bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implantable cardioverter defibrillators among elderly survivors of out-of-hospital cardiac arrest
Authors: Marcus M , Chan P S , Chang A , Merritt R K , Mcnally B , Link M S , Girotra S 
Published: October 2024

Abstract

Background
Survivors of out-of-hospital cardiac arrest (OHCA) with a shockable rhythm are at increased risk of cardiac arrest, and clinical practice guidelines recommend placement of an implantable cardioverter defibrillator (ICD) in the absence of a reversible cause and an expected meaningful survival of at least one year. Contemporary data on the prevalence of secondary prevention ICD placement among OHCA survivors remain limited.

Purpose
Examine patterns of secondary prevention ICD implantation in survivors of OHCA due to a shockable rhythm in a large national registry.

Methods
Using 2013-2019 data from the Cardiac Arrest Registry to Enhance Survival (CARES) linked to Medicare files, we identified 3,226 patients aged &gt;65 years who survived to discharge following OHCA due to an initial shockable rhythm from January 1, 2013 to December 31, 2019. Patients with severe neurological disability, prior history of cancer, and those discharged to hospice were excluded. We calculated cumulative prevalence of ICD implantation at discharge, 90 days, and 6 months post cardiac arrest. Multivariable hierarchical regression models with random hospital effects were used to determine the adjusted association of patient characteristics with ICD implantation and quantify the extent of variation in ICD implantation across sites, using a median odds ratio (OR) and 95% confidence interval (CI).

Results
Patients’ mean age was 72.2 years; 23.5% were women, 10% were Black and 4% Hispanic. Among 3,226 OHCA patients, 997 (30.9%) received an ICD before discharge; 1,266 (39.2%) received an ICD within 90 days of cardiac arrest, and 1,287 (39.9%) received an ICD by 6 months. After adjusting for differences in demographics and co-morbidities, the odds of receiving an ICD at discharge were significantly lower in patients aged 85 years and older, women, patients with prior history of stroke or diabetes, patients who presented with acute myocardial infarction (P&lt;0.05 for all). There was no significant difference in ICD implantation by race and ethnicity (P=0.94) (Table 1). Even after adjusting for patient demographics, co-morbidities, and presentation with acute myocardial infarction, there was large variation in hospital rate of ICD implantation at discharge, with a median odds ratio of 1.65 (95% CI 1.41-1.86).

Conclusion
Fewer than 1 in 3 patients with OHCA due to a shockable rhythm are discharged with a secondary prevention ICD. Although implantation of ICD was associated with patient variables, there was no difference in ICD implantation by race and ethnicity. There was large variation across hospitals in ICD implantation even after adjusting for patient variables highlighting an opportunity for improving post-arrest management of cardiac arrest survivors.
Evaluating lesion integrity with diamond temp system
Authors: Siddiqui U , Khanani A 
Published: October 2024

Abstract

Background
Pulmonary vein (PV) isolation by temperature-controlled (TC) radiofrequency ablation (RFA) is regaining popularity due to tissue-temperature feedback from thermocouples attached at the distal tip. The Diamond Temp (DT) ablation catheter system is uniquely able to monitor real time tissue temp during RFAs.
The DT catheter tip has a 1.1 mm split tip electrode, allowing precise bipolar pacing during RFA. Loss of capture (LOC) with High output pacing (HOP) has been considered a surrogate to assess lesion transmurality [1]. This study evaluated the utility of DT catheter distal pacing to achieve durable lesions.
Standard guidelines for TC ablation recommend achieving target tissue-temperature of 60ºC to produce durable lesions. The purpose of this study was to assess whether LOC is achieved at target tissue-temperature of 60ºC.

Objective
Pacing during ablation from distal tip micro electrode of the DT catheter and observing the time it takes for LOC at different segments around pulmonary veins. First pass isolation (FPI) percentage was also collected.

Methods
While target enrollment for this prospective study is 50 patients, these preliminary findings are based on analysis of the first 15 patients enrolled, all of whom had symptomatic, drug-refractory paroxysmal AF.
Point-by-point RF lesions were delivered around ipsilateral PVs, divided into 4 segments: superior, inferior, anterior, and posterior. Ablation was performed in a TC mode with max temp setting of 60°C and max power of 50 watts. HOP was performed prior to start of ablation and discontinued once LOC was observed. Time taken to LOC around all 4 segments of PVs were recorded. Intracardiac echocardiography (ICE) was used to guide contact and monitor lesion formation.

