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The prevalence and impact of perioperative atrial fibrillation (AF) during an admission for major emergency abdominal surgery are sparsely examined. Therefore, this study aimed to compare the 30-day and 1-year outcomes (AF-related hospitalization, stroke, and all-cause mortality) in patients with and without perioperative AF to their major emergency abdominal surgery. All patients without a history of AF who underwent major emergency abdominal surgery from 2000 to 2019 and discharged alive were identified using Danish nationwide registries. Patients with and without perioperative AF (defined as new-onset AF during the index hospitalization) were matched 1:4 on age, gender, year of surgery, and type of surgery. The cumulative incidences and hazard ratios of outcomes were assessed using a multivariable Cox regression analysis comparing patients with and without perioperative AF. A total of 2% of patients were diagnosed with perioperative AF. The matched cohort comprised 792 and 3,168 patients with and without perioperative AF, respectively (median age 78 years [twenty-fifth to seventy-fifth percentile 70 to 83 years]; 43% men). Cumulative incidences of AF-related hospitalizations, stroke, and mortality 1 year after discharge were 30% versus 3.4%, 3.4% versus 2.7%, and 35% versus 22% in patients with and without perioperative AF, respectively. The 30-day outcomes were similarly elevated among patients with perioperative AF. Perioperative AF during an admission for major emergency abdominal surgery was associated with higher 30-day and 1-year rates of AF-related hospitalization and mortality and similar rates of stroke. These findings suggest that perioperative AF is a prognostic marker of increased morbidity and mortality in relation to major emergency abdominal surgery and warrants further investigation., Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Aim: To examine temporal changes in incidence rates of atrial fibrillation/flutter (AF), treatment strategies, and AF readmission rates in patients <65 years., Methods: Using Danish nationwide registries, we identified patients <65 years with a first-time AF diagnosis from 2000 to 2018. The cohort was categorized according to calendar periods; 2000-2002, 2003-2006, 2007-2010, 2011-2014, and 2015-2018. In this retrospective cohort study the incidence rate (IR) of AF per 100,000 person years (PY), catheter ablation, electrical cardioversion, use of pharmacotherapy, and AF readmission, were investigated in the first year following AF diagnosis., Results: We identified 60,917 patients; 8150 (13.4%) in 2000-2002, 11,898 (19.5%) in 2003-2006, 13,560 (22.3%) in 2007-2010, 14,167 (23.3%) in 2011-2014, and 13,142 (21.6%) in 2015-2018. Apart from 2015 to 2018, a stepwise increase in the crude IR of AF was observed across calendar periods; 2000-2002: 78.7 (95% CI 77.0;80.4), 2003-2006: 86.3 (84.7;87.8), 2007-2010: 97.9 (96.3;99.6), 2011-2014: 102.3 (100.7;104.0), 2015-2018: 93.6 (92.0;95.2). Over the studied time-periods, we found a stepwise increase in the cumulative incidence of catheter ablation (1.2% to 7.6%) electrical cardioversion (2.0% to 8.7%) and treatment with oral anticoagulant therapy (OAC) (28.5% to 47.8%) within the first year of diagnosis. No temporal differences in incidence of 1-year AF readmission were identified (AF-readmissions: 2000-2002: 32.7%, 2003-2006: 31.1%, 2007-2010: 32.2%, 2011-2014: 32.1% and 2015-2018: 31.7%)., Conclusion: The incidence rate of AF in patients <65 years increased from 2000 to 2018, as did the use of catheter ablation, electrical cardioversion and OAC in the first year following AF diagnosis. 1-year AF readmission incidence remained stable around 32% over the study period., Competing Interests: Declaration of Competing Interest Lukas Schak, MB; None. Jeppe Kofoed Petersen, MB; None. Naja Emborg Vinding, MD; None. Charlotte Andersson MD, PhD; None. Peter E. Weeke MD, PhD; None. Søren Lund Kristensen MD, PhD; Astra Zeneca speaker fee outside submitted work. Anna Gundlund MD, PhD; None. Morten Schou MD, PhD; Speaker fee outside submitted work from Astra Zeneca, Novo Nordisk, Boehringer and Novartis. Lars Køber MD, DMSc; Speaker fee outside submitted work from Astra Zeneca, Bayer, Boehringer, Novartis and Novo Nordisk. Emil Loldrup Fosbøl MD, PhD; Independent research funding for project outside submitted work from Novo Nordisk and Danish Heart Association. Lauge Østergaard MD, PhD; None., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Aims: While clinical trials have suggested that a high ventricular rate is associated with increased risk of heart failure (HF) and mortality, all-comers studies are warranted., Objective: To assess 1-year risk of new-onset diagnosed HF and all-cause mortality among rate-control treated patients presenting with atrial fibrillation (AF) on an electrocardiogram (ECG) according