Radiofrequency versus cryoballoon ablation for atrial fibrillation in the setting of left common pulmonary veins.

BACKGROUND: A left common pulmonary vein (LCPV) accounts as the most frequent pulmonary vein (PV) variation. Our aim was to compare the performance of radiofrequency (RF) versus second-generation cryoballoon (CB-A) ablation in patients with atrial fibrillation (AF) and LCPVs. METHODS: In a total cohort of 716 patients undergoing PV isolation with preprocedural CT-scanning, LCPV+ patients were selected with measurement of PV ostial area and trunk distance. All LCPV+ patients were matched between RF and CB-A group in a 1:1 ratio based on propensity scores, and compared for outcome. RESULTS: Left common pulmonary veins were found in 31% (88/283) RF versus 34% (146/433) CB-A patients, respectively, (P = .44). In the matched population of 83 LCPV+ patients in each group, electrical isolation could be achieved in all left-sided PVs. No significant difference was noted for the rate of AF/left atrial tachyarrhythmia (LAT) recurrence between RF and CB-A group (30% vs 28%, P = .86), with similar AF/LAT-free survival (log rank, P = .71). There were 48 patients with AF/LAT recurrence (29%) during the follow-up. Recurrence rate between paroxysmal versus persistent AF was 27/120 (22.5%) versus 21/46 (46%), P = .004. Cox proportional regression analysis withheld LA volume and persistent AF as independent variables to predict AF/LAT recurrence. No increased hazard for AF/LAT recurrence was observed for patients with a long (>15 mm) vs short (5-15 mm) LCPV trunk (OR 1.14, 95% CI 0.6-2.2, P = .7). CONCLUSIONS: In our study, equal efficacy and outcome was noted in LCPV+ patients between RF and CB-A technology.

Recent advances in cryoballoon ablation for atrial fibrillation.

Introduction: Pulmonary vein isolation (PVI), by catheter ablation, represents the current treatment for drug-resistant atrial fibrillation (AF). Nowadays cryoballoon (CB) is a recognized ablation method in patients with atrial fibrillation, mainly due to its ease of use, leading to reproducible and fast procedures. This novel single shot technology literally revolutionized the approach to AF ablation. Areas covered: The historical development of the cryoballoon, ablation techniques and new approaches beyond the ordinary PVI and complications are summarized here. Expert opinion: Although cryoballoon ablation has greatly standardized the approach to PVI a few critical points still need to be clarified scientifically in order to further uniform this procedure in cath labs worldwide. Duration and dosage of the cryoapplication is undoubtedly a topic of great interest.

Mid-term outcome following second-generation cryoballoon ablation for atrial fibrillation in heart failure patients: effectiveness of single 3-min freeze cryoablation performed in a cohort of patients with reduced left ventricular systolic function.

PURPOSE: Currently, information on the mid-term outcome of cryoballoon ablation (CB-A) for drug-resistant atrial fibrillation in patients with reduced left ventricular systolic function is limited. METHODS: Thirty-eight consecutive patients with paroxysmal or persistent atrial fibrillation (84.2% male), with median left ventricular ejection fraction of 37.3% were included in our study. All patients underwent the procedure with the 28-mm cryoballoon advance. RESULTS: There were no mayor complications related to the CB-A procedure. Median follow-up was 26.5 ±â€Š13.7 months. The freedom from atrial fibrillation after a blanking period of 3 months was 42.9% in our cohort of patients. During the follow-up period, 13 patients underwent at least a new electrophysiological procedure. After a single procedure, the univariate predictors of clinical recurrence after the blanking period were age and persistent atrial fibrillation. CONCLUSION: Second-generation CB-A of atrial fibrillation seems feasible and safe in patients with heart failure with reduced ejection fraction and heart failure with mid-range ejection fraction, in terms of complications rate and number of applications per vein. All pulmonary veins could be isolated with the 28-mm cryoballoon advance only.

