Long-Term Outcomes of Resynchronization-Defibrillation for Heart Failure.

BACKGROUND: The Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT) showed a greater benefit with respect to mortality at 5 years among patients who received cardiac-resynchronization therapy (CRT) than among those who received implantable cardioverter-defibrillators (ICDs). However, the effect of CRT on long-term survival is not known. METHODS: We randomly assigned patients with New York Heart Association (NYHA) class II or III heart failure, a left ventricular ejection fraction of 30% or less, and an intrinsic QRS duration of 120 msec or more (or a paced QRS duration of 200 msec or more) to receive either an ICD alone or a CRT defibrillator (CRT-D). We assessed long-term outcomes among patients at the eight highest-enrolling participating sites. The primary outcome was death from any cause; the secondary outcome was a composite of death from any cause, heart transplantation, or implantation of a ventricular assist device. RESULTS: The trial enrolled 1798 patients, of whom 1050 were included in the long-term survival trial; the median duration of follow-up for the 1050 patients was 7.7 years (interquartile range, 3.9 to 12.8), and the median duration of follow-up for those who survived was 13.9 years (interquartile range, 12.8 to 15.7). Death occurred in 405 of 530 patients (76.4%) assigned to the ICD group and in 370 of 520 patients (71.2%) assigned to the CRT-D group. The time until death appeared to be longer for those assigned to receive a CRT-D than for those assigned to receive an ICD (acceleration factor, 0.80; 95% confidence interval, 0.69 to 0.92; P = 0.002). A secondary-outcome event occurred in 412 patients (77.7%) in the ICD group and in 392 (75.4%) in the CRT-D group. CONCLUSIONS: Among patients with a reduced ejection fraction, a widened QRS complex, and NYHA class II or III heart failure, the survival benefit associated with receipt of a CRT-D as compared with ICD appeared to be sustained during a median of nearly 14 years of follow-up. (RAFT ClinicalTrials.gov number, NCT00251251.).

A randomized clinical trial of catheter ablation and antiarrhythmic drug therapy for suppression of ventricular tachycardia in ischemic cardiomyopathy: The VANISH2 trial.

BACKGROUND: Recurrent ventricular tachycardia (VT) in patients with prior myocardial infarction is associated with adverse quality of life and clinical outcomes, despite the presence of implanted defibrillators (ICDs). Suppression of recurrent VT can be accomplished with antiarrhythmic drug therapy or catheter ablation. The Ventricular Tachycardia Antiarrhythmics or Ablation In Structural Heart Disease 2 (VANISH2) trial is designed to determine whether ablation is superior to antiarrhythmic drug therapy as first line therapy for patients with ischemic cardiomyopathy and VT. METHODS: The VANISH2 trial enrolls patients with prior myocardial infarction and VT (with one of: ≥1 ICD shock; ≥3 episodes treated with antitachycardia pacing (ATP) and symptoms; ≥5 episodes treated with ATP regardless of symptoms; ≥3 episodes within 24 hours; or sustained VT treated with electrical cardioversion or pharmacologic conversion). Enrolled patients are classified as either sotalol-eligible, or amiodarone-eligible, and then are randomized to either catheter ablation or to that antiarrhythmic drug therapy, with randomization stratified by drug-eligibility group. Drug therapy, catheter ablation procedures and ICD programming are standardized. All patients will be followed until two years after randomization. The primary endpoint is a composite of mortality at any time, appropriate ICD shock after 14 days, VT storm after 14 days, and treated sustained VT below detection of the ICD after 14 days. The outcomes will be analyzed according to the intention-to-treat principle using survival analysis techniques RESULTS: The results of the VANISH2 trial are intended to provide data to support clinical decisions on how to suppress VT for patients with prior myocardial infarction. CLINICALTRIALS: gov registration NCT02830360.

Computerized clinical decision support to improve stroke prevention therapy in primary care management of atrial fibrillation: a cluster randomized trial.

