The 35th annual advances in contrast ultrasound international bubble conference, Chicago 2021: synopsis and take-home messages.

The 35th Annual Advances in Contrast Ultrasound International Bubble Conference convened in Chicago, IL, USA, on September 30th to October 1st, 2021. It featured a range of novel research from animal studies to clinical applications in multiple organ systems, demonstrating the utility of contrast enhanced ultrasound (CEUS). A multidisciplinary group of experts on the use of CEUS, including physicians, basic scientists, engineers, and industry partners, convened to discuss cutting edge research and new applications for CEUS. The conference demonstrated the wide range of CEUS uses and potential uses, including cardiac risk stratification, sonothrombolysis, peripheral vascular reperfusion, liver and renal mass evaluation, lymphatic evaluation, sentinel node identification, and CEUS use in pediatrics. The International Contrast Ultrasound Society uses this information to continue advocating for the safe and appropriate use of CEUS.

Accuracy of contrast-enhanced computed tomography for thrombus detection prior to atrial fibrillation ablation and role of novel Left Atrial Appendage Enhancement Index in appendage flow assessment.

AIMS: To evaluate diagnostic accuracy of different protocols of contrast enhanced computed tomography venogram (CTV) for LAA thrombus detection in patients undergoing AF ablation and study the correlation of the novel LAA enhancement index (LAA-EI) to LAA flow velocity obtained using transesophageal echocardiography (TEE). METHODS: Study comprised of patients undergoing CTV and TEE on the same day from October 2016 to December 2017. Three CTV scanning protocols (described in results), were evaluated wherein ECG gating was used only for those with sinus rhythm on day of CTV. LAA-EI was calculated as Hounsfield Unit (HU) in the LAA divided by the HU unit in the center of the LA. The diagnostic accuracy for CTV was calculated in comparison to TEE. The LAA-EI was compared to LAA emptying velocities as obtained from TEE. RESULTS: 590 patients with 45.6% non-ECG-gated without delayed imaging, 26.9% non-ECG-gated with delayed imaging and 27.5% ECG-gated with delayed imaging, were included in the study. All three protocols had 100% negative predictive value with improvement in specificity from 61.8% to 98.1% upon adding delayed imaging. The LAA-EI correlated significantly with reduced LAA flow velocities (r = 0.45, p < .0001). The mean LAA emptying velocity in patients with LAA-EI of ≤ 0.6 was significantly lower than in those with LAA-EI of >0.6 (36.2 cm/s [95% CI: 32.6-39.7] vs, (58 cm/s [95% CI 55.3-60.8]), respectively (p < .0001). CONCLUSION: CTV with delayed imaging (with or without ECG gating) is highly specific in ruling out LAA thrombus. The novel LAA-EI can detect low LAA flow velocities.

Prevalence of Coronary Artery Calcification on Pre-Atrial Fibrillation Ablation CT Pulmonary Venograms and its Impact on Selection for Statin Therapy.

Atherosclerotic cardiovascular disease (ASCVD) shares many risk factors with atrial fibrillation (AF). Obtaining computed tomography images of the pulmonary veins (CTPV) before AF ablation procedures is common and can incidentally detect coronary artery calcification (CAC). The purpose of this study was to investigate the prevalence of CAC on pre-ablation CTPV, the frequency of CAC reporting on CTPV reports, and its impact on statin therapy among patients hospitalized for AF procedures. We retrospectively evaluated consecutive patients undergoing CTPV and AF procedures from October 2016 to December 2017 in a single-center tertiary hospital. The patients' demographic and clinical characteristics were analyzed. The CAC presence on CTPV was visually assessed. The severity was classified qualitatively. The statin therapy status was evaluated using the patient's admission and discharge medication lists. A total of 638 subjects were included in our study, with 34.5% female. The mean age was 63.3 ± 10.8 years. CAC was detected in 70.1% of all patients, and in 58.1% of patients without a history of ASCVD. When present, CAC was documented in 92.6% of the clinical CTPV reports. While coronary artery atherosclerosis was present in a majority of AF patients, and its presence was widely reported, it was not associated with increased statin therapy at discharge.

