Repurposing catheter ablation work-up to detect expiratory airflow limitation in patients with atrial fibrillation

Background

In atrial fibrillation (AF) patients, presence of expiratory airflow limitation may negatively impact treatment outcomes. AF patients are not routinely screened for expiratory airflow limitation, but existing examinations can help identify at-risk individuals. We aimed to assess the diagnostic value of repurposing existing assessments from the pre-ablation work-up to identify and understand the characteristics of affected patients.

Methods

We screened 110 consecutive AF patients scheduled for catheter ablation with handheld spirometry. Routine pre-ablation work-up included cardiac computed tomographic angiography (CCTA), transthoracic echocardiography and polygraphy. CCTA was analyzed qualitatively for emphysema and airway abnormalities. Multivariate logistic regression analysis was performed to determine predictors of expiratory airflow limitation.

Results

We found that 25 % of patients had expiratory airflow limitation, which was undiagnosed in 86 % of these patients. These patients were more likely to have pulmonary abnormalities on CCTA, including emphysema (odds ratio [OR] 4.2, 95 % confidence interval [CI] 1.12-15.1, p < 0.05) and bronchial wall thickening (OR 2.6, 95 % CI 1.0-6.5, p < 0.05). The absence of pulmonary abnormalities on CCTA accurately distinguished patients with normal lung function from those with airflow limitation (negative predictive value: 85 %). Echocardiography and polygraphy did not contribute significantly to identifying airflow limitation.

Conclusions

In conclusion, routine pre-ablation CCTA can detect pulmonary abnormalities in AF patients with airflow limitation, guiding further pulmonary assessment. Future studies should investigate its impact on ablation procedure success.

Platelet glycoprotein IIb/IIIa inhibitor tirofiban in clopidogrel-naïve patients undergoing elective percutaneous coronary intervention

BACKGROUND

The safety of administration of tirofiban, a platelet glycoprotein IIb/IIIa inhibitor, followed by a clopidogrel loading dose in clopidogrel-naïve patients undergoing ad-hoc percutaneous coronary intervention (PCI) is not yet clear.

METHODS

In a retrospective observational cohort analysis, clopidogrel-naïve patients undergoing ad-hoc PCI who received a high-dose bolus of tirofiban (25 μg/kg) followed by a 600-mg clopidogrel loading dose (group 1) were compared with patients undergoing elective PCI who were pretreated with clopidogrel (group 2), between September 2014 and October 2021. The primary outcome was major adverse cardiovascular events (MACE) defined as the composite of death, myocardial infarction, stroke, target-lesion revascularisation and bleeding at 30 days. Secondary outcomes were MACE at 7 days and individual components of the primary outcome at 7 and 30 days.

RESULTS

A total of 1404 patients were included: 432 (31%) in group 1 and 972 (69%) in group 2. Median age was 69 years, and 28% were female. At 7‑day follow-up, MACE occurred in 1.4% in group 1 versus 3.0% in group 2 (p = 0.08). 30-day MACE were observed in 1.9% in group 1 and 4.2% in group 2 (p = 0.03). Secondary outcomes were comparable between the groups. Cox regression analysis, corrected for baseline differences, revealed no significant difference in the primary outcome (hazard ratio: 1.8; 95% confidence interval: 0.8-3.9).

CONCLUSION

Ad-hoc PCI in clopidogrel-naïve patients who were treated with high-dose bolus of tirofiban followed by a clopidogrel loading dose immediately after the procedure appeared to be safe.

A case report of high-output heart failure due to arteriovenous shunt without bowel: how to address?

Background

High-output heart failure (HF) is a form of HF where patients present with a high-output state with low systemic vascular resistance. This report presents the case of high-output HF in a patient with an arteriovenous shunt and no options for oral-administered drugs.

Case summary

A 70-year-old male with a terminal jejunostomy fully depending on parenteral feeding through a vena saphena magna shunt presented with symptoms of shortness of breath. Echocardiography revealed eccentric hypertrophy with reduced left ventricular ejection fraction (LVEF) and atrial fibrillation with a heart rate of 70-100 b.p.m. Cardiac magnetic resonance imaging, endomyocardial biopsy, and cardiomyopathy lab revealed no cause of HF. High-output HF based on right heart catheterization due to the arteriovenous shunt or related to irregularity due to atrial fibrillation were potential causes. As a result of his malfunctioning gastrointestinal system, the pharmacological options were limited. He was treated with captopril sublingual, initially 6.25 mg three times daily (TID) and later 12.5 mg TID, which reduced blood pressure. Electrical cardioversion to sinus rhythm was successful but did not improve LVEF. Therefore, the patient was opted for surgically reducing the blood flow through the shunt, resulting in normalization of LVEF.

