Activated factor X stimulates atrial endothelial cells and tissues to promote remodeling responses through AT1R/NADPH oxidases/SGLT1/2

AIMS

Atrial fibrillation (AF), the most common cardiac arrhythmia favoring ischemic stroke and heart failure involves left atrial remodeling, fibrosis and a complex interplay between cardiovascular risk factors. This study examined whether activated factor X (FXa) induces pro-remodeling and pro-fibrotic responses in atrial endothelial cells (AECs) and human atrial tissues and determined the underlying mechanisms.

METHODS AND RESULTS

AECs were from porcine hearts and human right atrial appendages (RAA) from patients undergoing heart surgery. Protein expression levels were assessed by Western blot and immunofluorescence staining, mRNA levels by RT-qPCR, formation of reactive oxygen species (ROS) and NO using fluorescent probes, thrombin and angiotensin II generation by specific assays, fibrosis by Sirius red staining and senescence by senescence-associated beta-galactosidase (SA-β-gal) activity.In AECs, FXa increased ROS formation, senescence (SA-β-gal activity, p53, p21), angiotensin II generation and the expression of pro-inflammatory (VCAM-1, MCP-1), pro-thrombotic (tissue factor), pro-fibrotic (TGF-β and collagen-1/3a) and pro-remodeling (MMP-2/9) markers whereas eNOS levels and NO formation were reduced. These effects were prevented by inhibitors of FXa but not thrombin, protease-activated receptors antagonists (PAR-1/2) and inhibitors of NADPH oxidases, ACE, AT1R, SGLT1/SGLT2. FXa also increased expression levels of ACE1, AT1R, SGLT1/2 proteins which was prevented by SGLT1/2 inhibitors. Human RAA showed tissue factor mRNA levels that correlated with markers of endothelial activation, pro-remodeling and pro-fibrotic responses and SGLT1/2 mRNA levels. They also showed protein expression levels of ACE1, AT1R, p22phox, SGLT1/2, and immunofluorescence signals of nitrotyrosine and SGLT1/2 colocalized with those of CD31. FXa increased oxidative stress levels which were prevented by inhibitors of the AT1R/NADPH oxidases/SGLT1/2 pathway.

CONCLUSIONS

FXa promotes oxidative stress triggering premature endothelial senescence and dysfunction associated with pro-thrombotic, pro-remodeling and pro-fibrotic responses in AECs and in human RAA involving the AT1R/NADPH oxidases/SGLT1/2 pro-oxidant pathway. Targeting this pathway may be of interest to prevent atrial remodeling and the progression of atrial fibrillation substrate.

Predictors and health outcomes of tobacco smoking among the population of Gaza: A large-scale study

Tobacco smoking, a significant public health concern globally, is associated with a rise in noncommunicable diseases and preventable deaths, with pronounced impacts in conflict zones like Gaza. A study in Gaza focused on individuals over 40 years of age, aiming to identify predictors of tobacco use and its links to diseases like coronary artery disease, chronic lung disease, and stroke. The research, based on the Gaza NCD study data with 4576 participants and a 96.6% response rate, found an overall tobacco smoking prevalence of 19.4%, with higher rates among men. Adjusting for various factors, the study revealed significant associations between cigarette smoking in men and adverse health outcomes, such as coronary artery disease and chronic lung disease. However, after adjusting for independent variables, shisha smoking in men showed no association with these health outcomes. In conflict-affected regions like Gaza, this large-scale study sheds light on predictors of cigarette and shisha smoking and their impact on health outcomes, offering valuable insights for researchers, public health officials, healthcare professionals, and policymakers. The findings aid in predicting smoking prevalence, addressing current health challenges, and mitigating potential health and financial burdens associated with tobacco use in conflict zones.

Left atrial remodeling and voltage-guided ablation outcome in obese patients with persistent atrial fibrillation

Background

Obesity is a risk factor for atrial fibrillation (AF). Data regarding left atrial (LA) remodeling in obese patients are scarce. Whether obesity favors AF recurrence after catheter ablation (CA) is still controversial. We assessed the distribution of epicardial atrial fat on computed tomography (CT), LA bipolar voltage, low-voltage zone (LVZ) extent, and the outcome of voltage-guided ablation of persistent AF in obese and non-obese patients.

Methods

A total of 139 patients with persistent AF undergoing a first voltage-guided ablation were enrolled and divided into two groups: 74 were non-obese and 65 were obese. Epicardial adipose tissue (EAT) was assessed on a CT scanner. LA endocardial voltage maps were obtained using a 3D mapping system in sinus rhythm. LVZ was defined as a bipolar peak-to-peak voltage amplitude <0.5 mV.

