Periprocedural Anticoagulation Research Articles

Direct Thrombin Inhibitors as an Alternative to Heparin During CatheterAblation: A Multicenter Experience.

The goal of this study was to report a multicenter series of left-sided catheter ablations performed by using intravenous direct thrombin inhibitors (DTIs) as an alternative to heparin. Amidst a looming worldwide shortage of heparin, there are insufficient data to guide nonheparin-based peri-procedural anticoagulation in patients undergoing catheter ablation. This study reviewed all catheter ablations at 6 institutions between 2006 and 2019 to assess the safety and efficacy of DTIs for left-sided radiofrequency catheter ablation of atrial fibrillation and ventricular tachycardia. In total, 53 patients (age 63.0 ± 9.3 years, 68% male, CHA₂DS₂-VASc [congestive heart failure, hypertension, age≥75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score 2.8 ± 1.6, left ventricular ejection fraction 46 ± 15%) underwent ablation with DTIs (75% bivalirudin, 25% argatroban) due to heparin contraindication(s) (72% heparin-induced thrombocytopenia, 21% heparin allergy, 4% protamine reaction, and 4% religious reasons). The patient's usual oral anticoagulant was continued without interruption in 69%. Procedures were performed for atrial fibrillation (64%) or ventricular tachycardia/premature ventricular contractions (36%). Transseptal puncture was undertaken in 81%, and a contact force-sensing catheter was used in 70%. Vascular ultrasound was used in 71%, and femoral arterial access was gained in 36%. A bolus followed by infusion was used in all but 4 cases, and activated clotting time was monitored peri-procedurally in 72%, with 32% receiving additional boluses. Procedure duration was 216 ± 116min, and ablation time was 51 ± 22min. No major bleeding or embolic complications were observed. Four patients had minor self-limiting bleeding complications, including a small pericardial effusion (<1cm), a small groin hematoma, and hematuria. In this multicenter series, intravenous DTIs were safely used as an alternative to heparin for left-sided catheter ablation.

Uninterrupted anticoagulation during catheter ablation for atrial fibrillation: no difference in major bleeding and stroke between direct oral anticoagulants and vitamin K antagonists in an updated meta-analysis of randomised controlled trials

Background Periprocedural uninterrupted anticoagulation for catheter ablation of atrial fibrillation (AF) became standard after positive results of vitamin K antagonist (VKA) trials. Previous studies of uninterrupted direct oral anticoagulants (DOACs) vs. VKA have given controversial results. We thus aimed to elucidate the risk/benefit ratio of uninterrupted DOAC vs. VKA during catheter ablation of AF in an updated meta-analysis of randomised controlled trials (RCTs). Methods Online databases were searched for RCTs comparing uninterrupted DOAC to VKA in patients undergoing catheter ablation of AF. Data from retrieved studies were analysed in a comprehensive meta-analysis. Primary safety outcome was major bleeding; primary efficacy outcome was stroke or transient ischaemic attack (TIA). Secondary outcomes included a composite of major bleeding and stroke or TIA, minor bleeding, acute cerebral lesions on magnetic resonance imaging (MRI), and mortality. Results Six eligible RCTs comprising 2,369 patients were included. There were no significant differences in DOAC vs. VKA concerning the rates of major bleeding (2.2% vs. 3.8%; odds ratio (OR) 0.69, 95% confidence interval (CI) 0.30–1.56; p = .37) and stroke or TIA (0.2% vs. 0.2%; OR 0.97, CI 0.20–4.72; p = .97). Pooled meta-analysis of secondary outcomes revealed no significant differences (OR 0.73, p = .49 for composite of major bleeding and stroke or TIA; OR 1.08, p = .52 for minor bleeding; OR 1.12, p = .59 for acute cerebral lesions on MRI; and OR 0.60, p = .64 for all-cause mortality). Conclusion Our meta-analysis suggests that uninterrupted DOAC is not superior to VKA in patients undergoing catheter ablation of AF with comparable rates of major bleeding and stroke.

Intracardiac Fibrinolysis and Endothelium Activation Related to Atrial Fibrillation Ablation with Different Techniques.

