Felix Ayala-Paredes

Strategy of continued vs interrupted novel oral anticoagulant at time of device surgery in patients with moderate to high risk of arterial thromboembolic events: The BRUISE CONTROL-2 trial

BACKGROUND Patients who require perioperative anticoagulation during cardiac implantable electronic device surgery are at increased risk for bleeding complications. The BRUISE CONTROL trial demonstrated that continuing warfarin was safer than heparin bridging, reducing the incidence of clinically significant pocket hematoma. Novel oral anticoagulants are being increasingly prescribed in place of warfarin. The best perioperative management of these new anticoagulants is unknown. METHODS/DESIGN A randomized controlled trial to investigate whether a strategy of continued vs interrupted novel oral anticoagulant (dabigatran, rivaroxaban, or apixaban) at the time of device surgery, in patients with moderate to high risk of arterial thromboembolic events, reduces the incidence of clinically significant hematoma (defined as a hematoma requiring reoperation and/or resulting in prolongation of hospitalization, and/or requiring interruption of anticoagulation). The secondary outcomes include components of the primary outcome, composite of all other major perioperative bleeding events, thromboembolic events, all-cause mortality, cost-effectiveness, patient quality of life, perioperative pain, and satisfaction. Planned analyses include descriptive statistics of all baseline variables. For the primary outcome, interrupted vs continued novel oral anticoagulant arms will be compared using the χ(2) test. If any clinically significant differences are identified, a logistic regression analysis will be conducted. Quality of life will be assessed using EuroQol-5D, and perioperative pain using a visual analog scale. DISCUSSION BRUISE CONTROL-2 is a randomized trial evaluating the best strategy to manage novel oral anticoagulants at the time of device surgery. We hypothesize that device surgery can be performed safely without interruption of these medications.

Benefit of dual-chamber pacing with Closed Loop Stimulation in tilt-induced cardio-inhibitory reflex syncope (BIOSync trial): study protocol for a randomized controlled trial

BackgroundThe efficacy of dual-chamber cardiac pacing in neuro-mediated reflex syncope with a cardio-inhibitory response to the Tilt-Table test (TT) has not been definitively assessed so far. The lack of reproducibility of results from previous studies may be partially explained by discrepancies in subject selection and some weaknesses in design and methods. The European Society of Cardiology (ESC) has set a class IIb indication to pacemaker implantation in this population recommending further research.Methods/designThe BIOSync study is a multicenter, patient- and outcome-assessor-blind, randomized, parallel-arm, placebo-controlled trial with the objective of assessing the clinical benefit of cardiac pacing in patients with frequently recurrent reflex syncope, suspected (but not proven) to be triggered by asystolic pauses as showing a VASIS 2B response to the TT (>3-s pause regardless of blood pressure drop). The primary and secondary endpoints are time to first post-implantation recurrence of syncope or the combination of pre-syncope or syncope, respectively. One hundred and twenty-eight consenting patients will be 1:1 randomized to dual-chamber cardiac pacing ‘on’ or ‘off’ after pacemaker implantation, and followed up until the first adjudicated primary endpoint event for a maximum of 2 years. The so-called Closed Loop Stimulation function on top of dual-chamber pacing is the pacing mode selected in the study active arm. Participating patients are asked to self-report syncopal symptoms at least every 3 months with self-administered questionnaires addressed to an independent Adjudication Committee. Patients and members of the Adjudicating Committee are blinded to randomization. The study is designed to detect a 40% relative reduction in the 2-year incidence of syncopal recurrences with 80% statistical power.DiscussionThe BIOSync study is designed to definitively assess the benefit of pacing against placebo in reflex syncope patients with a cardio-inhibitory response to the TT. The study will also provide important information on the efficiency of the TT in appropriately selecting reflex syncope patients for cardiac pacing.Trial registrationClinicalTrials.gov, identifier: NCT02324920 (27 October 2016, date last accessed).

Intracardiac echo-facilitated 3D electroanatomical mapping of ventricular arrhythmias from the papillary muscles: assessing the 'fourth dimension' during ablation.

Aims Ventricular arrhythmias (VA) originating from a papillary muscle (PM) have recently been described as a distinct clinical entity with peculiar features that make its treatment with catheter ablation challenging. Here, we report our experience using an intracardiac echo-facilitated 3D electroanatomical mapping approach in a case series of patients undergoing ablation for PM VA. Methods and results Sixteen patients who underwent catheter ablation for ventricular tachycardia (VT) or symptomatic premature ventricular contractions originating from left ventricular PMs were included in the study. A total of 24 procedures (mean 1.5 per patient) were performed: 15 using a retrograde aortic approach and 9 using a transseptal approach. Integrated intracardiac ultrasound for 3D electroanatomical mapping was used in 15 of the 24 procedures. The posteromedial PM was the most frequent culprit for the clinical arrhythmia, and the body was the part of the PM most likely to be the successful site for ablation. The site of ablation was identified based on the best pace map matching the clinical arrhythmia and the site of earliest the activation. At a mean follow-up of 10.5 ± 7 months, only two patients had recurrent arrhythmias following a repeat ablation procedure. Conclusion An echo-facilitated 3D electroanatomical mapping allows for real-time creation of precise geometries of cardiac chambers and endocavitary structures. This is useful during procedures such as catheter ablation of VAs originating from PMs, which require detailed representation of anatomical landmarks. Routine adoption of this technique should be considered to improve outcomes of PM VA ablation.

