Search

BACKGROUND: The role of atrioventricular optimization (AVO) to improve cardiac resynchronization therapy outcomes remains controversial. Previous post hoc analyses of a multicenter trial showed that measures of electrical dyssynchrony (right ventricular–left ventricular [LV] or QLV durations) are associated with patients who benefit from AVO. METHODS: This was a global, multicenter, prospective, randomized trial of de novo cardiac resynchronization therapy implant patients with an right ventricular–LV duration ≥70 ms to determine whether AVO results in greater reverse remodeling. Patients were randomized 1:1 for either an AVO algorithm (SmartDelay) that determines atrioventricular delay and pacing chamber, biventricular or LV only, or a fixed atrioventricular delay of 120 ms with biventricular pacing. Paired echocardiograms performed at baseline and 6 months were evaluated. The primary end point was echocardiographic cardiac resynchronization therapy response, defined dichotomously as a >15% reduction in LV end-systolic volume. RESULTS: A total of 310 patients (n=120 women) were randomized and had completed 6 months of follow-up. The echocardiographic cardiac resynchronization therapy response rate did not statistically differ between the groups (SmartDelay, 74.8%; fixed, 67.7%; P =0.17). Analyses of prespecified secondary end points demonstrated significant improvements in the absolute (median: SmartDelay, −41.0 mL; fixed, −33.0 mL; P =0.01) and relative change in LV end-systolic volume (SmartDelay, −38.3%; fixed, −27.8%; P =0.03) for patients with SmartDelay optimization. Similar results were observed for the relative improvement in LV ejection fraction (SmartDelay, 46.7%; fixed, 32.1%; P =0.050); absolute improvement in LV ejection fraction trended to be higher with SmartDelay ( P =0.06). CONCLUSIONS: Analysis of reverse remodeling parameters demonstrated that AVO via SmartDelay, relative to the nonoptimized fixed atrioventricular delay comparator group, improved absolute and relative changes in LV function in patients with longer right ventricular–LV duration. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03089281.

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 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 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.

ImportanceRecurrent atrial fibrillation (AF) commonly occurs after catheter ablation and is associated with patient morbidity and health care costs.ObjectiveTo evaluate the superiority of an augmented double wide-area circumferential ablation (WACA) compared with a standard single WACA in preventing recurrent atrial arrhythmias (AA) (atrial tachycardia, atrial flutter, or atrial fibrillation [AF]) in patients with paroxysmal AF.Design, Setting, and ParticipantsThis was a pragmatic, multicenter, prospective, randomized, open, blinded end point superiority clinical trial conducted at 10 university-affiliated centers in Canada. The trial enrolled patients 18 years and older with symptomatic paroxysmal AF from March 2015 to May 2017. Analysis took place between January and April 2022. Analyses were intention to treat.InterventionsPatients were randomized (1:1) to receive radiofrequency catheter ablation for pulmonary vein isolation with either a standard single WACA or an augmented double WACA.Main Outcomes and MeasuresThe primary outcome was AA recurrence between 91 and 365 days postablation. Patients underwent 42 days of ambulatory electrocardiography monitoring after ablation. Secondary outcomes included need for repeated catheter ablation and procedural and safety variables.ResultsOf 398 patients, 195 were randomized to the single WACA (control) arm (mean [SD] age, 60.6 [9.3] years; 65 [33.3%] female) and 203 to the double WACA (experimental) arm (mean [SD] age, 61.5 [9.3] years; 66 [32.5%] female). Overall, 52 patients (26.7%) in the single WACA arm and 50 patients (24.6%) in the double WACA arm had recurrent AA at 1 year (relative risk, 0.92; 95% CI, 0.66-1.29; P = .64). Twenty patients (10.3%) in the single WACA arm and 15 patients (7.4%) in the double WACA arm underwent repeated catheter ablation (relative risk, 0.72; 95% CI, 0.38-1.36). Adjudicated serious adverse events occurred in 13 patients (6.7%) in the single WACA arm and 14 patients (6.9%) in the double WACA arm.Conclusions and RelevanceIn this randomized clinical trial of patients with paroxysmal AF, additional ablation by performing a double ablation lesion set did not result in improved freedom from recurrent AA compared with a standard single ablation set.Trial RegistrationClinicalTrials.gov Identifier: NCT02150902

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.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.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.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.