Objective The effect of pulmonary vein isolation (PVI) on fibrinolytic and endothelial activation with currently applied periprocedural anticoagulation has not been explored. We measured markers of fibrinolysis and endothelium activation before and after PVI with the second-generation cryoballoon (Cryo), pulmonary vein ablation catheter (PVAC-Gold), and irrigated radiofrequency (IRF). Methods Markers of fibrinolysis and endothelium activation in left atrial (LA) blood samples were measured in 31 patients before and after PVI (Cryo:10, PVAC-Gold: 7, IRF: 14). Periprocedural anticoagulation included uninterrupted vitamin K antagonist and iv heparin (ACT≥300 sec) during LA dwelling. Results Levels of D-dimer (median; interquartile range, mgFEU/L) increased with all techniques (PVAC: 0.34; 0.24–0.50 versus 0.70; 0.61–1.31; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; PAP complex level (ng/ml) increased after Cryo (247.3, 199.9–331.6 versus 270.9, 227.9–346.7; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; PAI-1 activity (%) decreased with the PVAC (1.931; 0.508–3.859 versus 0.735, 0.240–2.707; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; VWF antigen levels and FVIII activity increased after PVI with all the 3 techniques. The levels of soluble VCAM-1 (ng/ml) did not change after PVAC procedures, but increased after Cryo (542, 6; 428.5–753.1 versus 619.2; 499.8–799.0; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; Conclusion PVI with contemporary ablation techniques and periprocedural antithrombotic treatment induces coagulation and endothelium activation of similar magnitude with different ablation methods.

Thromboembolic and bleeding risk of periprocedural bridging anticoagulation: A systematic review and meta-analysis.

The risk and benefit of periprocedural heparin bridging is not completely clarified. We aimed to assess the safety and efficacy of bridging anticoagulation prior to invasive procedures or surgery. Heparin bridging was associated with lower risks of thromboembolism and bleeding compared to non‐bridging. PubMed, Ovid and Elsevier, and Cochrane Library (2000‐2016) were searched for English‐language studies. Studies comparing interrupted anticoagulation with or without bridging and continuous oral anticoagulation in patients at moderate‐to‐high thromboembolic risk before invasive procedures were included. Primary outcomes were thromboembolic events and bleeding events. Mantel‐Haenszel method and random‐effects models were used to analyze the pooled risk ratio (RR) and 95% confidence interval (CI) for thromboembolic and bleeding risks. Eighteen studies (six randomized controlled trials and 12 cohort studies) were included (N = 23 364). There was no difference in thromboembolic risk between bridged and non‐bridged patients (RR: 1.26, 95% CI: 0.61‐2.58; RCTs: RR: 0.71, 95% CI: 0.23‐2.24; cohorts: RR: 1.45, 95% CI: 0.63‐3.37). However, bridging anticoagulation was associated with higher risk of overall bleeding (RR: 2.83, 95% CI: 2.00‐4.01; RCTs: RR: 2.24, 95% CI: 0.99‐5.09; cohorts: RR: 3.09, 95% CI: 2.07‐4.62) and major bleeding (RR: 3.00, 95% CI: 1.78‐5.06; RCTs: RR: 2.48, 95% CI: 1.29‐4.76; cohorts: RR: 3.22, 95% CI: 1.65‐6.32). Bridging anticoagulation was associated with increased bleeding risk compared to non‐bridging. Thromboembolism risk was similar between two strategies. Our results do not support routine use of bridging during anticoagulation interruption.

Act Guided Heparin Administration in Elective Open Abdominal Aortic Aneurysm Repair: Results of A Pilot Study

Introduction: Almost all vascular surgeons use a bolus of 5 000 IU of unfractionated heparin (UFH). However, its dose-response and elimination curves are non-linear, and display a high inter-patient variability. The activated clotting time (ACT) is an established method to measure the level of anticoagulation. The purpose of this study was to evaluate the rate of arterial thrombo-embolic complications (ATEC) and bleeding complications in patients undergoing elective open abdominal aortic aneurysm repair (AAA), in which a bolus of 5 000 IU of UFH was compared to an ACT guided additional UFH dose protocol. Methods: All consecutive patients that underwent primary elective open AAA repair were included from a multicentre (1 academic and 2 peripheral hospitals) prospective study on ACT guided heparinization (MANCO: Measuring the ACT during non-cardiac arterial procedures, Clin. Trials.gov NCT 03426293). ACT measurements were performed as a bedside point-of-care test. During the first part of the study patients received a bolus of 5 000 IU. During the second part of the study patients received an initial bolus of 5 000 IU or 100 IU/kg and additional UFH dosages were administered, with a target ACT of 200 - 250 sec. The primary study endpoints were ATEC (graft thrombosis, embolism, myocardial infarction, transient ischemic attack, minor and major stroke, pulmonary embolism, bowel ischemia) detected during the procedure or during 30 day follow-up or during the same admission of the primary procedure, bleeding complications and mortality during 30 day follow-up. The secondary study endpoints were all other complications, the level of periprocedural anticoagulation as measured by the ACT and the additional and total UFH dosages administered. Results: 46 primary elective open AAA procedures were included, 18 patients in the standard dose group and 28 patients in the additional dose group. In the standard dose group 28% of patients reached an ACT of 200 sec. compared to 100% in the additional dose group. In the additional dose group the mean total periprocedural UFH dose administered was 9874 ± 2909 IU. ATEC occurred in 27.8% of patients in the standard dose group versus 14.3% in the additional dose group (P= 0.26). Bleeding complications did not increase in the additional dose group (38.9 versus 35.7%, P= 0.83). In both groups no patient died during 30 day follow-up. Conclusion: A standard dose of 5000 IU UFH leads to inadequate levels of heparinisation. Higher dosing of UFH aimed at an ACT of 200 sec. is safe, does not lead to increased bleeding, and potentially leads to a reduction in ATEC. A randomized controlled trial is needed to provide evidence on potential reduction in thrombo-embolic complications. Disclosure: Grant of Medtronic to perform the ACT measurements.

