predictor of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation, stronger than AF duration.

Objective

The aim of this study was to assess the value of left atrial stiffness (LAS) index as a new parameter evaluated by echocardiography to the prediction of AF recurrence after radiofrequency catheter ablation.

Methods

We retrospectively studied consecutive patients with paroxysmal or persistent AF submitted to radiofrequency catheter ablation at our institution between 2017 and 2019. We used transthoracic echocardiography to measure the LAV indexed to body surface area and the LAS index, defined as the ratio between the mitral E/e' (obtained with pulsed Doppler at the tip of the mitral leaflets – E, and tissue Doppler imaging at the mitral annulus – e') and the left atrial strain during the reservoir phase (obtained by speckle tracking echocardiography) [LAS index = (E/e') / LA reservoir strain]. The left ventricular ejection fraction (LVEF) was also evaluated. Patients with poor quality echocardiographic images were excluded. We compared 2 groups of patients, according to the recurrence of AF after the blanking period. We analysed the clinical characteristics and echocardiographic findings. The effect of clinical and echocardiography parameters on AF recurrence was evaluated by univariate and multivariate Cox Regression analysis.

Results

We studied 33 patients, 27 with paroxysmal AF and 6 with persistent AF. Baseline patients' characteristics are presented in Table 1. During a mean follow-up time of 17.9±10.4 months, 7 patients (21%) had AF recurrence, and none died. Patients with AF recurrence had a higher LAS index. After adjusting for confounding variables, only LAS index and LAV were independently associated with AF recurrence (Table 2). Every one unit increase in LAS index was associated with an 11-fold increased risk of AF recurrence (HR 10.86, 95% CI 1.38–85.56; p=0.024), while every one unit increase in LAV index was only associated with a 6% increased risk of AF recurrence (HR 1.06, 95% CI 1.01–1.11, p=0.010).

Conclusion

LAS index evaluated by echocardiography was a much stronger predictor of AF recurrence after radiofrequency catheter ablation than left atrial volume.

Funding Acknowledgement

Type of funding sources: None.

Patients with reflex syncope have a higher prevalence of atrial fibrillation than general population which is predicted by the type of the tilt table test response

Introduction

Reflex syncope is the result of an imbalance between the sympathetic and parasympathetic nervous system. The autonomic nervous system has been associated to some forms of atrial fibrillation (AF).

Objective

The aim of this study was to assess the prevalence of AF in patients with reflex syncope and a positive tilt table test and to identify the type of tilt test response in patients with AF in comparison to patients without AF.

Methods

We retrospectively studied consecutive patients that underwent a tilt table test at our institution between 2016 and 2019. We selected those patients with a positive test. Patients with an implanted pacemaker at the time of the tilt test and patients followed in a different institution were excluded. Previous diagnoses of AF episodes were assessed. We analysed the clinical characteristics and the tilt table test results according to previous history of AF.

Results

We studied 49 patients with a positive tilt test. Seven (14.3%) patients had previously diagnosed paroxysmal AF at the time of the tilt table test. Patients with AF were older, had more frequently hypertension, and the tilt test response was more frequently a vasodepressor than mixed or cardioinhibitory response (71.4% vs. 28.6%) (Table). In univariate analysis, age and hypertension were associated with AF, respectively, OR 1.08 (95% CI 1.01–1.17), p=0.034 and OR 10.80 (95% CI 1.19–98.36), p=0.035. A vasodepressor response was also associated with AF (OR 6.25, 95% CI 1.06–36.74, p=0.043).

Conclusions

Patients with reflex syncope and a positive tilt table test had a higher prevalence of AF than the general population. A vasodepressor response was associated with AF as were age and hypertension, demonstrating the possible impact of the autonomic nervous system and the multifactorial nature of AF.

Funding Acknowledgement

Type of funding sources: None.

Predictors of patient and system delay for primary percutaneous coronary intervention

Background

The delay times of the patient and the system for primary percutaneous coronary intervention (p-PCI) have a determining impact on the prognosis of patients with acute myocardial infarction with ST segment elevation (STEMI).

Purpose

To identify the predictors of patient and system delay for p-PCI in the period of 2020 at a reference hospital for p-PCI.

Methods

Patients submitted to p-PCI in the period from March to September 2020 were included and compared with the same period in 2019. We analyzed the differences between the two groups regarding the patient's delay times, time from the onset of symptoms to the first medical contact (FCM) and the system (time from the first contact with the health system to p-ICP). Data collection of the patient's previous history, coronary intervention performed and post-PCI follow-up was performed using the electronic patient record. Univariate analysis and logistic regression models from multivariate analysis were used to determine the predictors of “patient delay” and “system delay” and adjusted for confounding factors. The analysis was performed with a significance level of 5%.

Results

We included in the study 255 patients who underwent p-PCI, of which 122 in the period from 2020 and 133 in the period from 2019. Regarding the characteristics of the population, there were no significant differences between the two periods. Regarding the patient's delay time, there were no statistically significant differences. The variable first medical contact with a non p-PCI center was the only variable associated with system delay&gt;90 minutes in the multivariate analysis, OR (6.18: 95% CI, 1.91–20), p=0.002. There was a statistically significant association between the period of 2020 (pandemic period) and total ischemia time, but with a negative effect, dependent variable adjusted for confounding factors [adjusted OR: −0.10; 95% CI: −107.61 to −5.57; p=0.03].

Conclusion

In this study, the patient's admission to a non p-PCI centers was identified as the only predictor of longer delay until p-PCI (system delay). However, these results should serve as a contribution to decision making in order to mitigate risks, regardless of any associated catastrophe and eventually alert the population not to neglect the symptoms suspected of acute myocardial infarction.

Funding Acknowledgement

Type of funding sources: None.

Abstract MP237: Multi-omics Profiling Reveals Stearoylcarnitine As A Novel Biomarker Of Cardiometabolic Disease Development In Rat Offspring Exposed To Gestational Diabetes

Through unknown mechanisms, fetal exposure to gestational diabetes mellitus (GDM) increases the risk for cardiovascular disease development later in life. We hypothesize that fetal exposure to GDM alters offspring cardiomyocyte metabolism and left ventricular (LV) function with age. To induce GDM, female rats were fed a high fat (45% kcal) and sucrose diet prior to mating, throughout pregnancy and lactation. Lean controls received a low fat (10% kcal) diet. Fetal rat ventricular cardiomyocytes (FRVC) were isolated from e20 offspring for U-13C glucose metabolic flux analysis, mitochondrial respiration and calcium handling. The cardiac transcriptome and metabolome were measured in 3-month old offspring. LV morphology and function was assessed in the offspring from e18 to 12-months of age by transthoracic ultrasound. Offspring exposed to GDM exhibited increased LV posterior wall thickness and impaired LV filling across their life course (fetal to 12-months of age; p<0.05). Consistent with the development of diastolic dysfunction in vivo, alterations in calcium flux and sarcoplasmic reticulum-dependent calcium re-uptake (1.5 and 1.6-fold greater, respectively) were observed in FRVC isolated from GDM offspring (p<0.05). When FRVC were treated with isoproterenol, U-13C glucose metabolic flux through glycolysis and the citric acid cycle was reduced in GDM offspring, compared to Lean controls. In 3-month old GDM offspring serum and cardiac metabolomics revealed an altered acylcarnitine profile, with specific elevation in long chain acylcarnitine species including stearoylcarnitine. Alterations in the metabolome corresponded to changes in gene expression patterns identified by RNA-Seq associated with glucose metabolism and fatty acid transport pathways (e.g. Irs2, Slc2a4, Pfkfb2, Pdk4 and Cpt1a). These alterations corresponded with mitochondrial dysfunction, impaired cardiomyocyte metabolic flux and contractility, in concert with LV hypertrophy and diastolic dysfunction in the rat offspring. Multi-omics profiling reveals stearoylcarnitine as a novel biomarker and implicates mitochondrial oxidative metabolism as a mechanism that links early-life GDM exposure to the development of cardiovascular disease later in life.