to ventricular rate., Methods and Results: ECGs recorded at the Copenhagen General Practitioners Laboratory (2001-15) were used to identify patients with AF. Multivariate Cox proportional hazard regression models were used to compare risk of new-onset HF and all-cause mortality after first ECG presenting with AF according to ventricular rate on ECG [<60, 60-79, 80-99, and 100-110, > 110 beats per minute (bpm)]. We identified 7408 patients in treatment with rate control drugs at time of first ECG presenting with AF [median age 78 years (Q1,Q3 = 70-85 years)], 45.8% male, median ventricular rate 83 bpm, (Q1,Q3 = 71-101 bpm)]. During 1-year follow-up, 666 (9.0%) of all patients with AF developed HF and 858 (11.6%) died. Patients with AF ventricular rates 100-110 bpm and >110 bpm had a hazard ratio (HR) of 1.46 (CI: 1.10-1.95) and 2.41 (CI: 1.94-3.00) respectively for new-onset HF, compared with 60-79 bpm. Similarly, patients with AF ventricular rates 100-110 bpm and >110 bpm had a HR of 1.44 (CI: 1.13-1.82) and 1.34 (CI: 1.08-1.65) respectively for all-cause mortality, compared with 60-79 bpm., Conclusions: Ventricular rates ≥100 bpm among patients presenting with AF on ECG in treatment with rate control drugs were associated with greater risk of both new-onset HF and all-cause mortality., Competing Interests: Conflict of interest: Lucas Malta Westergaard: none, Amna Alhakak: none, Rasmus Rørth: none, Emil L. Fosbøl: none, and Søren L. Kristensen: speaker fee from Astra Zeneca. Advisory board at Bayer, Jesper H. Svendsen: research grant, payment to institution, and speaker fee from Medtronic. Advisory board at Medtronic, Claus Graff: none, Jonas B. Nielsen: is employed by Regeneron Pharmaceuticals Inc., New York, unrelated to this work; Gunnar H. Gislason: research grants from Boerhinger Ingelheim, Bristol-Myers Squibb, and Pfizer; Lars Køber: serves as a consultant for Boehringer Ingelheim and has received other support from AstraZeneca, Novartis, and Novo Nordisk; and Christian Torp-Pedersen: grant for randomized study from Bayer. Grant for epidemiological study from Novo Nordisk; Christina J-Y Lee: none; and Peter E. Weeke: none., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background Oral anticoagulation (OAC) is effective for stroke prevention in patients with atrial fibrillation. However, some patients experience stroke despite OAC therapy, and knowledge about the impact of prior treatment quality is lacking. Methods and Results Patients with atrial fibrillation on OAC therapy who had a first-time ischemic stroke were identified in the Danish Stroke Registry (2005-2018). Patients treated with vitamin K antagonist (VKA) therapy were compared according to the international normalized ratio just before stroke (international normalized ratio <2 [subtherapeutic], international normalized ratio 2-3 [therapeutic], international normalized ratio >3 [supratherapeutic]), and patients on underdosed, appropriately dosed, and overdosed direct OAC (DOAC) therapy were compared. Stroke severity was determined using the Scandinavia Stroke Scale (0-58 points), and the risk of very severe stroke (0-14 points) was analyzed by multivariable logistic regression. One-year mortality was determined using multivariable Cox regression. A total of 2319 patients with atrial fibrillation and stroke were included; 1196 were taking a VKA (subtherapeutic [46%], therapeutic [43%], supratherapeutic [11%]), and 1123 were taking DOAC (underdosed [23%], appropriately dosed [60%], and overdosed [17%]). Subtherapeutic and supratherapeutic VKA therapy (compared with therapeutic) and underdosed DOAC therapy (compared with appropriate and underdosed DOAC) patients were older, more often women, and more comorbid. Subtherapeutic VKA therapy was associated with very severe stroke (odds ratio [OR], 2.06 [95% CI, 1.28-3.31]), whereas supratherapeutic VKA therapy was not (OR, 1.24 [95% CI, 0.60-2.57]) compared with therapeutic VKA therapy. Patients on subtherapeutic and supratherapeutic VKA therapy had a higher 1-year mortality (hazard ratio [HR], 1.66 [95% CI, 1.29-2.13]); HR, 1.55 [95% CI, 1.08-2.22], respectively) than those on therapeutic VKA therapy. Treatment with underdosed or overdosed DOAC therapy was not associated with very severe stroke (OR, 1.27 [95% CI, 0.76-2.15]; OR, 0.73 [95% CI, 0.37-1.43], respectively) and was not associated with 1-year mortality (HR, 1.09 [95% CI, 0.83-1.44]; HR, 0.82 [95% CI, 0.57-1.18], respectively) than appropriate DOAC. Conclusions Half of the patients with atrial fibrillation with stroke were on inappropriate OAC therapy. Subtherapeutic VKA was associated with worse stroke severity and higher mortality rate than therapeutic VKA therapy. Neither underdosed nor overdosed DOAC was associated with worse outcomes in adjusted models compared with appropriately dosed DOAC. This study supports DOAC as a first-line therapy over VKA.