P4750Uninterrupted and minimally-interrupted direct oral anticoagulant therapy in patients undergoing catheter ablation for atrial fibrillation. An updated meta-analysis

Abstract Background Adequate anticoagulation in catheter ablation of atrial fibrillation (AF) is crucial in preventing both thromboembolic events and life-threatening bleeding. As clinicians gain more experience and reassurance with data from clinical trials, the usage of Direct Oral Anticoagulants (DOAC) in patients undergoing catheter ablation of AF has rapidly increased over the last years. The purpose of this updated meta-analysis was to assess the latest evidence and compare the safety and efficacy of uninterrupted and minimally interrupted periprocedural DOAC anticoagulation protocols with uninterrupted Vitamin K Antagonists (VKA) in this setting. Methods Randomized or prospective controlled observational studies comparing DOACs to VKAs were identified with multiple databases (Embase, PubMed, Cochrane, and Scopus). Uninterrupted and minimally interrupted DOAC (single dose of dabigatran or apixaban withheld) were distinguished, VKA therapy was always uninterrupted. The primary outcomes were stroke or transient ischemic attack (TIA), major bleeding, and net clinical benefit. Results 32 studies were included in the final analysis, encompassing a total of 19.437 patients. The incidence of thromboembolic events was rare (less than 0.2%), with no significant difference between groups. Occurrence of major bleeding and net clinical benefit were significantly improved in patients assigned to uninterrupted DOAC treatment compared to VKAs (1.5% vs 2.2%, POR: 0.74, CI: 0.56–0.98, I2=0,0% and 1.7% vs 2.4%, POR: 0.76; CI: 0.59–0.99, I2=0,0%, respectively). Net clinical benefit Conclusion This updated meta-analysis, based on a large database, showed that DOAC therapy is equally effective as VKA in preventing stroke and TIA. Minimally-interrupted DOAC therapy is a non-inferior peri-procedural anticoagulation strategy, however, uninterrupted DOAC therapy showed superiority when compared to VKA regarding major, life-threatening bleeding. Our findings showed that uninterrupted periprocedural DOAC therapy is a safe and preferable alternative to VKAs in patients undergoing catheter ablation for atrial fibrillation. Acknowledgement/Funding This study was supported by an Economic Development and Innovation Operative Programme Grant (GINOP 2.3.2-15-2016-00048).