Discussion

High-output HF is an uncommon form of HF with an uncertain prevalence. The most common aetiologies reported in the literature are obesity, cirrhosis, and arteriovenous shunts. Sublingual administration of captopril can be an effective treatment option for HF patients unable to absorb oral-administered drugs.

Implementation of a screening and management pathway for chronic obstructive pulmonary disease in patients with atrial fibrillation

AIMS

Chronic obstructive pulmonary disease (COPD) negatively impacts the efficacy of heart rhythm control treatments in patients with atrial fibrillation (AF). Although COPD is recognized as a risk factor for AF, practical guidance about how and when to screen for COPD is not available. Herein, we describe the implementation of an integrated screening and management pathway for COPD into the existing pre-ablation work-up in an AF outpatient clinic infrastructure.

METHODS AND RESULTS

Consecutive unselected patients accepted for AF catheter ablation in the Maastricht University Medical Center+ were prospectively screened for airflow limitation using handheld (micro)spirometry at the pre-ablation outpatient clinic supervised by an AF nurse. Patients with results suggestive of airflow limitation were offered referral to the pulmonologist. Handheld (micro)spirometry was performed in 232 AF patients, which provided interpretable results in 206 (88.8%) patients. Airflow limitation was observed in 47 patients (20.3%). Out of these 47 patients, 29 (62%) opted for referral to the pulmonologist. The primary reason for non-referral was low perceived symptom burden. Using this screening strategy 17 (out of 232; 7.3%) ultimately received a diagnosis of chronic respiratory disease, either COPD or asthma.

CONCLUSION

A COPD care pathway can successfully be embedded in an existing AF outpatient clinic infrastructure, using (micro)spirometry and remote analysis of results. Although one out of five patients had results suggestive of an underlying chronic respiratory disease, only 62% of these patients opted for a referral. Pre-selection of patients as well as patient education might increase the diagnostic yield and requires further research.

Atrial fibrillation-specific refinement of the STOP-Bang sleep apnoea screening questionnaire: insights from the Virtual-SAFARI study

BACKGROUND

Sleep-disordered breathing (SDB) is prevalent in up to 50% of patients referred for atrial fibrillation (AF) catheter ablation (CA). Currently, it remains unclear how to improve pre-selection for SDB screening in patients with AF.

AIM

We aimed to (1) assess the accuracy of the STOP-Bang screening questionnaire for detection of SDB within an AF population referred for CA; (2) derive a refined, AF-specific SDB score to improve pre-selection.

METHODS

Consecutive AF patients referred for CA without a history of SDB and/or SDB screening were included. Patients were digitally referred to the previously implemented Virtual-SAFARI SDB screening and management pathway including a home sleep test. An apnoea-hypopnoea index (AHI) of  ≥ 15 was interpreted as moderate-to-severe SDB. Logistic regression analysis was used to assess characteristics associated with moderate-to-severe SDB to refine pre-selection for SDB screening.

RESULTS

Of 206 included patients, 51% were diagnosed with moderate-to-severe SDB. The STOP-Bang questionnaire performed poorly in detecting SDB, with an area under the receiver operating characteristic curve (AUROC) of 0.647 (95% Confidence-Interval (CI) 0.573-0.721). AF-specific refinement resulted in the BOSS-GAP score. Therein, BMI with cut-off point ≥ 27 kg/m2 and previous stroke or transient ischaemic attack (TIA) were added, while tiredness and neck circumference were removed. The BOSS-GAP score performed better with an AUROC of 0.738 (95% CI 0.672-0.805) in the overall population.

CONCLUSION

AF-specific refinement of the STOP-Bang questionnaire moderately improved detection of SDB in AF patients referred for CA. Whether questionnaires bring benefits for pre-selection of SDB compared to structural screening in patients with AF requires further studies.

TRIAL REGISTRATION NUMBER

ISOLATION was registered NCT04342312, 13-04-2020.

