DREAM-ICD-II Study.

BACKGROUND: Regulatory authorities of most industrialized countries recommend 6 months of private driving restriction after implantation of a secondary prevention implantable cardioverter-defibrillator (ICD). These driving restrictions result in significant inconvenience and social implications. This study aimed to assess the incidence rate of appropriate device therapies in contemporary recipients of a secondary prevention ICD. METHODS: This retrospective study at 3 Canadian tertiary care centers enrolled consecutive patients with new secondary prevention ICD implants between 2016 and 2020. RESULTS: For a median of 760 days (324, 1190 days), 721 patients were followed up. The risk of recurrent ventricular arrhythmia was highest during the first 3 months after device insertion (34.4%) and decreased over time (10.6% between 3 and 6 months, 11.7% between 6 and 12 months). The corresponding incidence rate per 100 patient-days was 0.48 (95% CI, 0.35-0.64) at 90 days, 0.28 (95% CI, 0.17-0.45) at 180 days, and 0.21 (95% CI, 0.13-0.33) between 181 and 365 days after ICD insertion (P<0.001). The cumulative incidence of arrhythmic syncope resulting in sudden cardiac incapacitation was 1.8% within the first 90 days and subsequently dropped to 0.4% between 91 and 180 days (P<0.001) after ICD insertion. CONCLUSIONS: The incidence rate of appropriate therapies resulting in sudden cardiac incapacitation in contemporary recipients of a secondary prevention ICD is much lower than previously reported and declines significantly after the first 3 months. Lowering driving restrictions to 3 months after the index cardiac event seems safe, and revision of existing guidelines should be considered in countries still adhering to a 6-month period. Existing restrictions for private driving after implantation of a secondary prevention ICD should be reconsidered.

Leucocyte-derived micro-RNAs as candidate biomarkers in Brugada syndrome.

AIMS: Risk stratification for sudden cardiac death in patients with Brugada syndrome remains a major challenge. Contemporary risk prediction models have only modest predictive value. The aim of this study was to assess the role of micro-RNAs from peripheral blood as candidate biomarkers in Brugada syndrome. METHODS AND RESULTS: In this prospective study, Brugada patients and unaffected control individuals were enrolled for analysis of leucocyte-derived microRNAs (miRNAs) levels. Expression levels of 798 different circulating miRNAs were analysed on the NanoString® nCounter platform. All results were cross-validated by using a quantitative polymerase chain reaction. Micro-RNA expression levels of Brugada patients were compared with clinical data. A total of 21 definite Brugada patients (38% with a history of ventricular arrhythmia or cardiac arrest) and 30 unaffected control individuals were included in the study. Micro-RNA analysis showed a distinct expression profile in Brugada patients with 42 differentially expressed markers (38 up-regulated, 4 down-regulated miRNAs). The symptom status of Brugada patients was associated with a distinct miRNA signature. Micro-RNAs 145-5p and 585-3p were significantly up-regulated in symptomatic Brugada patients (P = 0.04). Incorporating miRNAs 145-5p and 585-3p into a multivariable model demonstrated significantly increased symptom prediction (area under the curve = 0.96; 95% confidence interval: 0.88-1.00). CONCLUSION: Brugada patients display a distinct miRNA expression profile compared with unaffected control individuals. There is also evidence that certain miRNAs (miR-145-5p and miR-585-3p) are associated with the symptom status of Brugada patients. The results suggest the principal utility of leucocyte-derived miRNAs as prognostic biomarkers for Brugada syndrome.

Incidence, predictors, and clinical impact of bleeding recurrence in patients with prior gastrointestinal bleeding undergoing LAAC.

BACKGROUND: Gastrointestinal bleeding (GIB) is associated with a high recurrence rate and a prior GIB episode is common in real-world left atrial appendage closure (LAAC) recipients. The present study sought to evaluate the clinical characteristics and outcomes of patients with prior GIB undergoing LAAC, and to determine the factors associated with and clinical impact of GIB recurrence. METHODS: Multicenter study including 277 consecutive patients who underwent percutaneous LAAC and had prior GIB. All-cause death, all bleeding, GIB recurrence, and clinical ischemic stroke were recorded. RESULTS: After a median follow-up of 17 (interquartile range: 6-37) months post-LAAC, the rates of death, bleeding, GIB recurrence, and ischemic stroke were 14.0 per 100 person-year (PY), 29.3 per 100 PY, 17.7 per 100 PY, and 1.1 per 100 PY, respectively. GIB recurrence occurred within 3 months post-LAAC in 55.8% of patients. A previous lower GIB (vs. upper or unclassified) (HR: 1.76; 95% CI: 1.09-2.82; p = .020) and eGFR < 45 mL/min (HR: 1.70; 95% CI:1.04-2.67; p = .033) determined an increased risk of GIB recurrence. By multivariable analysis, eGFR < 45 mL/min (HR: 2.72; 95% CI: 1.70-4.34; p < .001), GIB recurrence following LAAC (HR: 2.15; 95% CI: 1.33-3.46; p = .002), diabetes mellitus (HR: 1.77; 95% CI: 1.10-2.84; p = .018), and age (HR: 1.06; 95% CI: 1.03-1.10; p < .001) were associated with an increased mortality. CONCLUSIONS: Patients with prior GIB undergoing LAAC exhibited a relatively low rate of GIB recurrence, and prior lower GIB and moderate-to-severe chronic kidney disease determined an increased risk. GIB recurrence was associated with an increased mortality.

