Feasibility and safety of reprocessing of intracardiac echocardiography catheters for electrophysiology procedures - a large single center experience.

PURPOSE: Intra-cardiac echocardiography (ICE) has become an important tool for catheter ablation. Adoption of ICE imaging is still limited because of its prohibitively high cost. Our aim was to study the safety and feasibility of ICE catheters reprocessing and its environmental and financial impact. METHODS: This was a single center retrospective analysis of all consecutive electrophysiology procedures in which ICE catheters were used from 2015 to 2022. In total, 1128 patients were studied (70.6% male, mean age was 57.9 ± 13.2 years). The majority of procedures were related to atrial fibrillation ablation (84.6%). RESULTS: For the whole cohort, 57 new ICE catheters were used. Consequently one catheter could be used for 19.8 procedures. New catheters were only used when the image obtained by reused probes was not satisfactory. There were no cases of ICE probe steering mechanism malfunction, no procedure related infections and no allergic reactions that could be attributed to the resterilization process. In total, there was 8.6% of complications not related to ICE imaging. Financially, ICE probe reprocessing resulted with 90% cost reduction (> 2 millions of Euros savings for the studied period) and 95% waste reduction (639.5 kg less, mostly non degradable waste was produced). CONCLUSION: Our data suggests that ICE catheter reprocessing is feasible and safe. It seems that risk of infection is not increased. Significant economic and environmental savings could be achieved by ICE catheters reprocessing. Furthermore, ICE reprocessing could allow more extensive ICE usage resulting in safer procedures with a potential reduction of serious complications.

Initial rhythm control with cryoballoon ablation vs drug therapy: Impact on quality of life and symptoms.

BACKGROUND: Cryoballoon ablation (CBA) as a first-line rhythm control strategy is superior to antiarrhythmic drugs (AADs) for preventing atrial fibrillation (AF) recurrence; the impact of first-line CBA on quality of life (QoL) and symptoms has not been well characterized. METHODS: Patients aged 18 to 75 with symptomatic paroxysmal AF naïve to rhythm control therapy were randomized (1:1) to CBA (Arctic Front Advance, Medtronic) or AAD (Class I or III). Symptoms and QoL were assessed at baseline, 1, 3, 6, 9, and 12 months using the EHRA classification and Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) and SF-36v2 questionnaires. Symptomatic palpitations were evaluated via patient diary. RESULTS: Overall, 107 patients were randomized to CBA and 111 to AAD; crossovers occurred in 9%. Larger improvements in the AFEQT summary, subscale and treatment satisfaction scores were observed at 12 months with CBA vs AAD (all P <0.05). At 12 months, the mean adjusted difference in the AFEQT summary score was 9.9 points higher in the CBA group (95% CI: 5.5 -14.2, P <0.001). Clinically important improvements in the SF-36 physical and mental component scores were observed at 12 months in both groups, with no significant between group differences at this timepoint. In the CBA vs AAD group, larger improvements in EHRA class were observed at 6, 9 and 12 months (P <0.05) and the incidence rate of symptomatic palpitations was lower (4.6 vs 15.2 days/year post-blanking; IRR: 0.30, P <0.001). CONCLUSIONS: In patients with symptomatic AF, first-line CBA was superior to AAD for improving AF-specific QoL and symptoms. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT01803438.

Cryoballoon ablation vs. antiarrhythmic drugs: first-line therapy for patients with paroxysmal atrial fibrillation.