RADIO-FREQUENCY ABLATION: LET'S ADD IT TO THE CAUSES OF DIFFUSE ALVEOLAR HEMORRHAGE

SESSION TITLE: Monday Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Transcatheter ablation of pulmonary veins (PVI) is the mainstay of treatment for refractory atrial fibrillation (AF) [1]. Complications of ablative strategies include access site infection and bleeding, thromboembolism, pericarditis and tamponade. Pulmonary hemorrhage is a rare but life threatening complication of radiofrequency catheter ablation (RFA) with unknown incidence in literature [2]. Herein, we present a case of diffuse alveolar hemorrhage (DAH) post-RFA bringing forth the challenges associated with peri-procedural anti-coagulation among such patients. CASE PRESENTATION: A 69-year-old male was elected for PV isolation (PVI) by RFA due to symptomatic heart failure secondary to worsening burden of AF. The patient was receiving prior anticoagulation with Warfarin and had therapeutic international normalized ratio (INR) at the time of procedure. Per protocol, peri-procedural heparin was administered to maintain optimal anti-coagulation. Immediately post-procedure, bloody secretions were noted in the endotracheal tube warranting an emergent bronchoscopy. The latter showed bright red blood with clots throughout the tracheobronchial tree, most notably in the right lung. No signs of tracheal or bronchial tree injury were present. Subsequent computed tomography (CT) imaging showed extensive consolidation in bilateral lungs with normal pulmonary vasculature. Two subsequent bronchoscopies revealed active bleeding from right upper and lower lobes with serial aliquots suggestive of DAH. After instillation of thrombin to aid hemostasis, the patient was weaned off the ventilator and successfully extubated after 4 days. DISCUSSION: Hemoptysis and pulmonary hemorrhage are rare complications of PVI, typically occurring weeks to months post procedure as a result of PV stenosis. While PV stenosis has a mean incidence of 2% post PVI, up to 1 in 23 patients with PV stenosis post-ablation experience hemoptysis [2]. Acute hemoptysis (<2 weeks post-procedure) has been reported post cryoablation due to direct pulmonary vascular injury, high energy transfer causing bronchial erosion, or cryoinjury to the lung parenchyma. Interestingly, pulmonary hemorrhage after RFA is extremely rare, with only one case reported in literature so far. The overall success rate, procedural time and long-term complications between RFA & cryoablation are similar [3]. However, this raises the question of why hemoptysis and pulmonary hemorrhage are more frequently reported in one technique over the other. CONCLUSIONS: In current practice, regardless of pre-procedural anticoagulation treatment, all patients receive full anticoagulation with intravenous heparin during catheter ablation. This case serves as a reminder of a rare yet potentially lethal complication of RFA and raises the question of revisiting peri-procedural anticoagulation guidelines given the increasing demand of catheter ablation to treat AF. Reference #1: S.M. Hosseini, G. Rozen, A. Saleh, et al. Catheter ablation for cardiac arrhythmias: utilization and in-hospital complications 2000 to 2013. J Am Coll Cardiol EP, 3 (2017), pp. 1240-1248 Reference #2: B.C. Housley et al. Acute Pulmonary Hemorrhage Following Radiofrequency Ablation of Atrial Fibrillation. Journal of Cardiothoracic and Vascular Anesthesia 31 (2017) 1397-1400. Reference #3: Ali H. Hachem, Joseph E. Marine, Housam A. Tahboub, et al., “Radiofrequency Ablation versus Cryoablation in the Treatment of Paroxysmal Atrial Fibrillation: A Meta-Analysis,” Cardiology Research and Practice, vol. 2018 DISCLOSURES: No relevant relationships by Omer Bajwa, source=Web Response No relevant relationships by Garima Dahiya, source=Web Response No relevant relationships by Briana DiSilvio, source=Web Response No relevant relationships by Sheldon Rao, source=Web Response

P1902Comparison of efficacy of different anticoagulation strategies used during pulmonary vein isolation in left atrial blood samples

Abstract Introduction Ablation of atrial fibrillation is based on the isolation of the pulmonary veins (PVI) from the left atrium. Cerebral thromboembolism is a rare but serious complication of PVI, which highlights the importance of peri-procedural anticoagulation. Aim Studying the coagulation and endothelium activation during PVI in case of using different anticoagulation protocols. Method 52 patients undergoing PVI with cryoballoon technique were involved and were grouped according to three different pre-procedural anticoagulation strategies: in the first group patients received no anticoagulation before the procedure (non anticoag., 24 patients)-, in the second group patients received uninterrupted vitamin K antagonist therapy, and their INR value was in therapeutic range on the day of the procedure (VKA group, 11 patients) and in the third group patients were on uninterrupted dabigatran therapy (dabigatran group, 17 patients). Two blood samples were taken during PVI from the left atrium, the first one before ablation or iv. heparin administration, the second one directly after the last application at the end of the procedure. The samples were used to measure D-dimer, plasmin antiplasmin (PAP) complex, a2 plasmin inhibitor (a2PI), plasminogen, FVIII activity, von Willebrand factor (VWF) antigen levels. Results D-dimer levels increased in all three groups after ablation, but in the samples of patients on dabigatran therapy we detected significantly lower D-dimer levels in the pre- and post-procedural samples compared to patients on other therapeutic strategies (median values before or after PVI: non anticoag.: 0.48 and 1.09 mgFEU/L; VKA: 0.33 and 0.72 mgFEU/L, dabigatran: 0.12 and 0.30 mgFEU/L, p&lt;0.001 non anticoag. vs. dabigatran, p&lt;0.01 VKA vs. dabigatran). PAP complex values were increasing parallel with D-dimer levels and only in the dabigatran group did not increase significantly. VWF antigen and FVIII activity increased significantly in all three groups after ablation, but there was no significant difference between the groups. Conclusions the safest anticoagulation strategy for patients undergoing PVI was uninterrupted dabigatran therapy. The extend of endothelial damage was not affected by anticoagulation.

