Faculty Bibliography

Introduction: Large clinical trials have recently demonstrated stepwise linear ablation for non-paroxysmal atrial fibrillation (NPAF) to be inferior to pulmonary vein isolation alone. It is unknown whether the unfavorable outcomes observed in these trials can be attributed to the pro-arrhythmic effects of incomplete ablation lines. We hypothesized that improved lesion quality related to use of contact-force sensing (CFS) ablation catheters would improve procedural outcomes. Methods: We prospectively analyzed procedural outcomes of 74 consecutive patients with NPAF undergoing first-time radiofrequency catheter ablation with a CFS catheter (Smart Touch, Biosense Webster) using a step-wise approach (Group 1). The clinical outcomes of these patients were compared with 74 consecutive patients with NPAF who underwent catheter ablation between September 2013 and June 2014 with a non-contact force sense radiofrequency ablation catheter (Group 2) at a single tertiary care medical center. Arrhythmia recurrence was assessed using 2-week event monitors at 3-month intervals following index ablation. Results: Baseline characteristics of Group 1 and Group 2 were similar, although in Group 1 there was a greater prevalence of patients with persistent NPAF lasting for 6-months or longer prior to initial ablation (43% vs 21%, p=0.071). The recurrence rate at 1 year as estimated by the Kaplan-Meier method was not significantly different between Group 1 and Group 2 (25.7% vs 29.7%, p=0.582). The presenting recurrent arrhythmia was most frequently atrial tachycardia (AT) in both groups (Group 1: n=19, AT 68.4% and AF 31.6% vs Group 2: n=22, AT 59.1% and AF 40.9%). A similar proportion of patients in both groups underwent repeat ablation (Group 1: 17.6% vs Group 2: 13.5%, p=0.496). Conclusions: Utilization of a CFS ablation catheter was not associated with improved clinical outcomes for stepwise catheter ablation for NPAF. The optimal strategy for NPAF ablation using a contact-force sensing catheter remains undefined

Introduction: LA ablation for persistent AF that achieves organization to atrial tachycardia (AT) or sinus rhythm (SR) predicts greater long term ablation success. However, extensive LA ablation increases the risks of recurrent AT, adverse atrial remodeling and procedural complications. Preclinical and observational studies suggest that right atrial ablation may reduce AF risk. We hypothesized that CTI ablation may reduce the extent of LA ablation required to achieve organization of persistent AF. Methods: Persistent AF patients (n=107) were randomized to two arms (CTI-first or CTI-last) in a single center, prospective, single blind study. Excluding the CTI ablation, stepwise linear LA ablation was performed in a prespecified order. The primary endpoint was the percentage of patients who organized to AT or SR. The secondary endpoint was number of steps to organization. Results: CTI ablation first versus last during AF ablation did not significantly alter the percentage of patients who organized (Table). Among those who organized, the number of steps to organization did not differ between the two arms. No significant differences were found when patients were stratified by LA size or AF duration. Conclusions: CTI ablation does not alter the extent of LA ablation needed to achieve organization of AF. The utility of right atrial ablation for persistent AF ablation remains unclear. (Table presented)

Introduction: Transcatheter aortic valve replacement (TAVR) is becoming a widely accepted alternative treatment for patients with symptomatic aortic stenosis who are at high risk for surgical aortic valve replacement. A common complication of the procedure is the development of conduction defects requiring permanent pacemaker (PPM) implantation. It has been noted that in some patients, the conduction block is not permanent. Determine the incidence and predictors of resuming intrinsic conduction in patients that receive PPM implantation after TAVR. Methods: A retrospective chart review of patients undergoing TAVR at New York University Langone Medical Center was undertaken. Extracted data included patient demographics, pre-TAVR electrocardiogram, procedural, echocardiographic, catheterization, and device interrogation data. Evaluation of device interrogations done at one month follow-up or earlier to look for resumption of intrinsic conduction. Results: There were a total number of 451 patients who were status-post TAVR in our registry at NYU. Of the 451, 45 patients received a permanent pacemaker placement for complete heart block; 9.9% 45/451. The majority of patients were implanted within 48hrs post TAVR. Device follow-up information at 1 month or earlier was available for 33 of the 45 patients who received PPM. 5 patients who were recently implanted are still pending follow-up. 3 patients expired after implantation and 4 were lost to follow-up. Of the 33 patients, 14 (42%) patients had resumption of AV nodal conduction at 1 month follow-up. 19 patients (57%) remained dependent. Conclusions: 42% of patients who received a permanent pacemaker for complete heart block after TAVR had resumption of conduction. This suggests that many patients may not require long term PPM post TAVR. Patients that remained dependent had a higher incidence of preexisting RBBB and LAFB, however a lack thereof does not preclude an increased risk. These data suggest that waiting longer than 48 hours for resumption of AV nodal conduction would avoid unnecessary implantation in patients who develop complete heart block post TAVR

