bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate mitigation forestry—temporal trade-offs
Authors: Skytt Torbjörn , Englund Göran , Jonsson Bengt-Gunnar
Published: October 2021

The 1.5 °C target for global warming calls for evaluating short-term (30–50 years) climate change mitigation with different forests usage. In the current scientific literature and in the public debate, there are contrasting views on how forests should be managed to maximize total climate benefit, including the use of products and changes in carbon pools. Three major factors influence the conclusions in different studies: (a) time horizon, (b) site productivity, (c) substitution calculations. Here we show the dependency among these factors by an analysis of four harvest scenarios: 95%, 60%, 40% and 0% of growth, which are compared to a business as usual scenario (80%). The analyses are made for five counties in Sweden, which covers a wide range in forest productivities, from 2.5 m3 ha−1 yr−1 (north) to 11.5 m3 ha−1 yr−1 (south).

The results show:

(a) Reduced harvest levels provide increased climate benefits on short time scales (at least 50 years).

(b) Increased harvesting from current level is counterproductive on both short and long term.

(c) The potential effect on the carbon balance of a no-harvest scenario in the five counties, is larger (1.1–16 times) than the expected emissions from all other anthropogenic activities until 2045.

(d) Short-term climate benefits of reduced harvesting are largest in highly productive forests. Smaller but more long-lasting benefits can be obtained by aiming at harvest reductions in less productive forests.

(e) Strategies focused on short-term benefits need to be adapted to the future development of substitution factors and forest growth. If substitution effects become higher, increased harvest levels will be beneficial after 2050 in high productive forests. However, if future substitution effects decrease, which is a plausible and desired development, low harvest strategies are preferred in both short- and long-term time perspectives.

We conclude that even moderate reductions of harvest levels would provide substantial climate benefits.
Expanding infrastructure and growing anthropogenic impacts along Arctic coasts
Authors: Bartsch Annett , Pointner Georg , Nitze Ingmar , Efimova Aleksandra , Jakober Dan , Ley Sarah , Högström Elin , Grosse Guido , Schweitzer Peter
Published: October 2021

The accelerating climatic changes and new infrastructure development across the Arctic require more robust risk and environmental assessment, but thus far there is no consistent record of human impact. We provide a first panarctic satellite-based record of expanding infrastructure and anthropogenic impacts along all permafrost affected coasts (100 km buffer, ≈6.2 Mio km2), named the Sentinel-1/2 derived Arctic Coastal Human Impact (SACHI) dataset. The completeness and thematic content goes beyond traditional satellite based approaches as well as other publicly accessible data sources. Three classes are considered: linear transport infrastructure (roads and railways), buildings, and other impacted area. C-band synthetic aperture radar and multi-spectral information (2016–2020) is exploited within a machine learning framework (gradient boosting machines and deep learning) and combined for retrieval with 10 m nominal resolution. In total, an area of 1243 km2 constitutes human-built infrastructure as of 2016–2020. Depending on region, SACHI contains 8%–48% more information (human presence) than in OpenStreetMap. 221 (78%) more settlements are identified than in a recently published dataset for this region. 47% is not covered in a global night-time light dataset from 2016. At least 15% (180 km2) correspond to new or increased detectable human impact since 2000 according to a Landsat-based normalized difference vegetation index trend comparison within the analysis extent. Most of the expanded presence occurred in Russia, but also some in Canada and US. 31% and 5% of impacted area associated predominantly with oil/gas and mining industry respectively has appeared after 2000. 55% of the identified human impacted area will be shifting to above 0 ∘C ground temperature at two meter depth by 2050 if current permafrost warming trends continue at the pace of the last two decades, highlighting the critical importance to better understand how much and where Arctic infrastructure may become threatened by permafrost thaw.
Infinite series of time-dependent Dyson maps
Authors: Fring Andreas , Tenney Rebecca
Published: October 2021

We propose and explore a scheme that leads to an infinite series of time-dependent Dyson maps which associate different Hermitian Hamiltonians to a uniquely specified time-dependent non-Hermitian Hamiltonian. We identify the underlying symmetries responsible for this feature respected by various Lewis–Riesenfeld invariants. The latter are used to facilitate the explicit construction of the Dyson maps and metric operators. As a concrete example for which the scheme is worked out in detail we present a two-dimensional system of oscillators that are coupled to each other in a non-Hermitian

PT

-symmetrical fashion.
Understanding how an amphicarpic species with a mixed mating system responds to fire: a population genetic approach
Authors: Meyer Elena M , Swift Joel F , Bassüner Burgund , Smith Stacy A , Menges Eric S , Oberle Brad , Edwards Christine E
Published: October 2021