AIMS: Treatment guidelines for patients with atrial fibrillation (AF) suggest that patients should be managed with an antiarrhythmic drug (AAD) before undergoing catheter ablation (CA). This study evaluated whether pulmonary vein isolation employing cryoballoon CA is superior to AAD therapy for the prevention of atrial arrhythmia (AA) recurrence in rhythm control naive patients with paroxysmal AF (PAF). METHODS AND RESULTS: A total of 218 treatment naive patients with symptomatic PAF were randomized (1 : 1) to cryoballoon CA (Arctic Front Advance, Medtronic) or AAD (Class I or III) and followed for 12 months. The primary endpoint was ≥1 episode of recurrent AA (AF, atrial flutter, or atrial tachycardia) >30 s after a prespecified 90-day blanking period. Secondary endpoints included the rate of serious adverse events (SAEs) and recurrence of symptomatic palpitations (evaluated via patient diaries). Freedom from AA was achieved in 82.2% of subjects in the cryoballoon arm and 67.6% of subjects in the AAD arm (HR = 0.48, P = 0.01). There were no group differences in the time-to-first (HR = 0.76, P = 0.28) or overall incidence [incidence rate ratio (IRR)=0.79, P = 0.28] of SAEs. The incidence rate of symptomatic palpitations was lower in the cryoballoon (7.61 days/year) compared with the AAD arm (18.96 days/year; IRR = 0.40, P < 0.001). CONCLUSIONS: Cryoballoon CA was superior to AAD therapy, significantly reducing AA recurrence in treatment naive patients with PAF. Additionally, cryoballoon CA was associated with lower symptom recurrence and a similar rate of SAEs compared with AAD therapy.

Cryoballoon catheter ablation versus antiarrhythmic drugs as a first-line therapy for patients with paroxysmal atrial fibrillation: Rationale and design of the international Cryo-FIRST study.

BACKGROUND: Radiofrequency current (RFC) catheter ablation for patients with paroxysmal atrial fibrillation (AF) has been shown to be safe and effective in first-line therapy. Recent data demonstrates that RFC ablation provides better clinical outcomes compared to antiarrhythmic drug (AAD) in the treatment of early AF disease. Furthermore, studies comparing RFC and cryoballoon have established comparable efficacy and safety of pulmonary vein isolation (PVI) for patients with symptomatic paroxysmal AF. OBJECTIVES: The Cryo-FIRST trial was designed to compare AAD treatment against cryoballoon PVI as a first-line therapy in treatment naïve patients with AF. Efficacy and safety will be compared between the two cohorts and amongst subgroups. METHODS: The primary hypothesis is that cryoablation is superior to AAD therapy. To test this hypothesis, patients will be randomized in a 1:1 design. Using a 90-day blanking period, primary efficacy endpoint failure is defined as (at least) one episode of atrial arrhythmia with a duration >30 sec (documented by 7-day Holter or 12-lead ECG). Secondary endpoints (Quality-of-Life, rehospitalization, arrhythmia recurrence rate, healthcare utilization, and left atrial function) and adverse events will also be evaluated. Study enrollment will include 218 patients in up to 16 centers. CONCLUSIONS: This study will be a multi-national randomized controlled trial comparing cryoablation against AAD as a first-line treatment in patients with paroxysmal AF. The results may help guide the selection of patients for early AF disease therapy via cryoballoon ablation.

Learning curves in atrial fibrillation ablation - A comparison between second generation cryoballoon and contact force sensing radiofrequency catheters.

OBJECTIVE: To examine the learning curves of atrial fibrillation (AF) ablation comparing the cryoballoon (CB) and radiofrequency (RF) catheters. METHODS: We performed a retrospective data analysis from the initiation of AF ablation program in our center. For CB ablation, a second generation 28 mm balloon was utilized and for RF ablation. RESULTS: A total of 100 consecutive patients (50 in each group) have been enrolled in the study (male 74%, mean age 58.9 ± 10 years, paroxysmal AF 85%). The mean procedure time was shorter for CB (116.6 ± 39.8 min) than RF group (191.8 ± 101.1 min) (p < 0.001). There was no difference in the mean fluoroscopy time, 24.2 ± 10.6 min in RF and 22.4 ± 11.7 min in CB group, (p = 0.422). Seven major complications occurred during the study; 5 in RF group (10%) and 2 in CB group (4%) (p = 0.436). After the mean follow up of 14.5 ± 2.4 months, 15 patients in RF group (30%) and 11 in CB group (26%) experienced AF recurrences (P = 0.300). CONCLUSION: When starting a new AF ablation program, our results suggest that CB significantly shortens procedure while fluoroscopy time and clinical outcomes are comparable to RF ablation.