P1901Use of direct thrombin inhibitor on the day of atrial fibrillation ablation decreases incidence of silent cerebral ischemia detected by magnetic resonance imaging

Abstract Background There is increasing evidence to use direct oral anticoagulants (DOACs) in atrial fibrillation (AF) ablation. Uninterrupted use of DOACs is recommended for peri-procedural anticoagulation; the ways of choosing and/or using DOACs depend on physicians' decisions and preferences. Uninterrupted dabigatran (DAB), a direct thrombin inhibitor, reportedly decreased the risk of major bleeding (MB) in AF ablation, compared to uninterrupted warfarin (NEJM 2017; 376:1627). Among DOACs, only regular-dose of DAB (150 mg b.i.d.), showed superiority to warfarin for preventing ischemic thromboembolism (TE) in patients with non-valvular AF, implicating the powerful anti-thrombotic agent. DAB may decrease the potential risk of procedure-related TE. Purpose To evaluate whether use of DAB on the day of AF ablation decreases the prevalence of silent cerebral ischemia (SCI) detected by magnetic resonance imaging (MRI). Methods 414 AF patients on DOACs were enrolled and admitted on the day before AF ablation. Among 354 patients on factor Xa inhibitors (rivaroxaban, apixaban, and edoxaban), the original DOACs were switched to DAB (150 mg b.i.d.) on the day of the procedure in 172 patients (Group D); the treatment remained unchanged in 182 patients (Group non-D). In both groups, DOACs were continuously used throughout the procedure. After propensity-score matching, procedure-related parameters/events and the incidence of MRI-detected SCI were compared between Group D (n=134) and Group non-D (n=134). These parameters in patients originally taking DAB, used without interruption during the procedure (uninterrupted DAB, n=55), were also compared to Group D (n=55) after propensity-score matching. Results Baseline activated clotting time (ACT) before initial heparin injection was increased in Group D vs. Group-non-D (179±25* vs. 146±23 sec, *p&lt;0.05 vs. Group non-D). The time to achieve optimal ACT (&gt;300 sec) was shorter in Group D (34±29* vs. 43±32 min). The amounts of heparin needed to achieve optimal ACT and the total amount of heparin used during the procedure were unchanged between Group D and Group non-D. The incidence of SCI decreased in Group D (13.1%* vs. 21.9%), suggesting the potential anti-thrombotic efficacy of DAB. No MB or symptomatic TE events were observed in either group. Baseline ACT, the time to achieve ACT &gt;300 sec, and the incidence of SCI in Group D were comparable to those in uninterrupted DAB (183±38 vs. 181±32 sec, 39±31 vs. 42±28 min, and 14.5% vs. 16.4%, respectively). No MB or symptomatic TE events were observed either in Group D or uninterrupted DAB. Conclusions Temporarily switching to DAB from the other DOACs and using it on the day of procedure enable us to achieve optimal ACT quickly and decrease the incidence of SCI, showing similar potential anti-thrombotic efficacy to uninterrupted DAB. Use of DAB on the day of AF ablation also benefits from the availability of its antidote in the case of MB during the procedure.

The role of a specialist bridging service. A New Zealand prospective study of 600 patients

BackgroundA proposition for the Wellington hospital thrombosis service to manage periprocedure anticoagulation bridging was made after a number of cancellations and key incidents were caused by lack of a consistent management approach. We provided individual bridging assessments, with implementation, communication, and education. The only funded anticoagulants in New Zealand at that time were dabigatran, warfarin, and enoxaparin. MethodsOn initiation of the bridging service, we prospectively collected data on 600 consecutive patients referred to the periprocedure bridging service between May 2015 and February 2017. We recorded the 30‐day major bleeding events, thrombotic events, and related mortality. We followed the patients up for 30 days postprocedure. As part of this process, we ensured optimal transition back to their initial anticoagulant. ConclusionWe found low rates of major bleeding 1.9% and thrombosis 0.8% at day 30 comparable to randomized controlled trials. Of the 222 patients taking dabigatran experienced no major bleeding events. We believe using a specialist coagulation service is optimal to ensure surgery can proceed safely.

Periprocedural Anticoagulation Management For Nonoperating Room Anesthesia Procedures: A Clinical Guide.

Non-operating room anesthesia presents unique challenges for anesthesiologists. Limited preprocedural optimization and unfamiliarity with the location and procedure itself add to the difficulties in delivering safe care for these patients. Management of chronic oral anticoagulation can prove especially problematic since risks of bleeding for non-operating room procedures vary widely and differ from traditional surgeries. In addition, many physicians may not be familiar with the growing number of newly approved oral anticoagulants and their periprocedural management. This review will examine common non-operating procedures, their risks of bleeding, as well as pharmacokinetics of oral anticoagulants available on the market and periprocedural management options.