We all know A and B, but what about C? Exploring the management of modifiable risk factors in patients with atrial fibrillation

Background

The European Society of Cardiology (ESC) guidelines for the management of atrial fibrillation (AF) advise to treat AF according to the ABC pathway: A, anticoagulation, B, better symptom control, and C, comorbidities and cardiovascular risk factor management. Optimal treatment of comorbidities and risk factors slows AF progression and improves success rates of rhythm interventions for AF. However, several studies report underdiagnosis and therefore possible undertreatment for common cardiovascular comorbidities.

Purpose

This study aims to evaluate how common modifiable cardiovascular risk factors are managed in AF patients referred for catheter ablation.

Methods

This is a substudy of the ISOLATION study, a prospective cohort study including consecutive patients with paroxysmal or persistent AF referred for AF ablation. Screening for common modifiable risk factors for AF is structurally embedded in the work-up for AF ablation in the two participating centres. In the present study the prevalence of the following risk factors at this screening moment was assessed: (1) body mass index (BMI) above the target BMI for ablation (≥27 kg/m2), (2) hypertension, defined as on-site systolic blood pressure &gt;130 mmHg and/or diastolic blood pressure &gt;80 mmHg, (3) decreased glucose tolerance or diabetes mellitus, defined as HbA1c ≥6.5%, (4) dyslipidaemia, defined as low-density lipoprotein (LDL) ≥2.5 mmol/l, (5) regular alcohol consumption, defined as self-reported consumption of &gt;15 standardized units/week, and (6) sleep disordered breathing (SDB), defined as apnoea-hypopnoea index (AHI) ≥15 assessed with home sleep tests (subset of patients).

Results

Among the 981 patients studied (median age 65 [59–71] years old, 64% male, 69% paroxysmal AF), previously diagnosed comorbidities were common (46% hypertension, 7% diabetes, 22% dyslipidaemia, 10% SDB), and a large proportion of patients received targeted treatment (Table 1). However, non-optimally managed risk factors remained significant (Figure 1). BMI ≥27 kg/m2 was present in 56% of patients. High systolic and diastolic blood pressure were present in 62% and 51% of patients, respectively, and any form of high blood pressure (either systolic or diastolic) was seen in 72% of patients. HbA1c was found to be above target ranges in 9% patients and LDL in 56%. A weekly alcohol consumption of ≥15 units was reported by 4% of patients. Screening for SDB was performed in a subset of patients (n=287), for whom AHI was ≥15 in 52%. Overall, 9% of patients had 4 or more non-optimally controlled modifiable risk factors, whereas the median number of modifiable risk factors was 2 [1–3].

Conclusions

Structural screening revealed a high prevalence of non-optimally controlled modifiable cardiovascular risk factors in patients referred for AF catheter ablation. According to recent ESC guidelines, improving treatment of comorbidities may improve AF ablation success rates and even reduce mortality.

Funding Acknowledgement

Type of funding sources: None.

Rationale and Design of the ISOLATION Study: A Multicenter Prospective Cohort Study Identifying Predictors for Successful Atrial Fibrillation Ablation in an Integrated Clinical Care and Research Pathway

Introduction

Continuous progress in atrial fibrillation (AF) ablation techniques has led to an increasing number of procedures with improved outcome. However, about 30-50% of patients still experience recurrences within 1 year after their ablation. Comprehensive translational research approaches integrated in clinical care pathways may improve our understanding of the complex pathophysiology of AF and improve patient selection for AF ablation.

Objectives

Within the "IntenSive mOlecular and eLectropathological chAracterization of patienTs undergoIng atrial fibrillatiOn ablatioN" (ISOLATION) study, we aim to identify predictors of successful AF ablation in the following domains: (1) clinical factors, (2) AF patterns, (3) anatomical characteristics, (4) electrophysiological characteristics, (5) circulating biomarkers, and (6) genetic background. Herein, the design of the ISOLATION study and the integration of all study procedures into a standardized pathway for patients undergoing AF ablation are described.

Methods

ISOLATION (NCT04342312) is a two-center prospective cohort study including 650 patients undergoing AF ablation. Clinical characteristics and routine clinical test results will be collected, as well as results from the following additional diagnostics: determination of body composition, pre-procedural rhythm monitoring, extended surface electrocardiogram, biomarker testing, genetic analysis, and questionnaires. A multimodality model including a combination of established predictors and novel techniques will be developed to predict ablation success.

Discussion

In this study, several domains will be examined to identify predictors of successful AF ablation. The results may be used to improve patient selection for invasive AF management and to tailor treatment decisions to individual patients.