MANAGEMENT OF PATIENTS WITH CARDIAC IMPLANTABLE ELECTRONIC DEVICES UNDERGOING MAGNETIC RESONANCE IMAGING - PROPOSAL FOR UNIFIED HOSPITAL PROTOCOL: CROATIAN WORKING GROUP ON ARRHYTHMIAS AND CARDIAC PACING.

For many years, magnetic resonance imaging (MRI) was contraindicated in patients with cardiac implantable electronic devices (CIED). Today, there is a growing amount of evidence that MRI can be performed safely in the majority of patients with CIEDs. Firstly, there are devices considered MRI conditional by manufacturers that are available on the market and secondly, there is clear evidence that even patients with MRI non-conditional devices can also undergo MRI safely. Protocols have been developed and recommendations from different cardiac and radiologic societies have been published in recent years. However, the majority of physicians are still reluctant to refer these patients to MRI. Therefore, this document is published as a joint statement of the Croatian Working Group on Arrhythmias and Cardiac Pacing and Department of Radiology, Sestre milosrdnice University Hospital Centre to guide and ease the management of patients with CIED undergoing MRI. Also, we propose a unified protocol and checklist that could be used in Croatian hospitals.

TWARMI pilot trial: The value and optimal criteria of microvolt T-wave alternans in the diagnosis of reversible myocardial ischemia in patients without structural cardiac disease.

AIMS: Microvolt T-wave alternans (MTWA) testing is a beat-to-beat fluctuation in the amplitude of T wave. We investigated whether: (a) MTWA can be new non-invasive tool for detection of reversible ischemia in patients with suspected CAD without structural heart disease, (b) MTWA can detect ischemia earlier and with greater test accuracy compared with exercise ECG ST-segment testing, and (c) threshold value of MTWA and heart rate at which the alternans is estimated can be different compared to standard values. METHODS: A total of 101 patients with suspected stable coronary disease, but without structural heart disease, were included. Echocardiography, exercise ECG test, MTWA with classical and modified threshold alternans values, and coronary angiography were performed. RESULTS: About 33.3% patients had a false-positive result on exercise ECG test. The sensitivity of exercise ECG ST-segment test in the detection of coronary artery disease was 97.8%, and the specificity was 42.5% (DOR 33.89). In a group of angiographically positive patients, standard MTWA accurately identified 60% of patients, while 40% had a false-negative result. About 91.8% patients with negative angiography result were accurately identified with 8.2% false positives. The sensitivity of MTWA was 59.61% and specificity 91.83%. Best ratio of sensitivity and specificity (86.53% and 95.91%, DOR 151.06) had modified criteria for positive MTWA (MTWA >1.5 µV at heart rate 115-125/min). CONCLUSIONS: This study showed that MTWA can be the new non-invasive tool for the detection of reversible ischemia in patients with suspected CAD without structural heart disease. Also, MTWA can detect ischemia earlier and with greater accuracy compared with exercise ECG testing.

Early repolarization pattern as a predictor of atrial fibrillation recurrence following radiofrequency pulmonary vein isolation.

BACKGROUND: Early repolarization patterns (ERP) have been found to be associated with poor cardiovascular end points. We aimed to evaluate the ERP prevalence among patients with structurally normal hearts undergoing radiofrequency (RF) pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) ablation and its association with the AF recurrence. METHODS: All consecutive patients who underwent RF-PVI as index procedure for paroxysmal AF in our center were evaluated. EXCLUSION CRITERIA: structural heart disease, ongoing use of Class I/III antiarrhythmics, complete-bundle-branch-block. Lateral (I, aVL, V5 -V6 ), inferior (II, III, aVF), or infero-lateral (both) ERP were defined in baseline ECG as horizontal/downsloping J-point elevation ≥1 mm in two consecutive leads with QRS slurring/notching. Documented episodes of AF lasting ≥30 s were considered recurrence. RESULTS: Of 701 cases, 434 patients (305 males, 58 ± 11 years) were included for analysis. ERP observed in 67 patients (15.4%) (Infero-lateral n = 26, inferior n = 23, lateral n = 18) which were significantly younger, demonstrating longer PR-interval and lower heart rates. At a mean follow-up of 22.1 ± 9.7 months, AF recurrences were found in 107 patients (24.6%). In middle-aged patients (≥40-<60 years; n = 206, 79% male), those with an infero-lateral ERP had higher recurrence compared with the ones without (56.3% vs. 19%; p = 0.002). Infero-lateral ERP was significantly predicting recurrence (HR 2.42, 95% CI 1.21-4.82; p = 0.01). CONCLUSION: Early repolarization patterns was more prevalent in our AF population than in the general population. Infero-lateral ERP in baseline ECG might predict AF recurrence in the follow-up after RF-PVI in middle-aged patients.