Over-the-needle trans-septal access using the cryoballoon delivery sheath and dilator in atrial fibrillation ablation.

BACKGROUND: In the setting of second-generation cryoballoon (CB2) ablation, left atrial (LA) access is generally achieved using a standard sheath (SS) that is exchanged for the 15Fr cryoballoon delivery sheath (CBS) and dilator over a long wire (CBS over-the-wire technique, CBS-W). Our objective was to evaluate the direct use of the CBS to gain LA access, by advancing the latter over the trans-septal needle (CBS over-the-needle technique, CBS-N), under transesophageal echocardiographic (TEE) guidance. METHODS: Consecutive patients who underwent CB2 ablation with the CBS-N technique were evaluated for feasibility of gaining LA access using TEE guidance and fluoroscopy views. Complications related to the LA access were compared with a matched CBS-W control group. Subanalysis (30 CBS-W vs 30 CBS-N patients) evaluated time-to-LA of the CBS: time from superior vena cava (with SS vs CBS) to LA insertion of the CBS, after exchange or directly, respectively. RESULTS: LA access could be achieved in all 505 patients of the CBS-N group, without technique modification or additional equipment. Challenging interatrial septa were noted in 13% of these patients: previous atrial septal defect repair (1%), hypermobile (10%), aneurysmal (1%), and abnormally thickened/fibrotic (1%). Incidence of complications was similar to the CBS-W group. Subanalysis showed a shorter time-to-LA in the CBS-N versus CBS-W group, 72 ± 46 seconds versus 293 ± 180 seconds, P < .001. CONCLUSIONS: Our study showed that the CBS-N technique is feasible and safe under echocardiographic guidance. Without sheath exchange, it simplifies the CB2 procedure, is less costly, time sparing, and might reduce the risk of air embolism.

Predictors of long-term outcome in patients undergoing a first repeat ablation consisting solely of re-isolation of reconnected pulmonary veins.

AIMS: To define predictors of long-term outcome of a first repeat ablation solely consisting of re-isolation of reconnected pulmonary veins (PVs). METHODS: Three hundred seven patients (age 59 ± 9%, 77% males, non-paroxysmal AF 43%) with recurrent AF after first PVI were studied. Re-isolation of reconnected PVs was guided by a circular mapping catheter and 3D mapping system using RF ablations. A PV was defined as "triggering" in case of spontaneous ectopy or AF paroxysms originating from the PV. RESULTS: After a mean follow-up of 5.05 ± 2.21 years, 194 (63.2%) patients (73.0% in PAF vs 50.4% in non-PAF, log Rank <0.001) were free from AF. A "triggering" PV was present in 48 (15.6%) during the first PVI and in 52 (16.9%) at repeat. Independent predictors of recurrence were a non-PAF type (HR: 1.814, 95%CI: 1.090 - 3.018, p=0.022) and early recurrence (≤ 3 months) after first PVI (HR: 1.632, 95%CI: 1.091 - 2.443, p=0.017) while a "triggering" PV at first or repeat was a predictor of good outcome (HR: 0.574; 95%CI: 0.344 - 0.959; p=0.034) in the multivariable analysis. CONCLUSIONS: A repeat ablation solely consisting of re-isolation of reconnected PVs results in a high degree of long-term AF freedom, especially in PAF and in case of a PV trigger at index or repeat. Patients with non-PAF or experiencing early AF recurrence after first PVI are less responsive.

Evaluation of the luminal esophageal temperature behavior during left atrium posterior wall ablation by means of second-generation cryoballoon.