Amphicarpic plants produce both above-ground and below-ground seeds. Because below-ground seeds are protected in the soil and may maintain viability when above-ground conditions are stressful, they were proposed as an adaptation to recolonize a site after disturbance. However, whether below-ground seeds are the main colonizers after a disturbance remains unknown. Our goal was to understand whether recolonization by an amphicarpic species after fire was accomplished primarily through germination of seeds produced above-ground or below-ground. We investigated Polygala lewtonii, an amphicarpic, perennial species endemic to fire-prone Florida sandhill and scrub, where fire kills plants but subsequently increases recruitment and population sizes. Polygala lewtonii produces three flower types: above-ground chasmogamous flowers and above-ground and below-ground cleistogamous flowers, with previous research demonstrating chasmogamous flowers produce a much greater proportion of seeds than cleistogamous flowers. We quantified outcrossing in seeds produced by chasmogamous flowers to determine whether it differed from the 100 % self-fertilized below-ground seeds. Approximately 25 % of seeds from chasmogamous flowers showed evidence of cross-pollination. Assuming that chasmogamous flowers produce the majority of the above-ground seeds, as was shown previously, this indicates it is possible to differentiate between germination by above-ground versus below-ground seeds in post-fire colonization. We next compared genetic diversity, admixture, inbreeding and population genetic structure pre- and post-fire. If fire promoted germination of chasmogamous seeds, heterozygosity and admixture would increase, and genetic structure and inbreeding would decrease. Instead, inbreeding and genetic structure increased and admixture decreased, suggesting that the below-ground selfed seeds (with limited dispersal ability) increased their contribution to the population after fire, possibly because fire reduced above-ground seed viability. Additionally, new alleles not found previously in range-wide analyses emerged from the seed bank post-fire. These results suggest that amphicarpy is a powerful adaptation to preserve genetic variation, maintain adaptive potential and promote rapid post-fire colonization.
Epigenome signature as an immunophenotype indicator prompts durable clinical immunotherapy benefits in lung adenocarcinoma
Authors: Pan Xu , Zhang Caiyu , Wang Junwei , Wang Peng , Gao Yue , Shang Shipeng , Guo Shuang , Li Xin , Zhi Hui , Ning Shangwei
Published: October 2021

Intertumoral immune heterogeneity is a critical reason for distinct clinical benefits of immunotherapy in lung adenocarcinoma (LUAD). Tumor immunophenotype (immune ‘Hot’ or ‘Cold’) suggests immunological individual differences and potential clinical treatment guidelines. However, employing epigenome signatures to determine tumor immunophenotypes and responsive treatment is not well understood. To delineate the tumor immunophenotype and immune heterogeneity, we first distinguished the immune ‘Hot’ and ‘Cold’ tumors of LUAD based on five immune expression signatures. In terms of clinical presentation, the immune ‘Hot’ tumors usually had higher immunoactivity, lower disease stages and better survival outcomes than ‘Cold’ tumors. At the epigenome levels, we observed that distinct DNA methylation patterns between immunophenotypes were closely associated with LUAD development. Hence, we identified a set of five CpG sites as the immunophenotype-related methylation signature (iPMS) for tumor immunophenotyping and further confirmed its efficiency based on a machine learning framework. Furthermore, we found iPMS and immunophenotype-related immune checkpoints (IPCPs) could contribute to the risk of tumor progression, implying IPCP has the potential to be a novel immunotherapy blockade target. After further parsing of the role of iPMS-predicted immunophenotypes, we found immune ‘Hot’ was a protective factor leading to better survival outcomes when patients received the anti-PD-1/PD-L1 immunotherapy. And iPMS was also a well-performed signature (AUC = 0.752) for predicting the durable/nondurable clinical benefits. In summary, our study explored the role of epigenome signature in clinical tumor immunophenotyping. Utilizing iPMS to characterize tumor immunophenotypes will facilitate developing personalized epigenetic anticancer approaches.
Soil pollution by heavy metals correlates with levels of faecal glucocorticoid metabolites of a fossorial amphisbaenian reptile
Authors: Martín José , Barja Isabel , Rodríguez-Ruiz Gonzalo , Recio Pablo , García Luis V
Published: October 2021

Soil degradation may have strong negative consequences for soil biodiversity, but these potential effects are understudied and poorly understood. Concentration of nesting seabirds may be a source of soil pollution by heavy metals, which are incorporated into the food chain and may have toxicological effects in vertebrates, especially in fossorial animals with low dispersal ability. We examined whether contamination by heavy metals, derived from seagull depositions, and other soil characteristics, may affect the levels of faecal glucocorticoid metabolites (as a potential indicator of physiological stress) of the fossorial amphisbaenian reptile Trogonophis wiegmanni. We found a relationship between soil pollution by heavy metals and increased levels of faecal corticosterone metabolite of the amphisbaenians that live buried in those soils. This can be due to the strong endocrine disruption effect of heavy metals. In addition, there was an independent effect of the soil texture, with amphisbaenians showing higher levels of faecal corticosterone metabolite in soils with less sand and more silt and clay, which are more energetically costly to dig. Long-term exposure to high glucocorticoid levels might have serious effects on health state and fitness of fossorial animals that may be unnoticed. Our study emphasizes that, to prevent future conservation problems, we need to perform periodic surveys on the physiological health state of the little-known subterranean biodiversity.
Insights into emergency remote teaching in EFL
Authors: Can Iclal , Silman-Karanfil Leyla
Published: October 2021