Objective: To examine the long-term rates of heart failure (HF) and other adverse cardiovascular (CV) outcomes in a nationwide cohort of patients diagnosed with granulomatosis with polyangiitis (GPA) compared with the general population., Methods: Using Danish nationwide registries, patients with newly diagnosed GPA were identified and matched 1:4 by age, sex, and comorbidities with subjects from the general population. Outcomes were compared using Cox regression. Due to violation of the proportional hazard assumption, landmark analyses for the first year and from 1 year were performed., Results: Of the 1923 patients with GPA, 1781 patients (median age 59 yrs, 47.9% men) were matched with 7124 subjects from the general population. The median follow-up was 6.4 years. The absolute 10-year risk of HF was 6.8% (95% CI 5.5-8.2%) for patients with GPA and 5.9% (5.3-6.6%) for the general population. During the first year after diagnosis, GPA was associated with a significantly higher rate of HF (hazard ratio [HR] 3.60, 95% CI, 2.28-5.67) and other adverse outcomes, including atrial fibrillation/flutter (HR 6.50, 95% CI 4.43-9.55) and ischemic stroke (HR 3.24, 95% CI 1.92-5.48), compared with the general population. After the first year, GPA was not associated with higher rates of HF or other CV outcomes compared with the general population, except atrial fibrillation/flutter (HR 1.38, 95% CI 1.12-1.70)., Conclusion: During the first year after diagnosis, the rates of HF and other CV outcomes were higher in patients with GPA compared with the general population. However, after the first year, the rates of HF and other CV outcomes, except atrial fibrillation/flutter, were similar to those in the general population., (Copyright © 2022 by the Journal of Rheumatology.)

Aims: The aim of this study was to use human genetics to investigate the pathogenesis of sick sinus syndrome (SSS) and the role of risk factors in its development., Methods and Results: We performed a genome-wide association study of 6469 SSS cases and 1 000 187 controls from deCODE genetics, the Copenhagen Hospital Biobank, UK Biobank, and the HUNT study. Variants at six loci associated with SSS, a reported missense variant in MYH6, known atrial fibrillation (AF)/electrocardiogram variants at PITX2, ZFHX3, TTN/CCDC141, and SCN10A and a low-frequency (MAF = 1.1-1.8%) missense variant, p.Gly62Cys in KRT8 encoding the intermediate filament protein keratin 8. A full genotypic model best described the p.Gly62Cys association (P = 1.6 × 10-20), with an odds ratio (OR) of 1.44 for heterozygotes and a disproportionally large OR of 13.99 for homozygotes. All the SSS variants increased the risk of pacemaker implantation. Their association with AF varied and p.Gly62Cys was the only variant not associating with any other arrhythmia or cardiovascular disease. We tested 17 exposure phenotypes in polygenic score (PGS) and Mendelian randomization analyses. Only two associated with the risk of SSS in Mendelian randomization, AF, and lower heart rate, suggesting causality. Powerful PGS analyses provided convincing evidence against causal associations for body mass index, cholesterol, triglycerides, and type 2 diabetes (P > 0.05)., Conclusion: We report the associations of variants at six loci with SSS, including a missense variant in KRT8 that confers high risk in homozygotes and points to a mechanism specific to SSS development. Mendelian randomization supports a causal role for AF in the development of SSS., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Ablation is a widely used therapy for atrial fibrillation (AF); however, arrhythmia recurrence and repeat procedures are common. Studies examining surrogate markers of genetic susceptibility to AF, such as family history and individual AF susceptibility alleles, suggest these may be associated with recurrence outcomes. Accordingly, the aim of this study was to test the association between AF genetic susceptibility and recurrence after ablation using a comprehensive polygenic risk score for AF., Methods: Ten centers from the AF Genetics Consortium identified patients who had undergone de novo AF ablation. AF genetic susceptibility was measured using a previously described polygenic risk score (N=929 single-nucleotide