PURPOSE: The purpose of this study was to clarify the behavior of the luminal esophageal temperature (LET) in a cohort of patients undergoing second-generation cryoballoon (CB-A) for pulmonary vein isolation (PVI) and additional left atrium posterior wall (LAPW) ablation by means of CB-A. METHODS: Thirty patients with symptomatic persistent AF (PersAF), having undergone PVI + LAPW cryoballoon ablation with LET monitoring. RESULTS: Interruption of the application due to a LET below 15 °C occurred in 5 patients (16.6%), 2 at the LIPV and 3 in the LAPW. The 5 patients underwent gastroscopy the day after ablation. In all individuals, esophageal thermal lesion (ETL) was absent. CONCLUSION: The evaluation of LET might be an additional tool in helping to prevent damage to the esophagus during the LAPW ablation with the CB-A by stopping the freeze application when temperature reaches values of < 15 °C.

Quantification of acute parasympathetic denervation during cryoballoon ablation by using extracardiac vagal stimulation.

AIMS: The purpose of this study was to systematically quantify the level of acute parasympathetic denervation in a stepwise fashion by means of extracardiac vagal stimulation (ECVS) by positioning a quadripolar catheter in the internal jugular vein, in a cohort of patients undergoing second-generation cryoballoon ablation for paroxysmal atrial fibrillation. METHODS: Fifty patients with symptomatic paroxysmal atrial fibrillation, having undergone extracardiac vagal stimulation before and after ablation by means of second-generation cryoballoon second-generation cryoballoon ablation, were included. RESULTS: The extracardiac vagal stimulation performed preablation provoked cardioinhibitory responses in all patients with mean pause duration of 10130.6 ± 3280.0 ms. At the end of the procedure, the VRs were significantly diminished with mean pause of 1687.5 ms ± 2183.7 ms (P = 0.00 compared with the pause before the procedure). CONCLUSION: The ECVS proved to be a reproducible, feasible and reliable method to quantify the degree of parasympathetic denervation during CB-A. In all patients, significant cardiac parasympathetic denervation could be observed at the end of the procedure. Responses to ECVS were more specific to quantify the vagal denervation than the increase in the heart rate. However larger studies are needed to confirm this observation.

Impact of an additional right pulmonary vein on second-generation cryoballoon ablation for atrial fibrillation: a propensity matched score study.

PURPOSE: Cryoballoon (CB) technology in the context of anatomical pulmonary vein (PV) variants might hypothetically hamper successful PV isolation (PVI). Our aim was to assess the impact of a right middle PV (RMPV) in the setting of second-generation cryoballoon (CB advance-CB-A), on procedural parameters and on mid-term follow-up. METHODS: Consecutive patients with AF presenting RMPV (RMPV+) at the pre-procedural computed tomography who underwent PVI by CB-A were enrolled. Comparison with propensity score-matched patients without RMPV (RMPV-) was performed. Acute procedural parameters and clinical follow-up were assessed. RESULTS: A total of 240 patients (80 RMPV+) were included in the analysis. Twelve of 80 (15%) RMPV+ patients underwent a direct cryo-application in this variant and accomplished the isolation without phrenic nerve palsy, whereas in 25 of 80 (31%) RMPV+ patients, the RMPVs were not targeted directly nor indirectly (by co-occlusion during application at a major PV). At a median follow-up of 17.3 [interquartile range 11.3-26.5] months, there was no significant difference in AF-free survival between RMPV+ and RMPV- patients (78.8 vs 78.1%, P = 1.00), and the recurrence of atrial arrhythmias among patients with versus without an intentional or indirect cryo-application to the RMPV was not different (22 vs 20%, P = 1.00). CONCLUSIONS: Mid-term outcome after CB-A ablation did not differ between RMPV+ and RMPV- patients. Within RMPV+ patients, outcome was similar between those with versus without a cryo-application (either direct or indirect) to the additional vein.

Continuous monitoring after second-generation cryoballoon ablation for paroxysmal atrial fibrillation in patients with cardiac implantable electronic devices.

