Ebru Hacioglu

One-year follow-up after second-generation cryoballoon ablation for atrial fibrillation in a large cohort of patients: a single-centre experience

AIM The second-generation cryoballoon (CB-Adv) is effective in achieving pulmonary vein isolation (PVI) with encouraging results. In this study, we assessed the single-procedure outcome on a 1-year follow-up period in a large sample of patients having undergone PVI for drug-resistant atrial fibrillation (AF) using the CB-Adv. METHODS AND RESULTS A total of 393 patients (122 female, 31%; mean age 57.7 ± 12.9 years) with drug-refractory AF undergoing PVI using the novel CB-Adv were enrolled. Follow-up was based on outpatient clinic visits including Holter electrocardiograms. Recurrence of atrial tachyarrhythmias (ATas) was defined as a symptomatic or documented episode >30 s. A total of 1572 pulmonary veins (PVs) were identified and successfully isolated with 1.2 ± 0.3 mean freezes. Mean procedure and fluoroscopy times were 87.1 ± 38.2 and 14.9 ± 6.1 min, respectively. At a mean follow-up of 12 months, freedom from ATas after a single procedure was achieved in 85.8% of patients with paroxysmal atrial fibrillation and in 61.3% of patients with persistent AF (persAF). Similar success rates were observed between bonus freeze and single freeze strategies, 82.5 and 81.8%, respectively (P = 0.9). Multivariate analysis demonstrated that persAF (P = 0.04) and relapses during blanking period (BP) (P < 0.0001) were independent predictors of ATas recurrences. CONCLUSION Freedom from any ATa can be achieved in 81.9% of patients after a single CB-Adv procedure in a large cohort of patients. A bonus freeze does not influence the clinical outcome, and reducing the duration of the cryoapplication to 3 min offers excellent results. Persistent AF and arrhythmia recurrence during the BP are strong predictors of AF recurrence.

Phrenic nerve injury during ablation with the second-generation cryoballoon: analysis of the temperature drop behaviour in a large cohort of patients

AIMS The present study sought to analyse the relationship between the temperature drop during the cryoenergy application and the occurrence of phrenic nerve injury (PNI) in a large cohort of patients having undergone second-generation cryoballoon ablation (CB-A). METHODS AND RESULTS The first 550 consecutive patients having undergone CB-A for atrial fibrillation were enrolled. Attained temperatures at 20, 30, 40, and 60 s during cryoablation in the right-sided pulmonary veins (PVs) were collected. Diagnosis of PNI was made if reduced motility or paralysis of the hemidiaphragm was detected. The incidence of PNI in the study population was 7.3% (40/550); among them, only four (0.7%) did not resolve until discharge and one (0.2%) still persisted at 23 months. Patients with PNI exhibited significantly lower temperatures at 20, 30, and 40 s after the beginning of the cryoapplication in the right superior PV (RSPV) (P = 0.006, P = 0.003, and P = 0.003, respectively). The temperature drop expressed as Δ temperature/Δ time was also significantly higher in patients with PNI. Low temperature during the early phases of the freezing cycle (less than -38°C at 40 s) predicted PNI with a sensitivity of 80.5%, a specificity of 77%, and a negative predictive value of 97.9%. Among patients with a fast temperature drop during RSPV ablation, an RSPV diameter >23.55 × 17.95 mm significantly predicted PNI occurrence. CONCLUSION The analysis of the temperature course within the first 40 s after the initiation of the freezing cycle showed that the temperature dropped significantly faster in patients with PNI during ablation in the RSPV.

Incidence of real-time recordings of pulmonary vein potentials using the third-generation short-tip cryoballoon.

