Vedran Velagic

Single 3-minute freeze for second-generation cryoballoon ablation: One-year follow-up after pulmonary vein isolation

BACKGROUNDnThe second-generation cryoballoon (CB-Adv) is effective in achieving pulmonary vein isolation (PVI) with encouraging results. The mid-term clinical efficacy of a single 3-minute freeze, without a routine bonus application, has been recently demonstrated.nnnOBJECTIVEnThe purpose of this study was to assess long-term clinical outcome after PVI with the CB-Adv using a single 3-minute application.nnnMETHODSnA total of 143 consecutive patients (93 male [65%], mean age 59.6 ± 12.0 years) with paroxysmal atrial fibrillation (PAF; 113/143 [79%]) or early persistent atrial fibrillation (AF; 30/143 [21%]) underwent PVI using CB-Adv with a single 3-minute freeze. Atrial tachyarrhythmia recurrences were defined as symptomatic or documented episodes >30 seconds.nnnRESULTSnAfter a single freeze, isolation could be reached in 94.1% of all identified pulmonary veins. Complete PVI was successfully achieved with 1.1 ± 0.4 mean freezes. Persistent phrenic nerve palsy occurred in 5 of 143 patients (3.5%). At a mean 12.1 ± 4.4 months of follow-up, after a 3-month blanking period (BP), 80.4% (115/143) were in stable sinus rhythm (93/113 [82.3%] for PAF; 22/30 [73.3%] for early persistent AF). Fifteen patients underwent a second procedure with radiofrequency ablation showing reconnection in 7 of 15 right-sided (46.7%) and 6 of 15 left-sided (40%) pulmonary veins. Relapses during BP (P <.01), time to PVI (P = .02), and longer AF duration (P = .04) were independent predictors of recurrences.nnnCONCLUSIONnA single 3-minute freeze is highly effective, determining an atrial tachyarrhythmia freedom of 80.4% at 1-year follow-up. The incidence of persistent phrenic nerve palsy is 3.5%. Relapses during BP, time to PVI, and longer AF duration are predictors of recurrences. Routine use of an insurance freeze may not be needed.

On the Quest for the Best Freeze: Predictors of Late Pulmonary Vein Reconnections After Second-Generation Cryoballoon Ablation.

Background—The second-generation cryoballoon is effective in achieving acute pulmonary vein isolation (PVI) and favorable clinical outcome. To date, no data are available on factors affecting late PV reconnection after second-generation cryoballoon ablation. Methods and Results—A total of 29 consecutive patients (25 male, 86.2%; mean age 57.8±13.8 years) underwent a repeat procedure, after a mean 11.6±4.5 months (range, 3.5–19.7 months), after index ablation using the 28-mm second-generation cryoballoon. All repeat ablations were performed using a 3-dimensional electroanatomical mapping system. Among all 115 PVs, including 1 left common ostiums (LCOs), 25 (21.7%) showed a PV reconnection in 20 patients (1.25 per patient). Persistent PVI could be documented in 90 of 115 PVs (78.2%). In 9 of 29 patients (31%), all PVs were electrically isolated. In the multivariable analysis, time to PVI (P=0.03) and failure to achieve −40°C within 60 s (P=0.05) independently predicted late PV reconnection. At receiver-operator curve analysis, time to PVI <60 s identified the absence of PV reconduction (sensitivity, 86.7%; specificity, 86.2%; positive predictive value, 59.1%; and negative predictive value, 96.4%; area under the curve, 0.85; confidence interval, 0.73–0.97; P<0.001). Conclusions—The rate of late PV reconnection after second-generation cryoballoon ablation is low (1.25 PVs/patient). Faster time to isolation and achievement of −40°C within 60 s independently predict durable PVI. In addition, 60-s cut-off for time to PVI indicates persistent isolation with 96.4% negative predictive value. These parameters might guide the operator whether to perform further applications to ensure a long-lasting PVI.

Incidence and characteristics of complications in the setting of second-generation cryoballoon ablation: A large single-center study of 500 consecutive patients

BACKGROUNDnThe second-generation cryoballoon Advance (CB-A) recently launched on the market has technical modifications designed to significantly improve procedural outcome with respect to the first-generation device.nnnOBJECTIVEnThe purpose of this study was to evaluate the overall incidence of complications in a large sample of patients having undergone pulmonary vein (PV) isolation with CB-A technology.nnnMETHODSnAll consecutive patients who underwent PV isolation procedures using CB-A technology between June 2012 and February 2015 were considered. Exclusion criteria were presence of an intracavitary thrombus, uncontrolled heart failure, moderate or severe valvular disease, left atrial diameter ≥55 mm, and contraindications to general anesthesia.nnnRESULTSnDuring the study period, 500 consecutive patients (67% male, age 57.6 ± 12.9 years) were enrolled. Major complications occurred in 10 patients (2.0%): vascular complications at the puncture site in 6 (1.2%), and thromboembolic events, cardiac tamponade, persisting phrenic nerve palsy, and retroperitoneal hematoma all occurred in a single patient respectively (0.2%). Phrenic nerve palsy occurred in 36 patients (7.2%) and did not revert in only 1 patient at final follow-up of 20 months. No deaths related to the procedure occurred. No predictors of major complication were found.nnnCONCLUSIONnThe present findings highlight that PV isolation using CB-A technology can be safely performed with a low incidence of adverse events. The incidence of major complications after atrial fibrillation ablation procedures using CB-A technology was 2% in our study. The most frequent complication consisted of vascular complications at the puncture site. No deaths related to the procedure occurred.

