Abstract The Canadian Cardiovascular Society (CCS) Atrial Fibrillation (AF) Guidelines Committee provides periodic reviews of new data to produce focused updates that address clinically important ...advances in AF management. This 2016 Focused Update deals with: (1) the management of antithrombotic therapy for AF patients in the context of the various clinical presentations of coronary artery disease; (2) real-life data with non-vitamin K antagonist oral anticoagulants; (3) the use of antidotes for the reversal of non-vitamin K antagonist oral anticoagulants; (4) digoxin as a rate control agent; (5) perioperative anticoagulation management; and (6) AF surgical therapy including the prevention and treatment of AF after cardiac surgery. The recommendations were developed with the same methodology used for the initial 2010 guidelines and the 2012 and 2014 Focused Updates. Using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) standards, individual studies and literature were reviewed for quality and bias; the literature review process and evidence tables are included in the Supplementary Material, and on the CCS Web site. The section on concomitant AF and coronary artery disease was developed in collaboration with the CCS Antiplatelet Guidelines Committee. Details of the updated recommendations are presented, along with their background and rationale. This document is linked to an updated summary of all CCS AF Guidelines recommendations, from 2010 to the present 2016 Focused Update.
Abstract Atrial fibrillation (AF) is an extremely common clinical problem with an important population morbidity and mortality burden. The management of AF is complex and fraught with many uncertain ...and contentious issues, which are being addressed by extensive ongoing basic and clinical research. The Canadian Cardiovascular Society AF Guidelines Committee produced an extensive set of evidence-based AF management guidelines in 2010 and updated them in the areas of anticoagulation and rate/rhythm control in 2012. In late 2013, the committee judged that sufficient new information regarding AF management had become available since 2012 to warrant an update to the Canadian Cardiovascular Society AF Guidelines. After extensive evaluation of the new evidence, the committee has updated the guidelines for: (1) stroke prevention principles; (2) anticoagulation of AF patients with chronic kidney disease; (3) detection of AF in patients with stroke; (4) investigation and management of subclinical AF; (5) left atrial appendage closure in stroke prevention; (6) emergency department management of AF; (7) periprocedural anticoagulation management; and (8) rate and rhythm control including catheter ablation. This report presents the details of the updated recommendations, along with their background and rationale. In addition, a complete set of presently applicable recommendations, those that have been updated and those that remain in force from previous guideline versions, is provided in the Supplementary Material.
Objectives The purpose of this study was to evaluate the feasibility and safety of uninterrupted rivaroxaban therapy during atrial fibrillation (AF) ablation. Background Optimal periprocedural ...anticoagulation strategy is essential for minimizing bleeding and thromboembolic complications during and after AF ablation. The safety and efficacy of uninterrupted rivaroxaban therapy as a periprocedural anticoagulant for AF ablation are unknown. Methods We performed a multicenter, observational, prospective study of a registry of patients undergoing AF ablation in 8 centers in North America. Patients taking uninterrupted periprocedural rivaroxaban were matched by age, sex, and type of AF with an equal number of patients taking uninterrupted warfarin therapy who were undergoing AF ablation during the same period. Results A total of 642 patients were included in the study, with 321 in each group. Mean age was 63 ± 10 years, with 442 (69%) males and 328 (51%) patients with paroxysmal AF equally distributed between the 2 groups. Patients in the warfarin group had a slightly higher mean HAS- BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) score (1.70 ± 1.0 vs. 1.47 ± 0.9, respectively; p = 0.032). Bleeding and embolic complications occurred in 47 (7.3%) and 2 (0.3%) patients (both had transient ischemic attacks) respectively. There were no differences in the number of major bleeding complications (5 1.6% vs. 7 1.9%, respectively; p = 0.772), minor bleeding complications (16 5.0% vs. 19 5.9%, respectively; p = 0.602), or embolic complications (1 0.3% vs. 1 0.3%, respectively; p = 1.0) between the rivaroxaban and warfarin groups in the first 30 days. Conclusions Uninterrupted rivaroxaban therapy appears to be as safe and efficacious in preventing bleeding and thromboembolic events in patients undergoing AF ablation as uninterrupted warfarin therapy.
Abstract This article compares and contrasts the current recommendations, and highlights the important differences, in the American College of Cardiology (ACC)/American Heart Association (AHA)/Heart ...Rhythm Society (HRS), European Society of Cardiology (ESC), and Canadian Cardiovascular Society (CCS) atrial fibrillation (AF) guidelines. Although many of the recommendations of the various societies are similar, there are important differences in the methodologies underlying their development and the specific content. Specifically, key differences can be observed in: 1) the definition of non-valvular AF, which subsequently impacts anticoagulation choices and candidacy for non-vitamin K antagonist oral anticoagulants (NOACs); 2) the symptom-score used to guide management decisions and longitudinal patient profiling; 3) the stroke-risk stratification algorithm used to determine indications for OAC therapy; 4) the role of ASA in stroke prevention in AF; 5) the antithrombotic regimens employed in the context of coronary artery disease, acute coronary syndromes, and percutaneous coronary intervention; 6) the rate control target and medications recommended to achieve the target; and 7) the role of “first-line” catheter ablation, open surgical ablation, and left atrial appendage exclusion.