Additional file 5

Background: Multipolar, phased radiofrequency (RF) catheter ablation (PVAC) has been associated with reduced procedural times compared to traditional RF. We performed a multicenter study to assess the efficacy and efficiency of using this catheter. Methods: This is a multicenter, sequential, prospective, cohort study between 2012 to 2016 in 6 tertiary care centers (NCT01562912). Patients were enrolled if they had symptomatic, paroxysmal AF (less than 7 days) refractory to at least one antiarrhythmic medication. Patients were enrolled in a 2:1 ratio of PVAC (group A) to control point-by-point RF with 3D mapping (group B). ECG and 48 hour Holter monitor were used to assess patients at 3, 6, 9 and 12 months post-ablation follow up. Recurrence was defined as any atrial arrhythmia >30 seconds excluding an initial 3 month blanking period. Results: Overall, 230 patients consisting of 162 males (70.4%) with mean age 57±11 years were analyzed. By Kaplan-Meier analysis, freedom from any atrial arrhythmia at 12 months was 49% and 69.2% in group A and B respectively (p=0.033) (Figure1). Among patients with recurrence, 14.7% (21) in group A and 7.7% (6) in group B had redo procedure within 12 month post procedure(p=0.12). Procedure time was significantly lower in Group A than Group B (P Conclusion: This study demonstrated that the PVAC catheter is associated with significantly reduced procedure times for AF ablation, however, AF recurrence rates may be higher than contemporary point-by-point RF ablation with 3D mapping technology.

Introduction: Patients with Brugada syndrome (BrS) are at risk for ventricular arrhythmias (VAs) and sudden death. Identification of high-risk individuals beyond those with syncope or resuscitated SCD remains a major challenge. We sought to assess the value of clinical, electrophysiological, and ECG features of depolarization and repolarization in predicting arrhythmic events and SCD in a Quebec population. Methods: Consecutive patients with BrS diagnosed between 2002 and 2013 were recruited from three major university hospitals in the province of Quebec, Canada. Relevant clinical features were recorded at baseline. Qualifying ECGs with the highest type 1 ST-segment elevations were reviewed and analyzed by two electrophysiologists blinded to clinical history, with the following parameters assessed: S duration in V1, aVR sign, QRS duration in V6, R-J interval in V2, maximal Tp-e, duration, Tp-e dispersion, QRS-f, ST elevation and QTc in V2, and presence of an inferolateral ER pattern. Survival analyses considered a left truncation model to account for potential sampling bias, considering that those who died suddenly before recognition of BrS were necessarily excluded. Results: A total of 105 consecutive patients, 79.8% male, were diagnosed with BrS at a median age of 48 years and were followed for 5.0±1.2 years. Ten (9.5%) had a history of SCD, 37 (35.2%) had syncope, and 7 (6.7%) experienced 20 arrhythmic events during follow-up (7 anti-tachycardia pacing; 13 shocks). In multivariate Cox regression analyses adjusted for left truncation and Firth bias correction, a spontaneous type I ECG pattern (HR 10.80; 95% CI 1.03 to 113.87; p=0.0476)], maximal Tp-e duration ≥100ms (HR 29.73; 95% CI 1.33 to 666.37; p= 0.0325) and QRS duration in V6>110 ms (HR 15.27; 95% CI 1.07 to 217.42; p=0.0443) were independently associated with VAs or aborted SCD. Family history of SCD, AF, and inducible VAs during programmed ventricular stimulation were not associated with the primary endpoint. Conclusion: In a cohort of patients with BrS from the province of Quebec, VAs and SCD were independently associated with standard 12-lead ECG features including a spontaneous type 1 pattern, depolarization (QRS in V6 >110 ms), and repolarization (maximal Tp-e duration) criteria.

Warfarin and novel oral anticoagulants (NOACS) may have different pharmacokinetic/pharmacodynamics depending on patient’s body weight. We sought to evaluate the impact of body weights on the safety and efficacy of anticoagulants (AC) in unselected patients. We conducted a prospective