Feasibility and safety of uninterrupted apixaban in patients undergoing radiofrequency ablation for atrial fibrillation.

An optimal periprocedural anticoagulation strategy is essential for minimizing bleeding and thromboembolic complications during atrial fibrillation (AF) ablation. Limited data are available on the uninterrupted use of apixaban in patients with AF undergoing catheter ablation. This study aimed to evaluate the safety and efficacy of uninterrupted apixaban in patients undergoing radiofrequency ablation for AF. In particular, we evaluated silent cerebral infarction (CI) during radiofrequency catheter ablation of AF. This was a prospective and nonrandomized cohort study. A total of 259 consecutive patients who underwent AF ablation were evaluated; 157 patients received apixaban (Api group), and 102 patients received dose-adjusted (PT-INR 2.0-3.0) warfarin (Wf group). All oral anticoagulants were continued throughout the periprocedural period, including the morning of the procedure. Intravenous heparin was administered during the procedure and neutralized by protamine at the end of the procedure. Sixty-one patients underwent magnetic resonance imaging (MRI) after the procedure to evaluate for silent CI. Mean age was 66 ± 11years; there were 91 men (73.7%) and 148 cases of paroxysmal AF (57.1%). No symptomatic CI was observed. Silent CI occurred in 6/61 patients (9.8%). No significant difference was observed between the Api group (4/30 patients, 13.3%) and the Wf group (2/31 patients, 6.5%). There was no significant difference regarding major bleeding events between the Api group (1/157 patients, 0.6%) and the Wf group (2/102 patients, 2.0%). The safety and efficacy of uninterrupted apixaban for patients undergoing AF ablation were equivalent to warfarin for preventing bleeding and thromboembolic complications.

Current approaches to periprocedural anticoagulation treatment in patients undergoing atrial fibrillation ablation

Catheter ablation is a standard treatment for patient with symptomatic and drugrefractory atrial fibrillation. As for every invasive approach, ablation is associated with certain risk of complications. About 2-3% of adverse events are related to hemorrhage or thromboembolism. Therefore, periprocedural anticoagulation scheme is of paramount importance to minimize the risk of both types of complications. Here we describe the factors, associated with thromboembolic and bleeding risks, and the evolving approaches for periprocedural anticoagulation treatment. Special attention is paid to uninterrupted oral anticoagulation and potential role of reverse agent in management of procedure-related hemorrhages.

Update on catheter ablation research from The 2019 European Heart Rhythm Association Congress.

The 2019 European Heart Rhythm Association (EHRA) scientific meetings released several Late Breaking Clinical Trials that define important results for the fields of catheter ablation of atrial fibrillation (AF) and ventricular tachycardia (VT). Three independent multicenter randomized controlled trials have confirmed that AF ablation with point-by-point radiofrequency energy or cryoballoon technology are both equally and highly effective, and significantly superior to antiarrhythmic drug therapy in reducing recurrent AF episodes and preventing arrhythmia-related hospitalizations. Edoxaban has been shown a viable option for periprocedural oral anticoagulation in patients undergoing catheter ablation of AF in a large multicenter randomized study, with outcomes similar to uninterrupted warfarin. Important mechanistic studies have evaluated the electrophysiologic features of concealed substrate in reperfused myocardial infarction (MI) with small electrode mapping, and investigated the longitudinal evolution of the arrhythmogenic substrate following acute MI. Finally, encouraging results from multicenter observational studies support the emerging role of imaging integration with cardiac magnetic resonance or computed tomography to guide substrate ablation of VT. This article will provide an update on some of the most relevant studies in the field of catheter ablation of AF and VT presented at the latest EHRA conference.