AIMS The third-generation Cryoballoon Advance Short-tip (CB-ST) has been designed with a 40% shortened tip length compared with the former second-generation CB Advance device. Ideally, a shorter tip should permit an improved visualization of real-time (RT) recordings in the pulmonary vein (PV) due to a more proximal positioning of the inner lumen mapping catheter. In the present study, we sought to analyse the rate of visualization of RT recordings in our first series of patients with the CB-ST device. METHODS AND RESULTS All consecutive patients having undergone CB ablation using CB-ST technology were analysed. Exclusion criteria were the presence of an intracavitary thrombus, uncontrolled heart failure, moderate or severe valvular disease, and contraindications to general anaesthesia. A total of 60 consecutive patients (60.5 ± 11.2 years, 62% males) were evaluated. Real-time recordings were detected in 209 of 240 PVs (87.1%). Specifically, RT recordings could be visualized in 55 left superior PVs (91.7%), 51 left inferior PVs (85.0%), 53 right superior PVs (88.3%), and 50 right inferior PVs (83.3). CONCLUSION The rate of visualization of RT recordings is significantly high during third-generation CB-ST ablation. Real-time recordings can be visualized in ∼87.1% of veins with this novel cryoballoon.

Learning curve using the second-generation cryoballoon ablation.

Aims To study the learning curve with the second-generation cryoballoon technology focusing on safety, efficacy and procedural characteristics. Methods We included 300 patients (men 64.6%, mean age 58.3 ± 12.4 years), 240 of whom were treated by four operators without prior experience in atrial fibrillation ablation and compared them with 60 consecutive patients treated by senior operator. To study the learning curves, we divided the study period into two trimesters and analyzed procedure duration, fluoroscopy times, complications, characteristics of the freeze–thaw cycles and midterm outcomes. Results Hands-on help from senior operators to achieve pulmonary vein isolation was needed only in the first study trimester (24.1%), most commonly to achieve right inferior pulmonary vein isolation (55.2%). The mean procedure duration shortened from 76.7 ± 17.4 to 65.1 ± 11.4 min (P < 0.0001), and fluoroscopy time decreased from 18.5 ± 7.3 to 12.1 ± 4.3 min (P < 0.0001) for first and second trimester, respectively, and approached senior operators results (58.2 ± 12.8 and 8.7 ± 4.5 min). Most of the major complications (one stroke, four pseudoaneurysms and one retroperitoneal hematoma) occurred during the first study trimester. Most characteristics of the freeze cycles remained unchanged in both study periods. Compared with junior operators, the senior operator achieved lower nadir temperatures in both inferior veins. However, there was no significant difference in midterm outcomes between junior and senior operators (79.5 vs 83.3%, P = 0.589). Conclusion The learning curve with the second-generation cryoballoon is steep. Inexperienced operators, trained in high-volume centers, can achieve pulmonary vein isolation safely and efficiently with short procedure and fluoroscopy times after having performed 20–30 cases.

Second generation cryoballoon ablation for atrial fibrillation in young adults: midterm outcome in patients under 40 years of age

Aims Pulmonary vein isolation (PVI) has been demonstrated more effective in young patients, in which the substrate for atrial fibrillation (AF) is probably more confined to pulmonary vein potentials. The present study sought to focus on the midterm outcomes in patients under 40 years having undergone PVI with the Cryoballoon Advance because of drug resistant AF. Methods and results Between June 2012 and December 2015, 57 patients having undergone Cryoballoon ablation (CB-A) below 40 years of age for AF in our centre were retrospectively analysed and considered for our analysis. All patients underwent this procedure with the 28 mm Cryoballon Advance. All 227 veins were successfully isolated without the need for additional focal tip ablation. Median follow-up was 18 ±10 months. The freedom from AF after a blanking period of 3 months was 88% in our cohort of patients younger than 40 years old. The most frequent periprocedural complication was related to the groin puncture and occurred in 2 patients. After a single procedure, the only univariate predictor of clinical recurrence was the diagnosis of hypertrophic cardiomyopathy. Conclusion Young patients affected by AF can be effectively and safely treated with CB-A that grants freedom from AF in 88% of the patients at 18 months follow-up following a 3-month blanking period. All veins could be isolated with the large 28 mm Cryoballoon Advance only.