Abstract The Canadian Cardiovascular Society (CCS) published the complete set of 2010 Atrial Fibrillation (AF) Guidelines in the January, 2011 issue of the Canadian Journal of Cardiology . During its ...deliberations, the CCS Guidelines Committee engaged to a timely review of future evidence, with periodic composition of focused updates to address clinically important advances. In 2011, results were published from 3 pivotal AF trials: the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonist for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF), the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) study, and the Permanent Atrial Fibrillation Outcome Study Using Dronedarone on Top of Standard Therapy (PALLAS), comparing dronedarone with placebo in patients with permanent AF and additional cardiovascular disease risk-factor burden. Each of these large randomized trials provided clear results with major implications for AF management. Other important evidence that has emerged since the 2010 Guidelines includes findings about prediction instruments for AF-associated stroke and bleeding risk, stroke risk in paroxysmal-AF patients, risk-benefit considerations related to oral anticoagulation in patients with chronic kidney disease, and risk/benefit considerations in the use of antiplatelet agents, alone and in combination with each other or with oral anticoagulants, in AF patients. The Guidelines Committee judged that this extensive and important new evidence required focused updating of the 2010 Guidelines with respect to stroke prevention and rate/rhythm control. This report presents the details of the new recommendations, along with the background and rationale.
Summary Background Catheter ablation is increasingly used to manage atrial fibrillation, but arrhythmia recurrences are common. Adenosine might identify pulmonary veins at risk of reconnection by ...unmasking dormant conduction, and thereby guide additional ablation to improve arrhythmia-free survival. We assessed whether adenosine-guided pulmonary vein isolation could prevent arrhythmia recurrence in patients undergoing radiofrequency catheter ablation for paroxysmal atrial fibrillation. Methods We did this randomised trial at 18 hospitals in Australia, Europe, and North America. We enrolled patients aged older than 18 years who had had at least three symptomatic atrial fibrillation episodes in the past 6 months, and for whom treatment with an antiarrhythmic drug failed. After pulmonary vein isolation, intravenous adenosine was administered. If dormant conduction was present, patients were randomly assigned (1:1) to additional adenosine-guided ablation to abolish dormant conduction or to no further ablation. If no dormant conduction was revealed, randomly selected patients were included in a registry. Patients were masked to treatment allocation and outcomes were assessed by a masked adjudicating committee. Patients were followed up for 1 year. The primary outcome was time to symptomatic atrial tachyarrhythmia after a single procedure in the intention-to-treat population. The trial is registered with ClinicalTrials.gov , number NCT01058980. Findings Adenosine unmasked dormant pulmonary vein conduction in 284 (53%) of 534 patients. 102 (69·4%) of 147 patients with additional adenosine-guided ablation were free from symptomatic atrial tachyarrhythmia compared with 58 (42·3%) of 137 patients with no further ablation, corresponding to an absolute risk reduction of 27·1% (95% CI 15·9–38·2; p<0·0001) and a hazard ratio of 0·44 (95% CI 0·31–0·64; p<0·0001). Of 115 patients without dormant pulmonary vein conduction, 64 (55·7%) remained free from symptomatic atrial tachyarrhythmia (p=0·0191 vs dormant conduction with no further ablation). Occurrences of serious adverse events were similar in each group. One death (massive stroke) was deemed probably related to ablation in a patient included in the registry. Interpretation Adenosine testing to identify and target dormant pulmonary vein conduction during catheter ablation of atrial fibrillation is a safe and highly effective strategy to improve arrhythmia-free survival in patients with paroxysmal atrial fibrillation. This approach should be considered for incorporation into routine clinical practice. Funding Canadian Institutes of Health Research, St Jude Medical, Biosense-Webster, and M Lachapelle (Montreal Heart Institute Foundation).