Safety and effects of volume loading during transesophageal echocardiography in the pre-procedural work-up for left atrial appendage closure.

BACKGROUND: In patients undergoing left atrial appendage (LAA) closure, an accurate sizing of the LAA is key to optimize device sizing, procedural success and reduce complications. Previous studies have shown that intraprocedural volume loading increases LAA dimensions and improves device sizing. However, the safety and effects on LAA and device sizing of administering a fluid bolus during pre-procedural transesophageal echocardiography (TEE) are unknown. The aim of this study was to determine the safety and impact on LAA dimensions and device sizing of an intravenous (IV) fluid bolus administered during TEE in the setting of the pre-procedural work-up for LAA closure. METHODS: The study included a total of 72 patients who underwent TEE to assess suitability for LAAC and received a 500 ml IV bolus of normal saline. The LAA landing zone (LZ) and depth were measured by TEE before and after volume loading, and these measurements were used to predict the device size implanted during a subsequent percutaneous LAAC procedure. RESULTS: There were no complications associated with volume loading. The baseline mean LZ was 19.6 ± 3.6 mm at 90o, and 20.2 ± 4.1 mm at 135o. Following fluid bolus, the maximum diameter increased 1.5 ± 1.0 mm at 90o (p<0.001), and 1.3 ± 1.0 mm at 135o (p<0.001). The baseline mean depth of the LAA was 26.5 ± 5.5 mm at 90o, and 23.9 ± 5.8 mm at 135o. After fluid bolus, the mean depth increased by 1.5 ± 1.8 mm (p<0.001) and 1.6 ± 2.0 (p<0.001), at 90o and 135o, respectively. Sizing based on post-bolus measurements of the LZ significantly improved the agreement with the final device size selection during the procedure in 71.0% of cases (vs. 42.0% with pre-bolus measurements). CONCLUSIONS: Volume loading during ambulatory TEE as part of the pre-procedural work-up of LAAC is safe and significantly increases LAA dimensions. This strategy may become the new standard, particularly in centers performing LAAC with no TEE guidance, as it improves LAA sizing and more accurately predicts the final device size.

Transesophageal echocardiography complications associated with interventional cardiology procedures.

BACKGROUND: Although there have been several reports documenting complications related with transesophageal echocardiography (TEE) manipulation following cardiac surgery, there is a paucity of data regarding the safety of TEE used to guide catheter-based interventions. The aim of this study was to determine the prevalence, types and risk factors of complications associated with procedures requiring active TEE guidance. METHODS: This study included 1249 consecutive patients undergoing either transcatheter aortic valve implantation (TAVI), Mitraclip, left atrial appendage occlusion (LAAO) or paravalvular leak closure (PVLC). Patients were divided into 2 cohorts based on the degree of probe manipulation required to guide the procedure and the risk of developing a TEE-related complication: low-risk (TAVI, n = 1037) and high-risk (Mitraclip, LAAO and PVLC, n = 212). Patients were further analyzed according to the occurrence of major and minor TEE-related complications. RESULTS: The overall incidence of TEE-related complications was 0.9% in the TAVI group and 6.1% in the rest of the cohort (P < .001). Patients in the high-risk cohort had also a higher incidence of major-complications (2.8% vs 0.6%, P = .008), and factors associated with an increased risk were being underweight, having a prior history of gastrointestinal bleeding and the use of chronic steroids/immunosuppressive medications. Procedural time under TEE-manipulation was longer in patients exhibiting complications and was an independent predictor of major complications (OR = 1.13, 95% CI 1.01-1.25, for each 10 minutes increments in imaging time). Patients with major complications undergoing Mitraclip had the longest median time under TEE-manipulation (297 minutes) and a risk of developing a major-complication that was 10.64 times higher than the rest of the cohort (95% CI 3.30-34.29, P < .001). CONCLUSION: The prevalence of TEE-related complications associated with interventional procedures is higher than previously reported. Undergoing a prolonged procedure, particularly in the setting of Mitraclip, was the main factor linked to TEE-related complications.