Electrocardiographic and clinical predictors of permanent pacemaker insertion following Perceval sutureless aortic valve implantation.

BACKGROUND: Sutureless aortic valve replacement surgery (AVR) is a reasonable alternative surgical approach in those patients with aortic stenosis who would benefit from reduced cross clamp time, such as elderly and high-risk patients. We sought to evaluate the incidence of pacemaker (PM) implantation following sutureless AVR and to analyse possible pre-operative electrocardiographic and clinical predictors of PM implantation. METHODS AND RESULTS: Between November 2013 and March 2015, 58 patients (male 43%, age 77.9 ±â€¯4.9 years) having undergone sutureless AVR with a Perceval prosthesis (Sorin Biomedica Cardio Srl, Saluggia, Italy) were taken into consideration for our analysis. During a mean follow up of 13.8 ±â€¯5.0 months (median 13 months), 14 patients (24.1%) underwent pacemaker (PM) implantation following sutureless AVR procedure. Among these patients, 12 (86%) presented III degree atrioventricular (AV) block, 1 (7%) presented II degree AV block, and remaining one (7%) severe symptomatic bradycardia. The comparison of pre-operative characteristics between PM group and no PM group highlighted that QRS duration, EuroSCORE II index and chronic renal dysfunction were significantly associated with the development of AV conduction abnormalities/symptomatic bradycardia requiring PM implantation (respectively, p = 0.01, p = 0.02 and p = 0.03). CONCLUSIONS: The incidence of PM implantation after sutureless AVR was 24.1% in the present study. The EuroSCORE II, QRS duration and renal dysfunction were significantly associated with higher risk of AV conduction abnormalities/symptomatic bradycardia requiring PM placement.

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.

Ventricular tachycardia in a 16-year-old boy with primary hyperparathyroidism.

We report a case of primary hyperparathyroidism with hypercalcaemia in a 16-year-old boy who had spontaneous attack of ventricular tachycardia. To our knowledge, presentation of ventricular tachycardia caused by primary hyperparathyroidism in such a young patient has not been reported in medical literature so far.

Implantable cardioverter defibrillator therapy in young individuals: comparison of conventional and subcostal approaches-a single-centre experience.

AIM: The aim of our study is to compare two approaches of implantable cardiac defibrillator (ICD) implantation, conventional (supra/subpectoral) and subcostal in young adults in terms of procedural complications and adverse events encountered during follow-up. METHODS AND RESULTS: From January 2007 to December 2013, all patients under the age of 50 years who received an ICD in our centre were included in this study. Patient's hospital records were analysed for procedural complications and adverse events during follow-up until December 2014. Data from device on first interrogation after implantation and on follow-up were also noted. A total of 106 patients of which 40.6% had Brugada's syndrome (65.1% male, age 33.6 ± 10.97 years) were included in analysis; 71 (61%) had ICD placed in (sub/supra) pectoral and 35 (33%) in subcostal position. Only seven patients received an epicardial lead system. During the follow-up period of 2.1 ± 1.8 years, 84.90% of the patients had no adverse events. Most of the complications, procedural and during follow-up, occur in conventionally placed, pectoral ICD. Lead follow-up data in both groups, conventional and subcostal, showed no difference in right ventricular (RV) shock impedance and R wave sensing, P-value = 0.56 and 0.77, respectively. Lead survival was 95 and 97%, respectively, in conventional and subcostal groups over a mean follow-up of 2.1 ± 1.8 years. Log-rank test for lead survival was not significant in terms of site of implantation. CONCLUSION: To the best our knowledge, this is the first study demonstrating subcostal ICD placement in young adults and resulting in equivalent to better outcomes when compared with conventionally placed pectoral ICD. Subcostal ICD placement might be considered an alternative option in young adults as it results in better procedural outcomes and also comparable rate of adverse events during follow-up, but bigger studies with a larger number of patients are needed for a definitive conclusion.

