The Cost-Effectiveness of First-Line Cryoablation vs First-Line Antiarrhythmic Drugs in Canadian Patients With Paroxysmal Atrial Fibrillation

BACKGROUND

The EARLY-AF (NCT02825979), STOP AF First (NCT03118518), and Cryo-FIRST (NCT01803438) randomised controlled trials (RCTs) demonstrated that cryoballoon pulmonary vein isolation reduces atrial fibrillation (AF) recurrence compared with antiarrhythmic drugs (AADs) in patients with symptomatic paroxysmal atrial fibrillation (PAF). The present study developed a cost-effectiveness model (CEM) of first-line cryoablation compared with first-line AADs for PAF, from the Canadian health care payer's perspective.

METHODS

Data from the 3 RCTs were analysed to estimate key CEM parameters. The model structure used a decision tree for the first 12 months and a Markov model with a 3-month cycle length for the remaining lifetime time horizon. Costs were set at 2023 Canadian dollars, health benefits were expressed as quality-adjusted life years (QALYs), and both were discounted 3% annually. Probabilistic sensitivity analysis (PSA) considered parameter uncertainty.

RESULTS

The statistical analysis estimated that first-line cryoablation generates a 47% reduction (P < 0.001) in the rate of AF recurrence, a 73% reduction in the rate of subsequent ablation (P < 0.001), and a 4.3% (P = 0.025) increase in health-related quality of life, compared with first-line AADs. The PSA indicates that an individual treated with first-line cryoablation accrues less costs (-$3,862) and more QALYs (0.19) compared with first-line AADs. Cryoablation is cost-saving in 98.4% of PSA iterations and has a 99.9% probability of being cost-effective at a cost-effectiveness threshold of $50,000 per QALY gained. Cost-effectiveness results were robust to changes in key model parameters.

CONCLUSIONS

First-line cryoballoon ablation is cost-effective when compared with AADs for patients with symptomatic PAF.

Pulmonary Vein Isolation Followed by Biatrial Ablation of Rotational Activity in Patients with Persistent Atrial Fibrillation: Results of the Cryo-Vest Study

Background and Aims: Noninvasive mapping allows the identification of patient-specific atrial rotational activity (RA) that might play a key role in the perpetuation of persistent atrial fibrillation (PsAF). So far, the impact of pulmonary vein isolation by cryoballoon (Cryo-PVI) on RA is unclear. Moreover, the long-term effect of periprocedural termination of AF during the ablation procedure is controversial. Methods: Noninvasive electrocardiographic mapping with a 252-electrode vest was performed in 42 patients with PsAF. After the first analysis, Cryo-PVI was performed. The RA was analyzed again and then targeted by radiofrequency catheter ablation. The primary clinical endpoint was periprocedural termination of AF. The secondary endpoint was freedom from any atrial arrhythmia >30 s during a 12-month follow-up. Results: In 33 patients (79%), right atrial RA was identified leading to biatrial ablation, and nine patients (21%) had left atrial RA only. Twelve patients (28.6%) converted from AF to sinus rhythm (SR) (Group A). Thirteen patients (30.9%) converted to atrial tachycardia (AT) (Group B). In 17 patients (40.5%), AF was not terminated by ablation (Group C). After a mean follow-up time of 13.8 months, 26 patients were free from AF and AT (61.9%). In terms of rhythm, control Group A (75%) and B (83.3%) showed higher success rates than Group C (33.3%) (p < 0.01). Cryo-PVI had no substantial impact on RA. Conclusions: The RA-based ablation approach showed acceptable success rates. Periprocedural termination of AF had a positive predictive impact on the outcome. No difference was observed between conversion to SR or to AT. Cryo-PVI had no impact on RA.

Economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from an English National Health Service perspective

INTRODUCTION

Three recent randomised controlled trials have demonstrated that pulmonary vein isolation as an initial rhythm control strategy with cryoablation reduces atrial arrhythmia recurrence in patients with symptomatic paroxysmal atrial fibrillation (PAF) compared with antiarrhythmic drug (AAD) therapy. The aim of this study was to evaluate the cost-effectiveness of first-line cryoablation compared with first-line AADs for treating symptomatic PAF in an English National Health Service (NHS) setting.

METHODS

Individual patient-level data from 703 participants with PAF enrolled into Cryo-FIRST (Catheter Cryoablation Versus Antiarrhythmic Drug as First-Line Therapy of Paroxysmal Atrial Fibrillation), STOP AF First (Cryoballoon Catheter Ablation in an Antiarrhythmic Drug Naive Paroxysmal Atrial Fibrillation) and EARLY-AF (Early Aggressive Invasive Intervention for Atrial Fibrillation) were used to derive the parameters applied in the cost-effectiveness model (CEM). The CEM comprised a hybrid decision tree and Markov structure. The decision tree had a 1-year time horizon and was used to inform the initial health state allocation in the first cycle of the Markov model (40-year time horizon; 3-month cycle length). Health benefits were expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3.5% per year. Model outcomes were generated using probabilistic sensitivity analysis.

RESULTS

The results estimated that cryoablation would yield more QALYs (+0.17) and higher costs (+£641) per patient over a lifetime than AADs. This produced an incremental cost-effectiveness ratio of £3783 per QALY gained. Independent of initial treatment, individuals were expected to receive ~1.2 ablations over a lifetime. There was a 45% relative reduction in time spent in AF health states for those initially treated with cryoablation.

DISCUSSION

AF rhythm control with first-line cryoablation is cost effective compared with first-line AADs in an English NHS setting.

Impact of intracardiac echocardiography usage on the safety of cryoballoon atrial fibrillation ablation: Subanalysis of the prospective FREEZE cluster cohort study

INTRODUCTION

Cryoballoon ablation (CBA) aiming at pulmonary vein isolation (PVI) became a standardized atrial fibrillation (AF) ablation procedure. Life-threatening complications like cardiac tamponade exist. Intracardiac echocardiography (ICE) usage is associated with superior safety in radiofrequency ablation. It is unclear if ICE has an impact on safety of CBA.

METHODS

The FREEZE Cohort (NCT01360008) subanalysis included patients undergoing "PVI only" CBA. Patients with intraprocedural transesophageal echocardiography were excluded. Group A comprises conventional, group B ICE-guided CBA. Periprocedural results were compared.

