Vijay Swarup

Feasibility and Safety of Dabigatran Versus Warfarin for Periprocedural Anticoagulation in Patients Undergoing Radiofrequency Ablation for Atrial Fibrillation Results From a Multicenter Prospective Registry

OBJECTIVES The purpose of this study was to evaluate the feasibility and safety of periprocedural dabigatran during atrial fibrillation (AF) ablation. BACKGROUND AF ablation requires optimal periprocedural anticoagulation for minimizing bleeding and thromboembolic complications. The safety and efficacy of dabigatran as a periprocedural anticoagulant for AF ablation are unknown. METHODS We performed a multicenter, observational study from a prospective registry including all consecutive patients undergoing AF ablation in 8 high-volume centers in the United States. All patients receiving dabigatran therapy who underwent AF ablation on periprocedural dabigatran, with the dose held on the morning of the procedure, were matched by age, sex, and type of AF with an equal number of patients undergoing AF ablation with uninterrupted warfarin therapy over the same period. RESULTS A total of 290 patients, including 145 taking periprocedural dabigatran and an equal number of matched patients taking uninterrupted periprocedural warfarin, were included in the study. The mean age was 60 years with 79% being male and 57% having paroxysmal AF. Both groups had a similar CHADS(2) score, left atrial size, and left ventricular ejection fraction. Three thromboembolic complications (2.1%) occurred in the dabigatran group compared with none in the warfarin group (p = 0.25). The dabigatran group had a significantly higher major bleeding rate (6% vs. 1%; p = 0.019), total bleeding rate (14% vs. 6%; p = 0.031), and composite of bleeding and thromboembolic complications (16% vs. 6%; p = 0.009) compared with the warfarin group. Dabigatran use was confirmed as an independent predictor of bleeding or thromboembolic complications (odds ratio: 2.76, 95% confidence interval: 1.22 to 6.25; p = 0.01) on multivariate regression analysis. CONCLUSIONS In patients undergoing AF ablation, periprocedural dabigatran use significantly increases the risk of bleeding or thromboembolic complications compared with uninterrupted warfarin therapy.

Percutaneous Left Atrial Appendage Closure vs Warfarin for Atrial Fibrillation A Randomized Clinical Trial

IMPORTANCE While effective in preventing stroke in patients with atrial fibrillation (AF), warfarin is limited by a narrow therapeutic profile, a need for lifelong coagulation monitoring, and multiple drug and diet interactions. OBJECTIVE To determine whether a local strategy of mechanical left atrial appendage (LAA) closure was noninferior to warfarin. DESIGN, SETTING, AND PARTICIPANTS PROTECT AF was a multicenter, randomized (2:1), unblinded, Bayesian-designed study conducted at 59 hospitals of 707 patients with nonvalvular AF and at least 1 additional stroke risk factor (CHADS2 score ≥1). Enrollment occurred between February 2005 and June 2008 and included 4-year follow-up through October 2012. Noninferiority required a posterior probability greater than 97.5% and superiority a probability of 95% or greater; the noninferiority margin was a rate ratio of 2.0 comparing event rates between treatment groups. INTERVENTIONS Left atrial appendage closure with the device (n = 463) or warfarin (n = 244; target international normalized ratio, 2-3). MAIN OUTCOMES AND MEASURES A composite efficacy end point including stroke, systemic embolism, and cardiovascular/unexplained death, analyzed by intention-to-treat. RESULTS At a mean (SD) follow-up of 3.8 (1.7) years (2621 patient-years), there were 39 events among 463 patients (8.4%) in the device group for a primary event rate of 2.3 events per 100 patient-years, compared with 34 events among 244 patients (13.9%) for a primary event rate of 3.8 events per 100 patient-years with warfarin (rate ratio, 0.60; 95% credible interval, 0.41-1.05), meeting prespecified criteria for both noninferiority (posterior probability, >99.9%) and superiority (posterior probability, 96.0%). Patients in the device group demonstrated lower rates of both cardiovascular mortality (1.0 events per 100 patient-years for the device group [17/463 patients, 3.7%] vs 2.4 events per 100 patient-years with warfarin [22/244 patients, 9.0%]; hazard ratio [HR], 0.40; 95% CI, 0.21-0.75; P = .005) and all-cause mortality (3.2 events per 100 patient-years for the device group [57/466 patients, 12.3%] vs 4.8 events per 100 patient-years with warfarin [44/244 patients, 18.0%]; HR, 0.66; 95% CI, 0.45-0.98; P = .04). CONCLUSIONS AND RELEVANCE After 3.8 years of follow-up among patients with nonvalvular AF at elevated risk for stroke, percutaneous LAA closure met criteria for both noninferiority and superiority, compared with warfarin, for preventing the combined outcome of stroke, systemic embolism, and cardiovascular death, as well as superiority for cardiovascular and all-cause mortality. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00129545.

