Asaf Danon

Safety and Efficacy of Dabigatran Compared With Warfarin for Patients Undergoing Radiofrequency Catheter Ablation of Atrial Fibrillation: A Meta-analysis

BACKGROUND The safety and efficacy of dabigatran in the periprocedural period for patients undergoing atrial fibrillation ablation is not well established. We conducted a meta-analysis of the periprocedural use of dabigatran vs warfarin (with or without heparin bridging). METHODS A literature search was performed using multiple databases. Outcomes were (1) major bleeding; (2) minor bleeding; and (3) thromboembolic events. Odds ratios (ORs) were reported for dichotomous variables. RESULTS Eleven controlled studies (9 cohorts, 1 randomized controlled trial and 1 case-control study; 3841 patients) were identified. Dabigatran was used in 1463 patients, uninterrupted in 223 and held up to 36 hours in the remainder. No significant differences were noted in major bleeding rates between dabigatran and warfarin groups (1.9% vs. 1.6%; OR, 1.04 [95% confidence interval (CI), 0.51-2.13]; P = 0.92). Cardiac tamponade was observed in 1.4% in dabigatran vs 1.1% in warfarin groups (OR, 1.1; 95% CI, 0.55-2.11; P = 0.82). Similar rates for dabigatran vs. warfarin were reported for minor bleeding (3.8% vs. 4.5%; OR, 0.85; 95% CI, 0.58-1.25; P = 0.40), hematoma (2% vs. 2.7%; OR, 0.67; 95% CI, 0.41-1.08; P = 0.1), and thromboembolic events (0.6% vs. 0.1%; OR, 2.51; 95% CI, 0.78-8.11; P = 0.12). CONCLUSIONS This meta-analysis suggests that dabigatran and warfarin have similar safety and efficacy overall for periprocedural anticoagulation in patients undergoing radiofrequency atrial fibrillation ablation. Signals were seen favouring dabigatran (for hematomas) and warfarin (for thromboembolic events), but neither was statistically significant because of low event rates. More high-quality data are required to definitively compare the 2 strategies.

Robotically assisted ablation of atrial fibrillation: A systematic review and meta-analysis

BACKGROUND Robotic systems are becoming increasingly common in complex ablation procedures. We conducted systematic review and meta-analysis on the procedural outcomes of Magnetic Navigation System (MNS) in comparison to conventional catheter navigation for atrial fibrillation (AF) ablation. METHODS An electronic search was performed using multiple databases between 2002 & 2012. Outcomes were: acute and long-term success, complications, total procedure, ablation and fluoroscopic times. RESULTS Fifteen studies (11 nonrandomized controlled studies & 4 case series) involving 1647 adult patients were identified. In comparison between MNS and conventional groups, a tendency towards higher acute success was noted with conventional group but with similar long-term freedom from AF (95% vs. 97%, odds ratio (OR) 0.25 (95% confidence interval [CI] 0.06; 1.04, p=0.057); 73% vs. 75%, OR 0.92 (95% CI 0.69; 1.24, p=0.59), respectively). A significantly shorter fluoroscopic time was achieved with MNS (57 vs. 86 min, standardized difference in means (SDM) -0.90 (95% CI -1.68; -0.12, p=0.024)). Longer total procedure and ablation times were noted with MNS (286 vs. 228 min, SDM 0.7 (95% CI 0.28; 1.12, p=0.001); 67 vs. 47 min, SDM 0.79 (95% CI 0.18; 1.4, p=0.012), respectively). Overall complication rate was similar (2% vs. 5%, OR 0.48 (95% CI 0.18; 1.26, p=0.135)), however rate of significant pericardial complication defined either as tamponade or effusion requiring intervention/hospitalization was significantly lower in MNS (0.3% vs. 2.5%, p=0.005). CONCLUSIONS Our results suggest that MNS has similar rates of success and possibly superior safety outcomes when compared to conventional manual catheter ablation for AF.

Atrioesophageal Fistula: A Review

Catheter ablation of atrial ablation (AF) has become an important therapy in recent years. As with all evolving techniques, unexpected complication may occur. Atrioesophageal fistula is a very rare complication of AF catheter ablation. Described for the first time in two very experienced centers in 2004, this complication is the most dreadful and lethal among all the others related to AF catheter ablation. Its clinical presentation is extremely variable. Rapid diagnosis and surgical therapy may prevent death. This review article will summarize the risk factors, diagnosis, treatment and possible preventive strategies for this condition.