RESULTS

From 2011 to 2016, a total of 4189 patients were enrolled, and 1906 (45.5%) were included in this subanalysis, split up in two groups (A: 1066 [55.9%], B: 840 [44.1%]). Group A was younger (60.6 ± 10.8 vs. 62.4 ± 10.5 years, p < .001), with smaller left atria (41 vs. 43 mm, p < .001), and less persistent AF (23.1 vs. 38.1%, p < .001). Procedure, left atrial, and fluoroscopy times were shorter in group A as compared to group B. Dose area product was significantly higher in group A (2911 vs. 2072 cGyxcm2 , p < .001). In-hospital major adverse cerebrovascular and cardiac event rates including two deaths in group A were not different between groups (0.5% vs. 0.1%, p = .18). The rate of total procedural (10.4% vs. 5.1%, p < .001) and major complications (3.2% vs. 1.3%, p < .001) was significantly higher in group A. Cardiac tamponade occurred significantly more frequently in group A (8 [0.8%] vs. 1 [0.1%], p = .046). Independent predictors for major complications were female sex (odds ratio [OR] 2.03, p = .03) and non-ICE usage (OR 2.38, p = .02). No differences were observed for persistent phrenic nerve palsy, nor for groin complications.

CONCLUSION

CBA was significantly safer and required less radiation if ICE was used, although the procedures were more complex. The risk of groin complications was not increased with ICE usage. Non-ICE usage was the only modifiable independent predictor of major complications.

An economic evaluation of first-line cryoballoon ablation vs antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from a U.S. Medicare perspective

Background

Three recent randomized controlled trials have demonstrated that, as an initial rhythm control strategy, first-line cryoballoon ablation (cryoablation) reduces atrial arrhythmia recurrence compared with antiarrhythmic drugs (AADs) in patients with symptomatic paroxysmal atrial fibrillation (PAF).

Objective

The study sought to evaluate the cost-effectiveness of first-line cryoablation compared with first-line AADs for treating symptomatic PAF from a U.S. Medicare payer perspective.

Methods

Individual patient-level data from 703 participants with PAF enrolled into the Cryo-FIRST (NCT01803438), STOP AF First (NCT03118518), and EARLY-AF (NCT02825979) trials were used to derive parameters for the cost-effectiveness model. The cost-effectiveness model used a hybrid decision tree and Markov structure. The decision tree had a 1-year time horizon and was used to inform the initial health state allocation in the first cycle of the Markov model. The Markov model used a 40-year time horizon (3-month cycle length). Health benefits were expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3% per year.

Results

Cryoablation was estimated to yield higher QALYs (+0.17) and higher costs (+$4274) per patient over a 40-year time horizon than AADs. Ultimately, this produced an average incremental cost-effectiveness ratio of $24,637 per QALY gained. Independent of initial treatment, individuals were expected to receive ∼1.2 ablations over a lifetime. There was a 45% relative reduction in time spent in atrial fibrillation health states for those initially treated with cryoablation compared with AADs.

Conclusion

Initial rhythm control with first-line cryoballoon ablation is highly cost-effective compared with first-line AADs from a U.S. Medicare payer perspective.

Successful simultaneous stenting of a pulmonary artery and vein in pulmonary vascular stenosis due to silicosis. Case report and literature review

A 58-year-old patient was admitted to the emergency department due to severe respiratory insufficiency. Anamnesis revealed that the patient had experienced increasing stress dyspnea for a few months. Upon imaging, an acute pulmonary embolism was excluded, but peribronchial and hilar soft tissue proliferation with compression of central parts of the pulmonary circulation was found. The patient had a history of silicosis. The histology report showed tumor-free lymph node particles with prominent anthracotic pigment and dust depositions without evidence of IgG4-associated disease. The patient was administered steroid therapy and underwent simultaneous stenting of the left interlobular pulmonary artery and the upper right pulmonary vein. As a result, a significant improvement in symptoms and physical performance was achieved. The diagnosis of inflammatory or, in particular, fibrosing mediastinal processes can be challenging and important clinical symptoms must be taken into account, especially if the pulmonary vasculature is involved. In such cases, the possibility of interventional procedures should be examined in addition to drug therapy options.

A worldwide survey on incidence, management and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: The POTTER-AF study

AIMS

Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management and outcome are sparse.

METHODS AND RESULTS

This international multicenter registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553,729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed at 214 centers in 35 countries. In 78 centers 138 patients (0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (p<0.0001)) were diagnosed with an oesophageal fistula. Periprocedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8%, and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) (odds ratio 7.463 (2.414, 23.072) p<0.001).

CONCLUSIONS

Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high.

A rare case of right heart failure with the necessity for veno-arterial extracorporeal membrane oxygenation following pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation

Pulmonary vein stenosis (PVS) after radiofrequency energy-mediated percutaneous pulmonary vein isolation as a treatment option for atrial fibrillation is a serious complication and the prevalence in historical reports varies between 0% and 42%. Symptoms of PVS are nonspecific and can include general symptoms such as dyspnea, cough, recurrent pneumonia, and chest pain. Pathophysiologically it increases the postcapillary pressure in the pulmonary circuit and may result in pulmonary hypertension (PH). Misdiagnosis and delayed treatment are common. We here report a case of a 59-year-old female with a history of pulmonary vein ablation followed by progressive dyspnea (New York Heart Association IV), right heart failure, CPR, and the need for extracorporeal membrane oxygenation (ECMO). Further treatment strategy includes pulmonary vein dilatation and stenting of both the left superior pulmonary vein and left inferior pulmonary vein, as well as balloon dilatation of RIPV under temporary ECMO support. Symptomatic, severe PVS is a rare complication after catheter ablation of atrial fibrillation. PVS can result in life-threatening complications such as PH with acute right heart failure. Early diagnosis is crucial but challenging. Mechanical cardiopulmonary support by veno-arterial ECMO for bridging to angioplasty could be a lifesaving option.

Electrophysiology lab efficiency comparison between cryoballoon and point-by-point radiofrequency ablation: a German sub-analysis of the FREEZE Cohort study

BACKGROUND

Pulmonary vein isolation (PVI) is recommended to treat paroxysmal and persistent atrial fibrillation (AF). This analysis aimed to assess the hospital efficiency of single-shot cryoballoon ablation (CBA) and point-by-point radiofrequency ablation (RFA).

METHODS

The discrete event simulation used PVI procedure times from the FREEZE Cohort study to establish the electrophysiology (EP) lab occupancy time. 1000 EP lab days were simulated according to an illustrative German hospital, including 3 PVI cases per day using CBA at one site and RFA at the other.

RESULTS

The analysis included 1560 CBA patients and 1344 RFA patients from the FREEZE Cohort. Some baseline patients' characteristics were different between groups (age, AF type, and some concomitant diseases), without being statistically associated to ablation procedure time. Mean procedure time was 122.2 ± 39.4 min for CBA and 160.3 ± 53.5 min for RFA (p < 0.0001). RFA was associated with a more than five-fold increase of cumulative overtime compared to CBA over the simulated period (1285 h with RFA and 253 h with CBA). 70.7% of RFA lab days included overtime versus 25.7% for CBA. CBA was associated with more days with an additional hour at the end of the EP lab shift compared to RFA (47.8% vs 11.5% days with one hour left, respectively).