The transition to emergency remote teaching (ERT) in response to the COVID-19 pandemic has spawned many research studies. However, studies exploring EFL instructors’ emotions, in-class experiences, and relationships with their students and their colleagues during the pandemic are scarce. This mixed study captured nineteen EFL instructors’ emotions on ERT, their transformation of classroom practices, and how they related to students and colleagues during this period in North Cyprus. Data were gathered through a qualitative survey, supplemented with quantitative data from a technological pedagogical content knowledge (TPACK) scale. Our findings revealed that the instructors gradually adapted to ERT despite the challenges that hindered their classroom practice transformation. The findings further suggest that if the instructors develop their TPACK and relatedness with their students and colleagues with the support of their institutions, teaching in a remote environment in the ‘new pedagogy’ contributes to establishing a possible way forward in EFL.
LSI guided-high power short duration is safe and improves pulmonary vein isolation efficiency
Authors: Di Cori A , Della Volpe S , Parollo M , Mazzocchetti L , Giannotti M , De Lucia R , Segreti L , Viani S , Paperini L , Canu A , Grifoni G , Cellamaro T , Soldati E , Zucchelli G , Bongiorni M G
Published: October 2021

Introduction

High-power short-duration (HPSD) is an increasingly used ablation strategy for pulmonary vein isolation (PVI) procedures, but Lesion Index (LSI)-guided HPSD radio-frequency (RF) application has not been described in this clinical setting.

Purpose

We evaluated the procedural efficiency and safety of an LSI-guided HPSD strategy for atrial fibrillation (AF) ablation.

Methods

Paroxysmal and persistent AF patients scheduled for AF ablation were prospectively enrolled and divided in two groups, according to the ablation power used. The LSI-HP Group included patients ablated with a RF power of 50 Watts and the LSI-LP Group included patients ablated with 35 Watts. All patients underwent only PVI under LSI guidance (LSI between 5.5 and 6 anteriorly; LSI between 4.5 and 5 posteriorly) with a point by point strategy and an inter-lesion distance <6 mm. Procedural efficiency parameters were compared between groups.

Results

Forty-six patients with AF (60% paroxysmal) were prospectively enrolled, 25 in the LSI-HP Group and 21 in the LSI-LP Group. They were usually male (78%) with a low-intermediate CHA2DS2-Vasc score (1.8±1.1), a preserved ejection fraction (60±6%) and moderate left atrial dilatation (45±6 mm). Baseline clinical characteristics resulted comparable between groups (p=NS). PVI was successful in all patients. RF time (30.22±9.04 vs 47.85±11.87 min, p<0.0001), total procedure time (138.7±33.2 vs 177.6±49.77, p=0.006) and fluoroscopy time (13.92±5.34 vs 23.14±10.97 min, p=0.006) were significantly lower in the LSI-HP Group. No complication or steam pops was seen in either group.

Conclusions

LSI-HP AF ablation significantly improves procedural efficiency, reducing ablation time, total procedural duration and fluoroscopy use, while maintaining a comparable safety profile as lower powers.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2
Performance of transcatheter pacing system use in Relation to Patient Age
Authors: Nicosia A , Iacopino S , Nigro G , Zucchelli G , Tomasi L , D'Agostino C , Ziacchi M , Piacenti M , De Filippo P , Sgarito G , Foti R , Campisi G , Pepi P , Palmisano P
Published: October 2021

Background

Real-world safety data on the use of transcatheter pacing systems in particularly young and elderly patients is still limited.

Purpose

The aim of this analysis was to investigate the effect of age on the safety and efficacy of leadless pacemaker implant.

Methods

From May 2016 through July 2019, 577 patients were implanted with a leadless single chamber pacemaker according to current pacing indication in 15 Italian cardiologic centers. The population was divided into age quartiles for evaluation, including: 1) <70 years, 2) 70–77 years, 3) 78–83 years, and 4) ≥83 years. Procedural data, complications, electrical parameters were collected at baseline and during the follow up.

Results

Procedural-related complication occurrence was very low (<1.0%) and similar in the four subgroups according to age. No cardiac tamponade was reported. Among the groups, no difference was observed in procedural time, fluoroscopy time duration and electrical parameters (mean pacing impedance: 750±192 and 599±156, mean pacing threshold: 0.7±0.5 and 0.7±0.6, and mean right ventricular sensing 10.7±6.1 and 11.5±4.8 at implant and last follow up, respectively). Figure 1 showed the distribution of age in the patient population.

Conclusion

The reported data demonstrated a high degree of safety during leadless implant across all patient ages. Procedural complications and device electrical measurements were similar among the different ages.

Funding Acknowledgement

Type of funding sources: None.
Early vs late new-onset atrial fibrillation in STEMI patients: pathophysiological mechanisms and relationship with in-hospital outcomes
Authors: Biccire F G , Cardillo I , Chianta V , Ferrari I , Capone S , De Luca A C , Torromeo C , Acconcia M C , Tanzilli G , Barilla F , Pastori D
Published: October 2021

Background

New-onset atrial fibrillation (NOAF) represents the most common supraventricular arrhythmia in the setting of ST-elevation myocardial infarction (STEMI), with up to 21% patients affected. The occurrence of NOAF has clinical relevance as previous studies showed that atrial fibrillation (AF), whether pre-existent to the admission or newly developed during STEMI hospitalization, is associated with worse short- and long-term prognosis. More recently, two distinct phenotypes of NOAF have been described, such as early NOAF (EAF) for AF occurring within 24 h from STEMI, and late NOAF (LAF) for AF onset beyond 24h. The mechanisms underlying EAF or LAF are poorly described.