245 Rezūm Prostate Ablation for Large Gland (≥80 grams) Prostates

Convective radiofrequency water vapor thermal therapy is a minimally invasive technique to treat benign prostatic hyperplasia (BPH). Previous reports have been limited to use in patients with prostate glands <80 grams. We present our initial outcomes utilizing the Rezūm system in patients with large glands (≥80 grams) in a tertiary care center. We retrospectively reviewed 150 patient charts that underwent Rezūm therapy by three BPH surgeons since July 2017. Of these, 34 patients were treated with large glands. Planned post-procedure catheterization regimen included a minimum of 3 days and a maximum of 1 month in men with preoperative catheter dependence. Large glands (≥80 g) utilized stacked treatments and often received the max 15 Rezūm treatments per device. Post-operative results were compared by t-test and chi-squared analysis. Outcomes are reported in the attached table. Briefly, the average prostate gland size was 109.9 grams. Twenty one patients were catheter dependent preoperatively. Of these, 16 (71.4%) patients no longer required catheterization at follow up. Significant improvements were seen in AUA symptom score (p=0.005) and peak flow (p=0.006), whereas post void residual trended towards improvement (p=0.066). Ten patients required additional catheterization time (average 27.5 days, Range 1-106). Post-operative complications were rare. Peri-procedural anticoagulation was associated with post-operative hematuria requiring cystostopic clot evacuation (p=0.039). In these patients with significant hematuria, bleeding was identified and controlled by cauterizing the mucosal edges of prominent median/intravesical lobes. No men reported new onset ED.

Differences in prothrombotic response between the uninterrupted and interrupted apixaban therapies in patients undergoing cryoballoon ablation for paroxysmal atrial fibrillation: a randomized controlled study.

Periprocedural bleeding and thromboembolic events are worrisome complications of catheter ablation for atrial fibrillation (AF). Periprocedural anticoagulation management could decrease the risk of these complications. However, evaluation of the complications from pulmonary vein isolation using cryoballoon related to different anticoagulation strategies is limited. Therefore, we aimed to compare prothrombotic responses as assessed on the basis of D-dimer levels between the uninterrupted and interrupted apixaban therapies during cryoballoon ablation. Ninety-seven consecutive patients with paroxysmal AF scheduled to undergo cryoballoon ablation were randomly assigned in a 1:2 ratio to uninterrupted apixaban therapy (Group 1, n = 32) or interrupted apixaban therapy (Group 2, n = 65). D-Dimer levels were measured immediately before the ablation, at the end of the ablation, and 24 and 48h after the procedure. No statistical difference was observed in the baseline characteristics between the two groups. The rates of hemorrhagic complications were similar in both groups (major bleeding: 3.1 vs. 1.5%; p = 0.61, and minor bleeding: 3.1 vs. 4.6%; p = 0.73, respectively). No thromboembolic events occurred in either group. However, D-dimer levels 48h after the ablation increased more markedly following the procedure in Group 2 than in Group 1 (from 0.58 ± 0.16 to 1.01 ± 0.42μg/mL vs. 0.58 ± 0.20 to 0.82 ± 0.25μg/mL; p = 0.01). In conclusion, uninterrupted apixaban therapy during the periprocedural period of cryoballoon ablation for AF did not increase the risk of bleeding in this study and might reduce the periprocedural risk of subclinical hypercoagulable state.

Saving the brain from catheter ablation of atrial fibrillation: the role of pre- and peri-procedural anticoagulation.

Abstract

Prevalence and Characteristics of Venous Thrombosis after Catheter Ablation of Atrial Fibrillation in Patients Receiving Periprocedural Direct Oral Anticoagulants.

Periprocedural venous thromboembolisms (VTEs) area rare occurrence but a critical complication after catheter ablation of atrial fibrillation (AF).The aim of this study was to investigate the incidence of symptomatic deep vein thromboses (DVTs) and pulmonary thromboembolisms (PTEs) in patients who underwent AF catheter ablation and received periprocedural oral anticoagulation with direct oral anticoagulants (DOACs). A total of 2,193 consecutive patients undergoing AF catheter ablation with periprocedural DOACs were retrospectively analyzed.Two patients (0.091%) experienced symptomatic DVTs after the ablation, and no patients had any PTEs. One patient was a 72-year-old female who underwent cryoballoon ablation with periprocedural apixaban at a dose of 2.5 mg twice daily. The other patient was a 74-year-old male who underwent a Hot Balloon ablation and thereafter radiofrequency catheter ablation for recurrent AF with edoxaban at30 mg once daily. Both DVT patients underwent AF ablation by the right femoral vein approach, and after discharge had right leg pain and swelling on post-procedural days 4 and 8, respectively. TheDVT was treated by increasing the dose of apixaban and changing it from 30 mg/day of edoxaban to 15-30 mg/day of rivaroxaban, and the thrombi completely disappeared in both patients without any thromboembolic and hemorrhagic complications. AF catheter ablation with periprocedural DOAC treatment revealed anextremely low incidence of symptomatic VTEs, which may be successfully treated by increasing the DOAC dose or changing the DOAC type.