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.

Single 3-Minute versus Double 4-Minute Freeze Strategy for Second-Generation Cryoballoon Ablation: A Single-Center Experience.

INTRODUCTION: Second-generation cryoballoon (CB-Adv) ablation is highly effective in achieving pulmonary vein isolation (PVI) with promising mid-term clinical outcome. However, the ideal freezing strategy is still under debate. The aim of this study was to assess the efficacy of a single 3-minute approach compared to the conventional 4-minute plus bonus application using CB-Adv. METHODS AND RESULTS: One hundred and sixty patients (67% male; mean age 58.0 ± 13.3 years) underwent PVI using CB-Adv for paroxysmal atrial fibrillation (PAF). Among 160 patients, 80 received a single 3-minute approach (3-mns group), while the remaining 80 conventional 4-minute plus bonus-freeze (4-mns group). Mean procedure and fluoroscopy times were 90.6 ± 15.8 and 18.3 ± 6.9 in the 4-mns group, 75.2 ± 17.1 and 13.5 ± 8.7 in the 3-mns group (P < 0.001, respectively). First-freeze isolation rate was 91.6% in the 4- versus 90.6% in the 3-mns group (P = 0.78). Persistent phrenic nerve palsy (PNP) occurred in 6/80 (3.5%) in the 4-mns group and 4/80 in the 3-mns group (P = 0.75). The overall freedom from ATas 2 years after the procedure was 78.1% (125/160): 77.5% (62/80 patients) in the 3-mns and 78.8% (63/80 patients) in the 4-mns group (P = 0.82). In multivariate analysis, time to PVI and nadir temperature independently predicted ATa recurrences (P < 0.001). CONCLUSIONS: CB-Adv ablation for PAF is highly effective, resulting in 78% 2-year freedom from arrhythmic recurrences. A "single 3-minute strategy" showed equal efficacy as compared to the conventional 4-minute plus bonus freeze approach at 2-year follow-up, providing shorter procedure and fluoroscopy time. Nadir temperature and time to PVI were predictors of arrhythmic recurrences. "Bonus-freeze" strategy might be unnecessary.

Repeat Procedures After Hybrid Thoracoscopic Ablation in the Setting of Longstanding Persistent Atrial Fibrillation: Electrophysiological Findings and 2-Year Clinical Outcome.

INTRODUCTION: In order to increase success rates of invasive treatment of persistent atrial fibrillation, the hybrid approach was developed, combining video-assisted thoracoscopic epicardial procedure with conventional endocardial catheter ablation. Currently, there are no reports of electrophysiological findings and clinical outcomes of repeat procedures after the hybrid approach. METHODS AND RESULTS: Out of 64 patients who were treated by hybrid ablation for persistent atrial fibrillation (AF), 14 underwent the repeat catheter ablation and were selected for this study. All 14 patients initially presented with longstanding persistent atrial fibrillation and markedly dilated atria. The hybrid procedure was performed in a single act and the mean time to redo procedure was 346 ± 227 days. In 57% of patients indication for redo procedure was regular atrial tachycardia, and the rest presented with recurrent atrial fibrillation. In 36% of patients, recovered conduction was found along the previous ablation lesions. Only 9% of pulmonary veins were reconnected (0.36 veins per patient) and 7% of box lesions were not complete. The overall success rate at 2 years follow-up after the repeat procedure, including second repeat procedure and patients taking antiarrhythmic drugs, was 64% (57% without drugs and further ablation). One case of moderate pulmonary vein stenosis was detected as a consequence of hybrid procedure. CONCLUSION: Hybrid atrial fibrillation ablation results in durable lesions and high rates of chronic pulmonary vein isolation even after long-term follow-up. Most of the repeat procedures after the hybrid approach are related to left atrial flutters that could be successfully treated by catheter ablation.

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

AIMS: Phrenic 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. METHODS AND RESULTS: A 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. CONCLUSION: The 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.

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.

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.

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.

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.