Objective

To investigate atrial branches occlusion and EAF or LAF onset in STEMI patients undergoing primary percutaneous coronary intervention.

Methods

Retrospective cohort study including 155 STEMI patients. Patients were divided into 3 groups: sinus rhythm (SR), EAF or LAF. Clinical characteristics, angiographic features including occlusion of atrial branches, namely ramus ostia cavae superioris (ROCS), atrio-ventricular node artery (AVNA), right intermediate atrial artery (RIAA) and left intermediate atrial artery (LIAA), were assessed (Figure 1). We also investigated in-hospital adverse events (AEs) and death.

Results

Mean age was 63.8±11.9 years; 78.7% of men. NOAF was detected in 22 (14.2%) patients: 10 (6.4%) EAF and 12 LAF (7.7%). Compared to EAF, LAF patients were older (p=0.013), with higher GRACE risk score (p=0.014) and Killip class (p=0.015), depressed ejection fraction (p=0.007), elevated filling pressures (p=0.029), higher c-reactive protein (p=0.014) and more TIMI flow <3 (p=0.015). Compared to SR, EAF was associated with higher prevalence of occluded ROCS (p=0.010), AVNA (p=0.005) and RIAA (p<0.001) (Figure 2). Moreover, EAF patients had more frequently ≥2 diseased atrial branches than SR (19.5%, p<0.001) and LAF (25%, p<0.030) patients. In LAF patients, a higher incidence of AEs (p=0.019 vs SR; p=0.029 vs EAF) and death (p=0.004 vs SR) was found.

Conclusions

The occlusion of atrial branches is associated with early but not late NOAF following STEMI. LAF patients had worse in-hospital AEs and mortality.

Funding Acknowledgement

Type of funding sources: None. Anatomy of atrial branchesInvolvement of atrial branches
Outcomes and resource utilization of atrial fibrillation hospitalizations with type 2 myocardial infarction
Authors: Ariss R.W , Minhas A.M , Nazir S , Meenakshisundaram C , Ali M.M , Ahuja K.R , Grande R.D , Ramanathan P.K , Kayani W.T , Sheikh M
Published: October 2021

Background

Patients with atrial fibrillation (AF) are often elderly and have higher rates of comorbidities which may predispose them to an increased risk of myocardial oxygen demand-supply mismatch. Scarce data exist on the prognostic impact of type 2 myocardial infarction (MI) in AF.

Purpose

To examine the association of type 2 MI with outcomes and resource utilization in primary AF hospitalizations.

Methods

We utilized the Nationwide Readmission Database 2018 to identify primary AF hospitalizations with and without type 2 MI. The International Classification of Diseases, Tenth Revision (ICD-10) diagnosis codes I48.0, I48.1, I48.2, I48.91 were utilized to identify primary AF hospitalizations within the United States. Of these, AF hospitalizations complicated by type 2 MI were identified using ICD-10 code I21.A1. Comorbidities and outcomes were identified using the corresponding ICD-10 codes. Complex samples multivariable logistic and linear regression models were used to determine the association between type 2 MI and outcomes (in-hospital mortality, index length of stay [LOS], hospital costs, discharge to nursing facility, and 30-day all-cause readmissions). Predictors of in-hospital mortality in AF with type 2 MI were also determined.

Results

Of 382,896 primary AF hospitalizations included in this study, 7,375 (1.9%) had type 2 MI. Compared to AF hospitalization without type 2 MI, those with type 2 MI are older (74.5 vs. 70.7-years-old) and have higher prevalence of chronic pulmonary disease, dyslipidemia, diabetes mellitus, hypertension, heart failure, peripheral vascular disease, chronic kidney disease, neurological disorders, deficiency anemia, coagulopathy, valvular disease, prior myocardial infarction, prior coronary artery bypass grafting, prior percutaneous coronary intervention, and prior cerebrovascular accident (P for all <0.001). AF with type 2 MI is associated with significantly higher in-hospital mortality (1.3% vs. 0.5%; P<0.001), LOS (4.1 vs. 3.3 days; P<0.001), hospital costs ($10,293.6 vs. $8,820.3; P<0.001), discharges to nursing facility (18.1% vs. 10.2%; P<0.001), and 30-day all-cause readmissions (18.5% vs. 13.5%; P=0.001) compared to AF hospitalizations without type 2 MI (Table 1). Heart failure, chronic kidney disease, neurological disorders, and age (per year) were identified as independent predictors of in-hospital mortality among AF patients with type 2 MI (Figure 1).

Conclusion

In this large nationwide analysis, type 2 MI in the setting of AF hospitalization is associated with higher in-hospital mortality and increased resource utilization compared to AF hospitalizations without type 2 MI.