Findings of remote monitoring of implantable cardioverter defibrillators during the COVID-19 pandemic.

BACKGROUND: Monitoring of cardiac implantable electronic devices was highly impacted by the COVID-19 pandemic considering the high volume of in-person visits for regular follow-up. Recent recommendations highlight the important role of remote monitoring to prevent exposure to the virus. This study compared remote monitoring of implantable cardioverter defibrillators (ICDs) in patients whose in-person annual visit was substituted for a remote monitoring session with patients who were already scheduled for a remote monitoring session. METHODS: This was a cross-sectional observational study of 329 consecutive patients between 20 March and 24 April 2020. Group 1 included 131 patients whose in-person annual visit was substituted for a remote monitoring session. Group 2 included 198 patients who underwent a remote monitoring session as scheduled in their usual device follow-up. The time interval since the last in-person visit was 13.3 ± 3.2 months in group 1 and 5.9 ± 1.7 months in group 2 (P < .01). RESULTS: In group 1, 15 patients (11.5%) experienced a clinical event compared to 15 patients (7.6%) in group 2 (P = .25). Nineteen patients (14.5%) required a physician intervention in group 1 compared to 19 patients (9.6%) in group 2 (P = .22). Two patients (1.5%) in group 1 and four patients (2.0%) in group 2 required an early in-person follow-up visit during the pandemic (P > .99). CONCLUSION: Remote monitoring of ICDs is useful to identify clinical events and allows physicians to treat patients appropriately during the COVID-19 pandemic regardless of the time interval since their last in-person visit. It reduces significantly in-person visit for regular follow-up.

Orthodromic atrioventricular reentrant tachycardia using a concealed isoproterenol-sensitive accessory pathway.

Accessory pathways (APs) represent the substrate for atrioventricular reentrant tachycardia. Catecholamine-sensitivity is an uncommon feature of APs and has been almost exclusively been described in APs with antegrade conduction. We present the rare case of a catecholamine-dependent concealed AP that was only unmasked upon isoproterenol stimulation and successfully ablated. This case highlights the importance of systematic isoproterenol stimulation in patients referred for ablation of supraventricular tachycardia - in particular if the baseline electrophysiology study is negative. Otherwise, ablation targets may be missed. LEARNING OBJECTIVE: The absence of retrograde ventriculo-atrial conduction does not automatically exclude the presence of a concealed accessory pathway. Systematic isoproterenol stimulation should be part of any electrophysiology study for supraventricular tachycardia, to search for catecholamine-sensitive accessory pathways that may be otherwise missed.

Effectiveness of single- vs dual-coil implantable defibrillator leads: An observational analysis from the SIMPLE study.

INTRODUCTION: Dual-coil leads (DC-leads) were the standard of choice since the first nonthoracotomy implantable cardioverter/defibrillator (ICD). We used contemporary data to determine if DC-leads offer any advantage over single-coil leads (SC-leads), in terms of defibrillation efficacy, safety, clinical outcome, and complication rates. METHODS AND RESULTS: In the Shockless IMPLant Evaluation study, 2500 patients received a first implanted ICD and were randomized to implantation with or without defibrillation testing. Two thousand and four hundred seventy-five patients received SC-coil or DC-coil leads (SC-leads in 1025/2475 patients; 41.4%). In patients who underwent defibrillation testing (n = 1204), patients with both lead types were equally likely to achieve an adequate defibrillation safety margin (88.8% vs 91.2%; P = 0.16). There was no overall effect of lead type on the primary study endpoint of "failed appropriate shock or arrhythmic death" (adjusted HR 1.18; 95% CI, 0.86-1.62; P = 0.300), and on all-cause mortality (SC-leads: 5.34%/year; DC-leads: 5.48%/year; adjusted HR 1.16; 95% CI, 0.94-1.43; P = 0.168). However, among patients without prior heart failure (HF), and SC-leads had a significantly higher risk of failed appropriate shock or arrhythmic death (adjusted HR 7.02; 95% CI, 2.41-20.5). There were no differences in complication rates. CONCLUSION: In this nonrandomized evaluation, there was no overall difference in defibrillation efficacy, safety, outcome, and complication rates between SC-leads and DC-leads. However, DC-leads were associated with a reduction in the composite of failed appropriate shock or arrhythmic death in the subgroup of non-HF patients. Considering riskier future lead extraction with DC-leads, SC-leads appears to be preferable in the majority of patients.