Tafazzin Deficiency Reduces Basal Insulin Secretion and Mitochondrial Function in Pancreatic Islets From Male Mice

Tafazzin (TAZ) is a cardiolipin (CL) biosynthetic enzyme important for maintaining mitochondrial function. TAZ affects both the species and content of CL in the inner mitochondrial membrane, which are essential for normal cellular respiration. In pancreatic β cells, mitochondrial function is closely associated with insulin secretion. However, the role of TAZ and CL in the secretion of insulin from pancreatic islets remains unknown. Male 4-month-old doxycycline-inducible TAZ knock-down (KD) mice and wild-type littermate controls were used. Immunohistochemistry was used to assess β-cell morphology in whole pancreas sections, whereas ex vivo insulin secretion, CL content, RNA-sequencing analysis, and mitochondrial oxygen consumption were measured from isolated islet preparations. Ex vivo insulin secretion under nonstimulatory low-glucose concentrations was reduced ~52% from islets isolated from TAZ KD mice. Mitochondrial oxygen consumption under low-glucose conditions was also reduced ~58% in islets from TAZ KD animals. TAZ deficiency in pancreatic islets was associated with significant alteration in CL molecular species and elevated polyunsaturated fatty acid CL content. In addition, RNA-sequencing of isolated islets showed that TAZ KD increased expression of extracellular matrix genes, which are linked to pancreatic fibrosis, activated stellate cells, and impaired β-cell function. These data indicate a novel role for TAZ in regulating pancreatic islet function, particularly under low-glucose conditions.

Effects of lipid and starch supplementation as water intake mitigation techniques on performance and efficiency of nursing Holstein calves

Exploring alternative supplementation sources capable of maximizing feed and water efficiency in nursing Holstein calves is often ignored. The goals herein involve investigating the effects of two isoenergetic supplements on a nonmedicated milk replacer diet on total water intake, milk water intake, fresh water intake, feed intake parameters, and performance of Holstein nursing bull calves. Twenty-three animals (body weight [BW] = 94.67 ± 12.07 kg, age = 67 days old) were randomly assigned to one of three treatments for 68 days: control (CON; ad libitum milk replacer, n = 7), carbohydrate supplement (CHO; corn starch on top of ad libitum milk replacer-based diet, n = 8), or lipid supplement (FAT; menhaden fish oil on top of ad libitum milk replacer-based diet, n = 8). The isoenergetic supplementation consisted of 3% menhaden fish oil addition on DM basis for FAT. This was matched energetically with corn starch for the CHO group resulting in a 7% composition in DM basis. All animals were provided free access to mineral mix and 120 g daily dried microbrewer’s spent grains (BG). Data were analyzed with the GLMMIX procedure of SAS in a completely randomized design with the diets as a fixed effect. Dry matter intake (DMI) adjusted by average daily gain (ADG; DMI/ADG) resulted in significantly lower values for supplemented groups with CON = 2.48, CHO = 2.38, and FAT = 2.27 kg/kg _(ADG) (P = 0.033). Energy intake values were lower for CON when analyzing metabolizable energy intake (P < 0.0001), net energy intake for maintenance (P < 0.0001), and net energy intake for gain (P < 0.0001), followed by CHO, and then FAT. Total water intake (P < 0.0001), milk water intake (P < 0.0001), and fresh water intake (P < 0.0001) all resulted in CHO consuming 0.5 L or less water than the other two treatments. Energy requirements as digestible energy (P < 0.0001), metabolizable energy (P < 0.0001), net energy for maintenance (P < 0.0001), and net energy for gain (P < 0.0001) were lower for CHO, followed by CON, and then FAT having the highest requirements. Similar results were observed for residual feed (RFI; P = 0.006) and residual water intakes (RTWI; P = 0.902). Ultimately, no performance differences were detected with regards to BW (CON = 146.71, CHO = 146.25, and FAT = 150.48 kg; P > 0.1). These results indicate that lipid-based and starch-based supplementation can potentially increase feed efficiency and decrease voluntary water intake without adversely affecting performance.

Rapid atrial fibrillation increases cardiac biomarkers: decision to perform coronary angiography based on novel high-sensitivity Troponin I peak

Funding Acknowledgements

Type of funding sources: None.

Background

Since January 2018 the availability of high sensitivity Troponin I (hsTnI) has improved ischemia diagnosis. In patients with rapid atrial fibrillation (AF), the decision to undergo coronary angiography is usually due to elevated cardiac biomarkers. However, evidence to support the rentability of this approach is sparse.

Purpose

Evaluate if hsTnI in patients with rapid AF and elevated cardiac biomarkers has a good discriminative power to predict a positive coronary angiography.

Methods

We retrospectively studied consecutive patients admitted to the emergency department (ED) between January 2018 and December 2019 with rapid AF that underwent coronary angiography and had multiple hsTnI values obtained. We analysed risk factors, initial and peak hsTnI, time from ED admission to peak hsTnI and ST-T segment abnormalities (ST depression and/or T wave inversion). We evaluated the presence of significant coronary artery stenosis with the need of revascularization at coronary angiography. Univariable and multivariable analysis was performed to obtain the Odds Ratio (OR, 95% CI, p-value) for significant coronary artery disease (CAD).

Receiver operator characteristics (ROC) curve and area under the curve (AUC) were obtained to determine the discriminative power of peak hsTnI as predictor of a positive coronary angiography. Optimal cut-point value was obtained (Youden index) and patients were divided according to this value.

Results

From 1407 patients admitted to the ED with rapid AF, 30 patients, 60% male, median age 74 (IQR 61.25-80.75) years, were submitted to coronary angiography. Significant coronary artery stenosis was present in 17 (57%) patients.

Age, ST-T segment abnormalities and peak hsTnI were predictors of significant CAD, respectively 1.203, 1.064-1.361, 0.003; 25.00, 3.522-177.477, 0.001; and 1.000, 1.000-1.001, 0.015.

Optimal cut-point value for predicting the presence of significant coronary artery stenosis at coronary angiography was a peak hsTnI of 359 pg/mL (AUC 0.869, p-value 0.001, 95% CI 0.742-0.995). The two groups with hsTnI &lt; 359 and hsTnI &gt;359 differed in age and ST-T segment abnormalities (see Table).

After adjustment, peak hsTnI &gt;359 pg/mL was the only independent predictor of significant CAD (23.894, 1.310-435.669, 0.032).

Conclusion

In this group of patients with rapid AF, peak hsTnI &gt;359 pg/mL was the only independent predictor of significant coronary artery disease. Therefore, those patients should undergo coronary angiography. Abstract Figure.

Three-dimensional late gadolinium enhancement increases the diagnostic yield of cardiovascular magnetic resonance to detect low voltage in the right ventricular outflow tract

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac magnetic resonance (CMR) using late gadolinium enhancement (LGE) fails to detect scar tissue in patients with electroanatomical abnormalities and biopsy-proven structural heart disease. It has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT). Three- dimensional (3D) LGE enables high-spatial resolution more appropriate to the thin-walled right ventricle than two-dimensional (2D) LGE.

Objective

Our aim was to evaluate if the use of 3D-LGE would improve the performance of CMR to detect low voltage areas in the RVOT of patients with PVCs.

Methods

Since May 2020 we performed 3D-LGE CMR in 11 consecutive patients that underwent ablation of frequent PVCs. A control group of 11 consecutive patients that underwent catheter ablation by the same operator and had a 2D-LGE CMR performed before ablation was also studied. All patients had normal 2D-LGE CMR. A 3D electroanatomical bipolar voltage map of the RVOT was performed in sinus rhythm (0.5 mV-1.5 mV colour display). Areas with electrograms &lt;1.5 mV represented the LVA. The area adjacent to the pulmonary valve usually displays voltage between 0.5 and 1.5 mV and is classified as transitional-voltage zone. Presence of LVAs outside this transitional-voltage zone were estimated.  We compared the accuracy of CMR for detecting LVA in the two groups: 3D LGE and 2D LGE.