BACKGROUND: The second-generation cryoballoon (CB) is effective in achieving pulmonary vein isolation. Continuous monitoring would eliminate any over- or underestimated freedom from atrial fibrillation (AF) postablation. OBJECTIVE: The purpose of this study was to differentiate between arrhythmias occurring after cryoballoon ablation (CBA), detecting true AF in symptomatic patients and detecting silent subclinical AF. METHODS: Between June 2012 and January 2015, 54 patients with a preexisting cardiac implantable electronic device (CIED) who had undergone CBA for paroxysmal atrial fibrillation (PAF) were included in our retrospective study. Regular CIED controls, physical examination, and ECG recordings were performed by an experienced cardiologist blinded to the ablation procedure. Data on any hospitalization during follow-up were gathered. Patients were encouraged to note all clinical symptoms during follow-up. RESULTS: Continuous monitoring showed a success rate of 83.3% after 1 year and 75.93% after 3 years of follow-up. During the first year, 68% of episodes of palpitations after ablation were due to sinus tachycardia, nonsustained ventricular tachycardia, or supraventricular tachycardia. AF recurrence was detected in 15.6% of asymptomatic patients during follow-up. Total AF burden post-CBA had decreased to 0.64% ± 4.34% (P <.001) during long-term follow-up of 3.3 years. CONCLUSION: Although this is a selected group of patients with a preexisting CIED, continuous monitoring showed freedom from AF in 83.3% of patients post-CBA after 1 year and 75.93% after 3 years of follow-up.

Standardized Quantification of Vagal Denervation by Extracardiac Vagal Stimulation during Second Generation Cryoballoon ablation: a Vein per Vein Analysis.

AIMS: The purpose of this study was to evaluate the contribution in the acute loss in vagal innervation after ablation with the second generation cryoballoon (CB-A) in each distinct pulmonary vein (PV) by means of external cardiac vagal stimulation (ECVS) by positioning a catheter in the internal jugular vein in a cohort of 60 patients. METHODS: Sixty patients, 50 starting from the left superior pulmonary vein (LSPV) and 10 from the right superior pulmonary vein with symptomatic paroxysmal atrial fibrillation (PAF), having undergone ECVS before the first and after each PV ablation by means of CB-A ablation, were included. RESULTS: The ECVS performed pre-ablation provoked cardioinhibitory responses in all cases with mean pause duration of 10251.83 ms ± 2826.23 ms. At the end of the procedure, the vagal reactions (VR) were significantly diminished. Specifically, compared against the initial pause, responses were 8957.06 ± 2711.66 ms (p < 0.01) after left superior PV, 10017.36 ± 9127.0 ms (p = 0.88) after left inferior PV, 6020.16 ± 3780.709 ms (p < 0.001) after right inferior PV and 1687.5 ± 2183.7 ms (p < 0.001) after right superior PV. Noteworthy, if starting with ablation in the RSPV, VR was immediately reduced by 90.34%, 990.7 ± 379.78 ms (p < 0.001) as compared to baseline response. CONCLUSION: Although not directly targeting the ganglion plexuses, AF ablation with the CB-A causes a significant acute loss in parasympathetic innervation. The RSPV showed to be associated with the most significant reduction of acute loss in parasympathetic innervation.

Hybrid thoracoscopic epicardial ablation of right ventricular outflow tract in patients with Brugada syndrome.