Results

LA volume, voltage, and EAT amount were similar in the two groups. LVZ was less frequent in obese patients [12 (18.8%) vs. 26 (35.1%), p = 0.05], particularly on the anterior wall. The posterior and lateral EATs were correlated with posterior and lateral LVZ extent, respectively, in obese patients. After 36 months of follow-up, the AF-free survival rate was similar. Lateral EAT [odds ratio (OR) 1.21, 95% confidence interval (CI) 1-1.4, p = 0.04] and P-wave duration (OR 1.03, 95% CI 1-1.05, p = 0.03), but not body mass index (BMI), were predictors of AF recurrence after CA.

Conclusion

In obese patients, LVZ was less marked than in non-obese patients with similar LA volumes, voltage, and EAT amounts. In obese patients, posterior and lateral EATs were correlated with posterior and lateral LVZ extents. Obese patients had a similar and favorable 36-month outcome after AF ablation. BMI was not predictive of AF recurrence.

Long-Term Survival Outcomes After Transcatheter Aortic Valve Replacement: A Real-World Experience of a Large Tertiary Center

Transcatheter aortic valve replacement (TAVR) becomes the leading therapeutic choice for severe aortic stenosis. There is a growing body of knowledge on long-term survival outcomes, but available data from real-world observational studies are scarce. An observational cohort study was conducted on 705 consecutive patients who underwent TAVR at Strasbourg University Hospital between February 2010 and June 2017. We observed the living status (dead or alive) for each study participants by March 2023. The primary end point was to evaluate the all-cause mortality rate beyond 5 years after TAVR, compare the survival outcomes according to valve type, and identify predictors of mortality. Of the 705 study participants, 91.8% of the TAVR procedures were performed through the common femoral artery and 60.6% were treated with a balloon-expandable valve. Over a mean study period of 5.4 ± 3 years, the all-cause mortality rate was 45.8%. No difference in survival outcomes according to valve type was observed (p = 0.449). All-cause mortality rate was associated with age ≥90 years (hazard ratio [HR] 1.625, 1.109 to 2.380, p = 0.013), female gender (HR 0.228, 0.176 to 0.294, p <0.001), diabetes mellitus (HR 1.356, 1.070 to 1.719, p = 0.012), post-TAVR stroke (HR = 2.867, 1.690 to 4.865, p <0.001), and post-TAVR acute kidney injury (HR 1.977, 1.445 to 2.703, p <0.001). In conclusion, the present real-world large tertiary center experience showed that more than half of patients who underwent TAVR are alive beyond 5 years from procedure's date. All-cause mortality is mainly determined by advanced age and co-morbid conditions, and valve type has no advantage on the survival outcomes.

Impact of gender on left atrial low-voltage zones in patients with persistent atrial fibrillation: results of a voltage-guided ablation

Background

Gender-related differences have been reported in atrial fibrotic remodeling and prognosis of atrial fibrillation (AF) patients after ablation. We assessed in persistent AF the regional distribution of left atrial (LA) bipolar voltage and the extent of low-voltage zones (LVZ) according to gender as well as the results of a voltage-guided substrate ablation.

Methods

Consecutive patients who underwent a voltage-guided AF ablation were enrolled. LA endocardial voltage maps were obtained using a 3D electro-anatomical mapping system in sinus rhythm. LVZ was defined as <0.5 mV.

Results

A total of 115 patients were enrolled (74 men, 41 women). The LA bipolar voltage amplitude was twice lower in the whole LA (p < 0.01) and in each atrial region in women compared with men, whereas the LA indexed volume was similar. LVZ were found in 56.1% of women and 16.2% of men (p < 0.01). LVZ were also more extensive in women (p = 0.01), especially in the anterior LA. Atrial voltage alteration occurred earlier in women than in men. In a multivariate analysis, the female sex (OR 12.99; 95% CI, 3.23-51.63, p = 0.0001) and LA indexed volume (OR 1.09; 95% CI, 1.04-1.16, p = 0.001) were predictive of LVZ. Atrial arrhythmia-free survival was similar in men and women 36 months after a single ablation procedure.

Conclusion

The study reports a strong relationship between the female gender and atrial substrate remodeling. The female gender was significantly associated with higher incidence, earlier occurrence, and greater extent of LVZ compared with men. Despite the female-specific characteristics in atrial remodeling, LVZ-guided ablation may improve the AF ablation outcome in women.