Feasibility and Safety of Uninterrupted Rivaroxaban for Periprocedural Anticoagulation in Patients Undergoing Radiofrequency Ablation for Atrial Fibrillation

OBJECTIVES The purpose of this study was to evaluate the feasibility and safety of uninterrupted rivaroxaban therapy during atrial fibrillation (AF) ablation. BACKGROUND Optimal periprocedural anticoagulation strategy is essential for minimizing bleeding and thromboembolic complications during and after AF ablation. The safety and efficacy of uninterrupted rivaroxaban therapy as a periprocedural anticoagulant for AF ablation are unknown. METHODS We performed a multicenter, observational, prospective study of a registry of patients undergoing AF ablation in 8 centers in North America. Patients taking uninterrupted periprocedural rivaroxaban were matched by age, sex, and type of AF with an equal number of patients taking uninterrupted warfarin therapy who were undergoing AF ablation during the same period. RESULTS A total of 642 patients were included in the study, with 321 in each group. Mean age was 63 ± 10 years, with 442 (69%) males and 328 (51%) patients with paroxysmal AF equally distributed between the 2 groups. Patients in the warfarin group had a slightly higher mean HAS- BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) score (1.70 ± 1.0 vs. 1.47 ± 0.9, respectively; p = 0.032). Bleeding and embolic complications occurred in 47 (7.3%) and 2 (0.3%) patients (both had transient ischemic attacks) respectively. There were no differences in the number of major bleeding complications (5 [1.6%] vs. 7 [1.9%], respectively; p = 0.772), minor bleeding complications (16 [5.0%] vs. 19 [5.9%], respectively; p = 0.602), or embolic complications (1 [0.3%] vs. 1 [0.3%], respectively; p = 1.0) between the rivaroxaban and warfarin groups in the first 30 days. CONCLUSIONS Uninterrupted rivaroxaban therapy appears to be as safe and efficacious in preventing bleeding and thromboembolic events in patients undergoing AF ablation as uninterrupted warfarin therapy.

Radiofrequency Ablation of Premature Ventricular Ectopy Improves the Efficacy of Cardiac Resynchronization Therapy in Nonresponders

OBJECTIVES This study sought to examine whether suppressing premature ventricular contractions (PVC) using radiofrequency ablation improves effectiveness of the cardiac resynchronization therapy (CRT) in nonresponders. BACKGROUND CRT is an effective strategy for drug refractory congestive heart failure. However, one-third of patients with CRT do not respond clinically, and the causes for nonresponse are poorly understood. Whether frequent PVC contribute to CRT nonresponse remains unknown. METHODS In this multicenter study, CRT nonresponders with >10,000 PVC in 24 h who underwent PVC ablation were enrolled from a prospective database. RESULTS Sixty-five subjects (age 66.6 ± 12.4 years, 78% men, QRS duration of 155 ± 18 ms) had radiofrequency ablation of PVC from 76 foci. Acute and long-term success rates of ablation were 91% and 88% in 12 ± 4 months of follow-up. There was significant improvement in left ventricular (LV) ejection fraction (26.2 ± 5.5% to 32.7 ± 6.7 %, p < 0.001), LV end-systolic diameter (5.93 ± 0.55 cm to 5.62 ± 0.32 cm, p < 0.001), LV end-diastolic diameter (6.83 ± 0.83 cm to 6.51 ± 0.91 cm, p < 0.001), LV end-systolic volume (178 ± 72 to 145 ± 23 ml, p < 0.001), LV end-diastolic volume (242 ± 85 ml to 212 ± 63 ml, p < 0.001), and median New York Heart Association functional class (3.0 to 2.0, p < 0.001). Modeling of pre-ablation PVC burden revealed an improvement in ejection fraction when the pre-ablation PVC burden was >22% in 24 h. CONCLUSIONS Frequent PVC is an uncommon yet significant cause of CRT nonresponse. Radiofrequency ablation of PVC foci improves LV function and New York Heart Association class and promotes reverse remodeling in CRT nonresponders. PVC ablation may be used to enhance CRT efficacy in nonresponders with significant PVC burden.