Results
Overall mean time to LOC was 3.32 sec. Anterior sites exceeded this mean. Inferior, superior, and posterior sites generally had shorter times. 92.53% of locations achieved LOC within 2-5 sec of ablation. The right anterior PV had the longest time at 3.73 sec, exceeding the overall mean of 3.32 sec. All patient achieved FPI.

Conclusion
Reaching target therapeutic temp of 60°C alone may not be sufficient to achieve LOC around PVs. Ablation duration of 4 sec led to LOC in 92.53% of lesions. Certain anatomical regions like anterior locations required prolonged ablation time. Tissue thickness on ICE correlated directly with time required to LOC.
This analysis shows that TC ablation with DT is effective; however, a therapeutic stable temperature of 60°C for at least 4 sec may be needed to achieve durable lesions around PVs. Tissue thickness on ICE and stability of temperature appear to be independent variables affecting duration prior to LOC.
The connection site of the Bachmann bundle to the left atrium affects atrial electrical and anatomical remodeling
Authors: Mine T , Terao S , Sugitani M , Kogame T , Fukuhara E , Ishihara M 
Published: October 2024

Abstract

Background
A common route for the propagation of the conduction system from the right atrium to the left atrium (LA) is via the Bachmann bundle (BB) which is a parallel-aligned muscular structure. It is empirically known that the site of conduction from BB to LA differs depending on the patient.

Purposes
To clear the clinical significance of differences in the BB conduction sites in patients with atrial fibrillation (AF).

Methods
We studied 182 patients (90 non-paroxysmal AF, 121 males, and 68.2 ± 10.0 years) who received catheter ablation for AF. Clinical data, echocardiographic data, and blood samples were evaluated. High-density LA mapping during high right atrial pacing was constructed. The site of conduction from BB to LA, the global activation time, LA mean voltage, the abnormal conduction zone (ACZ), and the conduction block (CBZ) were evaluated. The conduction from BB was connected to the region surrounded by the left atrial roof line, the carina of the right pulmonary vein, and the base of the left atrial appendage in all patients (Figure 1). This area was divided into four regions (right-roof, mid-roof, right-anterior, and mid-anterior area), and BB conduction sites were classified into each area by three independent observers who did not know clinical data. Global activation time for the LA was calculated by subtracting the earliest from the latest activation within the LA. Isochronal activation maps were created at a 5-ms interval setting, and ACZ (Figure 2) and CBZ were identified on the activation map by locating a site with isochronal crowding of ≥3 isochrones and ≥8 isochrones, which were calculated as ≤27 cm/s and ≤10 cm/s.

Results
The conduction from BB was observed in 45 patients in the right-roof area, 24 in the mid-roof, 76 in the right-anterior, 23 cases in the mid-anterior, and 14 in multiple sites. Global activation time (right-roof 108±20, mid-roof 107±16, right-anterior 105±19, and mid-anterior 117±20ms, P=0.0781) was more prolonged and left atrium diameter was larger (42.1±6.6, 42.6±8.5, 42.5±6.6, and 46.4±6.6mm, P=0.0718) in patients with mid-anterior BB connections. LA mean voltage (4.90±1.94, 5.72±2.62, 4.13±1.58, and 4.88±1.96mV, P=0.0032) was higher and plasma brain natriuretic peptide level (139±138, 67±59, 128±139, and 164±197pg/mL, P=0.0861) was lower in patients with mid-roof BB connections. ACZ (41/45 91%, 20/24 83%, 73/76 96%, and 23/23 100%, P=0.0904) and CBZ (1/45 2%, 0/24 0%, 8/76 11%, and 2/23 9%, P=0.0850) appearance rates were lower in patients with mid-roof BB connections.

Conclusion
The connection site of the Bachmann bundle to the left atrium may affect atrial electrical and anatomical remodeling in patients with atrial fibrillation.
Incidence of silent brain injury in pacemaker implanted patients with atrial high-speed episodes (AHRE)
Authors: Cinar A , Gedikli O , Uyanik M , Avci B 
Published: October 2024

Abstract

Purpose
Atrial high rate episodes (AHRE) are tachyarrhythmia attacks that can be detected by implantable cardiac devices. In the European Society of Cardiology (ESC) 2020 AF guideline, AHRE is defined as ≥ 175 bpm for the device-programmed rate criterion and ≥ 5 minutes for the duration criterion. AHRE has been shown to be one of the predisposing factors of AF and stroke. However, the relationship between AHRE and SBI has not been clarified yet. Neuron spesific enolase (NSE) is a valid biomarker for quantifying the volume of neuronal damage. In this study, we aimed to evaluate the incidence of silent brain injury (SBI), defined as elevated NSE levels in AHRE detected patients.