polymorphisms) and tested for an association with clinical characteristics and time-to-recurrence with a 3 month blanking period. Recurrence was defined as >30 seconds of AF, atrial flutter, or atrial tachycardia. Multivariable analysis adjusted for age, sex, height, body mass index, persistent AF, hypertension, coronary disease, left atrial size, left ventricular ejection fraction, and year of ablation., Results: Four thousand two hundred seventy-six patients were eligible for analysis of baseline characteristics and 3259 for recurrence outcomes. The overall arrhythmia recurrence rate between 3 and 12 months was 44% (1443/3259). Patients with higher AF genetic susceptibility were younger ( P <0.001) and had fewer clinical risk factors for AF ( P =0.001). Persistent AF (hazard ratio [HR], 1.39 [95% CI, 1.22-1.58]; P <0.001), left atrial size (per cm: HR, 1.32 [95% CI, 1.19-1.46]; P <0.001), and left ventricular ejection fraction (per 10%: HR, 0.88 [95% CI, 0.80-0.97]; P =0.008) were associated with increased risk of recurrence. In univariate analysis, higher AF genetic susceptibility trended towards a higher risk of recurrence (HR, 1.08 [95% CI, 0.99-1.18]; P =0.07), which became less significant in multivariable analysis (HR, 1.06 [95% CI, 0.98-1.15]; P =0.13)., Conclusions: Higher AF genetic susceptibility was associated with younger age and fewer clinical risk factors but not recurrence. Arrhythmia recurrence after AF ablation may represent a genetically different phenotype compared to AF susceptibility.

Heart failure (HF) is a leading cause of morbidity and mortality worldwide. A small proportion of HF cases are attributable to monogenic cardiomyopathies and existing genome-wide association studies (GWAS) have yielded only limited insights, leaving the observed heritability of HF largely unexplained. We report results from a GWAS meta-analysis of HF comprising 47,309 cases and 930,014 controls. Twelve independent variants at 11 genomic loci are associated with HF, all of which demonstrate one or more associations with coronary artery disease (CAD), atrial fibrillation, or reduced left ventricular function, suggesting shared genetic aetiology. Functional analysis of non-CAD-associated loci implicate genes involved in cardiac development (MYOZ1, SYNPO2L), protein homoeostasis (BAG3), and cellular senescence (CDKN1A). Mendelian randomisation analysis supports causal roles for several HF risk factors, and demonstrates CAD-independent effects for atrial fibrillation, body mass index, and hypertension. These findings extend our knowledge of the pathways underlying HF and may inform new therapeutic strategies.

Atrial fibrillation (AF) affects more than 33 million individuals worldwide 1 and has a complex heritability 2 . We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait locus analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF.

It is unclear whether genetic markers interact with risk factors to influence atrial fibrillation (AF) risk. We performed genome-wide interaction analyses between genetic variants and age, sex, hypertension, and body mass index in the AFGen Consortium. Study-specific results were combined using meta-analysis (88,383 individuals of European descent, including 7,292 with AF). Variants with nominal interaction associations in the discovery analysis were tested for association in four independent studies (131,441 individuals, including 5,722 with AF). In the discovery analysis, the AF risk associated with the minor rs6817105 allele (at the PITX2 locus) was greater among subjects ≤ 65 years of age than among those > 65 years (interaction p-value = 4.0 × 10 -5 ). The interaction p-value exceeded genome-wide significance in combined discovery and replication analyses (interaction p-value = 1.7 × 10 -8 ). We observed one genome-wide significant interaction with body mass index and several suggestive interactions with age, sex, and body mass index in the discovery analysis. However, none was replicated in the independent sample. Our findings suggest that the pathogenesis of AF may differ according to age in individuals of European descent, but we did not observe evidence of statistically significant genetic interactions with sex, body mass index, or hypertension on AF risk.