CONCLUSION

CBA is faster and more predictable than point-by-point RFA, and enables improvements in EP lab efficiency, including: fewer cumulative overtime hours, more days where overtime is avoided and more days with remaining time for the staff or for any EP lab usage. Clinical trial registration NCT01360008 (first registration 25/05/2011).

Impact of cryoballoon application abortion due to phrenic nerve injury on reconnection rates: a YETI subgroup analysis

AIMS

Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). The most frequent complication during CB-based PVI is right-sided phrenic nerve injury (PNI) which is leading to premature abortion of the freeze cycle. Here, we analysed reconnection rates after CB-based PVI and PNI in a large-scale population during repeat procedures.

METHODS AND RESULTS

In the YETI registry, a total of 17 356 patients underwent CB-based PVI in 33 centres, and 731 (4.2%) patients experienced PNI. A total of 111/731 (15.2%) patients received a repeat procedure for treatment of recurrent AF. In 94/111 (84.7%) patients data on repeat procedures were available. A total of 89/94 (94.7%) index pulmonary veins (PVs) have been isolated during the initial PVI. During repeat procedures, 22 (24.7%) of initially isolated index PVs showed reconnection. The use of a double stop technique did non influence the PV reconnection rate (P = 0.464). The time to PNI was 140.5 ± 45.1 s in patients with persistent PVI and 133.5 ± 53.8 s in patients with reconnection (P = 0.559). No differences were noted between the two populations in terms of CB temperature at the time of PNI (P = 0.362). The only parameter associated with isolation durability was CB temperature after 30 s of freezing. The PV reconnection did not influence the time to AF recurrence.

CONCLUSION

In patients with cryoballon application abortion due to PNI, a high rate of persistent PVI rate was found at repeat procedures. Our data may help to identify the optimal dosing protocol in CB-based PVI procedures.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT03645577?term=YETI&cntry=DE&draw=2&rank=1 ClinicalTrials.gov Identifier: NCT03645577.

New evidence: Cryoballoon ablation vs. antiarrhythmic drugs for first-line therapy of atrial fibrillation

Atrial fibrillation (AF) is a commonly encountered chronic and progressive heart rhythm disorder, characterized by exacerbations and remissions. Contemporary clinical practice guidelines recommend a trial of antiarrhythmic drugs (AADs) as the initial therapy for sinus rhythm maintenance; however, these medications have modest efficacy and are associated with significant adverse effects. Recently, several trials have demonstrated that an initial treatment strategy of cryoballoon catheter ablation significantly improves arrhythmia outcomes (e.g. freedom atrial tachyarrhythmia and reduction in arrhythmia burden), produces clinically meaningful improvements in patient-reported outcomes (e.g. symptoms and quality of life), and significantly reduces subsequent healthcare resource utilization (e.g. hospitalization), without increasing the risk of serious or any adverse events. These findings are relevant to patients, providers, and healthcare systems, helping inform the decision regarding the initial choice of rhythm-control therapy in patients with treatment-naïve AF.

High Resting Heart Rates Are Associated with Early Posthospitalization Mortality in Low Ejection Fraction Patients

Guideline-directed medical therapy (GDMT) is crucial in reducing mortality in patients with heart failure with heart rate lowering by a beta blocker (BB) being an important therapeutic concept. We aimed to assess the usefulness of a wearable cardioverter/defibrillator (WCD) to provide detailed information about heart rate for managing patients with reduced left ventricular ejection fraction (LVEF) and symptoms of heart failure and to correlate mortality with the mean heart rate. A total of 4509 consecutive patients (mean age: 59 + 13 years, 88% male) were analyzed retrospectively. All patients had reduced LVEF and were prescribed a WCD for protection from sudden cardiac death (SCD) during GDMT uptitration awaiting LVEF recovery. The device continuously measured nighttime and daytime HR at the beginning and end of WCD use. Patients who died during wear time had significantly higher HRs compared with survivors: daytime beginning of use (BOU), 80 ± 15 bpm vs. 76 ± 13, p < 0.01; nighttime BOU, 76 ± 14 vs. 69 ± 13, p < 0.0001; daytime end of use (EOU), 84 ± 20 vs. 73 ± 13, p < 0.0001; nighttime EOU, 80 ± 20 vs. 65 ± 12, p < 0.0001). In conclusion, HR monitoring with a WCD yields important prognostic information and may assist in optimal usage of BB in patients with low LVEF.

Repeat procedures and reconnection rates after cryoballoon PVI with phrenic nerve injury

Funding Acknowledgements

Type of funding sources: None.

Aims

Cryoballoon (CB) based pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). The most frequent complication during CB-based PVI is right-sided phrenic nerve injury which is leading to premature abortion of the freeze cycle. Here we analysed repeat procedures and reconnection rates after CB-based PVI and phrenic nerve injury in a large-scale population. Due to the fact that the freezing process was prematurely interrupted the data may offer unique findings in optimizing the CB dosing protocols.

Methods and Results

In the YETI registry a total of 17356 patients underwent CB-based PVI in 33 centers and 731 (4.2%) patients experienced phrenic nerve injury. A total of 111 / 731 (15.2%) patients received a repeat procedure utilizing a 3D mapping system due to AF recurrence. In 94/111 (84.7%) of patients data on repeat procedures was available. During their initial PVI procedures, phrenic nerve injury occurred during treatment of RSPV (n=80), RIPV (n=13) and LSPV (n=1). A total of 89/94 (94.7%) target PVs have been isolated during the initial PVI (RSPV: 75/80, 94%; RIPV: 13/13; 100%; LSPV: 1/1; 100%). The mean freezing time was 127±46s and the mean minimal temperature was -49±7°C. During the repeat procedures 67 of initially 89 isolated PVs showed persistent isolation (75%, for RSPV: 55/75; 73%; RIPV: 11/13; 85%; LSPV: 1/1; 100%).

Conclusion

In patients initially treated by CB-based PVI with interruption of the freezing due to phrenic nerve injury, a high rate of durable isolated PVs has been detected at repeat procedures. Our data may help to identify the optimal dosing protocol in CB-based PVI procedures

Phrenic Nerve Injury During Cryoballoon-Based Pulmonary Vein Isolation: Results of the Worldwide YETI Registry

Supplemental Digital Content is available in the text.

Background:

Cryoballoon-based pulmonary vein isolation (PVI) has emerged as an effective treatment for atrial fibrillation. The most frequent complication during cryoballoon-based PVI is phrenic nerve injury (PNI). However, data on PNI are scarce.

Methods:

The YETI registry is a retrospective, multicenter, and multinational registry evaluating the incidence, characteristics, prognostic factors for PNI recovery and follow-up data of patients with PNI during cryoballoon-based PVI. Experienced electrophysiological centers were invited to participate. All patients with PNI during CB2 or third (CB3) and fourth-generation cryoballoon (CB4)-based PVI were eligible.