Method
Between January 2021 and June 2022, 80 patients who underwent routine pacemaker control, met the inclusion and exclusion criteria, and had AHRE detected in their permanent pacemaker records were included in a university faculty of medicine cardiology arrhythmia polyclinic. For the control group, patients who had a permanent pacemaker and did not have AHRE or any other arrhythmia were included. Of patients with AHRE detected in the last 6 months and those who had an AHRE attack within the last 72 hours were examined.

Results
Individuals included in the study were divided into subgroups according to AHRE duration. Group 1 (non-AHRE) 80 (50.0%), Group 2 (AHRE lasting &lt;5 min) 24 (15.0%), Group 3 (≥5 min - &lt;1h) 33 (20.6%), 19 (11.9%) patients in Group 4 (lasting ≥1 h - &lt;24 h) and 4 (2.5%) patients in Group 5 (lasting ≥24 h). There was a statistically significant difference in NSE median values between groups (p=&lt;0.001). In Mann Whitney U test with Bonferronni correction, the median values of all other groups were significantly different from each other (p=&lt;0.001). In the correlational analysis, there was a statistically significant positive relationship between AHRE duration and NSE values (r=0.842; p=&lt;0.001). Additionally, there was correlation between AHRE duration and age (r=0.235; p=0.036), CHA2DS2-VASc score (r=0.226, p=0.044) and LA diameter (r=0.300; p=0.007). NSE levels were positively correlated with AHRE duration (r=0.842; p=&lt;0.001) and LA diameter (r=0.242; p=0.030).

Conclusion
AHRE duration was longer in patients with advanced age, increased CHA2DS2-VASc score, and increased LA diameter. This may play a role in explaining the underlying pathophysiological changes in AHRE before AF develops. Since NSE levels are related to LA diameter as well as AHRE duration, it can be thought that increasing LA diameter contributes to the development of thrombus.
Blood pressure response to exercise in endurance athletes with and without paroxysmal atrial fibrillation.
Authors: Janssens K , Apelland T , Mitchell A , Enger S , Dausin C , Rowe S , D'ambrosio P , Foulkes S , Hawley J , Claessen G , Myrstad M , La Gerche A 
Published: October 2024

Abstract

Background
Atrial fibrillation (AF) is more prevalent among endurance-trained athletes when compared to non-athletes. The underlying pathophysiology and mechanisms for this phenomenon remain unknown but repeated exposure to an exaggerated blood pressure (BP) response during exercise may contribute to the development of AF in this population.

Purpose
We aimed to assess whether endurance athletes with AF have a higher maximal systolic BP (SBP) or a higher BP relative to exercise intensity compared to endurance athletes without AF.

Methods
Endurance athletes with paroxysmal AF (n=66, 96% male) from the ProAFHeart, NEXAF Detraining and Master@Heart studies were matched for age and sex to endurance athletes without AF (n=66, 96% male). Participants with a history of hypertension were excluded. All athletes underwent a maximal graded cardiopulmonary exercise test on a cycle ergometer to assess exercise BP using an automated auscultatory BP machine, maximal oxygen uptake (VO2peak) and peak workload. All athletes were in sinus rhythm at the time of testing and BP was measured pre-exercise seated on the bike and every 2 min throughout the test. Exercise BP measurements included the maximum exercise SBP (SBPmax) and the slopes of the relationships between SBP, diastolic BP (DBP) and workload (W) as determined from linear regression analysis (SBP/W-slope and DBP/W-slope, respectively). The resting SBP and DBP were measured in the supine position after 10min of rest. Independent T-test (parametric data) or the Mann-Whitney U-test (non-parametric data) assessed for the differences between the two groups.

Results
The 66 athletes with AF were of similar age and sex as the 66 athletes without AF, median age (55 [IQR 45, 61] vs 54 [IQR 44, 62] years, p=0.839), 4% female. There was no difference in (mean±SD) VO2peak (46 ±9 vs 49±10 mL/kg/min, p=0.114) and peak workload (365±67 vs 385±83 W, p=0.136), nor resting SBP (131±13 vs 128±13 mmHg, p=0.169) and resting DBP (76±9 vs 75±11 mmHg, p=0.465) between athletes with and without AF respectively (Table 1). Athletes with AF showed no significant difference to athletes without AF for exercise BP responses (Figure 1) including SBPmax (222±22 vs 219±28 mmHg, p=0.479), SBP/W-slope (0.22±0.07 vs 0.24±0.08 mmHg/W, p=0.310) and median DBP/W-slope (-0.01 [IQR -0.02, 0.01] vs -0.01 [IQR -0.03, 0.02] mmHg/W, p=0.703).