Aim: Rare variants of genes encoding the cardiac sodium channel and associated compounds have been linked with atrial fibrillation (AF). Nevertheless, current expert consensus does not support genetic testing in AF, which is in part based on the fact that "there is no therapeutic impact derived from AF genetic test results". However, there are no studies available supporting this recommendation. Consequently, this study analyzed the impact of rare variants affecting the cardiac sodium channel on rhythm outcome of AF catheter ablation., Methods and Results: In 137 consecutive patients with lone AF enrolled in the Leipzig Heart Center AF ablation registry, screening for mutations in SCN5A, SCN1B - 4B, CAV3, GPD1L, SNTA1 and MOG1 was performed. We identified 3 rare non-synonymous variants in SCN5A, 5 in SCN1B, 1 in SCN4B, 1 in CAV3, 6 in GPD1L, 3 in SNTA1 and 3 in MOG1 (16%). Variant carriers were otherwise comparable with non-variant carriers. Analysis of AF recurrence rates after radiofrequency AF catheter ablation by serial 7-day Holter ECG monitoring between 3 and 12 months revealed no difference between groups, i.e. 45% in variant carriers vs. 49% in non-variant carriers., Conclusions: Rare variants in genes encoding the cardiac sodium channel and associated compounds are frequently found in lone AF but were not found to impact the outcome of AF catheter ablation. This finding supports current recommendations not to screen for rare variants for the ablation outcome in AF. Nevertheless, it may at least be helpful for understanding AF mechanisms and larger studies are needed to further explore the possible association between genotype and response to AF therapies.

Atrial fibrillation affects more than 33 million people worldwide and increases the risk of stroke, heart failure, and death. Fourteen genetic loci have been associated with atrial fibrillation in European and Asian ancestry groups. To further define the genetic basis of atrial fibrillation, we performed large-scale, trans-ancestry meta-analyses of common and rare variant association studies. The genome-wide association studies (GWAS) included 17,931 individuals with atrial fibrillation and 115,142 referents; the exome-wide association studies (ExWAS) and rare variant association studies (RVAS) involved 22,346 cases and 132,086 referents. We identified 12 new genetic loci that exceeded genome-wide significance, implicating genes involved in cardiac electrical and structural remodeling. Our results nearly double the number of known genetic loci for atrial fibrillation, provide insights into the molecular basis of atrial fibrillation, and may facilitate the identification of new potential targets for drug discovery.

Aims: Non-vitamin K antagonist oral anticoagulation (NOAC) agents have been approved for stroke prophylaxis in atrial fibrillation (AF). We investigated 'real-world' information on how these drugs are being adopted., Methods and Results: Using Danish nationwide administrative registers, we identified all oral anticoagulation-naïve AF patients initiating oral anticoagulation from 22 August 2011 through 31 October 2013. Using logistic regression analysis, baseline characteristics and temporal utilization trends were compared between initiators of warfarin vs. one of the N OACs: dabigatran, rivaroxaban, or apixaban. We identified 18 611 oral anticoagulation-naïve AF patients of which 9902 (53%) initiated warfarin treatment, 7128 (38%) dabigatran, 1303 (7%) rivaroxaban, and 278 (1%) apixaban. Overall, 40% of newly initiated patients were started on dabigatran within the first 4 months of when the drug came on market. By October, 2013, 40% were being started on warfarin and dabigatran, respectively, and another 20% were started on either rivaroxaban or apixaban. Rivaroxaban and apixaban users generally had a higher predicted risk of stroke and bleeding compared with warfarin and dabigatran users. Older age, female gender, and prior stroke were some of the factors associated with NOAC use vs. warfarin, whereas chronic kidney disease, myocardial infarction, and heart failure showed the opposite association., Conclusion: Among oral anticoagulation-naïve AF patients initiated on oral anticoagulation in Denmark, warfarin initiation has declined since the introduction of dabigatran in August 2011. Dabigatran is the most frequently used alternative option to warfarin; however, use of rivaroxaban and apixaban is increasing. Patients initiated with rivaroxaban or apixaban in general have a higher predicted stroke and bleeding risks compared with warfarin or dabigatran initiators., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Background: Studies in individuals or small kindreds have implicated rare variants in 25 different genes in lone and familial atrial fibrillation (AF) using linkage and segregation analysis, functional characterization, and rarity in public databases. Here, we used a cohort of 20 204 patients of European or African ancestry with electronic medical records and exome chip data to compare the frequency of AF among carriers and noncarriers of these rare variants., Methods and Results: The exome chip included 19 of 115 rare variants, in 9 genes, previously associated with lone or familial AF. Using validated algorithms querying a combination of clinical notes, structured billing codes, ECG reports, and procedure codes, we identified 1056 AF cases (>18 years) and 19 148 non-AF controls (>50 years) with available genotype data on the Illumina HumanExome BeadChip v.1.0 in the Vanderbilt electronic medical record-linked DNA repository, BioVU. Known correlations between AF and common variants at 4q25 were replicated. None of the 19 variants previously associated with AF were over-represented among AF cases (P>0.1 for all), and the frequency of variant carriers among non-AF controls was >0.1% for 14 of 19. Repeat analyses using non-AF controls aged >60 (n=14 904), >70 (n=9670), and >80 (n=4729) years did not influence these findings., Conclusions: Rare variants previously implicated in lone or familial forms of AF present on the exome chip are detected at low frequencies in a general population but are not associated with AF. These findings emphasize the need for caution when ascribing variants as pathogenic or causative., (© 2014 American Heart Association, Inc.)