Funding Acknowledgement

Type of funding sources: None. Figure 1
Rate and rhythm control treatment in the elderly and very elderly patients with atrial fibrillation: an observational cohort study of 1,497 patients
Authors: Klamer T.A , Bots S.H , Neefs J , Tulevski I.I , Somsen G.A , Den Ruijter H.M , De Groot J.R
Published: October 2021

Aim

Stroke prevention and rate or rhythm control are crucial parts of the treatment of atrial fibrillation (AF). There is limited evidence for the efficacy or safety of rate and rhythm control in elderly or very elderly patients, although this population is rapidly increasing. Therefore, we analyzed electronic health record data from outpatient cardiology clinics to give insight in prescribing patterns and mortality of both treatment strategies in the elderly patients.

Methods and results

We extracted data from all patients with AF who were aged >75 years, used a pharmacological rate or rhythm control strategy and visited one of the independent outpatient cardiology clinics in the Netherlands between 2007 and February 2018. This resulted in 1,497 selected patients (54% women), of whom 316 (21%) were prescribed rhythm control (consisting of class 1 or 3 antiarrhythmic drugs) and 1,181 (79%) rate control (beta blockers, calcium antagonists or digoxin). Patients aged >85 years (OR: 2.28) and those with permanent AF (OR: 2.71) were more likely to receive rate control (OR: 2.28, OR: 2.71 respectively), whereas those with paroxysmal AF were more likely to receive rhythm control (OR: 0.42). After correcting for relevant confounders, the mortality risk for patients using rhythm control was similar to patients using rate control (HR: 0.89; 95% CI: 0.70; p=0.31).

Conclusion

Considering the similar mortality risks in both groups, a more liberal approach in prescribing a rhythm control strategy to the healthier elderly patient with AF seems safe. Our data underscores the need for a non-inferiority trial to provide definite answers on safety of rhythm control in elderly patients with AF.

Funding Acknowledgement

Type of funding sources: None.
Left atrial stiffness measured by echocardiography is a stronger predictor of atrial fibrillation recurrence after radiofrequency catheter ablation than left atrial volume
Authors: Farinha J.M , Fonseca M , Parreira L , Esteves A.F , Pinheiro A , Ferreira J , Coelho R , Mesquita D , Marinheiro R , Amador P , Caria R
Published: October 2021

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.
Poor glycemic control in diabetic patients increases the risk of recurrent atrial arrhythmia and cardiovascular hospitalizations among morbidly obese patients undergoing atrial fibrillation ablation
Authors: Stout K.M , Tandon H , Adomako R , Schleifer J.W , Payne J , Easley A , Khan F , Windle J , Tsai S , Anderson D , Peeraphatdit T , Naksuk N
Published: October 2021

Background/Introduction

Obesity and atrial fibrillation (AF) coexist and share multiple cardiovascular risk factors. Lifestyle modifications can reduce AF burden in obese patients. However, the time invested in pursing lifestyle changes may delay AF ablation, which could negate the procedural benefit.

Purpose

To examine the effects of lifestyle modifications and the timing of catheter ablation on morbidly obese patients with AF.

Methods

This retrospective study included 217 consecutive AF patients with a body mass index (BMI) ≥35 kg/m2 undergoing AF ablation at a tertiary care center from 2012 to 2019. Modifiable risks were examined, including the time from AF diagnosis to ablation, fluctuation of BMI >5% or an increase in BMI >3% prior to ablation, mean systolic blood pressure >130 mmHg or diastolic blood pressure >80 mmHg, obstructive sleep apnea with CPAP noncompliance, hyperlipidemia without statin therapy, tobacco use, excessive alcohol use, and diabetes mellitus with hemoglobin A1c (HbA1c) ≥6.5%. The primary outcome was a composite of recurrent atrial arrhythmias and cardiovascular (CV) hospitalizations following AF ablation. A multivariate analysis adjusting for age, gender and modifiable risks was performed.

Results

The mean age was 61±9 years old, 58% were female and 45% had persistent AF. A substantial portion of the study patients had modifiable risk factors, ranging from 2.7% with excessive alcohol use to 67.3% experiencing delayed AF ablation, Figure 1. The median time from diagnosed AF to ablation was 1.3 years. During a mean follow-up of 2.9 years after AF ablation, 136 (62.7%) patients met the primary outcome. Only HbA1c ≥6.5% was an independent risk factor with adjusted hazard ratio of 1.57, 95% confidence interval 1.02–2.36, P=0.0412, Figure 2A. Delayed AF ablation did not alter the outcome, Figure 2B. There was no interaction between time of ablation and HbA1c ≥6.5% (P=0.67).

Conclusion

Substantial portions of morbidly obese patients undergoing AF ablation have potentially modifiable risk factors. Poor glycemic control with HbA1c ≥6.5% predicts an increased risk of recurrent atrial arrhythmias and CV hospitalizations, while delayed AF ablation does not. This finding underscores an importance of optimizing HbA1c in morbidly obese patients with AF to reduce adverse outcomes after ablation.