Conclusion
When comparing endurance athletes with and without paroxysmal AF, there were no differences in the maximal BP attained during exercise or in their BP response indexed to external workload (SBP/W-slope) suggesting that exercise-induced hypertension does not explain the athletic predisposition to AF.
Outcome and life expectancy associated with novel subgroups of atrial fibrillation: a data-driven cluster analysis
Authors: Wang N , Yu Y , Li J , Sun Y , Yu B , Tan X , Wang B , Lu Y 
Published: October 2024

Abstract

Background/Introduction
Atrial fibrillation (AF) presents a significant global health burden, affecting millions and associated with elevated risks of mortality, heart failure, and stroke despite current treatment strategies. The current diagnosis of AF relies on episode characteristics, yet its heterogeneity calls for personalized assessment incorporating clinical features, biomarkers, and substrate determination for improved classification and management.

Purpose
This study aimed to develop a refined classification of AF according to comprehensive risk factors to identify patients at high-risk for poor prognosis and their life expectancy, aiming to facilitate personalized interventions.

Methods
A total of 7,391 participants aged 40-69 with AF at baseline, from UK Biobank, were recruited in the main analyses. Firstly, LASSO regression with Cox model and factor analysis were adopted for identification and integration of principal risk factors. Second, Consensus clustering analysis was employed to estimate the optimal cluster number and group all 7,391 participants. Difference in the risk of death and major complications, as well as reductions in life expectancy, among clusters were estimated. Replication was done in 2,399 participants with newly diagnosed AF within two years after baseline.

Results
Risk factors for AF were categorized into seven aspects (metabolic factors, respiratory factors, cardiovascular factors, renal and immunity diseases, mental health, acute illness, age), based on the correlation between them. Five distinct AF clusters were identified according to these seven characteristics: acute illness-related (Cluster 1), mental health-related (Cluster 2), cardiovascular disease-related (Cluster 3), immune-and-renal disease-related (Cluster 4), and respiratory-and-metabolism disease-related AF (Cluster 5). Patients with respiratory-and-metabolism disease-related AF had the highest risk of death, acute myocardial infarction, heart failure, and cerebral ischemic stroke, while those with acute illness-related AF had the lowest corresponding risk. In addition, compared with individuals with acute illness-related AF, those with respiratory-and-metabolism disease-related and mental health-related AF had the top 2 greatest loss of life expectancy. Furthermore, genetic variants for AF had different effect among the five clusters. Replication analysis confirmed the result stability.

Conclusion
A novel AF classification was developed, which provided insights into varying life expectancy and risks of death and complications among AF subgroups with distinct characteristics. It offers a practical approach for identifying high-risk patients, which may help to tailor precise interventions for AF management.Graphic abstractCluster features
Peripheral artery disease, antithrombotic treatment and outcomes in European and Asian patients with atrial aibrillation: a report from 2 prospective observational registries
Authors: Mei D A , Romiti G F , Bucci T , Corica B , Imberti J F , Bonini N , Vitolo M , Shantsila A , Tse H F , Chao T F , Boriani G Y H , Proietti M , Lip G Y H 
Published: October 2024

Abstract

Background
In patients with atrial fibrillation (AF), the impact of peripheral artery disease (PAD) on oral anticoagulant (OAC) therapy use and the risk of outcomes remains unclear.

Objective
To analyse the epidemiology of PAD in a large cohort of European and Asian AF patients, and the impact on treatment patterns and risks of adverse outcomes.

Methods
We analysed AF patients from two large prospective observational registries. We identified patients with PAD as reported by the investigators. Logistic regression analysis was used to assess factor associated with the presence of PAD at baseline.
OAC prescription and risk of outcomes were analyzed according to the presence of PAD, using adjusted Logistic and Cox regression analyses. The primary outcome was the composite of all-cause death and major adverse cardiovascular events (MACEs). Interaction analyses were also performed according to different subgroups.