BACKGROUND: Abnormal delayed electrograms (EGMs) from the anterior wall of the right ventricular outflow tract (RVOT) epicardium have become the ablation target in Brugada syndrome (BrS). OBJECTIVE: The aim of this study was to analyze the safety, feasibility, and efficacy of a novel hybrid thoracoscopic approach to perform epicardial RVOT radiofrequency ablation in BrS. METHODS: Thirty-six patients with BrS (26 men (72.2%); mean age 36.6±15.8 years; range 3-63 years) who underwent hybrid thoracoscopic epicardial ablation of RVOT from January 2016 to April 2018 were included in this study. Two expert electrophysiologists analyzed the EGMs during ajmaline challenge and guided the surgeon to perform ablation. Ajmaline challenge was repeated after 1 month to assess the absence of the BrS electrocardiographic pattern. Patients were followed by remote monitoring and outpatient visits every 6 months. RESULTS: The elimination of all abnormal EGMs was achieved in 94.4% of patients. After a mean follow-up of 16 ± 8 months (range 6-30 months), freedom from ventricular arrhythmias was obtained in 7 (77.8%) patients in secondary prevention 9/36 (25%) and in 24 (100%) patients in primary prevention 24/36 (75%). Major complications were observed in 1 patient (2.8%), who experienced late cardiac tamponade. CONCLUSION: Hybrid thoracoscopic epicardial RVOT ablation in BrS is a safe and feasible approach, allowing direct visualization of ablation during radiofrequency delivery. Because of ventricular arrhythmia recurrences, implantable cardioverter-defibrillator implantation is still mandatory in patients treated in secondary prevention and with high risk.

Second-Generation Cryoballoon Ablation for Atrial Fibrillation　- A Detailed Analysis of the Impact of Left Atrial Volume Index on Clinical Outcome.

BACKGROUND: Pulmonary vein isolation (PVI) by means of cryoballoon is increasingly being used for the treatment of atrial fibrillation (AF). This study assessed whether the left atrial volume index (LAVI) predicts AF recurrence following PVI by means of 2nd-generation cryoballoon (Cryoballoon Advance; CB-A) when comparing persistent AF (PeAF) and paroxysmal AF (PAF). Methods and Results: Patients with drug-resistant AF and undergoing preprocedural computed tomography (CT) and PVI with CB-A were included. LAV was estimated from 3D CT images. A total of 417 patients with AF were included (95 PeAF, 322 PAF patients). After a mean of 22.1±9.4 months follow-up, 45/95 (47%) PeAF patients and 254/322 (79%) PAF patients had no recurrence. LAVI was an independent predictor for AF recurrence in PeAF patients (hazard ratio 1.042 per 1 mL/m2; 95% confidence interval 1.006-1.080, P=0.02), but not in PAF patients. In PeAF patients with LAVI ≤61 mL/m2, the freedom from recurrence was 78.5% vs. 22.2% in those with LAVI >61 mL/m2 (hazard ratio 5.771, 95% confidence interval 2.434-13.682, P<0.001), and the mid-term success rate was comparable with PAF patients. CONCLUSIONS: LAVI predicted AF recurrence after PVI using CB-A in PeAF patients but not in PAF patients. If LAVI was ≤61 mL/m2, the mid-term efficacy among PeAF patients was equivalent to that for PAF patients.

Real-Time Recordings in Cryoballoon Pulmonary Veins Isolation: Comparison Between the 25mm and the 20mm Achieve Catheters.

AIMS: Real Time Recordings (RTR) of pulmonary vein (PV) activity provide important information in the setting of the 2nd generation Cryoballoon (CB-A), as a funcion of time to isolation. Visualization of RTR with the standard inner lumen mapping catheter (ILMC) 20mm Achieve (AC) is possible in roughly 50% of PVs. A novel 25mm-Achieve Advance (AC-A) has been developed with the aim of increasing the detection of RTR. The purpose of this study is to compare the AC-A with the AC, to feasibility and improvement of RTR. METHODS: We assigned 50 patients with paroxysmal or persistent atrial fibrillation to CB-A PVI, using the AC-A as ILMC. We compared this group with 50 patients, matched for age and left atrial volume, who previously underwent the CB-A PVI using the AC. RESULTS: RTR were more frequently observed with the AC-A than with the AC (74% vs 49%; p= 0.02). RTR in the left superior PVs was similar in both groups (74% vs 72%, p= 0.8). RTR with the AC-A were equally appreciated in left or right sided, superior or inferior PVs. No significant differences were found in terms of feasibility, procedure fluoroscopy and freezing times, nadir temperatures, and acute PVI. CONCLUSIONS: CB-A PVI with the AC-A is feasible and safe in all PVs. The AC-A has proven significantly superior in visualising RTR if compared to the AC, affording RTR in 74% of PVs.