Lumbosacral non-terminal myelocystocele associated with teratoma: case report and review of literature

Non-terminal myelocystoceles are commonly found in the cervical or thoracic spinal region. Their sac can rarely be associated with tumor. A rare case of an infant with a lumbosacral non-terminal myelocystocele and accompanying mature teratoma is reported in whom the tumor was attached to the placode not as a part of the sac.

Grain source and chromium supplementation: Effects on health, metabolic status, and glucose-insulin kinetics in Holstein heifer calves

Carbohydrate-rich diets may increase urinary excretion of chromium (Cr) and the need to supplement the diet with Cr to meet animal requirements. The present study was performed to examine the effect of the type of grain (corn vs. barley) and Cr-methionine supplementation on health-related variables, blood levels of metabolites and hormones related to energy metabolism, and insulin sensitivity in Holstein calves. Forty-eight newborn heifers (3 d of age) were assigned randomly to 4 diets in a 2 × 2 factorial arrangement. Experimental diets were either corn-based (CBD) or barley-based (BBD) diets supplemented with 0 or 0.05 mg/kg of metabolic body weight. Chromium was provided in milk before weaning (d 3-73 of age) and in prewarmed water after weaning (d 74-94 of age). There was no interaction between the type of grain and Cr on the health-related variables and blood metabolites and hormones. Type of grain did not affect fecal score, respiration rate, and rectal temperature; however, there were tendencies for higher diarrhea occurrence (odds ratio = 1.69) and lower chance of having pneumonia (odds ratio = 0.49) in calves fed BBD versus CBD despite longer duration of diarrhea (0.54 d) and shorter days with pneumonia (0.63 d) in calves fed BBD. Calves supplemented with Cr had lower fecal score during the preweaning and overall periods and respiration rate throughout the study. Supplemental Cr decreased the duration (0.63 d) and chance of having pneumonia (odds ratio = 2.01). Calves fed BBD had lower blood levels of urea N during the postweaning period, with no changes in other blood variables between CBD and BBD. Tendencies were detected for lower blood levels of β-hydroxybutyric acid during the preweaning and overall periods and higher cortisol in Cr-supplemented calves. Chromium supplementation increased insulin clearance rate and decreased the time to half-maximal concentration and the area under the curve in BBD but not CBD calves. The calves were generally healthy, and the type of grain did not affect the health and blood variables related to energy metabolism. However, Cr supplementation increased fecal consistency, decreased respiration rate and days with pneumonia, and increased insulin sensitivity when added to BBD.

Artemisinin can inhibit the calmodulin-mediated activation of phosphodiesterase in comparison with Cyclosporin A

Artemisinin and Cyclosporin A were examined for their ability to inhibit the calmodulin-mediated activation of phosphodiesterase, which is based on the hydrolysis of cAMP to AMP by phosphodiesterase in the presence or absence of inhibitors, followed by quantitative analysis using spectrophotometer method. Anti-calmodulin activity of these agents was investigated by spectrofluorometry. Our results indicates that Artemisinin and Cyclosporin A induced some conformational changes on calmodulin and increased the fluorescence emission, but Artemisinin increased fluorescence emission of calmodulin in higher amounts compared with the Cyclosporin A. Kinetic analysis of the Artemisinin-calmodulin and Cyclosporine A-calmodulin interaction showed that these agents competitively inhibited the activation of phosphodiesterase without affecting Vmax. Artemisinin increased Km value in higher amounts compared with the Cyclosporin A. Ki values of Artemisinin and Cyclosporin A were determined as 10 microM and 35 microM, respectively. The DeltaG (H2O), the best parameter for the estimation of macromolecule stability, was determined for calmodulin in the absence and presence of Artemisinin and Cyclosporin A. However, the degree of decrease in DeltaG (H2O) value was as follows: Artemisinin>Cyclosporin A, which means Artemisinin induced more instability in the calmodulin structure.In conclusion, our findings showed a good correlation between the ability of both Artemisinin and Cyclosporin A to block the activation of phosphodiesterase and their ability to bind to the activator and that Artemisinin is a more potent inhibitor of phosphodiesterase compared with Cyclosporin A.

Structure and antibacterial activity ofp6 new labdane diterpenoid from Salvia leriaefolia

Phytochemical investigation of the choloroform extract of Salvia leriaefolia afforded 8(17),12E,14-labdatrien-6,19-olide (1), and its structure was determined by a combination of spectral methods. Compound 1 was found to possess antibacterial activity against Staphylococcus aureus.