Validation of a novel single lead ambulatory ECG monitor - Cardiostat™ - Compared to a standard ECG Holter monitoring.

BACKGROUND: Cardiostat™ is a single lead ambulatory ECG monitor. Recording is made through 2 electrodes positioned in a lead 1-like configuration. We first validated its accuracy for atrial fibrillation detection compared to a 12-lead ECG. In the second phase of the study, arrhythmia detection accuracy was compared between Cardiostat™ ambulatory ECG and a standard 24 h Holter ECG monitoring. METHOD/RESULTS: Phase one of the study included patients undergoing cardioversion for atrial fibrillation (AF) or atrial flutter. Cardiostat™ tracings were compared with standard 12-lead ECG. In the second phase, patients undergoing 24 h ambulatory Holter ECG monitoring for control or suspicion of atrial fibrillation (AF) were included. Simultaneous Holter monitoring and Cardiostat™ ECG recordings were performed. Tracings were analysed and compared. Two hundred twelve monitoring were compared. AF was diagnosed in 73 patients. Agreement between Cardiostat™ ECG and standard Holter monitoring was 99% for AF detection with kappa = 0.99. Kappa correlation for atrial flutter detection was only moderate at 0.51. AF burden was similar in both recordings. Noise hindered analysis in a greater proportion with Cardiostat™ compared to Holter ambulatory ECG (8.5 vs 3.8%). CONCLUSION: Cardiostat™ ambulatory ECG device showed excellent correlation with the standard Holter ECG monitoring for AF detection. Holter monitoring was however superior to discriminate premature atrial and ventricular beats and to qualify the morphology of PVCs since it has more vectors for analysis. Added value of Cardiostat™ includes longer monitoring duration, less cumbersome installation and water resistance.

Sedation strategies for defibrillation threshold testing: safety outcomes with anaesthesiologist compared to proceduralist-directed sedation: an analysis from the SIMPLE study.

Aims: No standard practice exists with respect to anaesthesiologist-directed sedation (ADS) vs. sedation by proceduralist (PDS) for defibrillation threshold (DT) testing. We aimed to evaluate adverse events and safety outcomes with ADS vs. PDS for DT testing. Methods and results: A post hoc analysis of the Shockless Implant Evaluation (SIMPLE) study was performed among the 1242 patients who had DT testing (624 ADS and 618 PDS). We evaluated both intraoperative and in-hospital adverse composite events and two safety composite outcomes at 30-days of the main trial. Propensity score adjusted models were used to compute odds ratio (OR) and 95% confidence interval (CI) to evaluate the association between adverse and safety outcomes with method of sedation and independent predictors for use of ADS. Compared to PDS, patients who received ADS were younger (62 ± 12 years vs. 64 ± 12 years, P = 0.01), had lower ejection fraction (left ventricular ejection fraction 0.31 ± 13 vs. 0.33 ± 13, P = 0.03), were more likely to receive inhalational anaesthesia, propofol, or narcotics (P < 0.001, respectively) and receive an arterial line (43% vs. 8%, P = <0.0001). Independent predictors for ADS sedation were presence of coronary artery disease (OR 1.69, 95% CI 1.0-2.72; P = 0.03) and hypertrophic cardiomyopathy (OR 2.64, 95% CI 1.19-5.85; P = 0.02). Anaesthesiologist directed sedation had higher intraoperative adverse events (2.2% vs. 0.5%; OR 4.47, 95% CI 1.25-16.0; P = 0.02) and higher primary safety outcomes at 30 days (8.2% vs. 4.9%; OR 1.72 95% CI 1.06-2.80; P = 0.03) and no difference in other outcomes compared to PDS. Conclusion: Proceduralist-directed sedation is safe, however, this could be result of selection bias. Further research is needed.

Clinical performance of different DF-4 implantable cardioverter defibrillator leads.