Remote magnetic navigation for catheter ablation of atrioventricular nodal reentrant tachycardia: a systematic review and meta-analysis

Catheter ablation has become a well-established, first-line therapy for atrioventricular nodal reentrant tachycardia (AVNRT), the most common reentry supraventricular tachycardia in humans. Robotic systems are becoming increasingly common in both complex and simple ablation procedures with presumed potential improvements in procedural efficacy and safety. The authors of this article conducted a systematic review and meta-analysis on the effectiveness and safety of the magnetic navigation system (MNS) in comparison with conventional catheter navigation for AVNRT ablation. An electronic search was performed using Cochrane Central database, Medline, Embase and Web of Knowledge between 2002 and 2012. References were searched manually. Outcomes of interest were: acute and long-term success, complications, total procedure, ablation and fluoroscopic times. Continuous variables were reported as standardized difference in means (SDM); odds ratios (OR) were reported for dichotomous variables. Thirteen studies (seven of which were nonrandomized controlled, four were case series and two were randomized controlled studies) involving 679 adult patients were identified. Twelve studies were based on a single center and one study was multicentral. MNS was deployed in 339 patients. The follow-up period ranged between 75 and 180 days. Acute success and long-term freedom from arrhythmia were not significantly different between MNS and control groups (98 vs 98%, OR: 0.94 [95% CI: 0.21–4.1] and 97 vs 96%, OR: 1.18 [95% CI: 0.35–4.0], respectively). A shorter fluoroscopic time was achieved with MNS; however, this did not reach statistical significance (15 vs 19 min, SDM: -0.26 [95% CI: -0.64–0.12]). Longer total procedure but similar ablation times were noted with MNS (160 vs 148 min, SDM: 3.48 [95% CI: 0.75–6.21] and 4 vs 6 min, SDM: -0.83 [95% CI: -2.19–0.53], respectively). The overall complication rate was similar between both groups (2.7 vs 1.0%, OR: 1.28 [95% CI: 0.33–4.96]). Our data suggest that the usage of MNS results in similar rates of success and complications when compared with conventional manual catheter ablation for AVNRT. MNS had a trend for reduced fluoroscopic time. Longer total procedure time was observed with MNS while the actual ablation time remained similar. Prospective randomized trials will be needed to better evaluate the relative role of MNS for catheter ablation of AVNRT.

The role of high-intensity focused ultrasound in ablation of atrial fibrillation and other cardiac arrhythmias

Atrial fibrillation is the most prevalent arrhythmia of the heart, originating usually from ectopic atrial activity of the pulmonary veins. Therefore, one of the treatment options is pulmonary vein isolation. Among the novel approaches to pulmonary vein isolation, high- intensity focused ultrasound (HIFU) has been developed. The ultrasound energy can be focused on a specific area and would result in the formation of a lesion similar to that formed with radiofrequency (RF) ablation. Although preclinical studies were promising, clinical studies in patients resulted in lower efficacy and high complication rates in comparison to the standard ablation method, due to collateral damage. Using HIFU for epicardial approach during cardiac surgery and for extracorporeal ablation does seem to have a future role. In this review, we pres- ent the mechanism of HIFU lesion formation and the principal studies.

Magnetic resonance imaging of the left atrial appendage post pulmonary vein isolation: Implications for percutaneous left atrial appendage occlusion

There is increasing interest in performing left atrial appendage (LAA) occlusion at the time of atrial fibrillation (AF) ablation procedures. However, to date there has been no description of the acute changes to the LAA immediately following pulmonary vein (PV) isolation and additional left atrium (LA) substrate modification. This study assessed changes in the size and tissue characteristics of the LAA ostium in patients undergoing PV isolation.

Stenting versus surgery for atrial-esophageal fistula.