Results:

A total of 17 356 patients underwent cryoballoon-based PVI in 33 centers from 10 countries. A total of 731 (4.2%) patients experienced PNI. The mean time to PNI was 127.7±50.4 seconds, and the mean temperature at the time of PNI was −49±8°C. At the end of the procedure, PNI recovered in 394/731 patients (53.9%). Recovery of PNI at 12 months of follow-up was found in 97.0% of patients (682/703, with 28 patients lost to follow-up). A total of 16/703 (2.3%) reported symptomatic PNI. Only 0.06% of the overall population showed symptomatic and permanent PNI. Prognostic factors improving PNI recovery are immediate stop at PNI by double-stop technique and utilization of a bonus-freeze protocol. Age, cryoballoon temperature at PNI, and compound motor action potential amplitude loss >30% were identified as factors decreasing PNI recovery. Based on these parameters, a score was calculated. The YETI score has a numerical value that will directly represent the probability of a specific patient of recovering from PNI within 12 months.

Conclusions:

The incidence of PNI during cryoballoon-based PVI was 4.2%. Overall 97% of PNI recovered within 12 months. Symptomatic and permanent PNI is exceedingly rare in patients after cryoballoon-based PVI. The YETI score estimates the prognosis after iatrogenic cryoballoon-derived PNI.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03645577.

Graphic Abstract:

A graphic abstract is available for this article.

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.

Impact of comorbidities and ablation strategy on outcome after pulmonary vein isolation with cryo-balloon in patients with non- paroxysmal atrial fibrillation

Background

Presence of several comorbidities in patients with atrial fibrillation is well known, but impact of them on outcome after pulmonary vein isolation with cryo-balloon is not enough investigated. First aim of the study was analysis of the impact of comorbidities on long term outcome after PVI with cryo-balloon new generation (CBA) and secondary goal was evaluation of the impact of additional posterior roof ablation (PRA) in these patients.

Methods

Patients with non-paroxysmal AF ablated with CBA in our institution since May 2012 and completed follow up &gt;3 months were enrolled in the study. The history of AF, cardiac comorbidities (CAD, Non ischemic-cardiomyopathy, heart insufficiency, right ventricular dysfunction) diabetes mellitus, and renal failure were assessed at admission, all patients received echocardiographic examination and blood test.

After a single trans-septal access and PV angiography PVI was performed using a 28-mm CBA. Mapping of PV signals before, during, and after each cryo application was performed with a 3F lasso catheter. The procedural endpoint after PVI was defined as complete elimination of all fragmented signals at the PV antrum with verification of entrance and exit block. In some patients PRA was performed additionally to PVI at discretion of physician. The primary endpoint of this study was the first documented recurrence of atrial tachyarrhythmia (&gt;30 sec.), hospitalization due to cardio-vascular cause, re-do procedure or re-administration of anti-arrhythmic drugs.

Results

Among 560 patients 78 (13.9%) had no comorbidity and 299 (53.4%) were lasted with &gt;1 comorbidity. A total of 260 (46.4%) recurrences were obtained within median follow up of 28 (12–57) months. Female gender, long time from first diagnosis &gt;12 months and cardiac comorbidity were revealed to be independent predictors for long term recurrences whereas additional PRA performed in 176 pts independently improved outcome (61.9% vs 49.7%).

Conclusion

Cardiac comorbidities increased probability of post ablation recurrences, but performing of additional posterior roof ablation improved outcome in our cohort. These results should be confirmed in multi-center randomized study

Funding Acknowledgement

Type of funding sources: None.

Cryoballoon Ablation as Initial Treatment for Atrial Fibrillation: JACC State-of-the-Art Review

Atrial fibrillation (AF), the most common sustained arrhythmia observed in clinical practice, is a chronic and progressive disorder characterized by exacerbations and remissions. Guidelines recommend antiarrhythmic drugs as the initial therapy for the maintenance of sinus rhythm; however, antiarrhythmic drugs have modest efficacy to maintain sinus rhythm and can be associated with significant adverse effects. An initial treatment strategy of cryoballoon catheter ablation in patients with treatment-naïve AF has been shown to significantly improve arrhythmia outcomes (freedom from any, or symptomatic atrial tachyarrhythmia), produce clinically meaningful improvements in patient-reported outcomes (symptoms and quality of life), and significantly reduce subsequent health care resource use (hospitalization), and it does not increase the risk of serious or any adverse events compared with initial antiarrhythmic drug therapy. These findings are relevant to inform patients, providers, and health care systems regarding the initial choice of rhythm-control therapy in patients with treatment-naïve AF.

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.

Impact of initial rhythm control with cryoballoon ablation versus drug therapy on atrial fibrillation recurrence and quality of life: results from the Cryo-FIRST study

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic

OnBehalf

The Cryo-FIRST Investigators

Background

Cryoballoon ablation (CBA) as a first-line rhythm control strategy is superior to antiarrhythmic drugs (AADs) for preventing atrial arrhythmia recurrence; however, the impact of first-line CBA specifically on atrial fibrillation (AF) recurrence and quality of life (QoL) has not been well characterized.

Purpose

To compare AF recurrence and QoL following first-line CBA vs. AAD therapy in patients with paroxysmal AF within the CryoFIRST trial (NCT01803438).

Methods

Patients with recurrent symptomatic paroxysmal AF who had not been administered class I or III AAD therapy for &gt;48 hours were enrolled at 18 sites in 9 countries. Patients were randomized (1:1) to CBA or AAD treatment (Class I or III). Subjects were followed by 7-day Holter at 1, 3, 6, 9, and 12 months. Time-to-first AF recurrence outside of a 90-day blanking period was estimated by Kaplan-Meier analysis.  QoL was evaluated using the Atrial Fibrillation Effect on Quality of Life (AFEQT) and 36-Item Short Form Health Survey (SF-36) v2 questionnaires.

Results

Of the 218 randomized subjects, 187 (86%) completed the 12-month follow-up. By intention-to-treat (ITT) analysis, freedom from AF after blanking was achieved in 86.6% in the CBA and 74.5% in the AAD group (p = 0.023).  There was no difference in the time-to-first serious adverse event between groups. In total, 84.3% of patients in the CBA vs. 75.0% of patients in the AAD arm had a clinically important improvement (≥5 points) in the AFEQT summary score.  The adjusted mean difference in the AFEQT summary score at 12 months was 9.9 points higher in the CBA group (95% CI: 5.5-14.2; P &lt; 0.001).  All AFEQT subscale scores were more favorable in the CBA vs. AAD group at 12 months.  There were no significant group differences in any of the SF-36 health domain scores at 12 months in the ITT analysis.  In the per-protocol analysis, clinically important and significant group differences in favor of CBA were observed at 12 months for 3 of 8 SF-36 health domain scores (physical functioning, general health and social functioning).