Background : Isolated potentials (IPs) during sinus rhythm are indicators of fixed scar in patients with prior infarcts. IPs in conjunction with pace-mapping (PM) have been helpful to guide ablation of post-infarction ventricular tachycardia (VT). The purpose of this study was to determine the value of IPs in conjunction with PM to guide VT ablation in patients with non-ischemic cardiomyopathy. Methods : 32 consecutive patients (23 male, age 56±13 years, ejection fraction 0.30±0.14) with VT and non-ischemic cardiomyopathy were analyzed. Thirty/32 patients had an implanted cardioverter defibrillator (ICD). Electroanatomic maps of the left (n=21) and right ventricle (n=13), the coronary sinus (n=3), and the epicardium (n=4) were obtained during baseline rhythm. PM was performed at sites with low voltage ( Results : 173 VTs (cycle length 359±86 ms) were induced. Appropriate ablation sites with IPs during sinus rhythm were recorded in 19/32 patients (59%) (group A). In these patients, a total of 195 appropriate target sites were identified for 56/100 induced VTs (56%); 136/195 sites (70%) displayed IPs. In the remaining 13 patients, no target sites with IPs were identified (group B) despite combined endocardial and transcutaneous epicardial mapping in 3/13 patients. In these 13 patients, a total of 96 appropriate target sites were identified for 25/73 induced VTs (34%). Fifteen/19 patients (79%) in group A were non-inducible at the end of the procedure compared to 2/13 patients (15%) in group B. During a mean follow-up of 10±9 months, 15/19 patients (79%) in group A compared to 1/13 patients (8%) in group B remained arrhythmia free (p=0.0002). Conclusion : IPs in conjunction with PM are helpful in identifying critical isthmus areas for ablation of VT in patients with non-ischemic cardiomyopathy. Differences in the extent of fixed scar tissue may be the reason for differences in the prevalence of IPs, and this might explain better ablation results in some patients with non-ischemic cardiomyopathy.

Introduction: Identification of critical isthmus sites for post-infarction ventricular tachycardia (VT) ablation can be challenging. Unexcitable scar during pacing can identify one of the borders of the re-entry circuit. This area however is not thought to be critical to the circuit. Because of current-to-load mismatch, higher power might be required in order to obtain capture of individual surviving muscle bundles within scar tissue. The purpose of this study was to evaluate the value of high output capture of scar tissue in patients with post-infarction VT. Methods: In a consecutive series of 18 patients (15 men, age 62 ± 9, EF 0.28 ± 0.15) with post-infarction VT, mapping was performed using an electroanatomic mapping system. A voltage map was obtained during sinus rhythm and bipolar pace-mapping was performed in areas with low voltage (< 1.5 mV) with an output of 10 mA at a pulse width (PW) of 2 ms. High output capture was defined when capture at these settings failed but capture could be achieved with increased output. If there was no capture at the initial settings, output was increased to 20 mA at a PW of 2 ms, eventually the PW was increased up to 10 ms as required to achieve capture. A critical isthmus was defined as a site with a matching pace-map, and/or matching stimulus-QRS to electrogram-QRS intervals in the presence of concealed entrainment, and/or mechanical termination of VT and failure to induce VT after radiofrequency ablation. Results: Focal areas with high output capture could be observed in 10/18 (56%) patients. In 9/10 patients in whom high output capture was present (mean output: 20 mA; mean pulse width: 7.4 ms), this area was critical for the re-entry circuit of 10 VTs (cycle length 444 ± 72 ms). A total of 77 VTs (cycle length 390 ± 115 ms) was induced in these patients. Forty-three isthmus sites could be identified and effectively ablated for 56 of the VTs. During a follow-up of 4.9 ± 5.3 months 2 patients had VTs that were not targeted during the ablation. Conclusions: High output pacing is helpful in identifying critical areas of post-infarction VT that otherwise might be missed.

The aim of this study was to determine the mechanism of atrial tachycardia (AT) that occurs after ablation of atrial fibrillation (AF).Patients who undergo catheter ablation of AF may develop AT during follow-up.Seventy-eight patients underwent an ablation procedure for AT after circumferential pulmonary vein ablation (CPVA) for AF. The 3-dimensional maps from the AF and AT procedures were compared to determine whether AT arose from a prior ablation line.A total of 155 ATs were mapped, and the mechanism was re-entry in 137 (88%) and focal in 18 (12%). The most common left atrial (LA) ablation targets were the mitral isthmus, roof, and septum. The critical isthmus in 115 of the 120 LA re-entrant ATs (96%) traversed a prior ablation line, consistent with a gap-related mechanism. Catheter ablation was successful in 66 of the 78 patients (85%). After a mean follow-up of 13 +/- 10 months, 60 of the 78 patients (77%) were free of AT/AF without antiarrhythmic medications. Re-entrant septal AT was associated with recurrence (odds ratio 7.3; 95% confidence interval 1.5 to 36; p = 0.02), whereas PV isolation during the AT procedure was associated with a favorable outcome (odds ratio 0.17; 95% confidence interval 0.04 to 0.81; p = 0.03).Approximately 90% of ATs after CPVA are re-entrant, and nearly all are related to gaps in prior ablation lines. These findings suggest that the prevalence of these arrhythmias may be reduced by limiting the number of linear lesions, demonstration of linear block, and pulmonary vein disconnection during the initial AF procedure.