Results

The median number of points used for the voltage map was 344 (242-450). 18 patients (82%) displayed LVAs. The site of origin of the PVCs was the RVOT in 17 patients and the left ventricular outflow tract (LVOT) in 5. Comparison between groups is displayed in the table.  2D LGE CMR failed to demonstrate abnormalities of the RVOT in any of the patients that presented with LVAs. 3D CMR showed presence of fibrosis (Figure) in 3 out of 9 patients with LVAs (33%).

Conclusion

CMR using 3-D LGE techniques showed an increased power to diagnose structural abnormalities. This technique may be a better choice in initial stages of RVOT disease. All sampleN = 223D-LGE CMRN = 112D-LGE CMRN = 11p-valueAge in years, median (Q1-Q3)47 (35-68)62 (34-55)42 (34-55)0.243Male gender, n (%)8 (36)3 (27)5 (46)0.330PVCs RVOT/LVOT17/59/28/30.500Nº points in the map, median (Q1-Q3)344 (242-450)350 (259-450)300 (158-345)0.076Low voltage areas, n (%)18 (82)9 (82)9 (82)0.707Abstract Figure.

Optimal percentage of biventricular pacing to obtain CRT response: how high is high enough

Funding Acknowledgements

Type of funding sources: None.

Background

The greatest benefit with cardiac resynchronization therapy (CRT) is achieved when biventricular pacing (BivP) percentage (%) is close to 100%. However, in some patients that goal can be challenging to obtain.

Purpose

Determine whether a lower BivP% could lead to similar CRT response and events, as compared with patients with BivP% &gt;98%.

Methods

Patients with CRT followed up in a remote-monitoring network were retrospectively analyzed. BivP% was assessed and response to CRT was defined as an absolute increase in left ventricle ejection fraction (LVEF) &gt;5% or a relative increase in LVEF &gt;15%.

Low BivP% was defined as &lt;98%. Clinical, echocardiographic data and all-cause death during follow-up were evaluated. ROC curve and AUC were obtained to determine the discriminative power of BivP% as predictor of CRT response. Optimal cut-point value was obtained and patients were divided according to this value. Kaplan-Meyer survival function was used to compare survival in the different groups and the Log-rank test was used for comparison between the groups.

Results

88 patients, 76% male, median age 73.5 (IQR 65.75-79.25) years were included. A CRT-D was implanted in 69%. Etiology was ischemic in 44%. 93% were under beta-blockers. Median LVEF before CRT was 27% (IQR 20.25-32). 

44 patients (50%) had low BivP% (median 91%, IQR 96-99), 55% due to atrial fibrillation and 52% due to frequent premature ventricular complexes. After optimization of medical therapy, device programming and/or interventional procedures, we obtained a BivP &gt;98% in 26 out of the 44 patients (59%). However, in 18 patients (20%) BivP% was &lt;98% (median 95, IQR 92.25-96). 66% patients were CRT responders. Median follow-up was 36 (IQR 23.75-84) months. During follow-up, all-cause mortality was 27% (24 patients).

Optimal cut-point value for predicting CRT response was 91% BivP% (AUC 0.644, p-value 0.047, 95% CI 0.496-0.792). The characteristics of the two groups didn’t differ significantly (Table).

Survival was significantly higher in patients with BivP% &gt;91% (Log-rank 3.667, p-value 0.050) – Figure.

Conclusion

In this population, BivP% &gt;91% was sufficient to achieve CRT-response and was associated with a better survival. BivP% &lt;91%(n = 4)BivP% &gt;91%(n = 84)p-valueAge in years, median (IQR)72.50 (70.50-73.75)74.00 (65.00-80.00)0.666CRT-D, n (%)3 (75.0)58 (69.0)0.999Ischemic cardiopathy, n (%)3 (75.0)35 (41.7)0.311LVEF before CRT, median (IQR)27 (19-39)27 (20-32)0.795Beta-blockers, n (%)4 (100.0)78 (95.1)0.999Abstract Figure.

A new approach to atrial flutter ablation using functional substrate mapping with wavefront discontinuity during sinus rhythm

Funding Acknowledgements

Type of funding sources: None.

Background

Ultra high-density (UHD) mapping allows accurate identification of local abnormal electrograms and low voltage within a small area range, allowing precise identification of reentry circuits. Areas with high isochronal density in a small area known as deceleration zones (DZ) are responsible for reentry.

Purpose

Identify the DZ and areas of low voltage in sinus rhythm (SR) and evaluate the feasibility of performing atrial flutter (AFL) ablation by targeting those zones.

Methods

We prospectively enrolled patients in SR referred for AFL ablation (either typical or atypical). An isochronal late activation mapping (ILAM) during SR with UHD catheter was performed, annotating latest deflection of local electrograms. DZ were defined as areas with &gt;3 isochrones within 1cm radius, prioritizing zones with maximal density. Atrial flutter was then induced and ILAM during flutter was performed for comparison. Voltage mapping was also assessed (0.1-0.5mV). Ablation targeted DZ in SR that displayed the higher voltage. DZ in SR were compared to DZ in AFL. Number of radiofrequency (RF) applications needed to terminate AFL were assessed. After AFL termination, complete line of the slow conduction zone was completed, and pulmonary vein isolation (PVI) was done in case of left AFL. Categorical variables are presented in absolute and relative values and median and interquartile range were used for numerical variables, as well t-student test for correlation of numerical variables.

Results

We studied 6 AFL (4 atypical, 66.7%) in 5 patients, 2 male (40%), median age 70 (64- 72). UHD ILAM in SR with 2195 points (1212-2865) and 2197 points (1356-3102) in AFL (p = 0.62).  The UHD ILAM identified a median of (QR) DZ in SR, that colocalized with AFL isthmus and DZ in AFL in 100%. DZ were not always located in low voltage areas. Aiming at the higher voltage in the DZ terminated the AFL in all cases, with a median RF time of 38 (25-58) seconds and AFL was no longer inducible. However, according to protocol, the complete line of slow conduction zone was done, with a median RF time of 1049.5 (274-1194) seconds (p = 0,009).

Conclusions

Isochronal mapping in sinus rhythm with UHD catheters can display the functional substrate for reentry in AFL, allowing a substrate guided ablation in case of non-inducible AFL. Targeting the areas of high isochronal density, is effective in terminating AFL, obviating the need for extensive ablation. Abstract Figure.

Assessment of wavefront propagation speed on the right ventricular outflow tract: deceleration zones associated with the presence of low voltage areas

Funding Acknowledgements

Type of funding sources: None.

Background and aims

Activation wavefront is rapid and uniform in normal myocardium. Fibrosis is associated with deceleration zones (DZ) and late activated zones. The presence of low voltage areas (LVAs) in the right ventricular outflow tract (RVOT) of patients with premature ventricular contractions (PVCs) from this origin has been described previously. The aim of this study was to evaluate in sinus rhythm, the RVOT endocardial activation duration (EAD) and the presence of DZs, in patients with PVCs and in controls.

Methods

Consecutive patients with frequent (&gt;10.000/24 h) idiopathic PVCs with inferior axis subjected to ablation that had an activation and voltage map of the RVOT performed in sinus rhythm. A control group of patients without PVCs that underwent ablation of supraventricular arrhythmias was also studied. Patients with structural heart disease, previous ablation or conduction disease were excluded. The RVOT EAD was measured as the time interval between the earliest and the latest activated region. Also evaluated the number of 10 ms isochrones throughout the RVOT and the maximal number of 10 ms isochrones within 1 cm, and a DZ was defined as a zone with &gt; 3 isochrones within 1 cm. Low voltage areas (LVA) were defined as areas with local electrogram amplitude &lt;1.5 mV.

Results

42 patients, 29 in the PVC group and 13 control subjects. The site of origin of the PVCs was the RVOT in 23 patients and the LVOT in 6. The characteristics of the two groups are displayed in the Table. Patients with PVCS had longer RVOT EAD, total number of isochrones and presence of DZ was also significantly higher (See table).  LVAs were more frequent in PVCs from the RVOT than from the LVOT (83% vs 33%, p = 0.033). Patients with LVA had longer EAD 60 (52-67) vs 36 (34-40) ms, p &lt; 0.0001 (Figure A) and more DZ than patients without LVA 95% vs 0%, p &lt; 0.0001 (Figure B and C).