Single 3-min freeze per vein ablation strategy with the second-generation cryoballoon for atrial fibrillation in a large cohort of patients: long term outcome after a single procedure.

PURPOSE: The purpose of the present study was to assess the long-term success rate of a single 3-min freeze per vein ablation strategy in the setting of pulmonary vein isolation (PVI) by means of second-generation cryoballoon (CB-A; Arctic Front Advance, Medtronic, Minneapolis, MN, USA) in a large cohort of patients. METHODS: Three hundred and one patients with drug resistant atrial fibrillation (AF) having undergone PVI by means of CB-A using a single 3-min freeze per vein ablation strategy were included in the analysis. RESULTS: Paroxysmal AF (PAF) was documented in 70.8% of the patients, while 29.2% presented with persistent AF (PersAF). The mean number of CB applications was 1.09 ± 0.3 in the left superior pulmonary vein (LSPV), 1.04 ± 0.2 in the left inferior pulmonary vein (LIPV), 1.12 ± 0.3 in the right superior pulmonary vein (RSPV), and 1.12 ± 0.3 in the right inferior pulmonary vein (RIPV). All PVs were successfully isolated with a 28-mm CB-A only. After a mean follow-up of 38.1 ± 7.5 months, 207 (68.8%) patients were free of atrial tachyarrhythmia (ATa) recurrences following a single procedure. Specifically, 72.8% of patients presenting with PAF and 59.1% of individuals with PersAF did not experience a recurrence. CONCLUSIONS: A single 3-min freeze per vein strategy is effective in treating AF on a long term follow-up of 38 months. Specifically, it can afford freedom from ATa recurrences in 72.8% of patients affected by PAF and 59.1% of patients initially presenting with PersAF after a single CB-A procedure.

Anatomical and procedural predictors of pulmonary vein stenosis in the setting of second-generation cryoballoon ablation.

AIMS: Pulmonary vein stenosis (PVS) is a well recognized complication as a consequence of pulmonary vein isolation. In the current study, we sought to analyze potential anatomical and intraprocedural predictors of PVS during second-generation cryoballoon ablation, particularly focusing on the impact of freeze duration and number of cryoapplications. METHODS: Fifty-four patients who underwent cryoballoon ablation for atrial fibrillation were included retrospectively in this study. All patients underwent cardiac-enhanced multidetector computed tomography both before and after the ablation. The exclusion criteria were any contraindications for the procedure, including the presence of an intracavitary thrombus, uncontrolled heart failure and contraindications to general anesthesia. RESULTS: Mild (25-50%) PVS was only detected in one vein (0.4%) and neither moderate (50-75%) nor severe (>75%) PVS were found. Twenty-five pulmonary veins (12%) exhibited slight narrowing of the diameter (less than 25%). In the univariate analysis, a longer duration of cryoapplication and a larger pulmonary vein ostium preprocedure diameter and area were independently associated with pulmonary vein narrowing [odds ratio (OR): 1.004; confidence interval (CI): 1.001-1.008, P = 0.016; OR: 1.250, CI: 1.090-1.434, P = 0.001 and OR: 1.006; CI: 1.002-1.011, P = 0.006] respectively. CONCLUSION: Longer duration of cryoablation, an increased number of applications per vein and larger pulmonary vein ostia are associated with a higher risk of pulmonary vein diameter and area reduction. These findings might suggest to lower the dosing to a single and shorter application if isolation is attained, to reduce the possibility of future pulmonary vein narrowing.

Clinical value of induction protocol after second generation cryoballoon ablation for paroxysmal atrial fibrillation.