Funding Acknowledgement

Type of funding sources: None.
Catheter ablation of atrial fibrillation in patients under 45 years of age. Longterm outcome
Authors: Calero Nunez S , Hidalgo-Olivares V.M , Cubells-Pastor M , Prieto-Lobato A , Gil-Gomez S , Alcahud-Cortes C , Barajon-Bravo J.M , Cano-Garrigos J , Martinez-Galdon C , Enero-Navajo J
Published: October 2021

Introduction

Young patients (p) with atrial fibrillation (AF) tend to be more symptomatic and more reluctant to take long-term antiarrhythmic drugs. However, AF ablation (especially when persistent) is often used as second-line treatment regardless of age.

Purpose

The aim is to compare clinical outcome and safety of catheter ablation of atrial fibrillation in young adults in comparison to older adults. Secondary endpoints were to compare the influence of other comorbidities in AF ablation outcomes.

Methods

From 2012–2019, consecutive patients (mean age 56±9,4 years; 72,8% men) with symptomatic paroxysmal AF (PAF 68,8%) and persistent (Pers) AF (31,2%) underwent PVI through radiofrequency (91%) or cryoballoon (9%) at our centre. Two groups were defined (group A ≤45 years, group B >45 years). Follow-up was based on outpatient visits including 24h Holter-ECG at 3, 6 and, 12 months post ablation, and every 12 months thereafter.

Results

A total of 202 patients undergoing AF ablation were included (group A: 35, 17,3%; group B: 167, 82,7%). Male gender (91,4 vs 68,9%, p=0,006) and smoking (37,1% vs 13,2%, p=0,001) were significantly more often present in group A. HTA (50,9% vs 22,9%, p=0,002) and CHA2DS2-VASc score (1,3±1 vs 0,4±0,6; p=0,01) were higher in the older population group. Median follow-up was 29±18 months. After 12 months AF recurrence were less common in group A: 1-year arrhythmia-free survival was 88,6% (31/35) vs 73,7% (123/167) in the older group [P 0.049]. However, outcomes at the end of follow up were similar between the two groups, the freedom from AF was 57.1% (20/35) in young patients vs 65,3% (109/167) in older group, p=0,42. Multivariate analysis demonstrated that left atrial volume was a predictor of being freedom from AF recurrent [HR 0,96 (95% IC 0,95–0,99), p=0.003]. Major complications occurred more frequently in older patients, although without reaching statistical significance (4.8% (8) vs 2.9% (1); p=0.61), in the young there was only one complication that was pulmonary vein stenosis. Redo AF ablation rate was comparable between the two groups.

Conclusion(s)

Catheter ablation of AF in young adults is associated with higher 1-year success rates but similar long-term outcomes. The young patients tended to have lower rates of complications in comparison to the older population. These findings suggest that it may be appropriate to consider ablative therapy as first-line therapy in this age group, but further study may be needed to confirm this

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1
Does use of an antiarrhythmic drug prior to cryoballoon pulmonary vein isolation impact the duration of the post-ablation blanking period?
Authors: Saberito M , Milstein N , Bhatt A , Habibi M , Sichrovsky T , Preminger M , Shaw R , Mittal S , Musat D
Published: October 2021

Background

At time of cryoballoon (CB) pulmonary vein isolation (PVI), some patients with atrial fibrillation (AF) are on an antiarrhythmic drug (AAD) while others are not. The impact of AAD use at time of CB PVI on the duration of post-ablation blanking period (BP) is unknown.

Objective

To determine whether the optimal BP duration differs between pts who were and were not taking an AAD at time of CB PVI.

Methods

We enrolled consecutive pts with AF who had initial CB PVI; all pts had an implantable loop recorder (ILR). We prospectively followed all pts and determined the time to last AF episode during the 90-day post-PVI BP. This was then correlated with likelihood of having an AF recurrence between 3–12 months post-PVI.

Results

The cohort included 165 pts (66±9 years; 99 [60%] male; 91 [55%] PAF; CHA2DS2-VASc 2.7±1.6). An AAD was being used at some point prior to ablation in 120 (73%) pts. An AAD was being used at time of CB PVI in 92 (77%) of these 120 pts; this was stopped at a median of 80 [36, 105] days post-PVI.

We defined 4 distinct groups: (1) no AF in 90-day BP (n=75 [45%]); (2) last AF within 30 days of PVI (n=32 [19%]); (3) last AF within 60 days of PVI (n=17 [10%]); and (4) last AF within 90 days of PVI (n=41 [25%]). Patients not exposed to an AAD prior to CB PVI had significantly lower likelihood of having no AF in the first 90-days post ablation (p=0.004, Figure). In contrast, if AF was observed post-ablation, as time from ablation to recurrence increased, so did likelihood of long-term failure from ablation (Figure); this relationship was not impacted by use of an AAD.

Conclusion

The best long-term outcomes post CB PVI are seen in pts who had no prior exposure to an AAD and had no AF within the first 90 days of ablation. Subsequently, as the time from ablation to AF recurrence increased within the 90-day BP, so did likelihood of recurrent AF during long-term follow-up, irrespective of whether an AAD was or was not used.