Conclusions

The velocity of the wavefront propagation was slower and DZs were more frequently present in patients with PVCs and were associated with presence of LVAs. All sampleN= 42PVCsN = 29ControlsN = 13p-valueAge in years, median (Q1-Q3)56 (35-65)58 (38-66)53 (28-67)0.648Male gender, n (%)19 (45)14 (48)5 (39)0.401Nº points in the map, median (Q1-Q3)410 (338-589)467 (345-660)345 (333-465)0.056Activation duration in ms, median (Q1-Q3)41.8 (36-61)56 (41-66)39 (35-41)0.001Nº isochrones, median (Q1-Q3)4 (4-6)5 (4-6)4 (4-4)0.037Presence of DZs, n (%)20 (48)20 (69)0 (0)&lt;0.0001Presence of LVAs, n(%)21 (50)21 (72)0 (0)&lt;0.0001Abstract Figure.

Echocardiographic but not clinical response to CRT is an independent predictor of a better survival free from arrhythmic events

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac resynchronization therapy (CRT) is of proven benefit in heart failure patients, improving mortality and reducing hospital admissions. There is however uncertainty if the arrhythmic risk is reduced in responders.

Purpose

We aimed to assess if patients with a CRT implanted for primary prevention had less arrhythmic episodes if they responded to this therapy and if echocardiographic and clinical responses to CRT differ regarding the occurrence of ventricular arrhythmias.

Methods

We prospectively enrolled patients that underwent CRT implant for primary prevention according to ESC guidelines. Patients were classified as responders if they fulfilled one of four criteria (echocardiographic or clinical) at six months after implant: a 5% absolute improvement in LV ejection fraction (LVEF), a 15% improvement in LVEF, a 15% decrease in LV end-diastolic volume or a decrease in NYHA class. During follow-up with device interrogation, arrhythmic ventricular events (AVE) were classified as appropriate ICD therapies or sustained ventricular tachycardia either occurring in ICD monitoring zones or undetected by the device due to a slower rare, but clinically documented. All patients were further classified according to type of pacing, biventricular or LV only. Demographic characteristics of patients were also assessed.

Results

We enrolled 73 patients, 58 (79.5%) male, median age of 72 (65-77) years. Median LVEF was 28 (22-35) % (p = 0.95 between groups), ischemic etiology in 36 (46.6%, p = 1.00). The two groups with and without AVE did not differ significantly regarding clinical, echocardiographic, and electrocardiographic characteristics (table). CRT echocardiographic response criteria were met by 50 (68.5%) of patients and clinical criteria by 53 (72.6%) patients. AVE occurred in 15 (20.5%) patients. In univariate regression analysis, echocardiographic response was associated with reduced AVE (OR 0,14; p = 0,005). Clinical response to CRT was not associated with AVE (p = 0.07). LV only pacing was associated with a higher probability of AVE (OR 5.1; p = 0.038). In Cox regression multivariate analysis, response to CRT was the only independent predictor of better survival free from AVE (HR 0.28;CI 95%, p = 0.044) and LV only pacing was not associated with more episodes of ventricular arrhythmias (p = 0.17). Conclusions: Echocardiographic, but not clinical response to CRT therapy, is the only independent predictor of a higher survival free from arrhythmic events. In spite controversies regarding the arrhythmogenic role of LV pacing, this was not associated with higher ventricular arrhythmic events. Abstract Figure.

Clinical impact of transoesophageal echocardiography in acute brain ischaemia: who should we select?

Funding Acknowledgements

Type of funding sources: None.

Background

Stroke is a prevalent disease and is still the leading cause of death in Portugal. Transoesophageal echocardiography (TOE) is a sensitive test often performed to detect embolic sources. However, since its most common findings such as patent foramen ovale (PFO) and atheroma plaques do not necessarily mandate a change in treatment, there is still debate over its clinical impact in the context of brain ischaemia (BI) and which patients (pts) should be submitted to it. 

Purpose

To assess the clinical impact of TOE following BI and to identify clinical and diagnostic testing results that could help predict which pts benefit from it.

Methods

A retrospective study was conducted including all pts submitted to TOE in our hospital after acute BI in 2018 and 2019. Clinical and testing data (brain, vascular and cardiac imaging and 24h-Holter monitoring) was analysed and compared between 2 groups: the pts who had findings in TOE compatible with a source of embolism which resulted in a change in treatment ("relevant TOE" group) vs all other pts who had no such findings or whose findings did not result in change in treatment ("others"). Predictors of relevant TOE were also analysed.

Results

 Of the 87 pts (mean age of 57 and maximum of 83) included in the study, 51 (59%) had findings compatible with a potential source of embolism in TOE, PFO being the most common (n = 42). In only half of them did these findings result in a change in treatment (the relevant TOE group: n = 25; 29% of the overall population).

Age and other baseline characteristics did not significantly differ between groups. Pts with a relevant TOE presented more often with visual-field defects (32% vs 10%, p = 0.020) and were more likely to have visible acute lesions on brain imaging (96% vs 76%, p = 0.032) compared with the others. There was also a borderline significant association between the presence of infarct in the territory of the superior cerebellar artery and a relevant TOE (p = 0.054). On the contrary, the presence of significant lesions in extracranial arteries was negatively associated with a relevant TOE (p = 0.016).

Considering the whole population, there were no transthoracic echocardiography (TTE) predictors of a relevant TOE but when analysing only younger patients (age &lt; 50), the presence of any abnormality in TTE became associated with a relevant TOE (OR 8.5, CI 1.1-63.9; p = 0.044). We found no predictors of relevant TOE in 24h-Holter results.

Conclusions

TOE commonly identified potential sources of brain embolism, which proved relevant in half the cases. In the impossibility of submitting all BI patients to TOE, this study suggests that brain and vascular imaging rather than age or other baseline characteristics may be useful in predicting a relevant result. Moreover, TTE does not seem to be an adequate screening method to select patients for TOE, except possibly in younger patients. Studies with larger samples are needed to confirm these results.

Acute coronary syndrome in COVID-19 times: could it be business as usual?

Funding Acknowledgements

Type of funding sources: None.

Background

In an attempt to cope with the COVID-19 pandemic, several measures of social distancing and reorganization of health care systems have been adopted. In Portugal, these included suspending elective clinical activity and a temporary national lockdown. Data from multiple centres, including central hospitals in Portugal, has shown a reduction in hospital admissions for acute coronary syndrome (ACS) during the COVID-19 outbreak. Fear of going to the hospital and physical inactivity have been pointed as possible explanations.

Purpose

to assess the impact of this pandemic and the measures taken against it on the pattern of admissions and treatment of patients with ACS in a district hospital. 

Methods

A single-centre retrospective study was conducted in the Cardiology Department of a Portuguese district hospital, capable of performing 24h percutaneous coronary intervention. We analyzed the admissions for ACS during the peak of the first COVID-19 outbreak in Portugal (16th of March to 3rd of May 2020, coinciding with the suspension of elective activity) and compared it with two control periods: one immediately preceding the study period (27th of January to 15th of March - 2020 control) and one exactly one year before (16th of March to 3rd of May 2019 - 2019 control).

Results

During the 7 weeks of the first COVID-19 outbreak, 46 patients were hospitalized for ACS in our department, while 54 had been admitted during the 2020 control period and 40 in the 2019 control period, with a mean of 7 admissions/week (vs 8 and 6, respectively; p > 0.05). There were no significant differences between the study group and both controls regarding basal characteristics. Their presentation did not differ: the majority of patients (57%) was admitted for ST-elevation myocardial infarction and median time from symptom onset to admission to the emergency room was 3 hours, with 4% of patients presenting in Killip class ≥III (p > 0.05 for all). We also found no significant differences in the treatment administered nor in the outcomes (96% submitted to coronary angiography, median length of hospitalization of 4 days and in-hospital mortality rate of 2%, p > 0.05 for all). 