Periprocedural Interruption of Anticoagulation in Patients with Cancer-Associated VTE: An Analysis of Thrombotic and Bleeding Outcomes

Background: Approximately 10-20% of patients with venous thromboembolic events (VTE) have underlying malignancy. VTE is considered the second leading cause of death in patients with cancer, and patients with cancer-associated VTE are at higher risk of anticoagulant-related bleeding. Although patients with cancer often undergo diagnostic or therapeutic invasive procedures, there is a paucity of data on adverse outcomes following the periprocedural interruption of anticoagulation in this patient population.Methods: We did a single-center, retrospective chart review of consecutive patients with cancer-associated VTE who had periprocedural interruption of anticoagulation for invasive procedures between November 2015 and March 2018. Perioperative interruption of warfarin/low-molecular-weight heparin was done as per CHEST guidelines (Douketis et al. Chest 141(2 Suppl). Heparin bridging anticoagulation was used only for patients with recent (< 3 months) VTE. Perioperative interruption of direct oral anticoagulants (DOACs) was done as per Thrombosis Canada guidelines, with anticoagulation held for 3 half-lives prior to low bleeding risk procedures and 5 half-lives for high bleeding risk procedures. Active cancer was defined as per the HOKUSAI VTE CANCER trial (Raskob et al. NEJM 378(7)). Primary outcomes were 30-day post-operative rates of VTE and major bleeding. Secondary outcomes were 30-day post-operative rates of clinically relevant non-major bleeding (CRNMB) and mortality. Major bleeding and CRNMB were defined according to ISTH definitions. Data are reported on a per-interruption basis. Herein, we present an interim analysis of results.Results: To date, 82 perioperative interruptions are included, of whom 69.5% were receiving a DOAC. Mean age of the cohort was 65.8 years, 62.2% were male, 92.6% had active cancer and 41.5% had metastatic cancer. Thrombocytopenia (platelet count < 100 x 106/L) was present in 12.2% of interruptions. Procedures were stratified as high bleeding risk in 65.9% of cases. The 30-day rates of thromboembolism and major bleeding were both 3.70 % (95% confidence interval [CI] 1.25 to 10.2%), as was the 30-day rate of CRNMB. There were no deaths during the 30-day follow-up period.Conclusions: The periprocedural interruption of anticoagulation in patients with cancer-associated VTE appears to be associated with high rates of post-operative thrombotic and bleeding complications. Prospective studies are required to better quantify the risks of periprocedural anticoagulation interruption in this patient population. DisclosuresShaw:Portola Pharmaceuticals: Research Funding. Douketis:BMS: Other: Advisory Board; Janssen: Consultancy; Bayer: Other: Advisory Board; Pfizer: Other: Advisory Board; Daiichi-Sankyo: Other: Advisory Board; Portola: Other: Advisory Board; Astra-Zeneca: Other: Advisory Board; Sanofi: Consultancy, Other: Advisory Board; Biotie: Other: Advisory Board; Boehringer-Ingelheim: Consultancy, Other: Advisory Board, Research Funding; The Medicines Company: Other: Advisory Board. Carrier:Pfizer: Honoraria; Bayer: Honoraria; BMS: Honoraria, Research Funding; Leo Pharma: Research Funding.

Impact of periprocedural anticoagulation therapy on the incidence of silent stroke after atrial fibrillation ablation in patients receiving direct oral anticoagulants: uninterrupted vs. interrupted by one dose strategy.

Data on the comparison between uninterrupted and interrupted by one dose strategies for direct oral anticoagulant (DOAC) use during the periprocedural period of atrial fibrillation (AF) ablation are scarce. The purpose of this study is to investigate the feasibility of uninterrupted DOAC strategy by evaluating the incidence of silent stroke (SS) and perioperative trends in coagulation markers compared with the interrupted strategy. We randomly divided 200 consecutive patients receiving DOACs, who underwent AF ablation into uninterrupted group (UG = 100) and interrupted by one dose group (IG = 100). The rate of SS confirmed by post-operative magnetic resonance imaging and periprocedural trends in coagulation markers was investigated. A significant difference in SS incidence was found between the UG and IG (UG 4%, IG 17%, P < 0.005), although there were no differences in the rate of complications including bleeding and symptomatic thrombo-embolic events between the two groups. Intraoperative cardioversion [odds ratio (OR) 7.27, 95% confidence interval (CI) 1.76-30.0; P < 0.01] and the length of procedure time (OR 1.03, 95% CI 1.01-1.05; P < 0.05) independently predicted the occurrence of SS in the IG. A significant increase in prothrombin fragment 1 + 2 (PF1 + 2) values was observed in the IG compared with the UG on the operative and first post-operative days. Silent stroke incidence in the IG was significantly higher than that in the UG; this seems to be supported by the difference in PF1 + 2 values between the UG and IG. Intraoperative cardioversion and procedure time predicted the occurrence of SS in the IG.