OBJECTIVES/OBJECTIVE:This study aimed to evaluate the cumulative effect of treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) on atrial fibrillation (AF) recurrence. BACKGROUND:OSA is a known predictor for onset and recurrence of AF. The effect of treatment with CPAP on AF recurrence has been evaluated in small studies with varied outcomes. METHODS:We searched MEDLINE, EMBASE, CINAHL, Google Scholar, Cochrane Database of Systematic Reviews, and Cochrane Trials Register for relevant studies. Evaluation of AF recurrence in CPAP users and nonusers in patients with OSA was the primary outcome evaluated in this study. The secondary outcome was evaluation of AF recurrence in CPAP users and nonusers after pulmonary vein isolation (PVI). RESULTS: = 0%). The beneficial effect of CPAP use was statistically significant in both groups of patients: those who underwent catheter ablation with PVI and those who did not undergo ablation and were managed medically. No other study covariates had any significant association with these outcomes of AF reduction. CONCLUSIONS:The use of CPAP is associated with significant reduction in recurrence of AF in patients with OSA. This effect remains consistent and similar across patient populations irrespective of whether they undergo PVI.

PURPOSE: Transesophageal echocardiography (TEE) is routinely used to assess for thrombus in the left atrium (LA) and left atrial appendage (LAA) in patients undergoing atrial fibrillation (AF) ablation. However, little is known about the outcome of AF ablation in patients with documented LAA sludge. We hypothesize that AF ablation can be performed safely in a proportion of patients with sludge in the LAA and may have a significant benefit for these patients. METHODS: We performed a retrospective analysis of all patients undergoing AF ablation at New York University Langone Medical Center (NYULMC) from January 1st 2011 to June 30, 2013. Patients with sludge found on their TEE immediately prior to AF ablation were identified and followed for stroke, AF recurrence, procedural complications, major bleeding, or death. RESULTS: Among 1,076 patients who underwent AF ablation, 8 patients (mean age 69 +/- 13 years; 75 % men) with sludge were identified. Patients with sludge in their LAA had no incidence of early or late occurrence of stroke during mean follow-up of 10 months. One patient had a left groin hematoma, and two patients had atrial tachycardias that needed a repeat ablation. TEE at the time of repeat ablation demonstrated the presence of spontaneous echo contrast (smoke) and resolution of sludge. There were no deaths. CONCLUSION: In a cohort of eight patients with LAA sludge who underwent AF ablation, no significant thromboembolic events occurred during or after the procedure. AF ablation can be performed safely and may be beneficial in these patients. Larger studies are warranted to better determine the most appropriate management route.

BACKGROUND: Venous occlusion is not uncommon and total venous obstruction with more proximal patency may occur in as many as 10% of previous implants. Many techniques are available to obtain ipsilateral access; however, most require special equipment or skills. We describe a technique of infraclavicular cannulation of the brachiocephalic vein ipsilateral to the occlusion that is safe and feasible for most implanters. METHODS: Fourteen patients with subclavian/axillary occlusions ipsilateral to the implanted device and requiring revision or upgrade of their system or venous occlusion with contraindication to implant on the contralateral side underwent lead addition/placement via a brachiocephalic approach. Following venography, an 18-gauge needle was used to gain brachiocephalic access. The needle was initially positioned in a lateral infraclavicular location. The needle was then advanced under the clavicle in a horizontal plane and advanced toward the sternal notch under fluoroscopic guidance. RESULTS: Fourteen patients underwent an attempt at brachiocephalic access. Cannulation of the brachiocephalic was possible in all 14 and lead(s) were successfully implanted in all. There were no complications with the procedure, specifically no pneumothoraces. In follow-up (mean 36 months, range 1-86 months), all implanted leads function well, with no evidence of lead failure or impedance changes. CONCLUSION: A lateral infraclavicular approach is a safe and effective technique for obtaining brachiocephalic access when the subclavian/axillary vein is occluded. This technique is easy to learn and may be useful for implanters without the equipment or skills needed for lead extraction or microdissection or in cases where patients refuse these procedures.

Atrial fibrillation (AF), the most common cardiac arrhythmia, is a significant cause of embolic stroke. Although systemic anticoagulation is the primary strategy for preventing the thromboembolic complications of AF, anticoagulants carry major bleeding risks, and many patients have contraindications to their use. Because thromboembolism typically arises from a clot in the left atrial appendage (LAA), local therapeutic alternatives to systemic anticoagulation involving surgical or percutaneous exclusion of the LAA have been developed. Surgical exclusion of the LAA is typically performed only as an adjunct to other cardiac surgeries, thus limiting the number of eligible patients. Furthermore, surgical exclusion of the LAA is frequently incomplete, and thromboembolism may still occur. Percutaneous LAA exclusion includes two approaches: transseptal delivery of an occlusion device to the LAA and epicardial suture ligation of the LAA, the LARIAT procedure. In the LARIAT procedure, a pretied snare is placed around the epicardial surface of the LAA orifice via pericardial access. Proper snare placement is achieved with epicardial and endocardial magnet-tipped guidewires. The endocardial wire is advanced transvenously to the LAA apex after transseptal puncture. The epicardial wire, introduced into the pericardial space, achieves end-to-end union with the endocardial wire at the LAA apex. The snare is then placed over the LAA, tightened, and sutured. On the basis of early clinical experience, the LARIAT procedure has a high success rate of LAA exclusion with low risk for complications. The authors describe the indispensable role of real-time transesophageal echocardiography in the guidance of LAA epicardial suture ligation with the LARIAT device.