Conclusions

Our study suggests that the reduction in admissions for ACS during the COVID-19 outbreak is not universal. Additionally, severity at presentation, treatment administered and outcomes did not seem to differ. The relatively low prevalence of COVID-19 in our hospital"s region might be the cause, since people might fear and refrain less from going to the hospital. Larger studies with other centres in low-prevalence regions are needed to confirm this hypothesis.

Predictors of relapse after improved ejection fraction in patients with heart failure

Background

Patients with systolic dysfunction with improvement in left ventricular ejection fraction (LVEF) present a more favorable clinical profile when compared to those that maintain dysfunction. However, little is known about the characteristics of patients who “relapse” after LVEF improvement.

Purpose

Evaluate prevalence, clinical characteristics and outcomes of patients in whom ejection fraction declined after previous improvement.

Methods

We retrospectively studied patients followed at a heart failure (HF) clinic with LVEF improvement after an initial diagnosis of HF with reduced ejection fraction (EF), which was defined as having an LVEF &gt;40% on follow-up. We then evaluated the presence of LVEF “relapse” in these patients – a decline in LVEF to &lt;50% or &lt;40%, in cases where it recovered to preserved EF or to mid-range EF, respectively. We analysed patient demographics, clinical parameters and outcomes and used logistic regression to assess the predictors of LVEF “relapse”.

Results

98 patients were studied, 70 (71%) male, median age 69 (58–76) years.

Fifty-four (55%) patients had recovered EF (&gt;50%) and in 44 (45%) it had improved to mid-range values. In 36 (37%) occurred LVEF “relapse”: in 10 (10%) patients to an EF 40–50% and in 88 (90%) to an EF&lt;40%.

Ischemic cardiomyopathy and non-ischemic dilated cardiomyopathy were the main HF aetiologies (38% and 35%, respectively).

During a median follow-up of 7 years, 39 (40%) patients had at least one HF hospitalization. Global mortality was 30%, with no significant statistical difference between the two groups.

In univariate analysis, HF duration, type 2 diabetes mellitus (T2DM), left main or left anterior descending coronary (LAD) disease, valvular heart disease (VHD) and chronic kidney disease (CKD) predicted LVEF “relapse”.

In multivariate analysis, T2DM, left main or LAD disease and VHD were the only predictors of LVEF “relapse” (Table).

Conclusion

In this group of patients, LVEF “relapse” after it had initially improved was frequent and was predicted by the presence of T2DM, left main or LAD disease and VHD. Despite improved systolic function, these patients remain at high risk, thus the need to maintain treatment.

Funding Acknowledgement

Type of funding source: None

Substrate guided ablation of idiopathic right ventricular outflow tract premature ventricular contractions in patients with low arrhythmia burden during the procedure

Background

Ablation of premature ventricular contractions (PVCs) is currently based on activation mapping. This strategy is impaired by the absence or paucity of PVCs on the day of the procedure. Frequently, isolated diastolic potentials (DP) are present at the successful ablation site in sinus rhythm (SR), although their meaning is still a matter of debate.

Objective

Evaluate the feasibility and results of a substrate-based approach for ablation of idiopathic right ventricular outflow tract (RVOT) PVCs, in patients that present with a low PVC burden during the procedure.

Methods

We included 12 consecutive patients referred for ablation of frequent (&gt;10000/24 hours) idiopathic PVCs from the RVOT that present with less than 2 PVCs/min in the beginning of the procedure. The ablation was based on fast mapping of the RVOT in SR looking for DPs, defined as isolated small amplitude potentials occurring after the T wave of the surface ECG in SR (Figure). The area with DPs was marked and a reduced activation mapping of the PVCs was done in that area. We evaluated the procedure time, mapping, fluoroscopy and radiofrequency (RF) application times. The number of points used for the maps, the area of DPs, local activation time and success rate. Values are presented as median (Q1-Q3). Electroanatomical mapping of the RVOT in SR was also performed in a control group of 10 subjects that underwent ablation of supraventricular arrhythmias, to evaluate the prevalence of DPs in subjects without PVCs.

Results

The number of PVCs during the procedure was 1 (0.1–1.6)/min. Both groups did not differ in relation to age or gender. Median age 45 (34–65) years, 6 males in the PVC group and 40 (33–65) years, 6 males in the control group, p=0.821 and p=0.231 respectively. The number of points sampled per RVOT map in SR was 400 (193–500) in the PVC group and 330 (277–425) in the control group, p=0.539. All patients in the study group had DPs in the RVOT. None of the control group subjects had DPs in the RVOT. Ablation data is presented in the Table. The acute success rate was 100%. After a median follow-up time of 4 (3–6) months one patient had recurrence.

Conclusion

In these group of patients with very low PVC burden during the procedure, this approach partially based on substrate mapping, made ablation of the PVCs feasible, in a fast and efficient way.

Funding Acknowledgement

Type of funding source: None

Land Use Regression Model for Exposure Assessment to PM2.5 and PM10 in Rio de Janeiro, Brazil

Background

Air pollution is a major public health problem. The latest data from World Health Organization show that 9 out of 10 people breathe air containing high levels of pollutants and that about 4.2 million deaths were caused by exposure to fine particles in 2016. Therefore, the aim of our study was to elaborate a model for long-term exposure assessment to air pollution.

Methods

This study was developed in Rio de Janeiro city, it has 1,200.255 km² large, about 6.7 million residents and located in the southeastern region of Brazil. The information of PM2.5, PM10 and predictor variables were obtained from government agencies. The potential predictor variables have been used: temperature, relative humidity, vehicular traffic base, Census, altitude databases, vegetation cover, land use, rock masses, hydrographic and hydrographic sub-basins, urban zoning and road network. For the development of Land Use Regression models, linear regression models were specified using the supervised stepwise procedure. Cook D statistics were used to detect influential observations. The overall model performance was evaluated by leave-one-out cross validation (LOOCV).

Results

The annual mean of PM2.5 and PM10 was 11.73 (SD = ± 4.84) and 35.57 (SD = ± 8.91) μg·m−3, respectively. The R2 value in the final model for PM2.5 was 0.3812 and p-value: 0.0907. The performance evaluated by LOOCV was not also good, the RMSE was 0.2920, with R2 value of 0.1820. The R2 value in the final model for PM10 was 0.73, p-value: 0.001. The performance evaluated by LOOCV was also good, the RMSE was 0.1386, with R2 value of 0.5832.

Conclusions

The model could be applied in areas where there is no monitoring of air quality, thus, enabling the evaluation of the health impact of exposed populations, providing support for decision-making and development of public and investments policies, medium impact and long-term, more targeted in the following areas: health, environment, transportation and urban planning.

Key messages

Oswaldo Cruz Foundation. Universidade do Estado do Rio de Janeiro.

Evaluation of the effect of fluorinated tooth bleaching products using polarized Raman microscopy and particle induced gamma-ray emission

In this in vitro study, the effect of the application of tooth bleaching products in human enamel was evaluated using polarized Raman microscopy, particle induced gamma-ray emission (PIGE) and Vickers Hardness test. Due to their acidic nature, teeth whitening products are associated with changes in enamel mineralization. Consequently, products have appeared in the market that promote the incorporation of fluorine in order to decrease the solubility of the hydroxyapatite in enamel and prevent demineralization. This way, four commercial products with different active principle concentrations: 16% carbamide peroxide (Opalescence PF® and VivaStyle®) or 6% hydrogen peroxide (Opalescence Go PF® and VivaStyle Paint On®) and presence or not of fluorine were compared. The information on the crystalline state of the enamel was provided by the determination of the depolarization ratio of the symmetric stretching band of phosphate (at 959 cm^-1). Furthermore, the content and uptake of F was evaluated using PIGE in the two fluorinated products as well as in one negative control group. In order to evaluate the microhardness of enamel by means of Vickers test, another group of polished samples was prepared (using Opalescence PF®) and evaluated. Conversely to what could be expected, the obtained results determined a statistically significant decrease of depolarization ratio, leading to an increase of mineralization after the application of the bleaching products, except for VivaStyle®. For this group, no significant variation was obtained before-after treatment, most likely due to the acidity of the product (pH = 5.8). Additionally, an increase of concentration of F in the dental tissues was determined for the fluorinated products. On the other hand, enamel polishing, required for the application of the Vickers test, led to increased susceptibility to erosion, resulting in decreased hardness and an increased enamel depolarization ratio.