Arrhythmic Risk Following Recovery of Left Ventricular Ejection Fraction in Patients with Primary Prevention ICD.

Left ventricular ejection fraction (LVEF) recovers during follow‐up in a significant proportion of patients implanted with a cardioverter defibrillator (ICD) for primary prevention. Little is known about the midterm arrhythmic risk in this population, particularly in relation to the presence or absence of ischemic cardiomyopathy.

Canadian Registry of Implantable Electronic Device Outcomes: Surveillance of the Riata Lead Under Advisory.

Background—The Riata lead under advisory has posed a unique clinical scenario where inside-out abrasion results in externalization of conductor cables, with a higher risk of electrical failure. We developed a comprehensive registry to assist with clinical management of this lead. Methods and Results—This Canadian registry reports the findings of 3763 (74.2% of all Riata leads in Canada) Riata leads under advisory, with a mean follow-up time of 8.9±1.5 years. The overall electrical failure rate was 5.2% at 8 years, with no difference between 7-French and 8-French lead models. Cable externalization was found to be more common in the 8-French model (12.3% versus 5.2%, P<0.0001) and was associated with a higher risk of electrical failure. Predictors of electrical lead failure included cable externalization, higher left ventricular ejection fraction, younger age, higher body mass index, and a passive fixation lead. One patient died due to electrical failure, a further 2 patients survived an event where the device failed to deliver high-voltage therapy. Major complications because of lead extraction were higher when compared with lead abandonment, no difference among lead model observed. Two deaths occurred as a consequence of lead extraction, in the context of an underlying infection. Conclusions—The Riata lead under advisory has a steady electrical failure rate over time. There are identifiable predictors of lead failure that can assist with clinical decisions as to whether lead revision should be performed prophylactically.

Real-life experience with a new anticoagulation regimen for patients undergoing left-sided ablation procedures

Background Current guidelines for anticoagulation during left-sided procedures recommend the administration of unfractionated heparin (UFH) with an initial bolus of 50–100 U/kg, followed by continuous infusion to maintain an activated clotting time (ACT) ≥ 300 s. Our objective was to compare the effectiveness of this standard regimen (100 U/kg bolus) to a more aggressive approach (200 U/kg bolus). Methods We collected data on a series of consecutive patients undergoing left sided ablation procedures. Patients with an INR ≥2.0 on the day of the procedure were excluded. Procedural anticoagulation was performed using one of two UFH regimens: 1) 100 U/kg bolus, followed by 10 U/kg/hour infusion or 2) 200 U/kg bolus, followed by 20 U/kg/hour infusion. ACT was measured 10 min after the second bolus and then controlled every 20 min. Heparin was titrated throughout the procedure to maintain an ACT 300–400 s. Results 145 consecutive patients were included in the study: 34 received an initial bolus of 100 U/kg and 111 received 200 U/kg. The mean time required to reach an ACT ≥300 s was 15.25 min (95% CI 12.97–17.03) in the 200 U/kg group and 51.23 min (95% CI 40.65–61.81) in the 100 U/kg group (p < 0.001). There was no difference between groups with regard to thromboembolic or hemorrhagic complications. Conclusion Current anticoagulation guidelines for left-sided ablation procedures almost universally fail to achieve an initial ACT ≥300 s. A 200 U/kg heparin bolus is much more effective to promptly reach the target ACT, with a low rate of overshoot.

Continued vs. interrupted direct oral anticoagulants at the time of device surgery, in patients with moderate to high risk of arterial thrombo-embolic events (BRUISE CONTROL-2)