Aims: The predictive value of induction studies after catheter ablation for atrial fibrillation (AF) is still debatable. To date, these studies have not been implemented in patients after cryoballoon (CB) ablation. Our aim was to analyse the clinical value of AF induction in patients treated by second generation CB for paroxysmal AF. Methods and results: Seventy patients underwent at first an isoproterenol challenge after pulmonary vein (PV) isolation to assess AF induction and early PV reconnections (EPVR). Patients without EPVR were evaluated for premature atrial contraction (PAC) induction; atrial ectopy was considered frequent (PAC+) if >1/10 cycles or >6/min. After restitution of baseline heart rate, rapid atrial pacing (RAP) was performed on all patients. AF induction by isoproterenol occurred only in 3/70 (4%) patients of whom 2/3 (66%) patients with an EPVR of a triggering vein. In the 62 patients without EPVR, PAC+ occurred in 17 patients (27%). RAP could induce AF in 23/70 (33%) patients. At a mean follow-up of 13.5 months, there were 11/70 (16%) AF recurrences. There was no significant difference in the AF recurrence rate between RAP inducible vs. non-inducible patients (log-rank P = 0.33). A 41% recurrence rate (7/17 patients) was seen in the PAC+ group with significantly different AF-free survival for PAC+ vs. PAC- patients (log rank P < 0.0001). PAC+ was the only independent determinant to predict AF recurrence after multivariate analysis. Conclusion: PAC occurrence in response to isoproterenol could predict AF recurrence after PV isolation by CB, while RAP showed no prognostic implication.

Single freeze per vein strategy with the second-generation cryoballoon for atrial fibrillation: a propensity score-matched study between 180- and 240-s application time in a large cohort of patients.

Aims: The single-freeze strategy using the second-generation cryoballoon (CB-A, Arctic Front Advance, Medtronic, Minneapolis, MN, USA) has been reported to be as effective as the recommended double-freeze approach in several single-centre studies. In this retrospective, international, multicentre study, we compare the 3-min single-freeze strategy with the 4-min single-freeze strategy. Methods and results: Four hundred and thirty-two patients having undergone pulmonary vein isolation (PVI) by means of CB-A using a single-freeze strategy were considered for this analysis. A cohort of patients who were treated with a 3-min strategy (Group 1) was compared with a propensity score-matched cohort of patients who underwent a 4-min strategy (Group 2). Pulmonary vein isolation was successfully achieved in all the veins using the 28-mm CB-A. The procedural and fluoroscopy times were lower in Group 1 (67.8 ± 17 vs. 73.8 ± 26.3, P < 0.05; 14.9 ± 7.8 vs. 24.2 ± 10.6 min, P < 0.05). The most frequent complication was PNP, with no difference between the two groups (P = 0.67). After a mean follow-up of 13 ± 8 months, taking into consideration a blanking period of 3 months, 85.6% of patients in Group 1 and 87% of patients in Group 2 were free from arrhythmia recurrence at final follow-up (P = 0.67). Conclusion: There is no difference in acute success, rate of complications, and freedom from atrial fibrillation recurrences during the follow-up between 3-min and 4-min per vein freeze strategies. The procedural and fluoroscopy times were significantly shorter in 3-min per vein strategy.

Phrenic nerve injury during right inferior pulmonary vein ablation with the second-generation cryoballoon: clinical, procedural, and anatomical characteristics.