Abstract 242: Multi-omics Profiling of Rat Offspring Exposed to Gestational Diabetes Reveals Cardiometabolic Disease Development With Age

Through unknown mechanisms, fetal exposure to gestational diabetes mellitus (GDM) increases the risk for cardiovascular disease development later in life. We hypothesize that fetal exposure to GDM induces alterations in cardiomyocyte metabolism and induces left ventricular (LV) dysfunction with age. GDM was induced in female rats with a high fat (45% kcal) and sucrose diet prior to mating, throughout pregnancy and lactation. Lean control females received a low fat (10% kcal) diet. Fetal rat ventricular cardiomyocytes (FRVC) were isolated from e20.5 offspring for U-13C glucose metabolic flux analysis, mitochondrial respiration and calcium handling. The cardiac transcriptome and metabolome were measured in 3-month old offspring. LV morphology and function was assessed in the offspring from e18 to 12-months of age by transthoracic ultrasound. Offspring exposed to GDM exhibited increased LV posterior wall thickness across their life course (fetal to 12-months of age; p<0.05) and impaired LV filling beginning at 6-months of age (p<0.05). Consistent with the development of diastolic dysfunction in vivo, alterations in calcium flux and sarcoplasmic reticulum-dependent calcium re-uptake (1.5-fold and 1.6-fold greater, respectively) were observed in FRVC isolated from GDM offspring (p<0.05). When FRVC were treated with isoproterenol, U-13C glucose metabolic flux through glycolysis and the citric acid cycle was reduced in GDM offspring, compared to Lean controls. In 3-month old offspring serum metabolomics revealed reduced citric acid cycle intermediates and an altered acylcarnitine profile. These metabolic changes corresponded to alterations in gene expression patterns identified by RNASeq associated with glucose metabolism and fatty acid transport pathways (e.g. Irs2, Slc2a4, Pfkfb2, Pdk4 and Cpt1a) . Large-scale profiling revealed GDM induced alterations in the cardiac gene expression profile leading to modified serum metabolite levels in the offspring. These alterations corresponded with mitochondrial dysfunction, impaired cardiomyocyte metabolic flux and contractility, in concert with LV hypertrophy and diastolic dysfunction in the rat offspring. Our findings identify several mechanisms that link early-life GDM exposure to the development of cardiovascular disease later in life.

P1393Prolonged atrial electrical conduction as a predictor of atrial fibrillation after atrioventricular nodal reentrant tachycardia ablation

BACKGROUND

Patients (pts) with atrioventricular nodal reentrant tachycardia (AVNRT) have a higher incidence of atrial fibrillation (AF) during follow-up. Conventional risk factors can play a role in AF development, however atrial electrical conduction properties may be implicated in AF pathogenesis.

AIMS

to evaluate atrial conduction times and assess its effect on AF development during follow-up.

METHODS

We studied AVNRT pts who performed EPS and catheter ablation of the slow pathway between 2013 and 2016 in a single center. Pts with AF or valvular disease were excluded. We evaluated duration of symptoms due to AVNRT, conventional risk factors for AF (age, gender, obesity, hypertension, diabetes and structural heart disease (SHD)), left atrium (LA) enlargement and electrophysiologic study (EPS) time intervals related with atrial electrical conduction properties. We measured the time interval between: (1) the beginning of the P wave on the ECG to the A deflection in His-bundle electrogram (P-AHis); (2) the beginning of the P wave to the mid-distal coronary sinus (CS) atrial electrogram (P-CS) and (3) the beginning of the P wave to the H deflection in His-bundle electrogram (P-HHis).

RESULTS

Fifty-two pts were evaluated during a median follow-up of 63 months (IQR 51-69): 22% male, median age 55 years (IQR 42-67). AF occurred in 9 patients (17%) (39 cases per 1000 person-years). Patients with AF were older (67 vs 53 years, p= 0.005) and had more frequently LA enlargement (33% vs 7%, p= 0.024) but they did not differ in hypertension, obesity, diabetes, SHD and duration of symptoms. EPS measured intervals P-AHis and P-HHis interval were not different between the groups (26.0 vs 22.8 ms, p = 0.89 and 151 vs 106 ms, p= 0.56, respectively) but P-CS were prolonged in patients with AF (70 vs 55 ms, p = 0.02) (figure 1). Univariate logistic analysis for AF is presented in table 1. There was no interaction between P-CS and LA enlargement (p = 0.87). In multiavariate analysis, only P-CS was independently associated with AF (table).

CONCLUSIONS

In this group of patients with AVNRT, P-CS, but not other atrial conduction intervals, was independently associated with AF development. The possible role of LA electrical conduction impairment in AVNRT pts for AF development needs further studies.

Univariate and multivariate analysis Univariate analysis Multivariate analysis OR 95% CI p-value OR 95% CI p-value Age (years) 1.10 1.02-1.19 0.016 1.10 1.00-1.21 0.051 LA enlargement 7.00 1.10-44.71 0.040 3.42 0.41-28.03 0.255 P-CS 1.07 1.021.14 0.013 1.06 1.01-1.12 0.044 OR Odds ratio. CI: confidence interval

Abstract Figure. Box-plot for the studied intervals

235Anatomic guided ablation of the right ganglionated plexus is enough for cardiac autonomic denervation in patients with significant bradyarrhythmias

Background

In patients with significant bradyarrhytmias, cardiac denervation is an alternative therapeutic approach. Previous reports proposed different methods (as high frequency ednocardial stimulation of ganglionated plexus and specific atrial electrogram identification) and targets (right and left atrial ganglionated plexus) for adequate denervation. There is no consensus on the best way to perform these procedures, in spite the right atrial ganglia plexus (GP) ablation seeming to be the most contributive to its success.

Purpose

To assess the results of a purely anatomic approach for ablation of just the right atrial plexus in patients with severe vagal bradyarrhytmias.

Methods

We enrolled patients referred for ablation of cardiac parasympathetic ganglia, with or without atrial fibrillation ablation.  We performed eletroanatomic mapping of the right and left atria and used an irrigated tip catheter for ablation, aiming at the anterior right GP at the right pulmonary veins antrum along with ablation at the superior vena cava junction and the inferior right GP at the posterior aspect of the right inferior pulmonary vein along with ablation of the right aspect of the interatrial septum, between the posterior wall and coronary sinus ostium (Figure 1). We assessed the PW and Wenckenback cycle lengths (CL) pre and post procedure in patients with sinus arrest or AV block, respectively, and the patients had new 24h holter readings at least 30 days from the index procedure.

Results

We enrolled 12 patients: 9 males (75%), median age of 49,5 years (IQR 36-61,75). All patients had structurally normal hearts. 7 patients had only ablation of the parasympathetic ganglia and 5 patients had simultaneous pulmonary vein isolation for previously documented atrial fibrillation. 7 patients (58,3%) had sinus bradycardia (2 patients had sinus arrest with pauses of 8 and 13 seconds), 2 patients with cardioinhibitory syncope (with pauses of 23 and 28 seconds) and 3 patients had transient high degree AV block. The ablation procedure led to a median sinus rate acceleration of 15 bpm (IQR 3-29), a median decrease of 320 ms in PW (IQR 23,75-609,5) in patients with sinus arrest and a decrease of 80 ms in wenckenback CL (IQR 60-200) in patients with AV block. With a median follow up of 133,50 days (IQR 36-61,75), no patient had recurrence of symptoms or conduction disturbances.

Conclusions

In selected patients with severe functional paroxysmal bradyarrhytmias, cardiac denervation using an ablation strategy purely based on anatomic aspects and targeting only the right GP, seems to be an effective therapeutic approach.