Results
15,497 patients with AF (mean age 68.9, SD 11.6 years; 38.6% female, 30% from Asia) were included in the analysis. PAD was found in 941 patients (6.1%), with higher prevalence among European individuals compared to Asian (8.1% vs 1.2%, p&lt;0.001). Patients with PAD were older, more likely with permanent AF, more symptomatic and with higher thromboembolic and bleeding risk.
On logistic regression analysis, European patients had 6-fold higher odds of presenting with PAD compared with Asians (Figure 1, Panel A). Other comorbidities and increasing age were associated with higher odds of prevalent PAD (Figure 1 Panel A). Conversely, female sex was associated with lower odds of having PAD at baseline. With age modelled as a continuous variable, and odds of PAD at baseline, there was a non-linear relationship, with the odds of PAD increasing almost linearly until 70 years, plateauing afterwards (Figure 1 Panel B).
After adjustments, PAD was associated with lower use of OAC (OR 0.69, 95% CI 0.57-0.85). On Cox regression analysis, PAD was associated with a higher risk of the primary composite outcome (HR 1.28, 95%CI: 1.08-1.52) and all-cause death (HR 1.40, 95%CI: 1.16-1.69). A significant interaction was observed between PAD and age, with greater risks of PAD found in younger patients (&lt;65 years) for the primary outcome (pint=0.014, Figure 2, panel A). Consistent results were observed when we analysed the interaction between PAD and age, modelled as a restricted cubic spline, where the risk of the primary outcome followed a J-curve across age, while patients without PAD showed an approximately linear relationship (pint&lt;0.001, Figure 2, Panel B).

Conclusions
In patients with AF, PAD is associated with lower use of OAC and higher risk of adverse outcomes, with a greater risk seen in younger patients.Figure 1Figure 2
Atrial Fibrillation (AF) detected by repeat handheld ECG screening and the risk of heart failure hospitalization
Authors: Sun W , Yan B 
Published: October 2024

Abstract

Purpose
Heart failure and atrial fibrillation (AF) frequently complicate one another. Risk of heart failure in screen-detected patients was not investigated. We aimed to compare risk of hospitalization for heart failure (HHF) between screen-detected and clinically-diagnosed AF, and to evaluate the impact of AF burden.

Methods
Consecutive patients aged over 65 attending outpatient clinics were prospectively recruited for AF screening, using handheld single-lead ECG (AliveCor) during December 2014 and December 2017. Patients who had &gt;1 visits received repeat screening. All participants were divided into 5 cohorts: (i) previously known AF at enrolment; (ii) initial screen-detected AF; (iii) subsequent screen-detected AF; (iv) clinically-diagnosed AF during follow-up (FU); (v) No AF. Risk of HHF was estimated by adjusted sub-distribution hazard ratios (aSHR) derived from Fine and Gray regression, accounting for death as competing risk, adjusting for CHA2DS2VASC components and chronic kidney disease, AF diagnosis being handled as time-dependent variable. Patients who participated in repeat screening and previously known AF formed a sub-cohort. Patients with previously known AF who were in AF in the initial screening and those with repeat screen-positivity were defined probably persistent AF, otherwise paroxysmal AF (single screen-positivity) or no AF (never screen-positive). Risk of HHF was compared between groups stratified by AF burden (persistent vs. paroxysmal) and scenario of AF diagnosis (screen-detected vs. clinically-diagnosed).

Results
Of 11,972 subjects (mean age 76.6±7.8, female 49.2%), 18.7% (n=2,236) had known AF, 1.9% (n=223) initial screen-detected AF, 0.6% (n=71) subsequent screen-detected AF, 7.3% (n=867) clinically-diagnosed AF during FU, and 71.6% (n=8,559) no AF. During a median FU of 6.7 (IQR:4.4-8.0) years, risk of HHF was highest in patients with clinically-diagnosed AF (aSHR=3.5(2.7-4.5)), followed by subsequent screen-detected AF (aSHR=2.8(1.6-5.0)), previously known AF (aSHR=1.9(1.6-2.2)), and initial screen-detected AF (aSHR=1.7(1.1-2.4)) (Figure 1a). Sensitivity analysis excluded those with known heart failure at baseline, after which risk of HHF became comparable between previously known and initial screen-detected AF (Figure 1b). Sub-analysis for participants (32.2% (n=3,853), mean age 76.7±7.3, female 47.5%) of repeat screening showed screen-detected persistent AF (aSHR=3.7(1.9-7.2)) was at highest risk of HHF, followed by clinically-diagnosed AF (AF burden unassessed) (aSHR=3.3(2.2-5.0)), previously known persistent AF (aSHR=3.1(2.5-3.8)), screen-detected paroxysmal AF (aSHR=2.1(1.4-3.4)), previously known paroxysmal AF (aSHR=1.8(1.3-2.4) (Figure 1c).

Conclusion
Higher AF burden and FU new AF diagnosed by either screening or clinic visit was associated with higher risk of HHF. Screening facilitating early AF diagnosis and early downstream intervention, warranted further study.