Aims: To test the hypothesis that vulnerability to atrial fibrillation (AF) is associated with rare coding sequence variation in the SCN10A gene, which encodes the voltage-gated sodium channel isoform NaV1.8 found primarily in peripheral nerves and to identify potentially disease-related mechanisms in high-priority rare variants using in-vitro electrophysiology., Methods and Results: We re-sequenced SCN10A in 274 patients with early onset AF from the Vanderbilt AF Registry to identify rare coding variants. Engineered variants were transiently expressed in ND7/23 cells and whole-cell voltage clamp experiments were conducted to elucidate their functional properties. Resequencing SCN10A identified 18 heterozygous rare coding variants (minor allele frequency ≤1%) in 18 (6.6%) AF probands. Four probands were carriers of two rare variants each and 14 were carriers of one coding variant. Based on evidence of co-segregation, initial assessment of functional importance, and presence in ≥1 AF proband, three variants (417delK, A1886V, and the compound variant Y158D-R814H) were selected for functional studies. The 417delK variant displayed near absent current while A1886V and Y158D-R814H exhibited enhanced peak and late (INa-L) sodium currents; both Y158D and R818H individually contributed to this phenotype., Conclusion: Rare SCN10A variants encoding Nav1.8 were identified in 6.6% of patients with early onset AF. In-vitro electrophysiological studies demonstrated profoundly altered function in 3/3 high-priority variants. Collectively, these data strongly support the hypothesis that rare SCN10A variants may contribute to AF susceptibility., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Aims: Positional cloning and candidate gene approaches have shown that atrial fibrillation (AF) is a complex disease with familial aggregation. Here, we employed whole-exome sequencing (WES) in AF kindreds to identify variants associated with familial AF., Methods and Results: WES was performed on 18 individuals in six modestly sized familial AF kindreds. After filtering very rare variants by multiple metrics, we identified 39 very rare and potentially pathogenic variants [minor allele frequency (MAF) ≤0.04%] in genes not previously associated with AF. Despite stringent filtering >1 very rare variants in the 5/6 of the kindreds were identified, whereas no plausible variants contributing to familial AF were found in 1/6 of the kindreds. Two candidate AF variants in the calcium channel subunit genes (CACNB2 and CACNA2D4) were identified in two separate families using expression data and predicted function., Conclusion: By coupling family data with exome sequencing, we identified multiple very rare potentially pathogenic variants in five of six families, suggestive of a complex disease mechanism, whereas none were identified in the remaining AF pedigree. This study highlights some important limitations and challenges associated with performing WES in AF including the importance of having large well-curated multi-generational pedigrees, the issue of potential AF misclassification, and limitations of WES technology when applied to a complex disease., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Background: Rare variants in candidate atrial fibrillation (AF) genes have been associated with AF in small kindreds. The extent to which such polymorphisms contribute to AF is unknown., Objective: The purpose of this study was to determine the spectrum and prevalence of rare amino acid coding (AAC) variants in candidate AF genes in a large cohort of unrelated lone AF probands., Methods: We resequenced 45 candidate genes in 303 European American (EA) lone AF probands (186 lone AF probands screened for each gene on average [range 89-303], 63 screened for all) identified in the Vanderbilt AF Registry (2002-2012). Variants detected were screened against 4300 EAs from the Exome Sequencing Project (ESP) to identify very rare (minor allele frequency ≤0.04%) AAC variants and these were tested for AF co-segregation in affected family members where possible., Results: Median age at AF onset was 46.0 years [interquartile range 33.0-54.0], and 35.6% had a family history of AF. Overall, 63 very rare AAC variants were identified in 60 of 303 lone AF probands, and 10 of 19 (52.6%) had evidence of co-segregation with AF. Among the 63 lone AF probands who had 45 genes screened, the very rare variant burden was 22%. Compared with the 4300 EA ESP, the proportion of lone AF probands with a very rare AAC variant in CASQ2 and NKX2-5 was increased 3-5-fold (P <.05)., Conclusion: No very rare AAC variants were identified in ~80% of lone AF probands. Potential reasons for the lack of very rare AAC variants include a complex pattern of inheritance, variants in as yet unidentified AF genes or in noncoding regions, and environmental factors., (© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.)