BACKGROUND: Despite guidelines supporting antithrombotic therapy use in atrial fibrillation (AF), under-prescribing persists. We assessed whether computerized clinical decision support (CDS) would enable guideline-based antithrombotic therapy for AF patients in primary care. METHODS: This cluster randomized trial of CDS versus usual care (UC) recruited participants from primary care practices across Nova Scotia, following them for 12 months. The CDS tool calculated bleeding and stroke risk scores and provided recommendations for using oral anticoagulants (OAC) per Canadian guidelines. RESULTS: From June 14, 2014 to December 15, 2016, 203 primary care providers (99 UC, 104 CDS) with access to high-speed Internet were recruited, enrolling 1,145 eligible patients (543 UC, 590 CDS) assigned to the same treatment arm as their provider. Patient mean age was 72.3 years; most were male (350, 64.5% UC, 351, 59.5% CDS) and from a rural area (298, 54.9% UC, 315, 53.4% CDS). At baseline, a higher than anticipated proportion of patients were receiving guideline-based OAC therapy (373, 68.7% UC, 442, 74.9% CDS; relative risk [RR] 0.97 (95% confidence interval [CI], 0.87-1.07; P = .511)). At 12 months, prescription data were available for 538 usual care and 570 CDS patients, and significantly more CDS patients were managed according to guidelines (415, 77.1% UC, 479, 84.0% CDS; RR 1.08 (95% CI, 1.01-1.15; P = .024)). CONCLUSION: Notwithstanding high baseline rates, primary care provider access to the CDS over 12 months further optimized the prescribing of OAC therapy per national guidelines to AF patients potentially eligible to receive it. This suggests that CDS can be effective in improving clinical process of care. TRIAL REGISTRATION: Clinical Trials NCT01927367. https://clinicaltrials.gov/ct2/show/NCT01927367?term=NCT01927367&draw=2&rank=1.

Randomized Ablation-Based Rhythm-Control Versus Rate-Control Trial in Patients With Heart Failure and Atrial Fibrillation: Results from the RAFT-AF trial.

BACKGROUND: Atrial fibrillation (AF) and heart failure (HF) frequently coexist and can be challenging to treat. Pharmacologically based rhythm control of AF has not proven to be superior to rate control. Ablation-based rhythm control was compared with rate control to evaluate if clinical outcomes in patients with HF and AF could be improved. METHODS: This was a multicenter, open-label trial with blinded outcome evaluation using a central adjudication committee. Patients with high-burden paroxysmal (>4 episodes in 6 months) or persistent (duration <3 years) AF, New York Heart Association class II to III HF, and elevated NT-proBNP (N-terminal pro brain natriuretic peptide) were randomly assigned to ablation-based rhythm control or rate control. The primary outcome was a composite of all-cause mortality and all HF events, with a minimum follow-up of 2 years. Secondary outcomes included left ventricular ejection fraction, 6-minute walk test, and NT-proBNP. Quality of life was measured using the Minnesota Living With Heart Failure Questionnaire and the AF Effect on Quality of Life. The primary analysis was time-to-event using Cox proportional hazards modeling. The trial was stopped early because of a determination of apparent futility by the Data Safety Monitoring Committee. RESULTS: From December 1, 2011, to January 20, 2018, 411 patients were randomly assigned to ablation-based rhythm control (n=214) or rate control (n=197). The primary outcome occurred in 50 (23.4%) patients in the ablation-based rhythm-control group and 64 (32.5%) patients in the rate-control group (hazard ratio, 0.71 [95% CI, 0.49-1.03]; P=0.066). Left ventricular ejection fraction increased in the ablation-based group (10.1±1.2% versus 3.8±1.2%, P=0.017), 6-minute walk distance improved (44.9±9.1 m versus 27.5±9.7 m, P=0.025), and NT-proBNP demonstrated a decrease (mean change -77.1% versus -39.2%, P<0.0001). Minnesota Living With Heart Failure Questionnaire demonstrated greater improvement in the ablation-based rhythm-control group (least-squares mean difference of -5.4 [95% CI, -10.5 to -0.3]; P=0.0036), as did the AF Effect on Quality of Life score (least-squares mean difference of 6.2 [95% CI, 1.7-10.7]; P=0.0005). Serious adverse events were observed in 50% of patients in both treatment groups. CONCLUSIONS: In patients with high-burden AF and HF, there was no statistical difference in all-cause mortality or HF events with ablation-based rhythm control versus rate control; however, there was a nonsignificant trend for improved outcomes with ablation-based rhythm control over rate control. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01420393.

Paced P-wave morphology templates to guide atrial tachycardia localization: A derivation and validation study.