Electrophysiological findings following pulmonary vein isolation using radiofrequency catheter guided by contact-force and second-generation cryoballoon: lessons from repeat ablation procedures.

AIMSnTo assess the incidence of late pulmonary vein (PV) reconnection following index PV isolation (PVI) procedure initially achieved with radiofrequency contact-force catheter ablation (CFCA) and second-generation cryoballoon ablation (CB-AdvA).nnnMETHODS AND RESULTSnA total of 56 consecutive patients (41 male, 73.2%; mean age 60.8 ± 11.8 years) underwent a repeat ablation because of recurrent atrial tachyarrhythmias (ATas) after index PVI achieved with CFCA (30 patients) or CB-AdvA (26 patients). All repeat procedures were performed by the means of CFCA. In the CFCA group, among 119 PVs, 43 (36.1%) showed conduction gaps in 24 patients (1.8 per patient), whereas in the CB-AdvA group among 103 veins, 21 (20.4%) showed a PV reconnection in 18 patients (1.2 per patient) (P = 0.01). The left superior pulmonary vein was less frequently reconnected following CB-AdvA when compared with CFCA (2/25, 8% vs. 11/29, 37.9%; P = 0.01). In the CFCA group, the mean CF per-vein was lower in reconnecting veins when compared with those persistently isolated (10.9 ± 2.7 vs. 18.6 ± 3.1 g; P < 0.001). In the CB-AdvA group, late PV reconnection was associated with warmer nadir temperature (-48.9 ± 5.1 vs. -51.2 ± 4.7°C; P = 0.05) and longer time-to-isolation (71.1 ± 20.2 vs. 50.2 ± 32.9 s; P = 0.03).nnnCONCLUSIONnThe rate of late PV reconnection is significantly lower following CB-AdvA when compared with CFCA as index procedure. Lower CF values and warmer nadir temperature with longer time to effect were more frequently associated with PV reconnections in the setting of CFCA and CB-AdvA.

Second-generation cryoballoon ablation for paroxysmal atrial fibrillation: Predictive role of atrial arrhythmias occurring in the blanking period on the incidence of late recurrences

BACKGROUNDnAlthough consensus documents on catheter and surgical ablation of atrial fibrillation (AF) suggest a uniform blanking period of 3 months, recent evidence suggested that early recurrences of atrial tachyarrhythmias (ERATs) are strongly associated with late recurrences (LRs), especially if ERATs occurred in the last part of the blanking period.nnnOBJECTIVEnThe present study sought to assess the role of ERATs in predicting LRs in a large cohort of patients with paroxysmal AF who have undergone second-generation cryoballoon ablation.nnnMETHODSnConsecutive patients with drug-resistant paroxysmal AF who underwent pulmonary vein isolation using CB-A technology as the index procedure were retrospectively included in our analysis. The exclusion criteria were any contraindications for the procedure, including the presence of an intracavitary thrombus, uncontrolled heart failure, contraindications to general anesthesia, and persistent AF.nnnRESULTSnA total of 331 consecutive patients (104 women [31%]; mean age 56.7 ± 13.3 years) were enrolled. Atrial tachyarrhythmias/AF recurrences were detected in 57 patients (17.2%). The highest prevalence of ERATs was observed in the first 2 weeks (55%) after pulmonary vein isolation. Of note, all the ERATs occurring 1.5 months after AF ablation relapsed after 3 months and were confirmed as definitive recurrences. Late recurrence of AF and atrial tachycardia occurred in 20 of 29 patients with ERATs (69.0%) and 28 of 302 patients without ERATs (9.3%) (P < .0001). A multivariate Cox regression analysis showed that the early recurrence within the blanking period was significantly and independently associated with an increased risk of developing a late recurrence (hazard ratio 6.79; 95% confidence interval 3.52-10.14; P < .0001).nnnCONCLUSIONnOur findings reveal that ERATs are strongly associated with an LR after paroxysmal AF ablation using CB-A technology (hazard ratio 6.79; 95% confidence interval 3.52-10.14; P < .0001). Of note, when ERATs occurred later than 1.5 months, patients systematically experienced an LR.