Conclusion

CBA is superior to AAD for preventing AF recurrence and improving AF-specific QoL in patients with paroxysmal AF. AFEQT Scores at Baseline and 12 MonthsAFEQT Score, Mean ± Standard DeviationCBAAADAdjusted Mean Difference at 12 Months (CBA vs. AAD)p-valueBaseline12 MonthsBaseline12 MonthsDaily Activities65.3 ± 25.887.8 ± 17.161.0 ± 27.976.6 ± 25.48.9 (3.2-14.6)0.002Symptoms59.9 ± 24.888.8 ± 15.658.4 ± 25.280.9 ± 22.27.1 (1.5-12.7)0.014Treatment Concern59.9 ± 23.189.8 ± 14.060.4 ± 24.577.7 ± 22.212.7 (7.9-17.5)&lt;0.001AFEQT, Atrial Fibrillation Effect on Quality of Life questionnaire. CBA, cryoballoon ablation. AAD antiarrhythmic drug.Abstract Figure. Freedom From Atrial Fibrillation

Segmental nonocclusive cryoballoon ablation of pulmonary veins and extrapulmonary vein structures: Best practices III

Although cryoballoon ablation of atrial fibrillation (AF) traditionally has been guided by pulmonary vein (PV) occlusion, there is evidence and growing interest in performing segmental, nonocclusive cryoballoon ablation to target not only large/common PVs but extra-PV structures such as the left atrial (LA) roof and posterior wall in conjunction with PV isolation. A number of studies have demonstrated improved clinical efficacy associated with nonocclusive cryoballoon ablation of the LA roof and posterior wall in addition to PV isolation, particularly in patients with persistent AF. Not only can the cryoballoon be used for targeting extra-PV structures through segmental, nonocclusive ablation, but the large size and durability of cryolesions coupled with the enhanced stability afforded through cryoadhesion render the cryoballoon an effective tool for such an approach. This article reviews the rationale and practical approach to segmental, nonocclusive cryoballoon ablation of large/common PV antra and the LA roof and posterior wall.

Outcomes of cryoballoon or radiofrequency ablation in symptomatic paroxysmal or persistent atrial fibrillation

Aims

To evaluate the effectiveness and safety of cryoballoon ablation (CBA) compared with radiofrequency ablation (RFA) for symptomatic paroxysmal or drug-refractory persistent atrial fibrillation (AF).

Methods and results

Prospective cluster cohort study in experienced CBA and RFA centres. Primary endpoint was ‘atrial arrhythmia recurrence’, secondary endpoints were as follows: procedural results, safety, and clinical course. A total of 4189 patients were included: CBA 2329 (55.6%) and RFA 1860 (44.4%). Cryoballoon ablation population was younger, with fewer comorbidities. Procedure time was longer in the RFA group (P = 0.01). Radiation exposure was 2487 (CBA) and 1792 cGycm² (RFA) (P < 0.001). Follow-up duration was 441 (CBA) and 511 days (RFA) (P < 0.0001). Primary endpoint occurred in 30.7% (CBA) and 39.4% patients (RFA) [adjusted hazard ratio (adjHR) 0.85, 95% confidence interval (CI) 0.70–1.04; P = 0.12). In paroxysmal AF, CBA resulted in a lower risk of recurrence (adjHR 0.80, 95% CI 0.64–0.99; P = 0.047). In persistent AF, the primary outcome was not different between groups. Major adverse cardiovascular and cerebrovascular event rates were 1.0% (CBA) and 2.8% (RFA) (adjHR 0.53, 95% CI 0.26–1.10; P = 0.088). Re-ablations (adjHR 0.46, 95% CI 0.34–0.61; P < 0.0001) and adverse events during follow-up (adjHR 0.64, 95% CI 0.48–0.88; P = 0.005) were less common after CBA. Higher rehospitalization rates with RFA were caused by re-ablations.

Conclusions

The primary endpoint did not differ between CBA and RFA. Cryoballoon ablation was completed rapidly; the radiation exposure was greater. Rehospitalization due to re-ablations and adverse events during follow-up were observed significantly less frequently after CBA than after RFA. Subgroup analysis suggested a lower risk of recurrence after CBA in paroxysmal AF.

Trial Registration

ClinicalTrials.gov (NCT01360008), https://clinicaltrials.gov/ct2/show/NCT01360008.

Quality of life measured in first-line therapy during the Cryo-FIRST study: a comparison between cryoballoon catheter ablation versus antiarrhythmic drug therapy

Background

By consensus statements, catheter ablation is a recommended treatment for patients with symptomatic drug-refractory paroxysmal atrial fibrillation (AF), as patients try to alleviate the burdensome AF symptoms that reduce the Quality of Life (QoL). Yet, first-line treatment of symptomatic patients via catheter ablation prior to initiation of antiarrhythmic drugs (AADs) is only a reasonable alternative (Class IIa). Clearly, more clinical data is necessary that compares catheter ablation to AAD therapy in treatment naïve patients.

Purpose

The Cryo-FIRST trial was designed to compare AAD treatment against pulmonary vein isolation (PVI) while using a cryoballoon catheter (Arctic Front Advance; Medtronic, Inc.). This current data analysis examines the QoL endpoints when comparing AADs to cryoballoon ablation in patients with symptomatic treatment naïve paroxysmal AF.

Methods

This randomized multicenter trial enrolled 220 patients from 18 sites in 9 countries (Europe, Australia, and Latin America) in a prospective open-blinded endpoint study design. Patients had not been administered a class I or III AAD for longer than 48 hours for inclusion into the study. Subjects were randomized (1:1) into a cohort that was administered AAD therapy or a cohort that received PVI via cryoablation. The prespecified QoL endpoint at 12 months was measured using the Atrial Fibrillation Effect on Quality of Life (AFEQT) scores, and QoL recordings were taken at baseline, 1, 3, 6, 9, and 12 months following the index treatment.

Results

Of the 218 patients randomized (age 52±13 years, 68% male) 86% completed the 12-month follow-up. Crossovers occurred in 9% of subjects (N=20), including: 1 subject in the cryoablation arm and 19 subjects in the AAD arm. At 12 months, 86.5% of the patients in the cryoablation arm and 70.4% of the patients in the AAD arm where without symptoms (EHRA score 1). The mean AFEQT summary score was more favorable in the catheter ablation group compared to the drug therapy group at 12 months (88.9 vs. 78.1 points, respectively). The adjusted difference was 9.9 points (95% CI: 5.5–14.2; P&lt;0.0001).