Funding Acknowledgement

Type of funding sources: None.
Stroke prevention with non-vitamin K antagonist oral anticoagulants in high risk elderly atrial fibrillation patients at increased bleeding risk
Authors: Chao T , Lip G.Y.H , Chen S.A
Published: October 2021

Background

Elderly atrial fibrillation (AF) patients with risk factors of bleeding are often considered ineligible for standard oral anticoagulants (OACs). The ELDERCARE-AF trial recently showed that edoxaban 15mg/day was superior to placebo for preventing stroke or systemic embolism and did not result in a significantly higher incidence of major bleeding. Our aim was to investigate a real-world cohort of AF patients similar to the ELDERCARE-AF cohort, with regard to the impact of non-vitamin K antagonist oral anticoagulant (NOAC) use compared to non-OAC use, in relation to clinical outcomes.

Methods

From January 1, 2012 to December 31, 2016, 15,183 AF patients aged ≥80 years (mean age 86.63 years [SD 4.79]; 48.7% male) with a CHADS2 score >2 who met the enrollment criteria (generally similar to ELDERCARE-AF) were identified from the Taiwan National Health Insurance Research Database. Patients were categorized into 2 groups according to their stroke prevention strategies, ie. without OACs (n=9,084) and NOACs (n=6,099). Patients receiving NOACs were further stratified into reduced-dose or full-dose regimen groups.

Results

Compared to the non-OAC group as a reference, NOAC use (whether as reduced dose or full dose) was associated with a lower risk of ischaemic stroke (adjusted hazard ratio [aHR] 0.766, 95% confidence interval [CI] 0.667–0.879) and all-cause mortality (aHR 0.393, 95% CI 0.370–0.418) while the risks of ICH and major bleeding were similar. The risks of composite outcomes of “ischaemic stroke or mortality” (aHR 0.423, 95% CI 0.398–0.449) and “ischaemic stroke or major bleeding or mortality” (aHR 0.490, 95% CI 0.463–0.518) were significantly lower with NOAC use. When compared to non-OAC as the reference groups, NOACs (whether reduced dose or full dose) showed a positive NCB. The results were generally consistent even after the propensity matching (Figure 1).

Conclusions

In routine clinical care, NOACs (whether reduced or full dose) were associated with a lower risk of ischemic stroke, mortality and the composite endpoint, when compared to non-OAC use in high risk elderly AF patients at increased bleeding risk. Our findings provide complimentary “real world” data to support the generalizability of the results of ELDERCARE-AF trial into daily clinical practice.

Funding Acknowledgement

Type of funding sources: None. Figure 1
Impacts of hemoglobin levels and platelet counts on clinical outcomes in patients with atrial fibrillation: oral anticoagulant use for patients with anemia and/or thrombocytopenia
Authors: Chao T , Chan Y.H , Lip G.Y.H , Chen S.A
Published: October 2021

Background

Hemoglobin (Hgb) levels and platelet (PLT) counts have beeen associated with adverse clinical outcomes in some patients with cardiovascular conditions. We aimed to assess the risks of clinical events among patients with atrial fibrillation (AF) in relation to Hgb levels and PLT counts. Second, we investigated clinical outcomes on warfarin or non-vitamin K antagonist oral anticoagulants (NOACs) compared to no oral anticoagulant use (non-OAC), in different Hgb and PLT strata.

Methods

We used medical data from a multi-center healthcare system in Taiwan which included 37,074 AF patients. Patients were categorized into 3 groups based on their Hgb levels and PLT counts: Group 1 (Hgb>10g/dL and PLT>100K/uL; n=29,147), Group 2 (Hgb<10g/dL or PLT<100K/uL; n=7,078) and Group 3 (Hgb<10g/dL and PLT<100K/uL; n=849). Patients in each category were further stratified as 3 groups according to their stroke prevention strategies; that is, non-OAC, warfarin or NOACs.

Results

A higher Hgb level and/or PLT count was associated with a higher risk of ischemic stroke/systemic embolism (IS/SE), but lower risks of intracranial hemorrhage (ICH) and major bleeding. The composite risks of IS/SE, ICH and major bleeding were higher in Group 3 or Group 2, compared to Group 1 (6.75%/yr versus 6.41%/yr versus 4.13%/yr). Compared to non-OACs, the use of warfarin was not associated with a lower composite risk of IS/SE, ICH and major bleeding in the 3 groups. NOACs were associated with a lower composite risk in Group 1 (aHR 0.68, 95% CI 0.60–0.76) and Group 2 (aHR 0.73, 95% CI 0.53–0.99), but was non-significant in Group 3 (aHR 0.73, 95% CI 0.17–3.07) (Figure). The net clinical benefits were consistently positive in different weight models, in favor of NOAC use, in Group 2 and its subgroups with either anemia or thrombocytopenia.

Conclusions

AF patients with anemia and/or thrombocytopenia were a high-risk population. Compared to no OAC use, NOACs were associated with significantly better clinical outcomes for patients with advanced anemia (Hgb<10g/dL) or thrombocytopenia (PLT<100K/uL), but not for those with both conditions. Harms or benefits of NOACs should be carefully evaluated and balanced in this population.

