Acute Pulmonary Vein Reconnection after Ablation using Contact-force Sensing Catheters: Incidence, Timing, and Ablation Lesion Characteristics.

BACKGROUND: Acute pulmonary vein (PV) reconnection predicts atrial fibrillation (AF) recurrence after ablation. Contact-force (CF) sensing catheters improve lesion delivery. We assessed the incidence, timing, location, and lesion characteristics of acute reconnection after PV isolation with CF sensing catheters. METHODS: Patients undergoing radiofrequency ablation for AF from October 2016 to February 2017 were studied. Assessment for acute reconnection at 20 and 40 minute intervals was performed in each isolated PV. Additional lesions were applied as needed. Lesion location, contact force, power, duration, impedance, and force-time integral values were compared at sites with and without reconnection. RESULTS: Twenty-two patients (60.6 + 1.8 years; 36.4% female; 27.3% persistent AF; CHA2DS2VASC 1.9 + 0.3) were included. Eighty-eight veins were isolated. Eleven reconnections occurred in 10 patients; 9 occurred by 20 minutes and 2 between 20 - 40 minutes. Most reconnections (6/11) were in the left superior PV. Of 4993 ablation points analyzed, 72 were at acute reconnection sites, and no differences in average contact force (11.4 + 8.1 vs 11.3 + 7.1 gm, p=0.868), power (29.7 + 3.9 vs 29.9 + 4.6 watts, p=0.620), impedance (64.1 + 60 vs 72.5 + 60, p=0.236) and the force time integral (86.9 + 78.8 vs 99.7 + 100 gm/sec, p=0.282) were found. CONCLUSION: Acute PV reconnection rates using CF sensing catheters are roughly 12.5%, with the majority occurring within 20 minutes. We found no significant differences in characteristics of ablation points in areas of reconnection. Optimum wait periods after isolation to check for acute reconnection may be as brief as 20 minutes.

Increased rates of atrial fibrillation recurrence following pulmonary vein isolation in overweight and obese patients.

INTRODUCTION: Catheter ablation is common for patients with symptomatic, drug-refractory atrial fibrillation (AF). Obesity is a known risk factor for incident AF. The impact of obesity on AF ablation outcomes is incompletely understood. We sought to determine the impact of elevated body mass index (BMI) on pulmonary vein isolation (PVI) procedural outcomes and associated complications. METHODS AND RESULTS: We evaluated patients undergoing PVI from 2001 to 2015, dividing them into four groups: normal weight (BMI ≥ 18.5 to < 25), overweight (BMI ≥ 25 to < 30), obese (BMI > 30 to < 40), and morbidly obese (BMI ≥ 40). Demographic and procedural characteristics, complications, and ablation outcomes were compared among groups. A total of 701 patients (146 time-matched controls, 227 overweight, 244 obese, and 84 morbidly obese) with complete demographic, procedural, and follow-up data were included. Increasing BMI correlated positively with HTN, OSA, CHA2 DS2 -VASC score, and persistent AF (P ≤ 0.001 for all associations). Radiofrequency application time and intraprocedural heparin dose increased with BMI (P ≤ 0.001). Arrhythmia recurrence at 1 year was 39.9% in controls, while higher in all high-BMI groups (overweight, 51.3%; obese, 57%; morbidly obese, 58.1 %; P  =  0.007 for all versus controls). Impact of BMI on AF recurrence was not seen in persistent AF patients. Complication rates across groups were similar. CONCLUSIONS: AF recurrence after catheter ablation is higher in overweight, obese, and morbidly obese patients comparing to normal-weight controls, driven primarily by outcomes differences in paroxysmal AF patients. Complications were not associated with increased BMI.

Impact of rotor temperospatial stability on acute and one-year atrial fibrillation ablation outcomes.

BACKGROUND: The utility of rotor ablation using commercially available systems as an adjunct to pulmonary vein isolation (PVI) is controversial. Variable results may stem from heterogeneous practice patterns. We investigated whether a prespecified protocol to determine temperospatial rotor stability improved acute and intermediate outcomes following rotor ablation. HYPOTHESIS: Protocolized rotor mapping and ablation, with prespecified metrics to determine temporal rotor stability prior to ablation, will improve short- and long-term PVI/rotor ablation outcomes. METHODS: Patients undergoing PVI plus rotor ablation at Johns Hopkins during 2015 were included. The first cohort underwent rotor mapping and ablation at the operator's discretion, whereas the second cohort underwent protocolized rotor mapping, with ablation limited to temperospatially stable rotors. Both cohorts underwent PVI. Acute results (rotor elimination, atrial fibrillation [AF] termination), procedural data, and 1-year outcomes were assessed. RESULTS: Twenty-seven patients underwent ablation (mean age, 64.4 ± 9 years, male 81.5%, persistent AF 85.2%, long-standing persistent AF 14.8%, mean AF duration 4.4 ± 4 years, repeat cases 51.8%, and mean LA size 4.6 ± 0.8 cm). In the protocolized cohort, rotors were reproducible in 83% (10/12) of cases in at least 1 chamber. Acute rhythm change was achieved in 8/27 (29.6%) patients. Sinus rhythm on presentation (62.5% vs 15.8%, P = 0.03) and higher total targeted rotors (3.8 ± 1.7 vs 2.5 ± 1.0, P = 0.02) predicted acute change. At 12 months, freedom from AF/atrial tachycardia was achieved in 5/15 (33.3%) patients in the first cohort and 5/11 patients in the protocolized cohort (45.5%; P = 0.53 for comparison). CONCLUSIONS: Acute and intermediate results did not change with protocolized mapping designed to identify temperospatially stable rotors. Outcomes at 12 months were similar in both groups.

Trends in Transesophageal Echocardiography Use, Findings, and Clinical Outcomes in the Era of Minimally Interrupted Anticoagulation for Atrial Fibrillation Ablation.

OBJECTIVES: This study assessed trends in transesophageal echocardiography (TEE) use, rate of left atrial appendage (LAA) thrombus detection, and incidence of periprocedural cerebrovascular accident (CVA) since transitioning to a strategy of uninterrupted warfarin or briefly interrupted novel oral anticoagulant therapy in 2010. BACKGROUND: TEE is routinely performed before ablation for atrial fibrillation (AF) to ensure absence of LAA thrombus. METHODS: Patients with AF ablation presenting between January 2010 and September 2015 at Johns Hopkins Hospital were enrolled in an AF ablation registry; TEE and ablation outcomes were retrospectively analyzed. Presence of LAA thrombus, dense spontaneous echo contrast (SEC), or patent foramen ovale (PFO) were recorded. CVA incidence from procedure onset to 30 days post-procedure was evaluated using electronic medical record review. RESULTS: Pre-procedure TEE was performed in 646 of 1,224 AF ablation cases (52.8%). There was a decline in pre-procedure TEE use from 86% in 2010 to 42% in 2015 (p < 0.001). CVA incidence was 4/1,224 (0.33%) cases, and did not change during the study period. TEE findings included LAA thrombus (n = 6; 0.93%), PFO (n = 23; 3.6%), and dense spontaneous echo contrast (n = 99; 15.3%). Both SEC and LAA thrombus were associated with persistent AF, higher CHA2DS2VASC score, increased LA size, reduced LAA flow velocity, and decreased left ventricular ejection fraction. PFO was not associated with prior AF ablation, and SEC was not associated with increased CVA incidence. CONCLUSIONS: CVA is a rare complication of AF ablation in patients with minimally interrupted anticoagulation. Pre-ablation TEE may be reasonably avoided in patients without high-risk features.