Guidelines recommend a trial of one or more antiarrhythmic drugs before catheter ablation is considered in patients with atrial fibrillation. However, first-line ablation may be more effective in ...maintaining sinus rhythm.
We randomly assigned 303 patients with symptomatic, paroxysmal, untreated atrial fibrillation to undergo catheter ablation with a cryothermy balloon or to receive antiarrhythmic drug therapy for initial rhythm control. All the patients received an implantable cardiac monitoring device to detect atrial tachyarrhythmia. The follow-up period was 12 months. The primary end point was the first documented recurrence of any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) between 91 and 365 days after catheter ablation or the initiation of an antiarrhythmic drug. The secondary end points included freedom from symptomatic arrhythmia, the atrial fibrillation burden, and quality of life.
At 1 year, a recurrence of atrial tachyarrhythmia had occurred in 66 of 154 patients (42.9%) assigned to undergo ablation and in 101 of 149 patients (67.8%) assigned to receive antiarrhythmic drugs (hazard ratio, 0.48; 95% confidence interval CI, 0.35 to 0.66; P<0.001). Symptomatic atrial tachyarrhythmia had recurred in 11.0% of the patients who underwent ablation and in 26.2% of those who received antiarrhythmic drugs (hazard ratio, 0.39; 95% CI, 0.22 to 0.68). The median percentage of time in atrial fibrillation was 0% (interquartile range, 0 to 0.08) with ablation and 0.13% (interquartile range, 0 to 1.60) with antiarrhythmic drugs. Serious adverse events occurred in 5 patients (3.2%) who underwent ablation and in 6 patients (4.0%) who received antiarrhythmic drugs.
Among patients receiving initial treatment for symptomatic, paroxysmal atrial fibrillation, there was a significantly lower rate of atrial fibrillation recurrence with catheter cryoballoon ablation than with antiarrhythmic drug therapy, as assessed by continuous cardiac rhythm monitoring. (Funded by the Cardiac Arrhythmia Network of Canada and others; EARLY-AF ClinicalTrials.gov number, NCT02825979.).
Cardiac implantable electronic device infection is a major complication that usually requires device removal. PADIT (Prevention of Arrhythmia Device Infection Trial) was a large cluster crossover ...trial of conventional versus incremental antibiotics.
This study sought to investigate independent predictors of device infection in PADIT and develop a novel infection risk score.
In brief, over 4 6-month periods, 28 centers used either conventional or incremental prophylactic antibiotic treatment in all patients. The primary outcome was hospitalization for device infection within 1 year (blinded endpoint adjudication). Multivariable logistic prediction modeling was used to identify the independent predictors and develop a risk score for device infection. The prediction models were internally validated with bootstrap methods.
Device procedures were performed in 19,603 patients, and hospitalization for infection occurred in 177 (0.90%) within 1 year of follow-up. The final prediction model identified 5 independent predictors of device infection (prior procedures P, age A, depressed renal function D, immunocompromised I, and procedure type T) with an optimism-corrected C-statistic of 0.704 (95% confidence interval: 0.660 to 0.744). A PADIT risk score ranging from 0 to 15 points classified patients into low (0 to 4), intermediate (5 to 6) and high (≥7) risk groups with rates of hospitalization for infection of 0.51%, 1.42%, and 3.41%, respectively.
This study identified 5 independent predictors of device infection and developed a novel infection risk score in the largest cardiac implantable electronic device trial to date, warranting validation in an independent cohort. The 5 independent predictors in the PADIT score are readily adopted into clinical practice. (Prevention of Arrhythmia Device Infection Trial PADIT Pilot; NCT01002911)
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Abstract
Aims
The term idiopathic ventricular fibrillation (IVF) describes survivors of unexplained cardiac arrest (UCA) without a specific diagnosis after clinical and genetic testing. Previous ...reports have described a subset of IVF individuals with ventricular arrhythmia initiated by short-coupled trigger premature ventricular contractions (PVCs) for which the term short-coupled ventricular fibrillation (SCVF) has been proposed. The aim of this article is to establish the phenotype and frequency of SCVF in a large cohort of UCA survivors.
Methods and results
We performed a multicentre study including consecutive UCA survivors from the CASPER registry. Short-coupled ventricular fibrillation was defined as otherwise unexplained ventricular fibrillation initiated by a trigger PVC with a coupling interval of <350 ms. Among 364 UCA survivors, 24/364 (6.6%) met diagnostic criteria for SCVF. The diagnosis of SCVF was obtained in 19/24 (79%) individuals by documented ventricular fibrillation during follow-up. Ventricular arrhythmia was initiated by a mean PVC coupling interval of 274 ± 32 ms. Electrical storm occurred in 21% of SCVF probands but not in any UCA proband (P < 0.001). The median time to recurrent ventricular arrhythmia in SCVF was 31 months. Recurrent ventricular fibrillation resulted in quinidine administration in 12/24 SCVF (50%) with excellent arrhythmia control.