Aims: There is still sparse information regarding phrenic nerve injury (PNI) during ablation of the right inferior pulmonary vein (RIPV) by means of the second-generation cryoballoon advance (CB-A). The aim of this study was to describe the procedural, anatomical, and clinical characteristics of patients who experienced PNI during the RIPV ablation. Methods and results: Consecutive patients who had undergone pulmonary vein isolation (PVI) using CB-A and suffered PNI during RIPV ablation were retrospectively included in our study. A cohort of patients who did not suffer any PNI was randomly included in a 1:3 ratio as a control group. The incidence of PNI during RIPV cryoapplication was 3.5%, (34 of 979 patients). There were no significant differences in clinical characteristics between patients with and without PNI. The prevalence of right common ostium (RCO) was significantly higher in patients with a PNI [4 patients (11.8%) vs. 1 patient (1.0%); P < 0.01]. A temperature drop velocity from the basal temperature to - 20 °C of 2.38 °C/s rendered a sensitivity of 82.4% and a specificity of 51.0% with a negative predictive value of 89.7%. Temperature drop velocity from basal to - 20 °C and the presence of an RCO were predictors of PNI in the multivariate analysis [odds ratio (OR) 7.27, 95% confidence interval (CI) 2.54-20.80; P < 0.01 and OR 18.41, 95%CI 1.87-181.23; P = 0.01, respectively). Conclusion: PNI during RIPV freeze might occur in around 3.5% of cases. The presence of an RCO and a fast temperature drop must prompt a careful monitoring of the phrenic nerve function during cryoapplications on the RIPV.

Role of the burden of premature atrial contractions during the blanking period following second-generation cryoballoon ablation in predicting late recurrences of atrial arrhythmias.

PURPOSE: Recent data suggests that high burden of premature atrial complexes after pulmonary vein isolation predicts recurrences of atrial arrhythmias. The present study sought to assess the role of premature atrial complexes burden in predicting atrial arrhythmias recurrences in patients with atrial fibrillation (AF) who have undergone second-generation cryoballoon ablation (CB-Adv). METHODS: Consecutive patients with drug-resistant paroxysmal atrial fibrillation who underwent pulmonary vein isolation using CB-Adv technology as the index procedure were retrospectively included. Twenty-four-hour Holter recordings were performed for every patient. Based on previously published data, a burden of more than 76 premature atrial complexes per day was considered as being high. RESULTS: One hundred and seven patients were included in the analysis. The recurrence rate among the group of patients with more than 76 premature atrial complexes per day was significantly higher compared with the group with a lower burden of premature atrial complexes (47.5 vs 11.9%, respectively; p < 0.001). In the multivariate analysis, the documentation of more than 76 premature atrial complexes per day registered at 1 month and at the end of the blanking period, predicted late recurrence of atrial arrhythmias. CONCLUSIONS: Frequent premature atrial complexes in the early stages after CB-Adv ablation strongly predict late recurrences of atrial arrhythmias.

Second-generation cryoballoon ablation in the setting of left common pulmonary veins: Procedural findings and clinical outcome.

BACKGROUND: A left common pulmonary vein (LCPV) accounts for the most frequent PV variation. Use of the cryoballoon (CB) for isolating these veins is still debatable. To date, no data are available regarding the feasibility, acute PV isolation, and clinical outcome of the second-generation CB (CB-A) in this setting. OBJECTIVE: The purpose of this study was to investigate the performance of the CB-A in patients with LCPVs. METHODS: In a total cohort of 433 patients having undergone CB-A ablation for drug-refractory atrial fibrillation together with preprocedural computed tomographic scanning, 146 patients presented an LCPV. Measurement of ostial area and trunk distance was performed, together with analysis of procedural and fluoroscopic data in order to determine the ablation strategy. The latter 146 LCPV+ patients were compared for outcome with a cohort of 146 propensity-score matched LCPV- patients. RESULTS: Electrical isolation could be achieved in all left-sided veins. A long left common trunk (>15 mm) was found in 25% (37/146) of the LCPV+ patients. LCPVs treated with a single-shot freeze strategy presented a longer trunk (22 ± 5 mm vs 9 ± 4 mm, P <.001) and smaller ostial area (305 ± 109 mm2 vs 400 ± 108 mm2, P <.001) compared to LCPV patients in whom a segmental (superior and inferior) freeze was delivered. Survival free from atrial fibrillation was similar between LCPV+ and LCPV- patients during mean follow-up of 19 ± 10 months (log rank P = .33). CONCLUSION: CB-A ablation in LCPV+ patients is effective and showed no difference in clinical outcome compared to LCPV- patients.