Funding Acknowledgement

Type of funding sources: None.
Comparing the adverse outcomes of left atrial appendage occlusion in patients with diabetes
Authors: Gill J
Published: October 2021

Introduction

In patients with atrial fibrillation, it is estimated that greater than 90 percent of left atrial thrombi are located in the left atrial appendage. Multiple percutaneously implanted devices have been approved worldwide for left atrial appendage occlusion (LAAO) to reduce stroke risk in patients not suitable for long-term oral anticoagulation. Device implantation has been associated with a high success rate and low risk for peri-procedural complications. However, as the prevalence of diabetes continues to rise, there is a considerable need to establish peri-procedural risk in these patients.

Purpose

This study aimed to evaluate and compare the in-hospital outcomes of LAAO in patients with and without diabetes.

Methods

We performed a retrospective cross-sectional analysis using the 2018 National Inpatient Sample. All patients aged 18 years and older with atrial fibrillation and LAAO-related hospitalizations were included in this study. To mitigate selection bias and control for patient and institutional imbalances, propensity scoring method was used to select matched sample between patients with diabetes and patients without diabetes. The scoring was based on a multivariate logistic regression model accounting for age, gender, race, hospital type, hospital region, hospital teaching status, median household income, and medical comorbidities. Using an 8-to-1-digit match, we paired each admission in the diabetes group with one admission without diabetes.

Results

We identified a total of 3572 patients admitted for LAAO; 1298 of these patients had comorbid diabetes. Diabetics did not have a higher risk of in-hospital mortality with LAAO (0.2% vs 0.3%, p=0.620). The risk for 17 out of the 18 identified peri-procedural complications was similar in patients with and without diabetes. However, diabetes was associated with an increased risk of acute kidney injury (Adjusted OR 1.75; 95% CI 1.05–2.93, p=0.03). Interestingly, 0 endocarditis events were captured in both groups, indicating that this complication is only seen in long-term follow-up and had a peri-procedural risk of 0%.

Conclusion

As the use of implantable LAAO devices increases worldwide, clinicians should be cognizant of the increased risk for peri-procedural acute kidney injury in diabetics. Patients with diabetes often have diabetes-induced chronic kidney disease with susceptibility to acute injury. Therefore, volume status should be closely monitored in the peri-procedural period to mitigate further damage to the kidneys in these patients.

Funding Acknowledgement

Type of funding sources: None. Characteristics of the matched cohortOutcomes in the matched cohort
Actual management costs of patients with non-valvular atrial fibrillation treated with percutaneous left atrial appendage closure or oral anticoagulation
Authors: D'Ancona G , Arslan F , Safak E , Ince H
Published: October 2021

Background

Left atrial appendage closure (LAAC) is a safe and efficacious alternative to oral anticoagulation (OAC) therapy in patients with non-valvular atrial fibrillation (AF) who are at high risk for both stroke and bleeding. Data on cost-effectiveness of LAAO are limited and existing studies on the topic are based on simulation model approaches rather than on real-world costs.

Purpose

To compare actual management costs in patients with non-valvular AF treated with LAAC or OAC only.

Methods

Percutaneous LAAC was performed only in patients with at least one cerebral thromboembolic event, one major bleeding episode while under OAC, and with absolute contraindication to prolonged OAC. AF patients undergoing percutaneous LAAC were matched with AF patients treated with OAC only. Matching variables were gender, age, and Diagnosis Related Groups (DRG) clinical complexity level. Costs for cardiovascular outpatient clinic visits and hospitalizations were derived from the actual medical claims and reimbursement records. Data were prospectively collected and retrospectively analyzed.

Results

Between 1/2012 and 12/2016, 8478 patients with non-Valvular AF were referred to our institution: 7801 (92%) were managed with OAC only and 677 (8%) with LAAC. A total of 559 patients (279 per group) were matched. Mean age was 74.9±7.5 years, 244 were female (43.7%), and mean DRG clinical complexity level was 1.8±1.1.

Median annualized management cost before LAAC was €3110 (IQR €1281–8127). Median hospitalization cost for LAAC was €9601 (IQR: €9393–10007). After a mean follow-up of 4.5±1.4 years, median annualized management cost was €1297 (€607–2735) in patients with sole OAC and €1013 (IQR €0–4770) in patients after LAAC (p=0.003). Undergoing LAAC was the strongest independent determinant to reduce follow-up management costs (linear regression: beta = −0.335; CI: −1.09 to −0.682; p<0.0001). Estimated 3-year survival was similar in the LAAC (92%) and OAC patients (90%) (p=0.7).

Conclusion

LAAC significantly reduces management costs of patients with non-valvular AF. In patients referred for percutaneous LAAC, the drastic reduction in management costs following LAAC justifies the procedural costs. In spite of their complex comorbid profile, LAAC patients show a follow-up survival rate similar to those of patients solely treated with OAC. Management costs of patients solely on OAC are significantly higher than management costs of patients after LAAC. Future studies are necessary to investigate the potential net economic and clinical benefit of LAAC in patients that are treated with OAC only.

Funding Acknowledgement

Type of funding sources: None.