We read with great interest the article on atrialesophageal fistula (AEF) outcome with stenting versus surgical repair.1 We commend Mohanty et al. for this report that helps us better understand the management of this rare but dreadful complication. Mohanty’s work, in conjunction with other sporadic cases of stenting for AEF, supports the importance of early surgical repair when possible. Given the possibility of selection bias, we are interested if Monanty can comment whether patients undergoing stenting in their series would have otherwise been candidates for surgical repair? Furthermore, did the authors note any immediate peristenting deterioration related to esophageal air insufflations for stent placement or stent erosion? Knowledge of these 2 points is important to better understand the role of stenting for this condition as it is possible that stenting may be a temporary solution in order to facilitate transfer to a surgical center with experience managing AEF. We would like to highlight the surgical repair performed in all patients in Mohanty’s series that supports our prior work demonstrating that primary esophageal repair and interposition of a pericardial or intercostal muscle flap was

Single Versus Dual Lead Atrioventricular Sequential Pacing for Acquired Atrioventricular Block During Transcatheter Aortic Valve Implantation Procedures

Atrioventricular block (AVB) after transcatheter aortic valve implantation (TAVI) is common. Pacing platforms that preserve atrioventricular (AV) synchrony may be beneficial in these patients. Single lead AV sequential pacemakers (VDD) allow AV synchrony and, by virtue of implanting a single lead, can be advantageous when compared with traditional dual lead (DDD) pacemakers. The objective of this retrospective case-controlled study was to compare the strategy of AV sequential pacing with a VDD versus DDD pacemaker in consecutive TAVI patients (n = 120) with acquired AVB. Patients were classified as receiving a VDD (n = 73) or DDD (n = 47) pacemaker. Procedure characteristics, complications, and the need for long-term ventricular pacing reported. Pacemaker implantation time (51 vs 66 minutes and p <0.001), fluoroscopy time (3.7 vs 7.8 minutes and p = 0.004), and radiation exposure (dose area product: 6.5 vs 15.3 mGy/cm2 and p = 0.006) were lower in patients receiving VDD pacemakers. Procedural complications were similar in the 2 groups. Overall, 59% of the cohort required ≥50% ventricular pacing at 1-year follow-up. In conclusion, VDD pacemaker implantation was associated with shorter procedure times, lower radiation exposure, and similar safety outcomes when compared with DDD pacemaker implantation in TAVI patients with acquired AVB.

An Atypical Presentation of a Typical Arrhythmia

A 44-year-old man with a long history of a narrow complex tachycardia and prior left lateral accessory pathway (LL-AP) ablation was brought to the electrophysiology laboratory for a redo supraventricular tachycardia (SVT) ablation procedure. Catheters were positioned within the coronary sinus (CS) and right ventricular apex (RVa). The case was performed with the guidance of a 3D mapping system. A long RP tachycardia with a cycle length of 320 ms was easily induced with ventricular extrastimulus. Earliest atrial activation was present in the proximal (9, 10) CS electrodes with a ventricular to atrial (VA) time of 140 ms. Ventricular overdrive pacing was consistent with a V-A-V response with a post pacing interval minus tachycardia cycle length (PPI − TCL) of 175 ms, and stimulus to atrial (SA) activity during pacing minus VA activity during tachycardia time of 120 ms (Fig. 1A). A premature ventricular complex (PVC) introduced around the time of His-refractoriness did not change the timing of the subsequent atrial activation (Fig. 1B). In sinus rhythm, dual atrioventricular node (AVN) physiology was present and Para-Hisian pacing resulted in a VA time that was 52 ms shorter with His capture than with loss of capture (Fig. 2A). What is the possible mechanism of the tachycardia according to these findings? The differential diagnosis of long RP tachycardia with “concentric” activation is atypical atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reentrant tachycardia (AVRT) using a septal pathway as the retrograde limb or atrial tachycardia. The results of ventricular entrainment as well as His-refractory PVC and Para-Hisian pacing excluded atrial tachycardia and were supportive of atypical AVNRT

Resumption of dormant accessory pathway conduction with adenosine administration: a simple intervention to ensure successful accessory pathway ablation.

A 19-year-old with supraventricular tachycardia was referred for an electrophysiology study. Delta waves were absent and the HV interval 36 ms. Orthodromic atrioventricular reentrant tachycardia utilizing a left-septal accessory pathway (AP) was diagnosed and radiofrequency energy delivered at the site of earliest retrograde atrial …