Conclusion
Short-coupled ventricular fibrillation is a distinct primary arrhythmia syndrome accounting for at least 6.6% of UCA. As documentation of ventricular fibrillation onset is necessary for the diagnosis, most cases are diagnosed at the time of recurrent arrhythmia, thus the true prevalence of SCVF remains still unknown. Quinidine is effective in SCVF and should be considered as first-line treatment for patients with recurrent episodes.
Graphical Abstract
Short-coupled ventricular fibrillation (SCVF) is a distinct primary electrical disorder accounting for at least 6.6% of otherwise idiopathic VF. Quinidine is highly effective for SCVF.
Genetic testing is recommended in specific inherited heart diseases but its role remains unclear and it is not currently recommended in unexplained cardiac arrest (UCA). We sought to assess the yield ...and clinical utility of genetic testing in UCA using whole-exome sequencing (WES).
Survivors of UCA requiring external defibrillation were included from the Cardiac Arrest Survivor with Preserved Ejection fraction Registry. Whole-exome sequencing was performed, followed by assessment of rare variants in previously reported cardiovascular disease genes. A total of 228 UCA survivors (mean age at arrest 39 ± 13 years) were included. The majority were males (66%) and of European ancestry (81%). Following advanced clinical testing at baseline, the likely aetiology of cardiac arrest was determined in 21/228 (9%) cases. Whole-exome sequencing identified a pathogenic or likely pathogenic (P/LP) variant in 23/228 (10%) of UCA survivors overall, increasing the proportion of 'explained' cases from 9% only following phenotyping to 18% when combining phenotyping with WES. Notably, 13 (57%) of the 23 P/LP variants identified were located in genes associated with cardiomyopathy, in the absence of a diagnosis of cardiomyopathy at the time of arrest.
Genetic testing identifies a disease-causing variant in 10% of apparent UCA survivors. The majority of disease-causing variants was located in cardiomyopathy-associated genes, highlighting the arrhythmogenic potential of such variants in the absence of an overt cardiomyopathy diagnosis. The present study supports the use of genetic testing including assessment of arrhythmia and cardiomyopathy genes in survivors of UCA.
Objectives The aim of this study was to determine if exercise testing could expose a latent electrical substrate of arrhythmogenic right ventricular cardiomyopathy (ARVC) in asymptomatic gene ...carriers. Background Management of asymptomatic ARVC gene carriers is challenging because of variable penetrance of disease and the recognition that sudden cardiac death may be the first clinical manifestation. Methods Exercise-induced abnormalities during exercise treadmill testing (ETT) were initially compared in 60 subjects: 30 asymptomatic ARVC gene carriers and 30 healthy controls. In phase 2 of the study, ETT results of 25 patients with ARVC with histories of sustained ventricular arrhythmia or cardiac arrest were evaluated to determine if ETT abnormalities in asymptomatic gene carriers were common to patients with a malignant electrical form of the disease. Results Depolarization abnormalities during ETT were found to develop more frequently in asymptomatic gene carriers compared with healthy controls: epsilon waves appeared in 4 of 28 (14%) compared with 0 of 30 (0%) (p = 0.048), premature ventricular contractions in 17 of 30 (57%) compared with 3 of 30 (10%) (p = 0.0003), and new QRS terminal activation duration ≥55 ms in 7 of 22 (32%) compared with 2 of 29 (7%) (p = 0.03). Superior axis premature ventricular contractions occurred only in gene carriers. In the second phase of the study, the frequency of these abnormalities was found to be high in patients with symptomatic ARVC: new epsilon waves appeared in 3 of 18 (17%), superior axis premature ventricular contractions in 21 of 25 (84%), and new terminal activation duration ≥55 ms in 8 of 12 (67%). Conclusions Exercise testing exposes a latent electrical substrate in asymptomatic ARVC gene carriers that is shared by patients with ARVC with histories of ventricular arrhythmia. ETT may be useful in guiding treatment decisions, exercise prescription, and prioritizing medical surveillance in asymptomatic ARVC gene carriers.
The objectives of this national chart audit (January to June 2013) of 6,346 patients with atrial fibrillation (AF; ≥18 years without a significant heart valve disorder) from 647 primary care ...physicians were to (1) describe the frequency of stroke and bleed risk assessments in patients with nonvalvular AF by primary care physicians, including the accuracy of these assessments relative to established predictive indexes; (2) outline contemporary methods of anticoagulation used; and (3) report the time in the therapeutic range among patients prescribed warfarin. An annual stroke risk assessment was not undertaken in 15% and estimated without a formal risk tool in 33%; agreement with CHADS2 score estimation was seen in 87% of patients. Major bleeding risk assessment was not undertaken in 25% and estimated without a formal risk tool in 47%; agreement with HAS-BLED score estimation was observed in 64% with physician overestimation in 26% of patients. Antithrombotic therapy included warfarin (58%), dabigatran (22%), rivaroxaban (14%), and apixaban (<1%). Among warfarin-treated patients, the median international normalized ratio was 2.4 and time in therapeutic range (TTR) was 73%; however, the TTR was <50% in 845 (25%), 50% to 69% in 674 (20%), and ≥70% in 1,827 (55%) patients. In conclusion, we describe a contemporary real-world elderly population with AF at important risk for stroke. There is apparent overestimation of bleeding risk in many patients. Warfarin was the dominant stroke prevention treatment; however, the suggested TTR target was achieved in only 55% of these patients.