Aims While clinical trials have suggested that a high ventricular rate is associated with increased risk of heart failure (HF) and mortality, all-comers studies are warranted. Objective To assess 1-year risk of new-onset diagnosed HF and all-cause mortality among rate-control treated patients presenting with atrial fibrillation (AF) on an electrocardiogram (ECG) according to ventricular rate. Methods and results ECGs recorded at the Copenhagen General Practitioners Laboratory (2001–15) were used to identify patients with AF. Multivariate Cox proportional hazard regression models were used to compare risk of new-onset HF and all-cause mortality after first ECG presenting with AF according to ventricular rate on ECG [<60, 60–79, 80–99, and 100–110, > 110 beats per minute (bpm)]. We identified 7408 patients in treatment with rate control drugs at time of first ECG presenting with AF [median age 78 years (Q1,Q3 = 70–85 years)], 45.8% male, median ventricular rate 83 bpm, (Q1,Q3 = 71–101 bpm)]. During 1-year follow-up, 666 (9.0%) of all patients with AF developed HF and 858 (11.6%) died. Patients with AF ventricular rates 100–110 bpm and >110 bpm had a hazard ratio (HR) of 1.46 (CI: 1.10–1.95) and 2.41 (CI: 1.94–3.00) respectively for new-onset HF, compared with 60–79 bpm. Similarly, patients with AF ventricular rates 100–110 bpm and >110 bpm had a HR of 1.44 (CI: 1.13–1.82) and 1.34 (CI: 1.08–1.65) respectively for all-cause mortality, compared with 60–79 bpm. Conclusions Ventricular rates ≥100 bpm among patients presenting with AF on ECG in treatment with rate control drugs were associated with greater risk of both new-onset HF and all-cause mortality. [ABSTRACT FROM AUTHOR]

Aims A prolonged QT interval is associated with increased risk of Torsades de pointes (TdP) and may be fatal. We sought to investigate the extent to which clinical covariates affect the change in QT interval among ‘real-world’ patients treated with sotalol and followed in an electronic medical record (EMR) system. Methods and results We used clinical alerts in our EMR system to identify all patients in whom a new prescription for sotalol was written (2001–11). Rate-corrected QT (QTc) was calculated by Bazett's formula. Correlates of sotalol-induced change in the QTc interval and sotalol discontinuation were examined using linear and logistic regression, respectively. Overall, 541 sotalol-exposed patients were identified (n = 200 women, 37%). The mean first sotalol dose was 86 ± 39 mg, age 64 ± 13 years, and BMI 30 ± 7 kg/m2. Atrial fibrillation/flutter was the predominant indication (92.2%). After initial exposure, the change in the QTc interval from baseline was highly variable: ΔQTc after 2 h = 3 ± 42 ms (P = 0.17) and 11 ± 37 ms after ≥48 h (P < 0.001). Multivariable linear regression analysis identified female gender and age, reduced left ventricular ejection fraction, high sotalol dose, hypertrophic cardiomyopathy, and loop diuretic co-administration as correlates of increased ΔQTc at ≥48 h (P < 0.05 for all). Within 3 days of initiation, 12% discontinued sotalol of which 31% were because of exaggerated QTc prolongation. One percent developed TdP. Conclusion In this EMR-based cohort, the increase in QTc with sotalol initiation was highly variable, and multiple clinical factors contributed. These data represent an important step in ongoing work to identify real-world patients likely to tolerate long-term therapy and reinforces the utility of EMR-based cohorts as research tools. [ABSTRACT FROM PUBLISHER]