Conclusions

Cryoballoon ablation resulted in a significant improvement in QoL at 12 months compared to AAD therapy in treatment naïve patients with first-line symptomatic paroxysmal AF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic International Trading Sàrl

P1006Cryo-balloon ablation in elderly; Outcome and prediction of recurrence

Background

It is well known that prevalence of atrial fibrillation correlates with age, however the data on ablation of atrial fibrillation in elderly patients is poor. Aim of this study was analysis of outcome and prediction of recurrence after cryo-balloon ablation (CBA) in elderly patients based on available data in our registry.

Methods

The history of AF was assessed at admission. Additionally, all patients received echocardiographic examination and blood test. After a single trans-septal access and PV angiography PVI was performed using a 28-mm CBA. Mapping of PV signals before, during, and after each cryo application was performed with a 3F lasso catheter. The procedural endpoint after PVI was defined as complete elimination of all fragmented signals at the PV antrum with verification of entrance and exit block. Primary endpoint was first documented recurrence of AF, atrial tachycardia or atrial flutter (&gt;30 sec.). All patients received a follow-up every 3 month within 1st year, once yearly thereafter and in case of symptoms. Seven days Holter ECG was recorded by every follow up.

Results

A total of 44 (39%) of enrolled patients were male, 48 (43%) suffered non- paroxysmal AF(nPAF), 93 (82%) had hypertension, CAD was diagnosed by 27 (24%), 28 (25%) had DM (Hb1AC &gt; 6), Stroke/TIA was observed in 11 (10%). Median Age in elderly was 76 (75-78) y, BMI 25.77 (23.51-28.69), time since 1st diagnosis 40 (6-50) month, LA area index 11.36 (9.77-13.20), TAPSE 23 (19-26), GFR 74 (66-83) mL/min, LVEF 60 (57-62). A total of 44 patients (39%) reached endpoint within follow up of 20 (12-38) months. Univariate association with outcome was found by follows parameter: Time from 1st diagnosis &gt; 3 y (HR = 3.22 (1.66-6.27), p=.001); LA area index (HR = 1.17 (1.03-1.32), p=.013); DM (HR = 1.89 (1.02-3.55), p=.042); nPAF (HR = 1.90 (1.04-3.47), p=.036). After multivariate analysis only time from 1st diagnosis &gt; 3 y, (HR= 3.17 (1.62-6.16), p=.001 and nPAF (HR = 1.84 (1.01-3.36)), p=.048 were revealed to be predictive. The area under probability score calculated for these predictors was .731 (.638-8.25), p=.001. Follows complications were observed: 2 (2%) - pericard tamponades, 4 (4%) phrenicus nerve injury. Conclusion. PVI with cryo-balloon is effective for elderly patients providing freedom of arrhythmic events in 61% of patients. Longer history of AF over 3 years since 1st diagnosis was main predictor for post ablation recurrence. In elderly patients with shorter history of AF efficiency and safety of CBA is comparable with general population.

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.

Preventive or Deferred Ablation of Ventricular Tachycardia in Patients With Ischemic Cardiomyopathy and Implantable Defibrillator (BERLIN VT)

Background:

Catheter ablation for ventricular tachycardia (VT) reduces the recurrence of VT in patients with implantable cardioverter-defibrillators (ICDs). The appropriate timing of VT ablation and its effects on mortality and heart failure progression remain a matter of debate. In patients with life-threatening arrhythmias necessitating ICD implantation, we compared outcomes of preventive VT ablation (undertaken before ICD implantation to prevent ICD shocks for VT) and deferred ablation after 3 ICD shocks for VT.

Methods:

The BERLIN VT study (Preventive Ablation of Ventricular Tachycardia in Patients With Myocardial Infarction) was a prospective, open, parallel, randomized trial performed at 26 centers. Patients with stable ischemic cardiomyopathy, a left ventricular ejection fraction between 30% and 50%, and documented VT were randomly assigned 1:1 to a preventive or deferred ablation strategy. The primary outcome was a composite of all-cause death and unplanned hospitalization for either symptomatic ventricular arrhythmia or worsening heart failure. Secondary outcomes included sustained ventricular tachyarrhythmia and appropriate ICD therapy. We hypothesized that preventive ablation strategy would be superior to deferred ablation strategy in the intention-to-treat population.

Results:

During a mean follow-up of 396±284 days, the primary end point occurred in 25 (32.9%) of 76 patients in the preventive ablation group and 23 (27.7%) of 83 patients in the deferred ablation group (hazard ratio, 1.09 [95% CI, 0.62–1.92]; P =0.77). On the basis of prespecified criteria for interim analyses, the study was terminated early for futility. In the preventive versus deferred ablation group, 6 versus 2 patients died (7.9% versus 2.4%; P =0.18), 8 versus 2 patients were admitted for worsening heart failure (10.4% versus 2.3%; P =0.062), and 15 versus 21 patients were hospitalized for symptomatic ventricular arrhythmia (19.5% versus 25.3%; P =0.27). Among secondary outcomes, the proportions of patients with sustained ventricular tachyarrhythmia (39.7% versus 48.2%; P =0.050) and appropriate ICD therapy (34.2% versus 47.0%; P =0.020) were numerically reduced in the preventive ablation group.

Conclusions:

Preventive VT ablation before ICD implantation did not reduce mortality or hospitalization for arrhythmia or worsening heart failure during 1 year of follow-up compared with the deferred ablation strategy.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02501005.

6121Phrenic nerve injury during pulmonary vein isolation using the second-generation cryoballoon: characteristics and follow-up - The YETI registry

Background

Second-generation cryoballoon (CB2) based pulmonary vein isolation (PVI) has emerged as a safe and effective treatment option for symptomatic atrial fibrillation (AF). Although published complication rates of CB2 based-PVI are relatively low and several safety algorithms have been implemented in the protocols the most frequent complication is right-sided phrenic nerve injury (PNI). The reported incidence of PNI varies from 2–5% of patients. However data on PNI characteristics as well as follow-up is sparse.

Purpose

We aimed to evaluate the incidence, characteristics and outcome of PNI during after CB2 based-PVI in a large patients population.

Methods and results

From July 2012 to November 2018 a total of 13693 patients received CB2 or CB3 (third-generation) based-PVI in 23 EP centers (Germany: 12, China: 1, Turkey: 3, Japan: 3, USA: 1, Austria: 1, Poland: 1, Swizerland: 1). A total of 596 (4.4%) of patients experienced PNI during treatment of the right superior (84%) right inferior (15%) right middle (0.3%) (and left superior (0.3%) pulmonary veins. The mean time to PNI was 127±51 seconds and the mean temperature at the time of PNI was −49±7 °C. The target PV was isolated at time of PNI in 84% of cases. The applications were interrupted using double-stop technique in (71%). In 212/306 (52%) a CMAP was utilized.