Abstract β-Blockers are among the most frequently used drugs in patients with atrial fibrillation. They are often used for ventricular rate control, acutely in emergency situations and chronically, ...in patients with persistent or permanent atrial fibrillation. They are also used, with less evidence of benefit, to prevent the first occurrence or recurrence of atrial fibrillation, particularly in patients with hypertension. They are effective in reducing ventricular rate, potentially leading to an improvement in symptoms and well-being. They are particularly indicated in patients with heart failure and atrial fibrillation; the choice of β-blockers in this condition should be guided by tolerability and effects on symptoms and well-being.
Patients resuscitated from out-of-hospital cardiac arrest (OHCA) are at high risk of recurrence, posing a substantial burden on healthcare systems. Despite the established benefit of implantable ...cardioverter defibrillator (ICD) therapy in many such patients, and recommendations by guidelines, few studies have described the proportion of OHCA patients who receive guideline-concordant care.
The Canadian Institute for Health Information Discharge Abstract Database dataset was used to identify OHCA patients admitted to hospitals across Canada, excluding Quebec. We analyzed all patients without a probable ischemic or bradycardia etiology of cardiac arrest, who survived to discharge, to estimate the ICD implantation rates in patients who were potentially eligible to have an ICD.
Between 2013 and 2017, a total of 10,435 OHCA patients who were admitted to the hospital were captured in the database; 4486 (43%) survived to hospital discharge, and 2580 survivors (57.5%) were potentially eligible to receive an ICD. Among these potentially eligible patients, 757 (29.3%) received an ICD during their index admission or within 30 days after discharge from the hospital. The ICD implantation rate during index admission increased from 13.8% in 2013 to 19.6% in 2017 (P-value for time trend < 0.05). The rate of ICD implantations in potentially eligible patients was higher in urban than in rural settings (19.5% vs 11.1%) and in teaching vs community hospitals (34.7% vs 9.8%).
Although ICD implantation rates show an increasing trend among patients with OHCA who are likely eligible for secondary prevention, significant underutilization of ICDs persists in these patients.
Les patients ayant survécu à un arrêt cardiaque extra-hospitalier (ACEH) présentent un risque élevé de récidive, ce qui impose un lourd fardeau aux systèmes de soins de santé. Malgré l’avantage établi de la mise en place d’un défibrillateur cardioverteur implantable (DCI) chez un grand nombre de ces patients, et les recommandations des lignes directrices, peu d’études décrivent la proportion de patients victimes d’un ACEH ayant reçu des soins conformes aux lignes directrices.
Nous avons recensé les admissions à l’hôpital de patients ayant subi un ACEH au Canada, à l’exception du Québec à partir de l’ensemble de données de la Base de données sur les congés des patients de l’Institut canadien d’information sur la santé. Nous avons inclus dans notre analyse tous les patients pour lesquels la cause de l’arrêt cardiaque n’était probablement pas ischémique ou bradycardique et qui avaient survécu jusqu’à leur congé de l’hôpital, afin d’estimer les taux d’implantation d’un DCI chez les patients potentiellement admissibles à cette intervention.
Entre 2013 et 2017, un total de 10 435 patients ayant subi un ACEH ont été hospitalisés selon la base de données; 4 486 (43 %) avaient survécu jusqu’à leur congé de l’hôpital, et 2 580 survivants (57,5 %) étaient potentiellement admissibles à l’implantation d’un DCI. Parmi les patients potentiellement admissibles, 757 (29,3 %) avaient reçu un DCI au moment de leur admission initiale ou dans les 30 jours suivant leur congé de l’hôpital. Le taux d’implantation de DCI lors de l’admission initiale est passé de 13,8 % en 2013 à 19,6 % en 2017 (valeur p pour la tendance au fil du temps < 0,05). Le taux d’implantation d’un DCI chez les patients potentiellement admissibles était plus élevé en milieu urbain qu’en milieu rural (19,5 % contre 11,1 %) et dans les hôpitaux d’enseignement/universitaires par comparaison avec les hôpitaux communautaires (34,7 % contre 9,8 %).
Bien que les taux d’implantation de DCI affichent une tendance à la hausse chez les patients ayant subi un ACEH qui sont probablement admissibles à des interventions de prévention secondaire, les DCI demeurent largement sous-utilisés chez ces patients.
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