BACKGROUND: Surface ECG is a useful tool to guide mapping of focal atrial tachycardia (AT). OBJECTIVES: We aimed to construct 12-lead ECG templates for P-wave morphology (PWM) during endocardial pacing from different sites in both atria in patients with no apparent structural heart disease (derivation cohort), with the goal of creating a localization algorithm, which could subsequently be validated in a cohort of patients undergoing catheter ablation of focal AT (validation cohort). METHODS: We prospectively enrolled consecutive patients who underwent electrophysiology study, had no structural heart disease and no atrial enlargement. Atrial pacing, at twice diastolic threshold, was carried out at different anatomical sites in both atria. Paced PWM and duration were assessed. An algorithm was generated from the constructed templates of each pacing site. The algorithm was applied on a retrospective series of successfully ablated AT patients. Overall and site-specific accuracy were determined. RESULTS: Derivation cohort included 65 patients (25 men, age 37 ± 13 years). Atrial pacing was performed in 1025 sites in 61 patients (95%) in RA and in 15 patients (23%) in LA. The validation cohort included 71 patients (28 men, age 52 ± 19 years). AT were right atrial in 66.2%. The algorithm successfully predicted AT origin in 91.5% of patients (100% in LA and 87.2% in RA). It was off by one adjacent segment in the remaining 8.5%. CONCLUSIONS: A simple ECG algorithm based on paced PWM templates was highly accurate in localizing site of origin of focal AT in patients with structurally normal hearts.

Atomoxetine for suppression of vasovagal syncope.

OBJECTIVE: Vasovagal syncope (VVS) is a common clinical condition with few effective medical therapies. The study aimed to evaluate the effectiveness of atomoxetine in suppressing syncope in patients with recurrent VVS. METHODS: This was a retrospective, open-label, observational case series of 12 patients taking atomoxetine for suppression of recurrent vasovagal syncope. We compared syncope frequency in the 1 year before atomoxetine and while subjects were taking atomoxetine. We used novel applications of the Poisson distribution to describe the results as a collection of n = 1 studies. RESULTS: There were 12 subjects, eight female, with a mean age 47 ± 22 years and a mean Calgary Syncope Symptom Score of 2 (diagnostic of vasovagal syncope). The patients received a mean dose of atomoxetine of 66 ± 16 mg (1.06 ± 0.21 mg/kg). The mean follow-up period was 1.21 ± 1.01 years. While taking atomoxetine, 11/12 patients appeared to improve and 7/12 had no syncope in follow-up (p = 0.0046). The annualized syncope frequency decreased from a median 5.5 (IQR 4, 6.75) syncope per year to 0 (IQR 0, 0.88) syncope per year (p = 0.002, Wilcoxon rank-sum test). According to the Poisson distribution, 7/12 subjects significantly improved with p values of < 0.0001 to 0.0235, 3/12 did not faint but had too brief follow-up times to detect significance, and 2/12 did not improve significantly. CONCLUSIONS: In this case series, atomoxetine was a promising oral agent for the prevention of vasovagal syncope. The Poisson distribution permits individual patient-level assessment of improvement and detects insufficient follow-up despite apparent improvement.

Resource use and cost associated with computerized decision support system and usual care in managing patients with atrial fibrillation: analysis of IMPACT-AF randomized trial data.

BACKGROUND: IMPACT-AF is a prospective, randomized, cluster design trial comparing atrial fibrillation (AF) management with a computerized decision support system (CDS) to usual care (control) in the primary care setting of Nova Scotia, Canada. The objective of this analysis was to compare the resource use and costs between CDS and usual care groups. METHODS: Case costing data, 12-month self-administered questionnaires, and monthly diaries from IMPACT-AF were used in this analysis. Descriptive statistics were used to compare costs and resource use between groups. All costs are presented in 2021 Canadian dollars and cover the 12-month period of participation in the study. RESULTS: A total of 1,145 patients enrolled in the trial. Case costing data were available for 466 participants (41.1%), 12-month self-administered questionnaire data for 635 participants (56.0%) and monthly diary data for 223 participants (19.7%). Emergency department visits and hospitalizations comprised the most expensive component of AF care. Across all three datasets, there were no statistically significant differences in costs or resource use between CDS and usual care groups. CONCLUSIONS: Although there were no significant differences in resource use or costs among CDS and usual care groups in the IMPACT-AF trial, this study provides insight into the methodology and practical challenges of collecting economic data alongside a trial. REGISTRATION: Clinicaltrials.gov (registration number: NCT01927367, date of registration: 2013-08-20).