At the end of the procedure PNI persistent in 45% of patients. Fluoroscopic or sonographic evaluation of PNI was performed 1–3 days after the procedure and revealed persistent PNI in 35% of patients. Dyspnea before discharge was reported in 18% of patients with persistent PNI. Patients follow up at 1–3, and 6–12 months included fluoroscopy and a visit in an outpatient clinic. After 1–3 months 18% of patients showed persistent PNI including 13% of patients complaining of dyspnea. After 6–12 months of follow-up including fluoroscopic evaluation PNI was persistent in 1.8% of patients while dyspnea was reported by 1.7% patients. Only 0.08% of the overall population of 13693 patients showed permanent and symptomatic PNI.

Conclusion

The incidence of PNI during CB2-based PVI is low. About 55% of PNI recovered until the end of the procedure. Most of PNI recovered within 12 months. Symptomatic permanent PNI is very rare in patients after CB2/CB3-based PVI.

PLAAF score as a novel predictor of long-term outcome after second-generation cryoballoon pulmonary vein isolation

Aims

Predictors of atrial arrhythmia recurrence have not been described in a long-term follow-up study of patients undergoing pulmonary vein isolation (PVI) using the cryoballoon technique. We aimed to evaluate the efficacy of a second-generation cryoballoon and identify pre-procedural predictors of 3-year outcome after PVI.

Methods and results

For this observational cohort study, we enrolled 440 patients ablated at our institution with a second-generation cryoballoon. The endpoint was the first documented recurrence (>30 s) of atrial fibrillation (AF), atrial flutter, or atrial tachycardia after a 3-month blanking period. The impact of several pre-existing variables on clinical outcome was evaluated by univariate and multivariate analyses using the Cox proportional hazards regression model. The PLAAF (persistent AF, left atrial area, abnormal PV anatomy, AF history, female gender) score was defined to predict outcome. After a median follow-up of 36 months (interquartile range 25/75-27/42), the endpoint was achieved in 95 of 440 (21.6%) patients. Cox regression analysis showed that persistent AF, left atrial (LA) area, abnormal PV anatomy, AF history, and female gender independently predicted recurrence. The calculated optimal cut-offs for LA area and AF history were 21 cm2 and 3 years, respectively. Patients with a PLAAF score of 0 showed the best outcome, with an arrhythmia-free survival of 86.7%.

Conclusion

PVI using the cryoballoon technique shows acceptable long-term results depending on predictors described by the new PLAAF score, which may facilitate patient selection for PVI.

[Premature ventricular contractions and tachycardia in a structurally normal heart : Idiopathic PVC and VT]

Premature ventricular contractions (PVC) are a common, often incidental and mostly benign finding. Treatment is indicated in frequent and symptomatic PVC or in cases of worsening of left ventricular function. Idiopathic ventricular tachycardia (VT) is mostly found in patients with a structurally healthy heart. These PVC/VT usually have a focal origin. The most likely mechanism is delayed post-depolarization. Localization of the origin is based on the creation of an activation map with or without combination of pace mapping. Idiopathic PVC/VT are most frequently located on the outflow tracts of the right and left ventricles, including the aortic root. Other typical locations include the annulus of the tricuspid or mitral valve, papillary muscles and Purkinje fibers. Catheter ablation is an alternative to antiarrhythmic medication in symptomatic monomorphic PVC/VT. The success rate is good whereby mapping and ablation can often represent a challenge. This article is the fifth part of a series dedicated to specific advanced training in the field of special rhythmology and invasive electrophysiology. It describes the pathophysiological principles, types and typical findings that can be obtained during an electrophysiological investigation.

Silent cerebral lesions and cognitive function after pulmonary vein isolation with an irrigated gold-tip catheter: REDUCE-TE Pilot study

Introduction

Stroke is one of the most feared complications during catheter ablation of atrial fibrillation (AF). While symptomatic thromboembolic events are rare, magnetic resonance imaging (MRI) may identify asymptomatic (ie, silent) cerebral lesions (SCLs) following pulmonary vein isolation (PVI) procedures.

Methods and Results

The REDUCE‐TE Pilot was a prospective multicenter, single‐arm observational study investigating the incidence of SCL in patients with symptomatic paroxysmal AF undergoing PVI with a novel gold‐tip, externally irrigated ablation catheter. After ablation, cerebral diffusion‐weighted MRI and a postablation follow‐up were performed at 1 to 3 days after the ablation procedure. A neurocognitive test was done before and after ablation. The primary study endpoint was the occurrence of one or more new SCLs. Secondary study endpoints included neurocognitive status, procedural success rate, and periprocedural complications including symptomatic thromboembolic events. A total of 104 patients were enrolled (69% male, mean age: 61.5 ± 9.7 years, mean CHA₂DS ₂‐VASc score: 1.7 ± 1.2). Postprocedural MRI examination was performed in 97 patients, and in nine of them (9.3%; 95% CI: 4.3‐16.9%) a total of 11 SCLs were detected. Univariate analyses did not reveal any significant predictor for new SCLs. Nonsignificant trends were observed for low activated clotting time during ablation and for international normalized ratio value outside the range of 2 to 3 at ablation. There was no evidence of significant deterioration of neurocognitive function after PVI. In four patients, a pericardial tamponade was noted but all patients fully recovered during follow‐up.

Conclusions

Ablation of AF using a novel gold‐tip, externally irrigated ablation catheter, resulted in SCLs in approximately one out of 10 patients without a measurable effect on neurocognitive function.

Second-generation cryoballoon ablation as a first-line treatment of symptomatic atrial fibrillation: Two-year outcome and predictors of recurrence after a single procedure

INTRODUCTION

Antiarrhythmic drug (AAD) therapy of patients with atrial fibrillation (AF) has limitations. We investigated the 2-year outcome and pre-procedural predictors of recurrence for first-line catheter ablation using the second-generation cryoballoon (CB-Adv) in a large cohort of patients with symptomatic AF.

METHODS AND RESULTS

For this prospective observational study, we enrolled 457 patients with symptomatic AF (278 paroxysmal, 179 persistent) who had no history of AAD use and who underwent pulmonary vein isolation (PVI) with the CB-Adv at our institution. Follow-up data, including Holter-ECGs, were collected during outpatient clinic visits. The impact of several variables on outcome was evaluated in univariate and multivariate analyses and Cox proportional hazards regression models. Median follow-up duration was 28 (interquartile range 15/42) months. PVI was sufficient in restoring and maintaining sinus rhythm in 79.2% (n=362) of patients. The median procedure and fluoroscopy times were 90 (72/120) and 16 (12/21) min, respectively. Phrenic nerve injury occurred in 16 (3.5%) patients, persisting until hospital discharge in 6 (1.3%) patients; phrenic nerve function recovered in all patients during follow-up. Seven patients developed groin hematomas (1.5%). Cox regression analysis showed that left atrial area >21cm² independently predicted recurrence.