Objectives This study sought to examine whether suppressing premature ventricular contractions (PVC) using radiofrequency ablation improves effectiveness of the cardiac resynchronization therapy ...(CRT) in nonresponders. Background CRT is an effective strategy for drug refractory congestive heart failure. However, one-third of patients with CRT do not respond clinically, and the causes for nonresponse are poorly understood. Whether frequent PVC contribute to CRT nonresponse remains unknown. Methods In this multicenter study, CRT nonresponders with >10,000 PVC in 24 h who underwent PVC ablation were enrolled from a prospective database. Results Sixty-five subjects (age 66.6 ± 12.4 years, 78% men, QRS duration of 155 ± 18 ms) had radiofrequency ablation of PVC from 76 foci. Acute and long-term success rates of ablation were 91% and 88% in 12 ± 4 months of follow-up. There was significant improvement in left ventricular (LV) ejection fraction (26.2 ± 5.5% to 32.7 ± 6.7 %, p < 0.001), LV end-systolic diameter (5.93 ± 0.55 cm to 5.62 ± 0.32 cm, p < 0.001), LV end-diastolic diameter (6.83 ± 0.83 cm to 6.51 ± 0.91 cm, p < 0.001), LV end-systolic volume (178 ± 72 to 145 ± 23 ml, p < 0.001), LV end-diastolic volume (242 ± 85 ml to 212 ± 63 ml, p < 0.001), and median New York Heart Association functional class (3.0 to 2.0, p < 0.001). Modeling of pre-ablation PVC burden revealed an improvement in ejection fraction when the pre-ablation PVC burden was >22% in 24 h. Conclusions Frequent PVC is an uncommon yet significant cause of CRT nonresponse. Radiofrequency ablation of PVC foci improves LV function and New York Heart Association class and promotes reverse remodeling in CRT nonresponders. PVC ablation may be used to enhance CRT efficacy in nonresponders with significant PVC burden.
Controversy exists about the impact of acute atrial fibrillation (AF) termination and prolongation of atrial fibrillation cycle length (AFCL) during ablation on long-term procedural outcome.
The ...purpose of this study was to analyze the influence of AF termination and AFCL prolongation on freedom from AF in patients from the STAR AF II (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial-Part II) trial.
Acute changes in AFCL and AF termination were collected during the index procedure of the STAR AF II trial and compared to recurrence of AF at 18 months. Recurrence was assessed by ECG, Holter (3, 6, 9, 12, 18 months), and weekly transtelephonic ECG monitoring for 18 months.
AF terminated in 8% of the pulmonary vein isolation (PVI) arm, 45% in the PVI+complex electrogram arm, and 22% of the PVI+linear ablation arm (P <.001), but freedom from AF did not differ among the 3 groups (P = .15). Freedom from AF was significantly higher in patients who presented to the laboratory in sinus rhythm (SR) compared to those without AF termination (63% vs 44%, P = .007). Patients with AF termination had an intermediate outcome (53%) that was not significantly different from those in SR (P = .84) or those who did not terminate (P = .08). AF termination was a univariable predictor of success (P = .007), but by multivariable analysis, presence of early SR was the strongest predictor of success (hazard ratio 0.67, P = .004). Prolongation of AFCL was not predictive of 18-month freedom from AF.
Acute AF termination and prolongation in AFCL did not consistently predict 18-month freedom from AF. Presence of SR before or early during the ablation was the strongest predictor of better outcome.
Complex fractionated electrograms (CFEs) are continuous electrograms (EGMs) of very short cycle length (CL) representing substrate for atrial fibrillation (AF) perpetuation. Ablation of CFEs may ...result in AF slowing, termination, and prevention, but identifying them can be subjective.
The purpose of this study was to prospectively assess (1) whether an automated algorithm can identify CFE regions, (2) the acute effects of ablating these regions on AF, and (3) the long-term efficacy as an adjuvant strategy to pulmonary vein antrum isolation (PVAI).
Thirty-five patients (three centers, 61 +/- 9 years, left atrium LA 43 +/- 9 mm, ejection fraction 53% +/- 7%) with symptomatic paroxysmal (n = 21) or persistent (n = 14) AF were studied. A decapolar lasso (2-mm spacing) was used for mapping. A three-dimensional shell of the LA and pulmonary veins (PVs) was created. If not already in AF, AF was induced by burst pacing (with or without isoproterenol). Atrial EGMs during AF were mapped/analyzed using an automated CFE algorithm. The algorithm measures the time between discrete deflections in a local EGM over 5 seconds (based on selectable width and peak-to-peak >0.03 mV criteria). The mean CL of the local EGM is projected onto the LA shell as a color-coded display. Regions of CL <120 ms (published criteria) were targeted for ablation/elimination. Atrial fibrillation cycle length (AFCL) and regularity were measured from the CS. After CFE ablation, further ablation was done to achieve complete PVAI.
AF was spontaneous (n = 20) or induced (n = 15) in all patients. CFEs were most commonly found along the septum (97%), anterior LA (97%), PV antra (83%), base of appendage (83%), and annulus (71%). CFE ablation alone prolonged the AFCL (171 +/- 27 vs. 304 +/- 41 ms; P = .03) and regularized AF to left/right flutter (AFL) in 74% of patients. CFE ablation terminated AF/AFL in 19 patients (54%)-the other 16 were cardioverted-and AF became noninducible in 77%. CFE ablation alone did not cause PV isolation (0.1 +/- 0.3 PV isolated/patient). After combined CFE and PVAI ablation, the single-procedure, off-drug success rate was 83% (follow-up 13 +/- 4 months) versus 71% in matched controls who had PVAI alone (P = .045).
CFE ablation guided by an automated algorithm resulted in AFCL prolongation, regularization, and noninducibility in most patients. AF terminated in 54% of cases. PVAI with adjuvant CFE ablation has a high efficacy and may be superior to PVAI alone.
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