Endocardial (Watchman) vs epicardial (Lariat) left atrial appendage exclusion devices: Understanding the differences in the location and type of leaks and their clinical implications

BACKGROUND Watchman and Lariat left atrial appendage (LAA) occlusion devices are associated with LAA leaks postdeployment. OBJECTIVE The purpose of this study was to compare the incidence, characteristics, and clinical significance of these leaks. METHODS We performed a multicenter prospective observational study of all patients who underwent LAA closure. Baseline, procedural, and imaging variables along with LAA occlusion rates at 30-90 days and 1-year postprocedure were compared. RESULTS A total of 478 patients (219 with the Watchman device and 259 with the Lariat device) with successful implants were included. Patients in the Lariat group had a higher CHADS2 (congestive heart failure, hypertension, age >74 years, diabetes, stroke) score and a larger left atrium and LAA. A total of 79 patients (17%) had a detectable leak at 1 year. More patients in the Watchman group had a leak compared with those in the Lariat group (46 [21%] vs 33 [14%]; P = .019). All the leaks were eccentric (edge effect) in the Watchman group and concentric (gunny sack effect) in the Lariat group. The size of the leak was larger in the Watchman group than in the Lariat group (3.10 ± 1.5 mm vs 2.15 ± 1.3 mm; P = .001). The Watchman group had 1 device embolization requiring surgery and 2 pericardial effusions requiring pericardiocentesis. In the Lariat group, 4 patients had cardiac tamponade requiring urgent surgical repair. Three patients in each group had a cerebrovascular accident and were not associated with device leaks. CONCLUSION The Lariat device is associated with a lower rate of leaks at 1 year as compared with the Watchman device, with no difference in rates of cerebrovascular accident. There was no correlation between the presence of residual leak and the occurrence of cerebrovascular accident.

Percutaneous left ventricular assist devices in ventricular tachycardia ablation: multicenter experience.

Background—Data on relative safety, efficacy, and role of different percutaneous left ventricular assist devices for hemodynamic support during the ventricular tachycardia (VT) ablation procedure are limited. Methods and Results—We performed a multicenter, observational study from a prospective registry including all consecutive patients (N=66) undergoing VT ablation with a percutaneous left ventricular assist devices in 6 centers in the United States. Patients with intra-aortic balloon pump (IABP group; N=22) were compared with patients with either an Impella or a TandemHeart device (non-IABP group; N=44). There were no significant differences in the baseline characteristics between both the groups. In non-IABP group (1) more patients could undergo entrainment/activation mapping (82% versus 59%; P=0.046), (2) more number of unstable VTs could be mapped and ablated per patient (1.05±0.78 versus 0.32±0.48; P<0.001), (3) more number of VTs could be terminated by ablation (1.59±1.0 versus 0.91±0.81; P=0.007), and (4) fewer VTs were terminated with rescue shocks (1.9±2.2 versus 3.0±1.5; P=0.049) when compared with IABP group. Complications of the procedure trended to be more in the non-IABP group when compared with those in the IABP group (32% versus 14%; P=0.143). Intermediate term outcomes (mortality and VT recurrence) during 12±5-month follow-up were not different between both groups. Left ventricular ejection fraction ⩽15% was a strong and independent predictor of in-hospital mortality (53% versus 4%; P<0.001). Conclusions—Impella and TandemHeart use in VT ablation facilitates extensive activation mapping of several unstable VTs and requires fewer rescue shocks during the procedure when compared with using IABP.

Differences in complication rates between large bore needle and a long micropuncture needle during epicardial access: time to change clinical practice?

Background—A dry epicardial access (EA) is increasingly used for advanced cardiovascular procedures. Conventionally used large bore needles (Tuohy or Pajunk needle; LBN) have been associated with low but definite incidence of major complications with EA. Use of micropuncture needle (MPN) may decrease the risk of complications. We intended to compare the outcomes of LBN with MPN for EA. Methods and Results—We report a multicenter observational study of consecutive patients who underwent EA for ventricular tachycardia ablation or Lariat procedure using the LBN or MPN. Oral anticoagulation was stopped before the procedure. Baseline characteristics and procedure-related complications were collected and compared. Of the 404 patients, LBN and MPN were used in 46% and 54% of patients, respectively. There was no significant difference in the incidence of inadvertent puncture of myocardium between LBN and MPN (7.6% versus 6.8%, P=0.76). However, there was a significantly higher rate of large pericardial effusions with LBN compared with MPN (8.1% versus 0.9%; P<0.001). The incidence of pleural effusions were not significantly different between both (1.6% versus 2.3%; P=0.64). LBN group had an increase in other complications compared with MPN (open heart surgery to repair cardiac laceration [6 versus 0], injury to liver [1 versus 0], coronaries [1 versus 0], and superior epigastric artery requiring surgical exploration [0 versus 1]). Conclusions—The use of MPN is associated with decreased incidence of major complications, and the need for surgical repair and routine use should be considered for EA.