Augmented wide area circumferential catheter ablation for reduction of atrial fibrillation recurrence (AWARE) trial: Design and rationale.

BACKGROUND: Recurrence of atrial fibrillation (AF) after a pulmonary vein isolation procedure is often due to electrical reconnection of the pulmonary veins. Repeat ablation procedures may improve freedom from AF but are associated with increased risks and health care costs. A novel ablation strategy in which patients receive "augmented" ablation lesions has the potential to reduce the risk of AF recurrence. OBJECTIVE: The Augmented Wide Area Circumferential Catheter Ablation for Reduction of Atrial Fibrillation Recurrence (AWARE) Trial was designed to evaluate whether an augmented wide-area circumferential antral (WACA) ablation strategy will result in fewer atrial arrhythmia recurrences in patients with symptomatic paroxysmal AF, compared with a conventional WACA strategy. METHODS/DESIGN: The AWARE trial was a multicenter, prospective, randomized, open, blinded endpoint trial that has completed recruitment (ClinicalTrials.gov NCT02150902). Patients were randomly assigned (1:1) to either the control arm (single WACAlesion set) or the interventional arm (augmented- double WACA lesion set performed after the initial WACA). The primary outcome was atrial tachyarrhythmia (AA; atrial tachycardia [AT], atrial flutter [AFl] or AF) recurrence between days 91 and 365 post catheter ablation. Patient follow-up included 14-day continuous ambulatory ECG monitoring at 3, 6, and 12 months after catheter ablation. Three questionnaires were administered during the trial- the EuroQuol-5D (EQ-5D) quality of life scale, the Canadian Cardiovascular Society Severity of Atrial Fibrillation scale, and a patient satisfaction scale. DISCUSSION: The AWARE trial was designed to evaluate whether a novel approach to catheter ablation reduced the risk of AA recurrence in patients with symptomatic paroxysmal AF.

Comparative effectiveness of ventricular tachycardia ablation vs. escalated antiarrhythmic drug therapy by location of myocardial infarction: a sub-study of the VANISH trial.

AIMS: Complexity of the ventricular tachycardia (VT) substrate and the size and thickness of infarction area border zones differ based on location of myocardial infarctions (MIs). These differences may translate into heterogeneity in the effectiveness of treatments. This study aims to examine the influence of infarct location on the effectiveness of VT ablation in comparison with escalated pharmacological therapy in patients with prior MI and antiarrhythmic drug (AAD)-refractory VT. METHODS AND RESULTS: VANISH trial participants were categorized based on the presence or absence of an inferior MI scar. Inverse probability of treatment weighted Cox models were calculated for each subgroup. Of 259 randomized patients (median age 69.8 years, 7.0% women), 135 had an inferior MI and 124 had a non-inferior MI. Among patients with an inferior MI, no statistically significant difference in the composite primary outcome of all-cause mortality, appropriate implantable cardioverter-defibrillator (ICD) shock, and VT storm was detected between treatment arms [adjusted hazard ratio (aHR) 0.80, 95% confidence interval (CI) 0.51-1.20]. In contrast, patients with non-inferior MIs had a statistically significant reduction in the incidence of the primary outcome with ablation (aHR 0.48, 95% CI 0.27-0.86). In a sensitivity analysis of anterior MI patients (n = 83), a trend towards a reduction in the primary outcome with ablation was detected (aHR 0.50, 95% CI 0.23-1.09). CONCLUSION: The effectiveness of VT ablation versus escalated AADs varies based on the location of the MI. Patients with MI scars located only in non-inferior regions of the ventricles derive greater benefit from VT ablation in comparison to escalation of AADs in reducing VT-related events.

Ventricular tachycardia characteristics and outcomes with catheter ablation vs. antiarrhythmic therapy: insights from the VANISH trial.