INTRODUCTION: Implantable cardioverter-defibrillator (ICD) DF-4 connectors have been introduced to facilitate defibrillator lead connection and to reduce the size of device header. There are limited data regarding the overall performance of those leads and no comparison between different ICD DF-4 leads. METHODS: This is a cohort study of consecutive patients implanted with ICD DF-4 lead system at one University Centre between October 2010 and February 2015. A historical control group of patients with ICD DF-1 lead implantation was used for comparison. The following ICD DF-4 leads were evaluated: St. Jude Medical Durata 7122Q (St. Jude Medical, St. Paul, MN, USA), Medtronic Sprint Quattro Secure 6935 M (Medtronic Inc., Minneapolis, MN, USA), Boston Scientific Endotak Reliance 4-Site 0293 (Boston Scientific, Marlborough, MA, USA), and Boston Scientific Reliance 4-Front 0693. This study evaluated the acute and mid-term performances of those leads as well as complications. RESULTS: A total of 812 patients (age 63 ± 12 years, 80% male, left ventricular ejection fraction 31 ± 12%) underwent implantation of an ICD DF-4 lead. Acute and follow-up R-wave sensing and threshold were excellent. Compared to implantation, intrinsic R waves were higher at follow-up for Boston Scientific and Medtronic leads, and pacing lead impedances were lower for all leads at first follow-up (P < 0.001). The number of lead dislodgement or failure was similar between all leads. The estimated lead survival rates at 3 years were 95.6% for Boston Scientific Endotak 4-Site, 97.1% for Boston Scientific 4-Front, 97.7% for Medtronic Sprint Quattro, and 97.5% for St. Jude Durata (P  =  0.553). CONCLUSION: All ICD DF-4 leads had excellent acute and mid-term electrical performances. Longer follow-up will be necessary to confirm their sustained performance.

Left atrial appendage closure: Initial experience with the ultraseal device.

OBJECTIVES: We report the initial experience of percutaneous left atrial appendage (LAA) closure with the Ultraseal device. BACKGROUND: LAA closure is an alternative to oral anticoagulation for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) and high risk of bleeding. The Ultraseal device is a new LAA closure prosthesis that consists of a distal soft bulb and a proximal sail attached by an articulating joint that allows a high degree of device conformability to the different variations of the LAA anatomy. METHODS: We included 12 consecutive patients with NVAF who underwent LAA closure with the Ultraseal device between January and December 2015 in our center. Patients had clinical and transesophageal echocardiography (TEE) examinations at baseline and at 45 days following LAA closure. RESULTS: The device was successfully implanted in all patients, with no periprocedural complications. There were no episodes of bleeding, stroke, pericardial effusion, or device embolization at 45-day follow-up. No cases with residual leaks >5 mm were observed at TEE. One patient presented a device related thrombus without clinical consequences. CONCLUSIONS: This initial experience with the Ultraseal LAA closure device demonstrates preliminary safety and feasibility. Further larger studies with longer follow-up are warranted. © 2016 Wiley Periodicals, Inc.

Wound haematoma following defibrillator implantation: incidence and predictors in the Shockless Implant Evaluation (SIMPLE) trial.

AIMS: Pocket haematoma is a common complication after defibrillator [implantable cardioverter defibrillator (ICD)] implantation, which is not only painful, but also increases the risk of device-related infection, and possibly embolic events. The present study seeks to evaluate the rate and predictors of clinically significant pocket haematoma. METHODS AND RESULTS: This study included 2500 patients receiving an ICD in the SIMPLE trial. A clinically significant pocket haematoma was defined as a haematoma that required re-operation or interruption of oral anticoagulation (OAC) therapy. Clinically significant pocket haematoma occurred in 56 of 2500 patients (2.2%) of which 6 (10.7%) developed device-related infection. Patients who developed pocket haematoma were older (mean age 67.6 ± 8.8 years vs. 62.7 ± 11.6 years, P < 0.001), were more likely to have permanent atrial fibrillation (30.4 vs. 6.7%, P < 0.001) and a history of stroke (17.9 vs. 6.7%, P = 0.004), or were more likely to receive peri-operative OAC (50.0 vs. 28.4%, P < 0.001), unfractionated heparin (16.1 vs. 5.2%, P = 0.003), or low-molecular-weight heparin (37.5 vs. 17.5%, P < 0.001). Independent predictors of wound haematoma on multivariable analysis included the use of heparin bridging (OR 2.65, 95% CI 1.48-4.73, P = 0.001), sub-pectoral location of ICD (OR 2.00, 95% CI 1.12-3.57, P =0.020), previous stroke (OR 2.47, 95% CI 1.20-5.10, P = 0.015), an upgrade from permanent pacemaker (OR 2.52, 95% CI 1.07-5.94, P = 0.035), and older age (OR 1.03, 95% CI 1.00-1.06, P = 0.049). CONCLUSION: Pocket haematoma remains an important complication of ICD implantation and is associated with a high risk of infection. Independent predictors of pocket haematoma include heparin bridging, prior stroke, sub-pectoral placement of ICD, older age, and upgrade from a pacemaker.

Cardioverter defibrillator implantation without induction of ventricular fibrillation: a single-blind, non-inferiority, randomised controlled trial (SIMPLE).