Accessory pathways in monozygotic twins with different clinical phenotypes: a case report

Background

The atrioventricular reentrant tachycardia (AVRT) is the most common tachycardia associated with accessory pathways (APs). Although sporadic Wolff-Parkinson-White (WPW) syndrome has been well-described, AP occurrence in identical twins with WPW syndrome remains rarely reported.

Case presentation

We report a case of 14-year-old monozygotic twin brothers referred for an electrophysiology (EP) study. Twin A presented with recurrent symptomatic narrow complex tachycardia after exercise, noted for 3 years. His 12-lead surface electrocardiogram (ECG) did not show ventricular pre-excitation. However, an orthodromic AVRT utilizing a concealed right posteroseptal AP was found and successfully ablated. AVRT did not recur 12 months after the procedure. Twin B was asymptomatic. During his medical examination for firefighter volunteerism, his 12-lead ECG showed a spontaneous ventricular pre-excitation. EP study revealed a short anterograde right midseptal AP, which was then successfully eliminated by catheter ablation. His 12-lead ECG showed no ventricular pre-excitation recurrence 12 months after the procedure.

Conclusions

These identical twin brothers had a right-side AP in almost the same place but showed completely different phenotypes. This case clearly illustrates the difficulty in understanding genetic contribution in the origin of atrioventricular APs. Environmental exposure could play a role in their clinical presentations and AP electrophysiological properties.

Effective Orifice Area of Balloon-Expandable and Self-Expandable Transcatheter Aortic Valve Prostheses: An Echo Doppler Comparative Study

Published data on the size-specific effective orifice area (EOA) of transcatheter heart valves (THVs) remain scarce. Here, we sought to investigate the intra-individual changes in EOA and mean transvalvular aortic gradient (MG) of the Sapien 3 (S3), CoreValve (CV), and Evolut R (EVR) prostheses both at short-term and at 1-year follow-up. The study sample consisted of 260 consecutive patients with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI). EOAs and MGs were measured with Doppler echocardiography for the following prostheses: S3 23 mm (n = 74; 28.5%), S3 26 mm (n = 67; 25.8%), S3 29 mm (n = 20; 7.7%), CV 23 mm (n = 2; 0.8%), CV 26 mm (n = 15; 5.8%), CV 29 mm (n = 24; 9.2%), CV 31 mm (n = 9; 3.5%), EVR 26 mm (n = 22; 8.5%), and EVR 29 mm (n = 27; 10.4%). Values were obtained at discharge, 1 month, 6 months, and 1 year from implantation. At discharge, EOAs were larger and MGs lower for larger-size prostheses, regardless of being balloon-expandable or self-expandable. In patients with small aortic annulus size, the hemodynamic performances of CV and EVR prostheses were superior to those of S3. However, we did not observe significant differences in terms of all-cause mortality according to THV type or size. Both balloon-expandable and self-expandable new-generation THVs show excellent hemodynamic performances without evidence of very early valve degeneration.

Delayed pulmonary embolism after COVID-19 pneumonia: a case report

Background 

Since the onset of the COVID-19 pandemic, several cardiovascular manifestations have been described. Among them, venous thromboembolism (VTE) seems to be one of the most frequent, particularly in intensive care unit patients. We report two cases of COVID-19 patients developing acute pulmonary embolism (PE) after discharge from a first hospitalization for pneumonia of moderate severity.

Case summary 

Two patients with positive RT-PCR test were initially hospitalized for non-severe COVID-19. Both received standard thromboprophylaxis during the index hospitalization and had no strong predisposing risk factors for VTE. Few days after discharge, they were both readmitted for worsening dyspnoea due to PE. One patient was positive for lupus anticoagulant.

Discussion 

Worsening respiratory status in COVID-19 patients must encourage physicians to search for PE since SARS-CoV-2 infection may act as a precipitant risk factor for VTE. Patients may thus require more aggressive and longer thromboprophylaxis after COVID-19 related hospitalization.

Retrospective cohort study on clinical predictors for acute abnormalities on CT scan in adult patients with abdominal pain

PURPOSE

Identification of clinical predictors of acute and surgical pathologies on abdominal CT in patients with non-traumatic abdominal pain (NTAP).

METHODS

Retrospective chart review cohort study of adults who had abdominal CT scans for investigation of NTAP in the Emergency Department in a tertiary care center in Lebanon. Multivariate analyses were performed to identify predictors of pathologies on CT scan.