AIMS: Catheter ablation is superior to escalated antiarrhythmic drugs among patients with ventricular tachycardia (VT) and prior myocardial infarction (MI). However, it is uncertain whether clinical VT characteristics, should influence choice of therapy. The purpose of this study was to evaluate whether presentation with electrical storm and the clinical VT cycle length predicted response to ablation vs. escalated antiarrhythmic therapy. METHODS AND RESULTS: All patients enrolled in the Ventricular Tachycardia Ablation vs. Escalated Antiarrhythmic Drug Therapy in Ischaemic Heart Disease (VANISH) trial were included. The association between VT cycle length and presentation with electrical storm and the primary outcome of death, subsequent VT storm or appropriate ICD shock was evaluated. Among the study population of 259 patients, escalated antiarrhythmic drug therapy had worse outcomes for those presenting with a VT cycle length >400 ms [<150 b.p.m., 89/259, hazard ratio (HR) 1.7 (1.02-3.13)]. This effect was more pronounced among those taking amiodarone at baseline [HR of 2.22 (1.19-4.16)]. Presentation with VT storm (32/259) did not affect the primary outcome between groups. However, those presenting with VT storm on amiodarone had a trend towards worse outcomes with escalated antiarrhythmic therapy [HR 4.31 (0.55-33.93)]. CONCLUSION: The VT cycle length can influence response to either ablation or escalated drug therapy in patients with VT and prior MI. Those with slow VT had improved outcomes with ablation. Patients presenting with electrical storm demonstrated similar outcomes to the overall trial population, with a trend to benefit of catheter ablation, particularly in those on amiodarone.

Oral anticoagulation for patients with atrial fibrillation in the ED: RE-LY AF registry analysis.

Oral anticoagulation (OAC) reduces stroke risk in patients with atrial fibrillation (AF). We sought to determine predictors of OAC initiation in AF patients presenting to the emergency department (ED). Secondary analysis of the RE-LY AF registry which enrolled individuals from 47 countries between 2007 and 2011 who presented to an ED with AF and followed them for 1 year. A total of 4149 patients with AF as their primary diagnosis who were not already taking OAC and had a CHA2DS2-VASc ≥ 1 for men or ≥ 2 for women were included in this analysis. Of these individuals, 26.8% were started on OAC (99.2% vitamin K antagonists) in the ED and 29.8% were using OAC one year later. Factors associated with initiating OAC in the ED included: specialist consultation (relative risk [RR] 1.84, 95%CI 1.44-2.36), rheumatic heart disease (RR 1.60, 95%CI 1.29-1.99), persistence of AF at ED discharge (RR 1.33, 95%CI 1.18-1.50), diabetes mellitus (RR 1.32, 95%CI 1.19-1.47), and hospital admission (RR 1.30, 95%CI 1.14-1.47). Heart failure (RR 0.83, 95%CI 0.74-0.94), antiplatelet agents (RR 0.77, 95%CI 0.69-0.84), and dementia (RR 0.61, 95%CI 0.40-0.94) were inversely associated with OAC initiation. Patients taking OAC when they left the ED were more likely using OAC at 1-year (RR 2.81, 95%CI 2.55-3.09) and had lower rates of death (RR 0.55, 95%CI 0.38-0.79) and stroke (RR 0.59, 95%CI 0.37-0.96). In patients with AF presenting to the ED, prompt initiation of OAC and specialist involvement are associated with a greater use of OAC 1 year later and may result in improved clinical outcomes.

A randomized ablation-based atrial fibrillation rhythm control versus rate control trial in patients with heart failure and high burden atrial fibrillation: The RAFT-AF trial rationale and design.

Heart failure (HF) and atrial fibrillation (AF) are 2 cardiac conditions that are increasing in prevalence and incidence. The 2 conditions frequently coexist, and are associated with increased morbidity and mortality. Catheter ablation of AF has been successfully performed in patients with HF, with an improvement in HF and AF, when compared to amiodarone, but further data is required to compare this to rate control. OBJECTIVES: The primary objective is to determine whether AF treated by catheter ablation, with or without antiarrhythmic drugs reduces all-cause mortality and hospitalizations for HF as compared with rate control in patients with HF and a high burden AF. METHODS: This is a multi-center prospective randomized open blinded endpoint (PROBE) study. Patients with NYHA class II-III HF (HF with reduced ejection fraction (<35%) or HF with preserved ejection fraction), and high burden AF are included in the trial. Patients are randomized to either rate control or catheter ablation-based AF rhythm control in a 1:1 ratio. Patients in the rate control group receive optimal HF therapy and rate control measures to achieve a resting hazard ratio (HR) < 80 bpm and 6-minute walk HR < 110 bpm. Patients randomized to catheter ablation-based AF rhythm control group receive optimal HF therapy and one or more aggressive catheter ablation, which include PV antral ablation and LA substrate ablation with or without adjunctive antiarrhythmic drug. The primary outcome is a composite of all-cause mortality and hospitalization for heart failure defined as an admission to a health care facility. The sample size is 600. Enrolment has been completed.