BACKGROUND: Defibrillation testing by induction and termination of ventricular fibrillation is widely done at the time of implantation of implantable cardioverter defibrillators (ICDs). We aimed to compare the efficacy and safety of ICD implantation without defibrillation testing versus the standard of ICD implantation with defibrillation testing. METHODS: In this single-blind, randomised, multicentre, non-inferiority trial (Shockless IMPLant Evaluation [SIMPLE]), we recruited patients aged older than 18 years receiving their first ICD for standard indications at 85 hospitals in 18 countries worldwide. Exclusion criteria included pregnancy, awaiting transplantation, particpation in another randomised trial, unavailability for follow-up, or if it was expected that the ICD would have to be implanted on the right-hand side of the chest. Patients undergoing initial implantation of a Boston Scientific ICD were randomly assigned (1:1) using a computer-generated sequence to have either defibrillation testing (testing group) or not (no-testing group). We used random block sizes to conceal treatment allocation from the patients, and randomisation was stratified by clinical centre. Our primary efficacy analysis tested the intention-to-treat population for non-inferiority of no-testing versus testing by use of a composite outcome of arrhythmic death or failed appropriate shock (ie, a shock that did not terminate a spontaneous episode of ventricular tachycardia or fibrillation). The non-inferiority margin was a hazard ratio (HR) of 1·5 calculated from a proportional hazards model with no-testing versus testing as the only covariate; if the upper bound of the 95% CI was less than 1·5, we concluded that ICD insertion without testing was non-inferior to ICD with testing. We examined safety with two, 30 day, adverse event outcome clusters. The trial is registered with ClinicalTrials.gov, number NCT00800384. FINDINGS: Between Jan 13, 2009, and April 4, 2011, of 2500 eligible patients, 1253 were randomly assigned to defibrillation testing and 1247 to no-testing, and followed up for a mean of 3·1 years (SD 1·0). The primary outcome of arrhythmic death or failed appropriate shock occurred in fewer patients (90 [7% per year]) in the no-testing group than patients who did receive it (104 [8% per year]; HR 0·86, 95% CI 0·65-1·14; pnon-inferiority <0·0001). The first safety composite outcome occurred in 69 (5·6%) of 1236 patients with no-testing and in 81 (6·5%) of 1242 patients with defibrillation testing, p=0·33. The second, pre-specified safety composite outcome, which included only events most likely to be directly caused by testing, occurred in 3·2% of patients with no-testing and in 4·5% with defibrillation testing, p=0·08. Heart failure needing intravenous treatment with inotropes or diuretics was the most common adverse event (in 20 [2%] of 1236 patients in the no-testing group vs 28 [2%] of 1242 patients in the testing group, p=0·25). INTERPRETATION: Routine defibrillation testing at the time of ICD implantation is generally well tolerated, but does not improve shock efficacy or reduce arrhythmic death. FUNDING: Boston Scientific and the Heart and Stroke Foundation (Ontario Provincial office).

Apical versus Non-Apical Lead: Is ICD Lead Position Important for Successful Defibrillation?

INTRODUCTION: We aim to compare the acute and long-term success of defibrillation between non-apical and apical ICD lead position. METHODS AND RESULTS: The position of the ventricular lead was recorded by the implanting physician for 2,475 of 2,500 subjects in the Shockless IMPLant Evaluation (SIMPLE) trial, and subjects were grouped accordingly as non-apical or apical. The success of intra-operative defibrillation testing and of subsequent clinical shocks were compared. Propensity scoring was used to adjust for the impact of differences in baseline variables between these groups. There were 541 leads that were implanted at a non-apical position (21.9%). Patients implanted with a non-apical lead had a higher rate of secondary prevention indication. Non-apical location resulted in a lower mean R-wave amplitude (14.0 vs. 15.2, P < 0.001), lower mean pacing impedance (662 ohm vs. 728 ohm, P < 0.001), and higher mean pacing threshold (0.70 V vs. 0.66 V, P = 0.01). Single-coil leads and cardiac resynchronization devices were used more often in non-apical implants. The success of intra-operative defibrillation was similar between propensity score matched groups (89%). Over a mean follow-up of 3 years, there were no significant differences in the yearly rates of appropriate shock (5.5% vs. 5.4%, P = 0.98), failed appropriate first shock (0.9% vs. 1.0%, P = 0.66), or the composite of failed shock or arrhythmic death (2.8% vs. 2.3% P = 0.35) according to lead location. CONCLUSION: We did not detect any reduction in the ICD efficacy at the time of implant or during follow-up in patients receiving a non-apical RV lead.

Contact-Force Catheters: Efficacy Versus Safety? Case Report of 2 Atrioesophageal Fistulae.

Contact-force (CF) catheters appear to be more effective compared to standard ablation catheters for complex radiofrequency ablation including atrial fibrillation (AF) ablation when optimal CF >10 g is achieved. Some have suggested that this technology could also improve procedural safety. We report 2 cases of atrioesophageal fistulae (AEF), a rare but catastrophic complication of AF ablation. These are to our knowledge the first cases of AEF described after using CF catheters.