TRAIL-Dependent Resolution of Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is the most common form of interstitial lung disease characterized by the persistence of activated myofibroblasts resulting in excessive deposition of extracellular matrix proteins and profound tissue remodeling. In the present study, the expression of tumor necrosis factor- (TNF-) related apoptosis-inducing ligand (TRAIL) was key to the resolution of bleomycin-induced pulmonary fibrosis. Both in vivo and in vitro studies demonstrated that Gr-1+TRAIL+ bone marrow-derived myeloid cells blocked the activation of lung myofibroblasts. Although soluble TRAIL was increased in plasma from IPF patients, the presence of TRAIL+ myeloid cells was markedly reduced in IPF lung biopsies, and primary lung fibroblasts from this patient group expressed little of the TRAIL receptor-2 (DR5) when compared with appropriate normal samples. IL-13 was a potent inhibitor of DR5 expression in normal fibroblasts. Together, these results identified TRAIL+ myeloid cells as a critical mechanism in the resolution of pulmonary fibrosis, and strategies directed at promoting its function might have therapeutic potential in IPF.

Eleven-year trends of inpatient pacemaker implantation in patients diagnosed with sick sinus syndrome.

BACKGROUND: Pacemakers (PM) are used for managing sick sinus syndrome (SSS). This study evaluates predictors and trends of PM implantation for SSS. METHODS: Patients were identified from the National Inpatient Sample dataset (2003-2013). Included patients were ≥18 years old, had a diagnosis of sinus node dysfunction and atrial arrhythmia (i.e., SSS). Patients who died, transferred out, who had prior device, or had a defibrillator or resynchronization therapy device implanted were excluded. Included patients were then stratified by if a PM was implanted. Data regarding SSS, trends of PM utilization, and multivariable models of factors associated with PM implantation are presented. RESULTS: Note that 328,670 patients satisfied study criteria. This study compared patients who underwent (87.4%) PM implantation to those who did not undergo (12.6%) PM implantation. The annual trends for hospitalization with SSS and PM placement have been decreasing (P <0.001). Variables associated with lower likelihood for PM implantation include young age, female sex, non-Caucasian race, chronic heart failure, Charlson Comorbidity Score ≥1, emergency room and weekend admission, hospital stay ≤3 days, and high cardiology inpatient volume. Greater likelihood for PM implantation was associated with hyperlipidemia, hypertension, and hospitals that were either private, large, Northeastern location, or with high cardiac procedural volume. CONCLUSIONS: Analyzing 11-year data from a national inpatient database demonstrate a number of relevant variables that impact PM utilization that include not only clinical but also nonclinical variables such as socioeconomic status, gender, and hospital features. Racial and gender bias toward PM implantation are unchanged and persist through 2013.

The protective role of TLR6 in a mouse model of asthma is mediated by IL-23 and IL-17A.

TLRs are a family of receptors that mediate immune system pathogen recognition. In the respiratory system, TLR activation has both beneficial and deleterious effects in asthma. For example, clinical data indicate that TLR6 activation exerts protective effects in asthma. Here, we explored the mechanism or mechanisms through which TLR6 mediates this effect using mouse models of Aspergillus fumigatus-induced and house dust mite antigen-induced (HDM antigen-induced) chronic asthma. Tlr6-/- mice with fungal- or HDM antigen-induced asthma exhibited substantially increased airway hyperresponsiveness, inflammation, and remodeling compared with WT asthmatic groups. Surprisingly, whole-lung levels of IL-23 and IL-17 were markedly lower in Tlr6-/- versus WT asthmatic mice. Tlr6-/- DCs generated less IL-23 upon activation with lipopolysaccharide, zymosan, or curdlan. Impaired IL-23 generation in Tlr6-/- mice also corresponded with lower levels of expression of the pathogen-recognition receptor dectin-1 and expansion of Th17 cells both in vivo and in vitro. Exogenous IL-23 treatment of asthmatic Tlr6-/- mice restored IL-17A production and substantially reduced airway hyperresponsiveness, inflammation, and lung fungal burden compared with that in untreated asthmatic Tlr6-/- mice. Together, our data demonstrate that TLR6 activation is critical for IL-23 production and Th17 responses, which both regulate the allergic inflammatory response in chronic fungal-induced asthma. Thus, therapeutics targeting TLR6 activity might prove efficacious in the treatment of clinical asthma.