Canadian Registry of Electronic Device Outcomes: remote monitoring outcomes in the Abbott battery performance alert-a multicentre cohort.

AIMS: Cardiac implantable electronic devices with device advisories have the potential of device malfunction. Remote monitoring (RM) of devices has been suggested to allow the identification of abnormal device performance and permit early intervention. We sought to describe the outcomes of patients with and without RM in devices subject to the Abbott Premature Battery Depletion (PBD) advisory with data from a Canadian registry. METHODS AND RESULTS: Patients with an Abbott device subject to the PBD advisory from nine implantable cardioverter defibrillator (ICD) implanting centres in Canada were included in the registry. The use of RM was identified from baseline and follow-up data in the registry. The primary outcome was detection of PBD and all-cause mortality. A total of 2666 patients were identified with a device subject to the advisory. In all, 1687 patients (63.2%) had RM at baseline. There were 487 deaths during follow-up. At a mean follow-up of 5.7 ± 0.7 years, mortality was higher in those without a remote monitor compared with RM at baseline (24.7% vs. 14.5%; P < 0.001). Pre-mature battery depletion was identified in 36 patients (2.1%) with RM vs. 7 (0.7%) without RM (P = 0.004). Time to battery replacement was significantly reduced in patients on RM (median 5 vs. 13 days, P = 0.001). CONCLUSION: The use of RM in patients with ICD and cardiac resynchronization therapy under advisory improved detection of PBD, time to device replacement, and was associated with a reduction in all-cause mortality. The factors influencing the association with mortality are unknown and deserve further study.

The role of brain natriuretic peptide in atrial fibrillation: a substudy of the Substrate Modification with Aggressive Blood Pressure Control for Atrial Fibrillation (SMAC-AF) trial.

BACKGROUND: Catheter ablation is an established therapy for atrial fibrillation but is limited by recurrence; efforts have been made to identify biomarkers that predict recurrence. We investigated the effect of baseline NT-proBNP on AF recurrence following catheter ablation in patients randomized to aggressive (< 120/80 mmHg) or standard blood pressure management (< 140/90 mmHg) in the Substrate Modification with Aggressive Blood Pressure Control trial (SMAC-AF). METHODS: The SMAC-AF study included 173 patients resistant or intolerant to at least one class I or III antiarrhythmic drug. We studied the effect of baseline NT-proBNP on the primary outcome of AF recurrence > 3 months post-ablation. RESULTS: Of the 173 patients, 88 were randomized to the aggressive cohort, and 85 into the standard group. The primary outcome occurred in 61.4% of those in the aggressive arm, versus 61.2% in the standard arm. In the aggressive group, logNT-proBNP predicted recurrence (HR 1.28, p = 0.04, adjusted HR 1.43, p = 0.03), while in the standard cohort, it did not (HR 0.94, p = 0.62, adjusted HR 0.83, p = 0.22). NT-proBNP ≥ 280 pg/mL also predicted occurrence in the aggressive (HR 1.98, p = 0.02) but not the standard cohort (HR 1.00, p = 1.00). CONCLUSION: We conclude that pre-ablation NT-proBNP may be useful in predicting recurrence in hypertensive patients and identifying patients who benefit from aggressive blood control and upstream therapies. TRIAL REGISTRATION: NCT00438113, registered February 21, 2007.

Canadian national electrophysiology ablation registry report 2011-2016.

