Reconduction After Second-Generation Cryoballoon-Based Pulmonary Vein Isolation　― Impact of Different Ablation Strategies ―

Abstract

and fewer CB applications and demonstrated comparable clinical outcomes. 3,4 After identifying the time to PVI (time-to-effect, TTE) as an essential indicator for durability of PVI, latest ablation strategies implemented the individual TTE. 5 Reducing the ablation time, omitting the bonus-freeze cycle and implementing the TTE to recent protocols resulted in shorter procedure duration and reduced periprocedural complications without affecting clinical outcomes. 3 Nevertheless, data on the impact of different ablations protocols on durability after CB2-based PVI are limited. 6 The present study aimed to evaluate the rate of electrical reconduction in patients presenting for repeat ablation due to recurrence of atrial tachyarrhyth-P ulmonary vein isolation (PVI) forms the cornerstone of invasive treatment of atrial fibrillation (AF). Latest AF guidelines state that PVI should be performed using either radiofrequency (RF) or cryoballoon (CB) catheters. 1 The second-generation CB (CB2; Arctic Front Advance, Medtronic Inc., Minneapolis, MN, USA) has demonstrated high procedural success rates, relatively short procedure times, high durability of PVI and convincing long-term clinical success rates. 2 Ablation strategies predominantly imply fixed freeze-cycle durations of 180-240s, oftentimes followed by a bonus-freeze cycle. 3 To potentially reduce complications as well as procedure duration, the protocols were modified, aiming for shorter

Experience and procedural efficacy of pulmonary vein isolation using the fourth and second generation cryoballoon: The shorter, the better?

“…The FIRE AND ICE trial prospectively randomized 762 patients with drug‐refractory PAF to either RF‐ or CB‐based PVI and demonstrated the noninferiority of CB ablation with respect to efficacy and overall safety 2 . Recent studies focusing on CB2 ablation demonstrated a high rate of PVI (84%–90%) during the index freeze cycle, excellent 1‐ to 5‐year clinical outcomes even if “no‐bonus” freeze protocols or a shorter freeze cycle duration were applied, and a high rate of durable PVI as demonstrated in patients undergoing repeat procedures for recurrent atrial tachyarrhythmia after index CB2 ablation 4,24,27–30 . TTE‐based ablation protocols aim for a reduction in total energy transfer per PV, which in turn may contribute to an even better safety profile of CB‐based PVI as compared to protocols with fixed freeze cycle duration with or without bonus‐freeze 9,11,18,25,28 .…”

Novel Cryoballoon Ablation System for Single Shot Pulmonary Vein Isolation ― The Prospective ICE-AGE-X Study ―

“…The detailed intraprocedural management has been described in previous studies from our center. 13,14 In brief, the procedure was performed in patients under deep sedation using midazolam, sufentanyl and propofol. Two ultrasound-guided right femoral vein punctures were performed and 2x 8F short sheaths were inserted.…”

“…17, 18 The detailed intraprocedural management utilizing AF-CB2 and AF-CB4 has been described in previous studies. 9, 13 The pop-out phenomenon was defined by the observation of a balloon dislodgement from the PV ostium after initializing the freezing process. This was evaluated by a second injection of contrast medium and fluoroscopy 5-10 s after initializing the freezing process.…”

“…10 The clinical outcome is based on a high rate of durable PVI ranging between 69% and 77% for patients undergoing repeat procedures due to AF recurrence. [11][12][13] The recently introduced POLARx cardiac cryoablation system (Boston Scientific, St. Paul, MN, USA) offers unique design changes and features to possibly patients prior to PVI to rule out intracardiac thrombi and to assess the LA diameter. No further pre-procedural imaging was performed.…”

Shorter RSPV cryoapplications result in less phrenic nerve injury and similar 1‐year freedom from atrial fibrillation

“…With patient numbers in the mentioned studies ranging from around 18 to 66, our study with 30 patients is comparable. A retrospective study by Heeger et al with 192 patients found no differences in reconduction rate per PV 22 . The different dosing protocols adopted in these studies may have accounted for differences in outcome.…”