PA/Lateral chest X-ray is equivalent to cine-fluoroscopy for the detection of conductor externalization in defibrillation leads.

BACKGROUND: Riata™ and Riata ST defibrillation leads (St. Jude Medical, Sylmar, CA, USA) are susceptible to insulation defects with conductor externalization. Cine-fluoroscopy is considered to be the gold standard for the documentation of insulation defects, but similar detection rates have been reported for posterior-anterior (PA)/lateral chest x-ray (CXR) with zooming. OBJECTIVE: Prospective single-center study to assess the diagnostic equivalence of a PA/lateral CXR with zooming for the detection of Riata insulation defects in a direct comparison to cine-fluoroscopy. METHODS: Seventy-eight consecutive patients underwent 3-view cine-fluoroscopy and a PA/lateral CXR. All CXRs and cine-fluoroscopy images were reviewed by blinded electrophysiologists and staff radiologists. RESULTS: Forty-four of 78 patients had an abnormal cine-fluoroscopy (56%). The diagnostic correlation between PA/lateral CXR and cine-fluoroscopy was excellent (κ = 0.90; 95% confidence interval 0.80-1.00). PA/lateral CXR was equivalent to cine-fluoroscopy for the detection of conductor externalization showing a sensitivity of 97.7% and a specificity of 91.2%. The mean radiation effective dose of CXR was significantly lower compared to cine-fluoroscopy (0.09 millisievert [mSV] vs 0.85 ± 0.47 mSv; P < 0.001). Also, CXR was significantly less expensive. CONCLUSION: PA/lateral CXR with zooming is equivalent to cine-fluoroscopy for the detection of Riata insulation defects and should be considered as the preferred screening method.

Detection of high incidence of Riata lead breaches by systematic postero-anterior and lateral chest X-ray in a large cohort.

AIMS: Insulation breaches with externalization of conductor cables have been described for St-Jude Medical Riata™ defibrillation leads. Published data on the incidence of Riata lead abnormalities are quite heterogeneous. The objective of this study was to estimate systematically the prevalence of lead abnormalities using a postero-anterior (PA) and lateral chest X-ray (CXR). METHODS AND RESULTS: From 2002 to 2008, 552 Riata defibrillation leads were implanted at our centre. We evaluated patients for potential insulation breaches. A PA and lateral CXR was obtained. Chest X-rays were reviewed by two electrophysiologists using a zooming function with magnification up to factor 7.5 and were classified as normal or abnormal for the presence of conductor externalization. A total of 284 patients were included. Riata lead models were 1570, 1580, 1582, 1590, 1592, 7000, 7002, and 7022. The total frequency of radiological lead defects was 24.3%. Insulation breaches occurred at zones of major lead curvature. Mean maximal spacing between extruding lead components was 3.6 ± 1.9 mm (range 2.0-12.4). Abnormal CXRs were more frequent in 8F leads (31.4% vs. 6.3%; P < 0.001). Most defects occurred with lead models 1582 (41.2%) and 1580 (31.4%). Mean time since implantation was longer in abnormal leads (6.7 vs. 5.9 years; P < 0.001). Abnormal leads had higher pacing thresholds (1.1 ± 0.8 V vs. 0.9 ± 0.4 V; P = 0.02). CONCLUSION: The incidence of insulation breach in Riata leads is much higher than quoted by the manufacturer or reported by most of the literature. A PA and lateral CXR with zooming appears adequate to identify lead breaches when reviewed by an electrophysiologist. Riata lead breaches without electrical abnormalities present a management dilemma and will require further studies.

Antithrombotic Management After Left Atrial Appendage Closure: Current Evidence and Future Perspectives.

Left atrial appendage closure is an alternative to chronic oral anticoagulation to prevent embolic events related to nonvalvular atrial fibrillation. After device implantation, antithrombotic treatment is prescribed to prevent device-related thrombosis, a dreadful complication associated with an increased risk of ischemic events. However, the optimal antithrombotic treatment after left atrial appendage closure, effective on both device-related thrombus prevention and bleeding risk mitigation, remains to be determined. In more than 10 years experience with left atrial appendage closure, a wide range of antithrombotic treatments have been used, mostly in observational studies. In this review, we analyzed the body of evidence for each antithrombotic regimen after left atrial appendage closure to provide tools to guide the physician choice and describe future perspectives in the field.

The Canadian WATCHMAN Registry for Percutaneous Left Atrial Appendage Closure.