BACKGROUND/PURPOSE: Interventional cardiac electrophysiology (EP) is a rapidly evolving field in Canada; a nationwide registry was established in 2011 to conduct a periodic review of resource allocation. METHODS: The registry collects annual data on EP lab infrastructure, imaging, tools, human resources, procedural volumes, success rates, and wait times. Leading physicians from each EP lab were contacted electronically; participation was voluntary. RESULTS: All Canadian EP centres were identified (n = 30); 50 and 45 % of active centres participated in the last 2 instalments of the registry. A mean of 508 ± 270 standard and complex catheter ablation procedures were reported annually for 2015-2016 by all responding centres. The most frequently performed ablation targets atrial fibrillation (PVI) arrhythmia accounting for 36 % of all procedures (mean = 164 ± 85). The number of full time physicians ranges between 1 and 7 per centre, (mean = 4). The mean wait time to see an electrophysiologist for an initial non-urgent consult is 23 weeks. The wait time between an EP consult and ablation date is 17.8 weeks for simple ablation, and 30.1 weeks for AF ablation. On average centres have 2 (range: 1-4) rooms equipped for ablations; each centre uses the EP lab an average of 7 shifts per week. While diagnostic studies and radiofrequency ablations are performed in all centres, point-by-point cryoablation is available in 85 % centres; 38 % of the respondents use circular ablation techniques. CONCLUSIONS: This initiative provides contemporary data on invasive electrophysiology lab practices. The EP registry provides activity benchmarks on national trends and practices.

Integrated Management Program Advancing Community Treatment of Atrial Fibrillation (IMPACT-AF): A cluster randomized trial of a computerized clinical decision support tool.

BACKGROUND: Clinical decision support (CDS) tools designed to digest, filter, organize, and present health data are becoming essential in providing clinical and cost-effective care. Many are not rigorously evaluated for benefit before implementation. We assessed whether computerized CDS for primary care providers would improve atrial fibrillation (AF) management and outcomes as compared to usual care. METHODS: Overall, 203 primary care providers were recruited, randomized, and then cluster stratified by location (urban, rural) to usual care (n = 99) or CDS (n = 104). Providers recruited 1,145 adult patients with AF to participate. The intervention was access to an evidenced-based, point-of-care computerized CDS designed to support guideline-based AF management. The primary efficacy outcome was a composite of unplanned cardiovascular hospitalizations and AF-related emergency department visits; the primary safety outcome was major bleeding, both over 1 year. Patients were the units of intention-to-treat analysis. RESULTS: No significant effects on the primary efficacy (130 control, 118 CDS, hazard ratio: 0.98 [95% CI 0.71-1.37], P = .926) or safety (n = 7 usual care, n = 8 CDS, 1.3% total, P = .939) outcomes were observed at 12-months. CONCLUSIONS: IMPACT-AF rigorously assessed a CDS tool in a highly representative sample of primary care providers and their patients; however, no impact on outcomes was observed. Considering the proliferating use of CDS applications, this study highlights the need for efficacy assessments prior to adoption and clinical implementation.

Characteristics and outcomes of atrial fibrillation in patients without traditional risk factors: an RE-LY AF registry analysis.

AIMS: Data on patient characteristics, prevalence, and outcomes of atrial fibrillation (AF) patients without traditional risk factors, often labelled 'lone AF', are sparse. METHODS AND RESULTS: The RE-LY AF registry included 15 400 individuals who presented to emergency departments with AF in 47 countries. This analysis focused on patients without traditional risk factors, including age ≥60 years, hypertension, coronary artery disease, heart failure, left ventricular hypertrophy, congenital heart disease, pulmonary disease, valve heart disease, hyperthyroidism, and prior cardiac surgery. Patients without traditional risk factors were compared with age- and region-matched controls with traditional risk factors (1:3 fashion). In 796 (5%) patients, no traditional risk factors were present. However, 98% (779/796) had less-established or borderline risk factors, including borderline hypertension (130-140/80-90 mmHg; 47%), chronic kidney disease (eGFR < 60 mL/min; 57%), obesity (body mass index > 30; 19%), diabetes (5%), excessive alcohol intake (>14 units/week; 4%), and smoking (25%). Compared with patients with traditional risk factors (n = 2388), patients without traditional risk factors were more often men (74% vs. 59%, P < 0.001) had paroxysmal AF (55% vs. 37%, P < 0.001) and less AF persistence after 1 year (21% vs. 49%, P < 0.001). Furthermore, 1-year stroke occurrence rate (0.6% vs. 2.0%, P = 0.013) and heart failure hospitalizations (0.9% vs. 12.5%, P < 0.001) were lower. However, risk of AF-related re-hospitalization was similar (18% vs. 21%, P = 0.09). CONCLUSION: Almost all patients without traditionally defined AF risk factors have less-established or borderline risk factors. These patients have a favourable 1-year prognosis, but risk of AF-related re-hospitalization remains high. Greater emphasis should be placed on recognition and management of less-established or borderline risk factors.