RESULTS

This study included 147 patients who had abdominal CT scans for NTAP. Mean age was 39.8 ± 15.1 years and 58.5 % of patients were females. Less than half (44.9 %) had normal scans. Women had significantly higher rates of normal scans compared to males. Right lower quadrant (RLQ) tenderness was associated with significantly higher odds of having acute abnormalities on CT and of having surgical diagnoses, while epigastric tenderness was negatively associated with these two outcomes. Right and left upper quadrants and diffuse abdominal tenderness, and an abnormal neutrophil count were found to be associated with surgical diagnoses on CT.

CONCLUSIONS

Women are less likely to have acute and surgical pathologies on CT ordered for non traumatic abdominal pain. Epigastric tenderness is negatively associated with abnormal and surgical CT results while RLQ tenderness is associated with an abnormal CT that is likely surgical in nature. These findings should help improve diagnostic accuracy of ordering providers and improve resource utilization.

Post-traumatic stress disorder in adult victims of cluster munitions in Lebanon: a 10-year longitudinal study

OBJECTIVE

This study aims to explore the short-term and long-term prevalence and effects of post-traumatic stress disorder (PTSD) among victims of cluster munitions.

DESIGN AND SETTING

A prospective 10-year longitudinal study that took place in Lebanon.

PARTICIPANTS

Two-hundred-and-forty-four Lebanese civilian victims of submunition blasts, who were injured in 2006 and were over 18 years old, were interviewed. Included were participants who had been diagnosed with PTSD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) and the PTSD Checklist - Civilian Version in 2006. Interviewees were present for the 10-year follow-up.

MAIN OUTCOME MEASURES

PTSD prevalence rates of participants in 2006 and 2016 were compared. Analysis of the demographical data pertaining to the association of long-term PTSD with other variables was performed. p Values <0.05 were considered statistically significant for all analyses (95% CI).

RESULTS

All the 244 civilians injured by cluster munitions in 2006 responded, and were present for long-term follow-up in 2016. The prevalence of PTSD decreased significantly from 98% to 43% after 10 years (p<0.001). A lower long-term prevalence was significantly associated with male sex (p<0.001), family support (p<0.001) and religion (p<0.001). Hospitalisation (p=0.005) and severe functional impairment (p<0.001) post-trauma were significantly associated with increased prevalence of long-term PTSD. Symptoms of negative cognition and mood were more common in the long run. In addition, job instability was the most frequent socioeconomic repercussion among the participants (88%).

CONCLUSIONS

Psychological symptoms, especially PTSD, remain high in war-affected populations many years after the war; this is particularly evident for Lebanese civilians who were victimised by cluster munitions. Screening programmes and psychological interventions need to be implemented in vulnerable populations exposed to war traumas. Officials and public health advocates should consider the socioeconomic implications, and help raise awareness against the harm induced by cluster munitions and similar weaponry.

Smoking among Lebanese medical students: Prevalence and attitudes

INTRODUCTION:

The tobacco epidemic is a major public health threat facing the world. Tobacco dependence is recognized as the greatest preventable cause of disease and death. Medical students are in key position influencing future tobacco cessation programs.

OBJECTIVES:

The primary objective of this study is to evaluate the prevalence of smoking among medical students across Lebanon and their smoking attitudes. It also investigates their attitude toward smoking, showing where they really stand on this major public health issue. This study helps better tackle anti-smoking campaigns among both physicians and patients.

METHODS:

This cross-sectional study was conducted by sending a questionnaire to currently enrolled medical students at all seven medical schools in Lebanon. The 32-item questionnaire was used, comprised three sections assessing sociodemographic characteristics, smoking habits, and attitudes toward smoking among Lebanese medical students. The questionnaire was launched online on Limesurvey to retain anonymity. The data were then transferred to Statistical Package for Social Sciences for analysis. Data were expressed as percentages for discrete variables and as mean ± standard deviation for continuous variables.

RESULTS:

One hundred sixty-three complete responses remained of the 182 obtained responses. Forty-two of the total 163 students identified themselves as either daily or occasional smokers yielding a prevalence of 25.8%. Smokers were less likely to ask patients about their smoking habit and to counsel them about smoking cessation. Almost one-third of smokers felt that they had no obligations toward the society.

CONCLUSION:

Approximately 1 in 4 Lebanese medical students is a smoker. Students who smoke are less likely to ask patients about their smoking habits and to counsel them on smoking cessation. This is a major drawback in the fight against tobacco. This calls for better education of our future doctors on smoking cessation to decrease the smoking burden on our Lebanese society and worldwide.