Abstract Figure 1: Abl of right ganglionated plex

P1506Prolonged and recurrent hospital admissions predict risk of cardiac implantable electronic device infections in hospitalized patients with bacteriaemia

Background

As the use of Cardiac Implantable Electronic Devices (CIED) is expanding, the burden of device-related infections, particularly infectious endocarditis, is also increasing. Furthermore, with the increase in life expectancy, these devices are being implanted in patients who are older, with more serious co-morbidities and who are frequently hospitalized.

Purpose

To assess incidence and predisposing factors for infective endocarditis (IE) in hospitalized patients with CIED and nosocomial bacteraemia.

Methods

We performed a retrospective analysis of all hospitalized patients with CIED and positive blood cultures admitted to the Cardiology department between January 2012 and February 2019. Endocarditis was defined according to modified Duke criteria. We analyzed clinical parameters, device- and procedure-related characteristics, length of hospital stay and hospitalizations in the previous year.

Results

25 patients had positive blood cultures, 4 patients (16.0%) were diagnosed with infective endocarditis (median age 59.25 years, 75.0% male).

Patients characteristics are displayed in the Table.

In univariable analysis, the number and presence of hospitalizations in the previous year and the length of hospital stay was significantly associated with the possibility of endocarditis (respectively, OR 3.411, 95% CI 1.164-9.998, p-value 0.025; OR 18.000, 95% CI 1.375-235.686, p-value 0.028; and OR 1.047, 95% IC 1.001-1.096, p-value 0.046).

Conclusion

In this group of patients with positive blood cultures during hospitalization, the possibility of CIED infection was predicted by the length of hospital stay and the presence and number of hospitalizations in the previous year.

With CIED-IE Without CIED-IE p-value Age in years, median (IQR) 63 (16) 76 (16) 0.002 Heart failure, n (%) 4 (100%) 10 (47.6%) 0.105 LVEF in %, median (IQR) 21 (9) 51 (30) 0.008 LV dilation, n (%) 4 (100%) 8 (38.1%) 0.039 Device revision/upgrade/substitution, n (%) 2 (50.0%) 6 (28.57%) 0.570 LOS in days, median (IQR) 58.5 (83) 20 (15) 0.004 Hospital admissions in the previous year, n (%) 3 (75.0%) 3 (14.3%) 0.031 No. of hospital admissions in the previous year, mean (standard deviation) 1.67 (1.528) 0.29 (0.784) 0.005 Use of central venous access, n (%) 4 (100%) 4 (19.05%) 0.008 LOS – Length of Stay; LV – Left Ventricle; LVEF – Left Ventricle Ejection Fraction

P518Inappropriate shocks in atrial fibrillation patients: are they really deleterious?

Introduction

Data suggest inappropriate defibrillator shocks are associated with a higher risk of all-cause mortality, particularly those delivered for atrial fibrillation (AF). However, the impact of inappropriate shocks has not been studied specifically in a population with AF.

Aims

to determine if AF-triggered inappropriate shocks are associated with long- term mortality in patients with AF and defibrillators implanted for primary prevention.

Methods

Retrospective single-center study. We analyzed all patients with defibrillators implanted for primary prevention in whom AF was diagnosed until the end of 2017. The cause of inappropriate shocks was evaluated by analysis of the stored intracardiac electrogram. Basal characteristics, cardiovascular risk factors, left ventricle ejection fraction, heart failure etiology (ischemic and non-ischemic), kidney function (creatinine) and medication were evaluated. Death was assessed during the follow-up.

Results

We studied 177 patients [median age 66 years (IQR 59-71); 82% male], with defibrillators and AF. AF was diagnosed before defibrillator implantation in 131 patients (74%) and after the implantation in the remaining 46 (26%). Inappropriate shocks occurred in 31 patients and 24 (14%) were caused by AF with rapid ventricular response: 13 patients with previously diagnosed AF and 11 with new-onset AF. During a median follow-up of 65 (IQR: 36-104) months, 74 patients died. Multivariate Cox-regression analysis demonstrated inappropriate shocks caused by AF were not independently related with death (adjusted HR 0.53; CI 0.23-1.23, p = 0.14). Kaplan-Meier survival curve demonstrated patients with AF-triggered inappropriate shocks had a better survival comparing to those with AF but without inappropriate shocks (logrank, p = 0.03) (figure).

Conclusions

In this group of AF patients, inappropriate shocks caused by AF did not increase the risk of death. Instead, these patients had a better survival comparing to those with AF but no shocks, probably due to a re-evaluation of the patient´s status and subsequent closer medical monitoring, strictly control of symptoms and optimization of drug treatment. These results demonstrate that inappropriate shocks are probably not deleterious per si through a direct mechanism.

Abstract Figure. Kaplan-Meier survival curve

P3563The influence of circadian patterand obstructive sleep apnean of blood pressure in nocturnal arrhythmias in hypertensive patients

Introduction

There is growing evidence suggesting hypertension is related to the occurrence of arrhythmias. When occurring predominantly during the night, two potential entities commonly present in hypertensive patients could be related with increased arrhythmogenesis: (1) the lack of normal nocturnal dipping of blood pressure (BP) (non-dipping pattern of hypertension) or (2) obstructive sleep apnea (OSA). Thus, nocturnal arrhythmias (NAs) can identify hypertensive patients with OSA and/or non-dipping pattern, both related with adverse outcomes.

Aims

To determine if NAs are related with non-dipping hypertension, OSA or both.

Methods

We studied hypertensive patients who performed ambulatory blood pressure monitoring (ABPM) and also polysomnography and 24-hour Holter monitoring. Non-dipping pattern was considered when nocturnal BP reduction was inferior to 10%. Based on Holter monitoring, NAs were present when atrial fibrillation, frequent premature atrial contractions (PACs) (>30 PACs/hour), runs of >4 consecutive PACs, frequent premature ventricular contractions (PVCs) (>30PVCs/hour) or runs of >4 consecutive PVCs were present predominantly during sleeping hours. During polyssonography, apnoea/hypopnoea index (AHI) and oxygen saturation (SaO2) were analysed. Moderate to severe OSA was considered when AHI >15.

Results

We studied 104 patients [median age 62 (54–70) years, 65% male): 42 (40%) had moderate to severe OSA (median AHI=11 (6–26), mean SaO2=94% (92–95)] and 64 (61%) were non-dippers. NAs occurred in 18 patients (17%) and they were independently associated with AHI (Odds Ratio (OR) for a one unit increase 1.04, 95% confidence interval (CI) 1.01–1.07, p=0.03) but not with SaO2 (OR 0.96, CI 0.78–1.19, p=0.73) nor non-dipping pattern (OR 1.23, CI 0.38–3.98, p=0.72). No interaction was found between OSA and non-dipping hypertension (p=0.35). In patients with dipping pattern (n=40), AHI was higher in NAs patients comparing with no NAs patients (median AHI 29 versus 10, p=0.04), while in those with non-dipping pattern (n=64), AHI was not statistically different between patients with and without NAs (21 versus 11, p=0.12) (figure).

Figure 1

Conclusion

In this population of hypertensive patients, the presence of NAs was associated with OSA severity (i.e AHI), but not with the non-dipping pattern of hypertension. The importance of obstructive events in arrhythmogenesis seemed to be more pronounced in dipping patients, suggesting the abnormal high blood pressure during the night may also have some impact on NAs in non-dipping patients. Overall, our results suggest that OSA screening should be considered when nocturnal arrhythmias are detected in hypertensive patients, but ABPM should not be forgotten since multiple mechanisms can be involved in nocturnal arrhythmogenesis.

P3795Should we also screen for obstructive sleep apnea in patients presenting with excessive supraventricular ectopic activity?

Background

It is recommended to consider obstructive sleep apnoea (OSA) screening in atrial fibrillation (AF) patients with risk factors, due to the strong evidence of an association between these two entities. Excessive supraventricular ectopic activity (ESVEA) has been proposed to be a risk factor for AF. However, strong evidence between ESVEA and OSA has not been established.

Objective

We aimed to determine if ESVEA is associated with moderate to severe OSA since its treatment may prevent AF.