Aims Guidelines recommend warfarin continuation rather than heparin bridging for pacemaker and defibrillator surgery, after the BRUISE CONTROL trial demonstrated an 80% reduction in device pocket haematoma with this approach. However, direct oral anticoagulants (DOACs) are now used to treat the majority of patients with atrial fibrillation. We sought to understand the best strategy to manage the DOACs at the time of device surgery and specifically hypothesized that performing device surgery without DOAC interruption would result in a reduced haematoma rate. Methods and results We randomly assigned patients with atrial fibrillation and CHA2DS2-VASc score ≥2, to continued vs. interrupted DOAC (dabigatran, rivaroxaban, or apixaban). The primary outcome was blindly evaluated, clinically significant device pocket haematoma: resulting in re-operation, interruption of anticoagulation, or prolonging hospital stay. In the continued arm, the median time between pre- and post-operative DOAC doses was 12 h; in the interrupted arm the median time was 72 h. Clinically significant haematoma occurred in of 7 of 328 (2.1%; 95% CI 0.9-4.3) patients in the continued DOAC arm and 7 of 334 (2.1%; 95% CI 0.9-4.3) patients in the interrupted DOAC arm (P = 0.97). Complications were uncommon, and included one stroke and one symptomatic pericardial effusion in each arm. Conclusions These results suggest that, dependent on the clinical scenario, either management strategy (continued DOAC or interrupted DOAC) might be reasonable, at least for patients similar to those enrolled in our trial.

Canadian Registry of Implantable Electronic Device Outcomes: Longer Term Follow up of the Riata Lead Under Advisory

BACKGROUND The Riata lead advisory was announced in 2011 and has posed unique management challenges because of cable externalization and insulation abrasion, in some cases leading to sudden loss of defibrillation. OBJECTIVE The purpose of this study was to provide further data on the rate of electrical failure in a population of patients with a Riata lead under advisory. METHODS Using the Canadian Registry of Electronic Device Outcomes, prospective follow-up data were collected on 1352 Riata leads under advisory in 17 implantable cardioverter-defibrillator (ICD) implantation centers in Canada. Data on electrical and structural failure were collected, as well as periprocedural complications related to lead revision (abandonment or extraction). RESULTS Of the 1352 leads included in this 12-month follow-up cohort, 110 leads were revised. Mean follow-up time was 10.4 ± 1.5 years. The 12-year rate of electrical failure for the 8Fr lead was 9.45%, whereas the 10-year failure rate for the 7Fr lead was 7.25% and was not found to be accelerating. Of the leads revised because of advisory only (patient preference, advisory related, electrical or structural failure), the majority were abandoned (n = 54 [76.0%]), whereas 17 (24.0%) were extracted using power tools. The rate of major complications in each group was 5.6% and 5.9%, respectively. CONCLUSION This report provides further data on the risk of electrical lead failure over a long lead dwell time. The risk of failure exceeds the risk of periprocedural major complications, indicating that the risk-to-benefit ratio is favorable to revise the lead in appropriate clinical scenarios.

Multidetector cardiac tomography: A useful tool before cardiac resynchronization therapy

BACKGROUND Left ventricular lead placement in a suitable coronary vein is a key determi-nant of responsiveness to cardiac resynchronization therapy (CRT). Multidetector cardiac tomography (MDCT) is a non-invasive alternative to depict cardiac venous anatomy although coronary sinus (CS) retrograde venography (RV) is the gold standard. The aim of this study was to evaluate the accuracy of MDCT to determine the presence of CS tributaries before CRT. METHODS A retrospective analysis of 41 consecutive patients eligible to CRT was performed. MDCT was assessed in all patients before CRT and RV was achieved in 39 patients. Both methods evaluated the presence of the inferior interventricular vein (IIV), posterior vein (PV) and lateral main vein (LMV). CS ostium diameter and distance between the CS ostium and right atrium (RA) lateral wall were also measured. RESULTS The IIV was identified in 100% of MDCT and in 43.6% of RV. In comparison to RV, the MDCTs sensitivity to identify PV and LMV was 100% for both, kappa coefficient of 0.792 (CI 95% 0.46-0.93) and 0.69 (CI 95% 0.46-0.91), respectively. There was no significant difference between ischemic and non-ischemic patients regarding the presence of PV or LMV. Median CS antero-posterior diameter was 10.3 mm (IQR 7.5-13) and supero-inferior was 14.1 mm (IQR 11.5-17) (p < 0.01). A positive correlation (p < 0.001) between echocardiographic RA area and the distance from CS ostium to the RA lateral wall in the MDCT was observed. CONCLUSIONS MDCT is as accurate as RV to depict CS and its tributaries (IIV, PV, LMV), and it could be useful as a non-invasive technique before CRT.

AVNRT Ablation: Significance of Anatomic Findings and Nodal Physiology

The AV node is a fascinating region, with particular and complex anatomy and physiology. It well illustrates the evolution of the rhythm disorders and their treatments; it was the first target when invasive electrophysiology started; from His recordings to DC ablation and from selective radiofrequency “slow pathway” modification to cryoablation, we have followed a long road of learning while burning; as our knowledge broadens, we can now very precisely target this region to invasive treatments. This chapter reviews the literature and discusses an approach regarding anatomic findings and physiology and its relationship to AVNRT ablation.