The effect of revascularization on mortality and risk of ventricular arrhythmia in patients with ischemic cardiomyopathy.

BACKGROUND: There is clear evidence that patients with prior myocardial infarction and a reduced ejection fraction benefit from implantation of a cardioverter-defibrillator (ICD). It is unclear whether this benefit is altered by whether or not revascularization is performed prior to ICD implantation. METHODS: This was a retrospective cohort study following patients who underwent ICD implantation from 2002 to 2014. Patients with ischemic cardiomyopathy and either primary or secondary prevention ICDs were selected for inclusion. Using the electronic medical record, cardiac catheterization data, revascularization status (percutaneous coronary intervention or coronary bypass surgery) were recorded. The outcomes were mortality and ventricular arrhythmia. RESULTS: There were 606 patients included in the analysis. The mean age was 66.3 ± 10.1 years, 11.9% were women, and the mean LVEF was 30.5 ± 12.0, 58.9% had a primary indication for ICD, 82.0% of the cohort had undergone coronary catheterization prior to ICD implantation. In the overall cohort, there were fewer mortality and ventricular arrhythmia events in patients who had undergone prior revascularization. In patients who had an ICD for secondary prevention, revascularization was associated with a decrease in mortality (HR 0.46, 95% CI (0.24, 0.85) p = 0.015), and a trend towards fewer ventricular arrhythmia (HR 0.62, 95% CI (0.38, 1.00) p = 0.051). There was no association between death or ventricular arrhythmia with revascularization in patients with primary prevention ICDs. CONCLUSION: Revascularization may be beneficial in preventing recurrent ventricular arrhythmia, and should be considered as adjunctive therapy to ICD implantation to improve cardiovascular outcomes.

Ventricular Tachycardia Ablation versus Escalation of Antiarrhythmic Drugs.

BACKGROUND: Recurrent ventricular tachycardia among survivors of myocardial infarction with an implantable cardioverter-defibrillator (ICD) is frequent despite antiarrhythmic drug therapy. The most effective approach to management of this problem is uncertain. METHODS: We conducted a multicenter, randomized, controlled trial involving patients with ischemic cardiomyopathy and an ICD who had ventricular tachycardia despite the use of antiarrhythmic drugs. Patients were randomly assigned to receive either catheter ablation (ablation group) with continuation of baseline antiarrhythmic medications or escalated antiarrhythmic drug therapy (escalated-therapy group). In the escalated-therapy group, amiodarone was initiated if another agent had been used previously. The dose of amiodarone was increased if it had been less than 300 mg per day or mexiletine was added if the dose was already at least 300 mg per day. The primary outcome was a composite of death, three or more documented episodes of ventricular tachycardia within 24 hours (ventricular tachycardia storm), or appropriate ICD shock. RESULTS: Of the 259 patients who were enrolled, 132 were assigned to the ablation group and 127 to the escalated-therapy group. During a mean (±SD) of 27.9±17.1 months of follow-up, the primary outcome occurred in 59.1% of patients in the ablation group and 68.5% of those in the escalated-therapy group (hazard ratio in the ablation group, 0.72; 95% confidence interval, 0.53 to 0.98; P=0.04). There was no significant between-group difference in mortality. There were two cardiac perforations and three cases of major bleeding in the ablation group and two deaths from pulmonary toxic effects and one from hepatic dysfunction in the escalated-therapy group. CONCLUSIONS: In patients with ischemic cardiomyopathy and an ICD who had ventricular tachycardia despite antiarrhythmic drug therapy, there was a significantly lower rate of the composite primary outcome of death, ventricular tachycardia storm, or appropriate ICD shock among patients undergoing catheter ablation than among those receiving an escalation in antiarrhythmic drug therapy. (Funded by the Canadian Institutes of Health Research and others; VANISH ClinicalTrials.gov number, NCT00905853.).