Background: Access to left atrial appendage closure (LAAC) in Canada is limited, due to funding restrictions. This work aimed to assess Canadian clinical practice on patient selection, postprocedural antithrombotic therapy, and safety and/or efficacy with WATCHMAN device implantation. Methods: Seven Canadian centres implanting the WATCHMAN device participated in this prospective multicentre, observational registry. All procedures were done under general anesthesia with transesophageal echocardiography guidance. Patients were prospectively followed for 2years. The long-term stroke rate was compared with the expected rate based on the CHA2DS2-VASc score. Results: A total of 272 patients who underwent LAAC with the WATCHMAN device between December 2013 and August 2019 (mean age: 75.4 years [standard deviation {SD}: 8.75]; male, 63.2%; CHA2DS2-VASc score: 4.35 [SD: 1.64]; HAS-BLED score: 3.55 [SD: 0.94]) were included. Most patients (90.4%) had prior history of bleeding (major, 80.5%; minor, 21.7%). The WATCHMAN device was successfully implanted in 269 patients (98.9%), with a few procedure-related complications, including 5 pericardial effusions requiring drainage (1.8%), and 1 death (0.4%; 22 days post-LAAC from respiratory failure). Post-LAAC antithrombotic therapy included dual antiplatelet therapy in 70.6%, single antiplatelet therapy in 18.4%, and oral anticoagulation in 13.6%. During the follow-up period (mean: 709.7 days [SD: 467.2]), an 81.4% reduction of the ischemic stroke rate occurred, based on the expected rate from the CHA2DS2-VASc score (6.0% expected vs 1.1% observed). Device-related thrombus was detected in 1.8%. Conclusions: The majority of Canadian patients who underwent LAAC had oral anticoagulation contraindication due to prior bleeding, and most were safely treated with antiplatelet therapy post-LAAC, with a low device-related thrombus incidence. Long-term follow-up demonstrated that LAAC achieved a significant reduction in ischemic stroke rate.

Contexte: Au Canada, l'accès à la fermeture de l'appendice auriculaire gauche (FAAG) est limité en raison de restrictions quant au financement de cette intervention. Le présent rapport visait à évaluer les pratiques cliniques canadiennes sur la sélection des patients, le traitement antithrombotique après l'intervention et l'innocuité ou l'efficacité par l'implantation d'un dispositif WATCHMAN. Méthodologie: Sept centres canadiens procédant à l'implantation du dispositif WATCHMAN ont participé à ce registre observationnel, prospectif et multicentrique. Toutes les interventions ont été réalisées sous anesthésie générale avec guidage par échocardiographie transœsophagienne. Les patients ont par la suite été suivis de manière prospective pendant deux ans. Le taux d'AVC à long terme a été comparé au taux attendu, selon le score CHA2DS2-VASc. Résultats: Ont été inclus à l'étude 272 patients ayant subi une FAAG avec implantation d'un dispositif WATCHMAN entre décembre 2013 et août 2019 (âge moyen : 75,4 ans [écart-type {É.-T.} : 8,75]; hommes : 63,2 %; score CHA2DS2-VASc : 4,35 [É.-T. : 1,64]; score HAS-BLED : 3,55 [É.-T. : 0,94]). La plupart des patients (90,4 %) avaient des antécédents de saignements (majeurs : 80,5 %; mineurs : 21,7 %). Le dispositif WATCHMAN a bien été implanté chez 269 patients (98,9 %), avec quelques complications associées à l'intervention, dont cinq effusions péricardiques nécessitant un drainage (1,8 %) et un décès (0,4 %; 22 jours après la FAAG, en raison d'une insuffisance respiratoire). Le traitement antithrombotique après la FAAG comprenait une bithérapie antiplaquettaire dans 70,6 % des cas, une monothérapie antiplaquettaire dans 18,4 % des cas et une anticoagulothérapie orale dans 13,6 % des cas. Pendant la période de suivi (durée moyenne : 709,7 jours [É.-T. : 467,2]), on a noté une réduction de 81,4 % du taux d'AVC ischémique observé par rapport au taux attendu selon le score CHA2DS2-VASc (taux attendu : 6,0 %; taux observé : 1,1 %). Un thrombus associé au dispositif a été détecté dans 1,8 % des cas. Conclusions: La majorité des patients canadiens qui ont subi une FAAG présentaient des contre-indications à l'anticoagulothérapie orale en raison de leurs antécédents de saignements, et la plupart ont été traités de manière sécuritaire par des thérapies antiplaquettaires après la chirurgie, avec un faible taux d'incidence de thrombus associé au dispositif. Le suivi à long terme a montré que la FAAG permet d'obtenir une réduction importante du taux d'AVC ischémique.