Complications in the setting of percutaneous atrial fibrillation ablation using radiofrequency and cryoballoon techniques: A single-center study in a large cohort of patients

BACKGROUNDnThe aim of this study was to assess the overall incidence of complications in a large sample of consecutive patients having undergone pulmonary vein (PV) isolation, evaluating also the rate of complications in radiofrequency (RF) and cryoballoon (CB) ablation technologies.nnnMETHODS AND RESULTSnFrom January 2008 to December 2014, 1352 consecutive PV isolation procedures were performed in our center; a total amount of 1233 AF ablation procedures fulfilling inclusion criteria was finally taken into consideration for our analysis. A total of 642 procedures were performed using RF ablation technology and 591 using CB system. Serious adverse events occurred in 36 procedures (2.9%): specifically, vascular complications in 14 (1.1%); cardiac tamponade in 13 (1.0%); a thromboembolic event in 4 (0.3%); and atrial-esophageal fistula, PV intramural hematoma, retroperitoneal hematoma, pleural hematoma and persisting phrenic nerve palsy all occurred in 1 patient individually (0.1%). No deaths related to the procedure occurred. The complication rate did not significantly differ in the RF and CB groups (respectively, 3.6% vs 2.2%; p=0.1). Complication rates considerably decreased over the study period from 4.67% in 2008 to 1.55% in 2014. Interestingly, each 1-point increase in the CHA2DS2-VASc score was found to increase by 51% the likelihood of a serious adverse event.nnnCONCLUSIONSnThe incidence of serious adverse events following AF ablation procedures was 2.9%. Vascular complications were the most frequent complication followed by tamponade and thromboembolic events. The rate of complications considerably decreased over time. CHA2DS2-VASc score was found to be associated with higher risk of complications.

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

AIMSnThe 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).nnnMETHODS AND RESULTSnThe 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.nnnCONCLUSIONnThe 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.

Anatomic predictors of phrenic nerve injury in the setting of pulmonary vein isolation using the 28-mm second-generation cryoballoon

BACKGROUNDnPhrenic nerve injury (PNI) is the most frequently observed complication during pulmonary vein (PV) isolation using the second-generation cryoballoon.nnnOBJECTIVEnThe purpose of this study was to analyze anatomic predictors based on preprocedural computed tomographic imaging data.nnnMETHODSnForty-one patients with PNI during the procedure and 123 age-, gender-, and body mass index-matched controls were included. A total of 343 right PVs were evaluated for axial/coronal orientation, ostial diameters with cross-sectional area, ovality index, and branching pattern. External angle between the right superior pulmonary vein (RSPV) and the anterolateral wall of the left atrium (LA) was measured (RSPV-LA angle). Distance from this vertex to the superior vena cava (SVC) was considered the RSPV-SVC distance.nnnRESULTSnFor the RSPV, more anterosuperior orientation, larger dimensions, shorter RSPV-SVC distance, and more obtuse RSPV-LA angle (all P <.001) were associated with PNI on univariate analysis. Independent variables after multivariable analysis were RSPV-LA angle (odds ratio 1.03 per degree, 95% confidence interval 1.01-1.04, P <.001) and RSPV area (odds ratio 1.2 per mm², 95% confidence interval 1.1-1.3, P <.001), with a cutoff value ≥141° for RSPV-LA angle (91% sensitivity, 85% specificity) and ≥275 mm² for RSPV area (88% sensitivity, 85% specificity). RIPV area was an independent predictor for PNI at RIPV. A right-sided long common trunk was seen exclusively in 3 patients in the PNI group.nnnCONCLUSIONnPreprocedural anatomic assessment of right PVs is useful in evaluating the risk of PNI. Ostial vein area and external RSPV-LA angle measurement showed excellent predictive value for PNI at the RSPV.

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

AIMSnThe 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.nnnMETHODS AND RESULTSnAll 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).nnnCONCLUSIONnThe 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.

Fluoroscopic position of the second-generation cryoballoon during ablation in the right superior pulmonary vein as a predictor of phrenic nerve injury

AIMSnPhrenic nerve injury (PNI) is the most frequently observed complication during pulmonary vein isolation procedure using the second-generation cryoballoon (CB). Our objective was to analyse the correlation between the fluoroscopic position of the 28 mm CB during ablation in the right superior pulmonary vein (RSPV) and the occurrence of PNI.nnnMETHODS AND RESULTSnA total of 165 patients having undergone the large 28 mm CB ablation were retrospectively reviewed. Positioning of the CB relative to the cardiac silhouette was classified under fluoroscopic guidance in antero-posterior projection during RSPV ablation. Regarding the lower half of the balloon, CB positioning was defined as follows: (A) completely inside the cardiac shadow; (B1) <1/3 outside the cardiac shadow; and (B2) ≥1/3 outside the cardiac shadow. Phrenic nerve injury occurred in 9.7% (16/165) during ablation in the RSPV. The occurrence of PNI was 0.9, 10.6, and 90.1% in positions A, B1, and B2, respectively (A vs. B1, P = 0.01; B1 vs. B2, P < 0.0001). Among other pre-procedural and procedural variables, the B2 position was the strongest independent determinant for predicting PNI at RSPV (P = 0.001, odds ratio: 119.9; 95% confidence interval: 11.6-1234.7) after multivariable analysis.nnnCONCLUSIONnThe incidence of PNI at the RSPV significantly increased in case of more distal positioning of the CB relative to the cardiac shadow. This simple and straightforward intra-procedural indicator might prone the operators to attempt occluding the RPSV more proximally in order to avoid PNI.