Erwin Ströker

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

BACKGROUND The 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. OBJECTIVE The 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. METHODS All 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. RESULTS During 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. CONCLUSION The 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.

AIMS To 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). METHODS AND RESULTS A 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). CONCLUSION The 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.

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

BACKGROUND The 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. METHODS AND RESULTS From 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. CONCLUSIONS The 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.

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.

Second-generation cryoballoon ablation without the use of real-time recordings: A novel strategy based on a temperature-guided approach to ablation

BACKGROUND The achievement of -40°C within the first 60 seconds during cryoenergy applications has proven to independently predict durable pulmonary vein (PV) isolation in the setting of second-generation cryoballoon (CB-A; Medtronic, Minneapolis, MN) ablation. OBJECTIVE We sought to evaluate a strategy based on the attainment of the specific parameter of -40°C within the first 60 seconds during cryoenergy applications in the setting of CB-A ablation without the use of an inner lumen mapping catheter (Achieve, Medtronic) for the visualization of real-time recordings. METHODS A total of 52 patients having undergone CB ablation for paroxysmal atrial fibrillation (AF) between 1 February 2015 and 30 June 2015 who underwent a temperature-guided approach based on achieving -40°C within 60 seconds without real-time recordings (wire group) were compared with a cohort of 52 propensity score-matched patients having undergone CB ablation performed with an inner lumen mapping catheter (Achieve group). All PVs were checked for electrical isolation at the end of the procedure with a circular mapping catheter in the wire group. RESULTS Electrical isolation could be obtained in all patients in the Achieve group and in 99% of PVs in the wire group. Freedom from AF without antiarrhythmic drugs at a mean follow-up of 12.4 ± 3.0 months did not significantly differ between both groups (85% vs 88%, respectively; P = .56). CONCLUSION A temperature-guided approach based on achieving -40°C within 60 seconds is effective in producing PV isolation and affords freedom from AF at 12-month follow-up in 85% of patients affected by paroxysmal AF after a 3-month blanking period.

Midterm clinical outcomes of concomitant thoracoscopic epicardial and transcatheter endocardial ablation for persistent and long-standing persistent atrial fibrillation: a single-centre experience.

Aims The purpose of this study was to analyse the efficacy and complication rates of the simultaneous hybrid procedure in a series of patients with persistent and long-standing persistent atrial fibrillation (AF) in a midterm follow-up. Methods and results Sixty-four consecutive patients (56 males, 59.7 ± 8.7 years) having undergone isolation of pulmonary veins (PVs) and posterior wall of left atrium (LA) by means of hybrid thoracoscopic ablation for symptomatic persistent (n = 21, 33%) and long-standing persistent AF (n = 43, 67%) were analysed. At a mean follow-up of 23.1 ± 14.1 months (median 21; range 6–57), the success rate without antiarrhythmic therapy was achieved in 67.2% of patients. Procedure-related complications were observed in 13 patients (20.3%) including 2 LA perforations (3.1%) requiring, respectively, conversion to sternotomy and small left-sided thoracotomy. The success rate did not significantly differ between persistent and long-standing persistent AF (respectively, 71.4 and 65.1%; P = 0.4). Patients with AF relapse during the blanking period were 4.60 times more likely to have AF recurrence after 3 months from the ablation procedure. Conclusion The hybrid procedure yields promising results in the setting of both persistent and long-standing persistent AF after midterm follow-up, at the expense of a non-negligible rate of adverse events. Our findings need to be confirmed by further larger and prospective studies.

Prevalence and Clinical Impact of Early Repolarization Pattern and QRS-Fragmentation in High-Risk Patients With Brugada Syndrome

BACKGROUND The phenotypic heterogeneity of Brugada syndrome (BrS) can lead some patients to show an additional inferolateral early repolarization pattern (ERP), or fragmented QRS (f-QRS). The aim of the study was to investigate the prevalence and clinical impact of f-QRS, ERP or combined f-QRS/ERP in high-risk patients with BrS. METHODSANDRESULTS Patients with spontaneous or drug-induced BrS and an indication to receive an implantable cardioverter-defibrillator (ICD) were considered eligible for this study. From 1992 to 2012, a total of 176 consecutive patients with BrS underwent ICD implantation. Among them, 48 subjects (27.3%) presented with additional depolarization and/or repolarization abnormalities. f-QRS was found in 29 (16.5%), ERP in 15 (8.5%), and combined f-QRS/ERP in 4 patients (2.3%). After a mean follow-up of 95.2±51.9 months, spontaneous sustained ventricular arrhythmias were documented in 8 patients (16.7%). No significant difference was found in the rate of appropriate shocks between patients presenting with f-QRS or ERP and those without abnormalities. Patients with both f-QRS and ERP had a significantly higher rate of appropriate shocks (HR: 4.1; 95% CI: 1.1-19.7; P=0.04). CONCLUSIONS Fragmented QRS and ERP are common ECG findings in high-risk BrS patients, occurring in up to 27% of cases. When combined, f-QRS and ERP confer a higher risk of appropriate ICD interventions during a very long-term follow-up. (Circ J 2016; 80: 2109-2116).

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

BACKGROUND Phrenic nerve injury (PNI) is the most frequently observed complication during pulmonary vein (PV) isolation using the second-generation cryoballoon. OBJECTIVE The purpose of this study was to analyze anatomic predictors based on preprocedural computed tomographic imaging data. METHODS Forty-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. RESULTS For 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. CONCLUSION Preprocedural 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.