Background: Patients with diabetes mellitus (DM) have high risk of heart failure. Whether some of the risk is directly linked to metabolic derangements in the myocardium or whether the risk is primarily caused by coronary artery disease (CAD) and hypertension is incompletely understood. Echocardiographic tissue Doppler imaging was therefore performed in DM patients without significant CAD to examine whether DM per se influenced cardiac function. Methods: Patients with a left ventricular (LV) ejection fraction (EF) > 35% and without significant CAD, prior myocardial infarction, cardiac pacemaker, atrial fibrillation, or significant valve disease were identified from a tertiary invasive center register. DM patients were matched with controls on age, gender and presence of hypertension. Results: In total 31 patients with diabetes and 31 controls were included. Mean age was 58 ± 12 years, mean LVEF was 51 ± 7%, and 48% were women. No significant differences were found in LVEF, left atrial end systolic volume, or left ventricular dimensions. The global longitudinal strain was significantly reduced in patients with DM (15.9 ± 2.9 vs. 17.7 ± 2.9, p = 0.03), as were peak longitudinal systolic (S') and early diastolic (E') velocities (5.7 ± 1.1 vs. 6.4 ± 1.1 cm/s, p = 0.02 and 6.1 ± 1.7 vs. 7.7 ± 2.0 cm/s, p = 0.002). In multivariable regression analyses, DM remained significantly associated with impairments of S' and E', respectively. Conclusion: In patients without significant CAD, DM is associated with an impaired systolic longitudinal LV function and global diastolic dysfunction. These abnormalities are likely to be markers of adverse prognosis. [ABSTRACT FROM AUTHOR]

Vernakalant (RSD1235) is a novel antiarrhythmic agent for conversion of rapid onset atrial fibrillation (AF). It is an atria-selective multichannel ion blocker (blocks IKur, INa, ICa, L, Ito and IKr), with a small effect on ventricular repolarization. In clinical Phase II and III studies, vernakalant was moderately (∼50%) effective in converting AF of short duration (< 7 days), and effective (∼70-80%) in converting AF of less than 72 h, but was not effective in converting long duration AF (>7 days) or atrial flutter. Vernakalant seems to have only a small proarrhythmic effect, with no reported cases of torsades de pointes in direct relation to vernakalant administration in Phase II and III studies. Overall, there are few reported serious adverse events. [ABSTRACT FROM AUTHOR]

Whether the increased risk of coronary artery disease (CAD) in patients with breast cancer may be linked to shared genetics is unknown. Our objective was to investigate the association of genetic predisposition to breast cancer with CAD risk via 1) a polygenic risk score 2) a nationwide case-control study. We studied the associations of a polygenic risk score based on 91 single nucleotide polymorphisms previously associated with breast cancer in genome-wide association studies with the risk of CAD in a sample of patients undergoing coronary angiography. Secondary outcomes were prevalent atrial fibrillation, heart failure and breast cancer. Logistic regression models were used to analyze the associations. The risk of CAD associated with having a mother with breast cancer was analyzed with conditional logistic regression in the case-control study. Among 4985 patients undergoing coronary angiography (median age 66 years (Quartile (Q) 1-Q3 57–73), 65% male) 3724 (75%) had CAD. Increasing polygenic risk score was not associated with risks of CAD (odds ratio (OR) 1.01, 95% confidence interval (CI) 0.94–1.08), atrial fibrillation (OR 1.03, CI 0.94–1.12), or heart failure (OR 0.97, CI 0.90–1.05). In women, increasing polygenic risk score was associated with the risk of breast cancer (OR 1.40, CI 1.14–1.73). The risk of CAD was not significantly increased in children with vs. without mothers with breast cancer (Hazard ratio 0.89 95% CI 0.83–0.96, p = 0.002). Our study found no evidence of a shared genetic predisposition of breast cancer with CAD, atrial fibrillation, or heart failure. Unlabelled Image • Polygenic predisposition to breast cancer was not associated with coronary artery disease. • No familial clustering of breast cancer and coronary artery disease • Coronary artery disease in patients with breast cancer is not due to shared genetics. [ABSTRACT FROM AUTHOR]