Use of non-warfarin oral anticoagulants instead of warfarin during left atrial appendage closure with the Watchman device

BACKGROUND In the stroke prevention trials of left atrial appendage closure with the Watchman device (Boston Scientific), a postimplantation antithrombotic regimen of 6 weeks of warfarin was used. OBJECTIVE Given the clinical complexity of warfarin use, the purpose of this study was to study the relative feasibility and safety of using non-warfarin oral anticoagulants (NOACs) instead of warfarin during the peri- and initial postimplantation periods after Watchman implantation. METHODS This was a retrospective multicenter study of consecutive patients undergoing Watchman implantation and receiving peri- and postprocedural NOACs or warfarin. Transesophageal echocardiography or chest computed tomography was performed between 6 weeks and 4 months postimplant to assess for device-related thrombosis. Bleeding and thromboembolic events also were evaluated at the time of follow-up. RESULTS In 5 centers, 214 patients received NOACs (46% apixaban, 46% rivaroxaban, 7% dabigatran, and 1% edoxaban) in either an uninterrupted (82%) or a single-held-dose (16%) fashion. Compared to a control group receiving uninterrupted warfarin (n = 212), the rates of periprocedural complications, including bleeding events, were similar (2.8% vs 2.4%, P = 1). At follow-up, the rates of device-related thrombosis (0.9% vs 0.5%, P = 1), composite of thromboembolism or device-related thrombosis (1.4% vs 0.9%, P = 1), and postprocedure bleeding events (0.5% vs 0.9%, P = .6) also were comparable between the NOAC and warfarin groups. CONCLUSION NOACs proved to be a feasible peri- and postprocedural alternative regimen to warfarin for preventing device-related thrombosis and thromboembolic complications expected early after appendage closure with the Watchman device, without increasing the risk of bleeding.

Catheter Ablation for Atrial Fibrillation in Patients With Watchman Left Atrial Appendage Occlusion Device: Results from a Multicenter Registry

There have been an increasing number of atrial fibrillation (AF) patients with Watchman left atrial appendage occlusion (LAAO) device, requiring catheter ablation (CA) for maintenance of normal sinus rhythm. In this study, we describe our experience with the feasibility and safety of CA in patients with a preexisting Watchman LAAO device.

Recurrent Post-Ablation Paroxysmal Atrial Fibrillation Shares Substrates With Persistent Atrial Fibrillation : An 11-Center Study

INTRODUCTION The role of atrial fibrillation (AF) substrates is unclear in patients with paroxysmal AF (PAF) that recurs after pulmonary vein isolation (PVI). We hypothesized that patients with recurrent post-ablation (redo) PAF despite PVI have electrical substrates marked by rotors and focal sources, and structural substrates that resemble persistent AF more than patients with (de novo) PAF at first ablation. METHODS In 175 patients at 11 centers, we compared AF substrates in both atria using 64 pole-basket catheters and phase mapping, and indices of anatomical remodeling between patients with de novo or redo PAF and first ablation for persistent AF. RESULTS Sources were seen in all patients. More patients with de novo PAF (78.0%) had sources near PVs than patients with redo PAF (47.4%, p=0.005) or persistent AF (46.9%, p=0.001). The total number of sources per patient (p=0.444), and number of non-PV sources (p=0.701) were similar between groups, indicating that redo PAF patients had residual non-PV sources after elimination of PV sources by prior PVI. Structurally, left atrial size did not separate de novo from redo PAF (49.5±9.5 vs. 49.0±7.1mm, p=0.956) but was larger in patients with persistent AF (55.2±8.4mm, p=0.001). CONCLUSIONS Patients with paroxysmal AF despite prior PVI show electrical substrates that resemble persistent AF more closely than patients with paroxysmal AF at first ablation. Notably, these subgroups of paroxysmal AF are indistinguishable by structural indices. These data motivate studies of trigger versus substrate mechanisms for patients with recurrent paroxysmal AF after PVI.