Methods

We studied patients who performed polysomnography and 24-hour Holter monitoring. Patients with atrial fibrillation were excluded. ESVEA was defined as more than 30 PACs per hour (frequent PACs) or runs of >4 consecutive PACs. The circadian pattern of PACs was also evaluated. Sleeping hours were used to define “nocturnal”. Moderate to severe OSA was defined when polyssonography demonstrated a apnoea/hypopnoea index (AHI) >15. We examined the association between ESVEA and moderate to severe OSA during wakefulness and sleep.

Results

We studied 290 patients [median age 65 (55–72) years, 62% males, body mass index (BMI) 30 (27–34)]. 112 (38%) had moderate to severe OSA. Median AHI was 11 (5–24) and mean oxygen saturation was 94% (92–95). Median PACs was 35 (9–117) and 29 patients (10%) had frequent PACs. Runs of >4PACs occurred in 114 patients (39%). Forty-three patients (15%) had predominant nocturnal PACs and 42 (14%) had nocturnal runs of PACs. Multivariate logistic regression analysis demonstrated only nocturnal PACs were associated with moderate to severe OSA (p=0.027) (table 1).

Multivariate logistic regression Odds Ratio 95% Confidence Interval p-value Male gender 4.49 2.48–8.17 <0.001 Body mass index (kg/m2) 1.09 1.03–1.15 0.002 Nocturnal PACs 4.12 1.17–14.46 0.027 Variables not included in the model: age, number of PACs/h, frequent PACs (>30 PAcs/hour), runs of PACs (>4 consecutive PACs), nocturnal frequent PACs and nocturnal runs of PACs.

Conclusion

OSA screening in patients presenting with nocturnal PACs should be routinely considered, especially in male and obese. Treating moderate to severe OSA patients with CPAP has a potential benefit in preventing ESVEA and consequently AF.

A reproductive role for the nonapeptides vasotocin and isotocin in male zebrafish (Danio rerio)

Two distinct nonapeptide systems, vasotocin- and oxytocin-related peptides, evolved in vertebrates. Their role in male zebrafish reproduction has not been formally investigated. We hypothesized that the teleost nonapeptides vasotocin and isotocin stimulate male zebrafish reproductive physiology and success by affecting central neuronal and/or peripheral endocrine pathways. Pharmacological inhibition experiments revealed that both vasotocin and isotocin contribute significantly to male reproductive success, which in the case of vasotocin correlated significantly with indices of male courtship behavior. Interestingly, co-administration of vasotocin and isotocin antagonists completely abolished male reproductive success without affecting male courtship behavior and endocrine indices, possibly linked to a synergistic action of nonapeptides on male pheromone release. To further probe the nonapeptides' role in male zebrafish reproduction, we subsequently tested whether male zebrafish nonapeptide systems were acutely activated by the female releaser pheromone PGF_2α, a strong chemoattractant and important reproductive cue in males which stimulates courtship behavior. Male zebrafish attracted to PGF_2α in a choice assay exhibited acute increases in neuronal activation marker p-ERK immunoreactivity in the ventral glomerulus of the olfactory bulb and the preoptic area, however no co-localization with isotocin was observed. Conversely, PGF_2α time-dependently stimulated whole brain isotocin mRNA abundance, suggesting secondary longer-term effects of PGF_2α exposure on the central isotocinergic system. While the current lack of vasotocin-specific antibodies for zebrafish does not allow to probe acute activation of vasotocinergic neurons, whole brain vasotocin mRNA was not significantly affected by PGF_2α exposure. Together, our results identify a role for nonapeptides in male zebrafish reproductive physiology and success.

Abstract 547: Metabolomic and Transcriptomic Profiling of Rat Offspring Exposed to Gestational Diabetes Reveals Altered Cardiac Gene Expression and Metabolism

Gestational diabetes mellitus (GDM) is the most common complication of pregnancy. Children exposed to GDM are at an increased risk of developing cardiometabolic diseases later in life, though the mechanisms responsible are unknown. We hypothesize that fetal exposure to GDM induces alterations in cardiomyocyte metabolism and concomitant left ventricular (LV) dysfunction with age. GDM was induced in female rats with a high fat (45% kcal) and sucrose diet prior to mating, throughout pregnancy and lactation. Lean control females received a low fat (10% kcal) diet. Fetal rat ventricular cardiomyocytes (FRVC) were isolated from e20.5 offspring for U-13C glucose metabolic flux analysis and mitochondrial respiration. Serum metabolites and cardiac transcriptome profiles were measured in 3-month old offspring. LV morphology and function was assessed through the life course of the offspring (e18 to 12-months of age) by transthoracic ultrasound. Offspring exposed to GDM exhibited increased LV posterior wall thickness across their life course (fetal to 12-months of age; p<0.05) and impaired LV filling beginning at 6-months of age (p<0.05). U-13C glucose metabolic flux through glycolysis and the citric acid cycle was reduced in FRVC from GDM offspring when treated with isoproterenol, and compared to Lean FRVC. Basal and maximal mitochondrial oxygen consumption was reduced for glucose (35% and 68%) and fatty acid (49% and 52%) substrates in FRVC isolated from GDM offspring (p<0.05). In 3-month old GDM offspring, serum metabolomics revealed elevated levels of beta-hydroxybutyrate (2.4-fold, p<0.05) and reduced levels of several citric acid cycle intermediates, which also corresponded to alterations in gene expression patterns identified by RNASeq transcript analysis. Large-scale profiling revealed GDM induced alterations in the cardiac gene expression profile leading to modified serum metabolite levels in the offspring. These alterations corresponded with mitochondrial dysfunction, impaired cardiomyocyte metabolic flux and contractility, in concert with LV hypertrophy and diastolic dysfunction in the rat offspring. Our findings identify several mechanisms that link early-life GDM exposure to the development of cardiovascular disease later in life.

Effect of Zirconia Pigmentation on Translucency

PURPOSE

the aim of this study was to investigate the effect of shading on translucency and mean grain size of three Zirconia systems (Lava Frame, Ice Zirkon Translucent and Prettau Zirkon).

MATERIALS AND METHODS

specimens pigmented in A1, A4 and a non-pigmented specimen was evaluated with Scanning Electron Microscopy and spectrophotometery.

RESULTS

the transmittance ranged between 0.18 and 0.52, in Ice Zirkon Translucent A4 and Prettau Zircon non-pigmented, respectively. The pigmentation A1 and A4 significantly reduced the light transmission in all the systems evaluated (p⟨0.05), with the exception of Lava A1. The light transmittance of each ceramic system is different from each other in the three pigmentations, except for the Prettau Zirkon A1, which did not show a significant difference compared with Lava A1 (p⟩0.05). The mean grain size increased with pigmentation. The mean grain size ranged between 0.43 μm, for Prettau Zirkon non-pigmented, and 0.82 μm for Prettau Zirkon A4.

CONCLUSION

Light transmission and mean grain size was affected by pigmentation of dental zirconia ceramics.

Impact of working hours on sleep and mental health

Background

The number of hours people are required to work has a pervasive influence on both physical and mental health. Excessive working hours can also negatively affect sleep quality. The impact at work of mental health problems can have serious consequences for individuals' as well as for organizations' productivity.

Aims

To evaluate differences in sleep quality and anxiety and depression symptoms between longer working hours group (LWHG) and regular working hours group (RWHG). To examine factors influencing weekly working hours, sleep quality and anxiety and depressive symptoms.

Methods

Participants were divided into two groups, RWHG and LWHG, based on working hours, with a cut-off of 48 h per week. We used the Hospital Anxiety and Depression Scale (HADS) to assess anxiety and depression symptoms and the Pittsburgh Sleep Quality Index (PSQI) to measure the quality and patterns of sleep.

Results

The response rate was 23%. Among the 429 study participants, those in the LWHG group (n = 256, 53%) had significantly more depressive and anxiety symptoms and worse sleep quality than those in RWHG (n = 223, 47%). Working time was significantly positively correlated with higher corporate position and HADS scores. Moreover, HADS scores were positively correlated with PSQI scores and negatively correlated with age.

Conclusions

This study suggests that longer working hours are associated with poorer mental health status and increasing levels of anxiety and depression symptoms. There was a positive correlation between these symptoms and sleep disturbances.