CONCLUSION

This is the first demonstration that PVI with CB-Adv is safe and effective as a first-line treatment of symptomatic AF. Sinus rhythm persisted in 79.2% of patients even 2years after ablation. The success rate was lower in patients with enlarged left atria.

Remote vs. conventional navigation for catheter ablation of atrial fibrillation: insights from prospective registry data

BACKGROUND

Robotic (RNS) or magnetic navigation systems (MNS) are available for remotely performed catheter ablation for atrial fibrillation (AF).

OBJECTIVE

The present study compares remotely assisted catheter navigation (RAN) to standard manual navigation (SMN) and both systems amongst each other.

METHODS

The analysis is based on a sub-cohort enrolled by five hospitals from the multicenter German ablation Registry.

RESULTS

Out of 2442 patients receiving catheter ablation of AF, 267 (age 61.4 ± 10.4, 69.7% male) were treated using RAN (RNS n = 187, 7.7% vs. MNS n = 80, 3.3%). Fluoroscopy time [RNS median 17 (IQR 12-25) min vs. MNS 22 (16-32) min; p < 0.001] and procedure duration [RNS 180 (145-220) min vs. MNS 265 (210-305) min; p < 0.001] were significantly different. Comparing RAN (11%) to SMN (89%) fluoroscopy time (RAN 19 (13-27) min, vs. SMN 25 (16-40) min; p < 0.001), energy delivery (RAN 3168 (2280-3840) s vs. SMN 2640 (IQR 1799-3900) s; p = 0.008) and procedure duration [RAN 195 (150-255) min vs. SMN 150 (120-150) min; p = 0.001] differed significantly. In terms of acute and 12 months outcome, no differences were seen between the two systems or in comparison to SMN.

CONCLUSION

AF ablation can be performed safely, with high acute success rates using RAN. RNS results in less fluoroscopy burden and shorter procedure durations. Compared to SMN, a reduced fluoroscopy burden, prolonged procedure and ablation duration were observed using RAN. Overall, the number of RAN procedures is small suggesting low impact on clinical routine of AF ablation.

[Noninvasive mapping for catheter ablation of arrhythmias using the CardioInsight™ ECG vest]

BACKGROUND

CardioInsight™ is a noninvasive three-dimensional mapping system technology which offers a unique method for arrhythmia characterization and localization. With a 252-lead ECG vest on the patient's torso and a noncontrast CT scan, epicardial potentials are detected and by means of reconstruction algorithms activation and phase maps are created, offering a deeper understanding of localization and mechanisms of arrhythmias including atrial fibrillation without the need for an endocardial catheter.

MATERIALS AND METHODS

The system has proven to be accurate and applicable in the clinical setting of accessory pathways, premature ventricular contractions (PVC), atrial tachycardias and atrial fibrillation. Beat-to-beat analysis offers detection and thus a therapeutic approach for arrhythmias which occur only paroxysmally such as supraventricular extrasystoles, atrial bursts or PVCs. Another advantage is the simultaneous display of various heart chambers such as the left and right atrium. However, major multicenter prospective randomized data are still lacking.

CONCLUSION

If in the future noninvasive mapping could be achieved with MRI and if the technology was compatible with invasive mapping systems so that catheter positioning and noninvasive maps can be merged, the authors believe that this would represent a new dimension of mapping technology and ablation strategy of arrhythmias.

Cryoballoon ablation of persistent atrial fibrillation: feasibility and safety of left atrial roof ablation with generation of conduction block in addition to antral pulmonary vein isolation

Aims

Although the generation of linear lesions by ablation improves success rates in patients with persistent atrial fibrillation (AF), the procedure has been considered unsuitable for cryoablation balloon catheter technologies. We developed a technique for linear ablations, using second-generation cryoballoon technology.

Methods and results

This was a single-arm, prospective study in 76 patients with persistent AF treated consecutively at our centre. Cryoablation was performed using a 28 mm second-generation cryoballoon. The first cryoenergy application was performed in close proximity to the position during isolation of the left superior pulmonary vein (PV). Sequential overlapping freezes were applied along the left atrial (LA) roof by slight clockwise rotation of the sheath in combination with slight retraction of the sheath and incremental advancement of the cryoballoon, until reaching the original position for right superior PV isolation. The acute endpoint was the creation of a roofline, defined as complete conduction block across the LA roof >120 ms and ascending activation across the posterior LA wall. Acute success in roofline generation was achieved in 88% of patients, applying on average five (median 4-6) freezes with nadir temperature of -40°C (-36 to -44°C). In five patients, conduction block could not be achieved. No phrenic nerve injuries occurred during roofline generation.

Conclusion

Generation of linear roofline lesions is possible with the second-generation cryoballoon. The technique can be used in combination with PV isolation to treat persistent AF with good acute success rates, short procedure times, and acceptable safety concerns. If validated by further studies, the method would be an appealing alternative to radiofrequency ablation techniques.

The slope of the initial temperature drop predicts acute pulmonary vein isolation using the second-generation cryoballoon

Aims

There is no objective, early indicator of occlusion quality, and efficacy of cryoballoon pulmonary vein isolation. As previous experience suggests that the initial cooling rate correlates with these parameters, we investigated the slope of the initial temperature drop as an objective measure.

Methods and results

A systematic evaluation of 523 cryoapplications in 105 patients using a serial ROC-AUC analysis was performed. We found the slope of a linear regression of the temperature-time function to be a good predictor (PPV 0.9, specificity 0.72, sensitivity 0.71, and ROC-AUC 0.75) of acute isolation. It also correlated with nadir temperatures (P< 0.001, adjusted R2= 0.43), predicted very low nadir temperatures, and varied according to visual occlusion grades (ANOVA P< 0.001).

Conclusions

About 25 s after freeze initiation, the temperature-time slope predicts important key characteristics of a cryoablation, such as nadir temperature. The slope is the only reported predictor to actually precede acute isolation and thus to support decisions about pull-down manoeuvres or aborting a cryoablation early on. It is also predictive of very low nadir temperatures and phrenic nerve palsy and thus may add to patient safety.

Updated Survey on Interventional Electrophysiology: 5-Year Follow-Up of Infrastructure, Procedures, and Training Positions in Germany

OBJECTIVES

This study provides an update and comparison to a 2010 nationwide survey on cardiac electrophysiology (EP), types and numbers of interventional electrophysiological procedures, and training opportunities in 2015.

BACKGROUND

In 2010, German cardiology centers performing interventional EP were identified and contacted to provide a survey on cardiac EP.

METHODS

German cardiology centers performing interventional EP in 2015 were identified from quality reports and contacted to repeat the 2010 questionnaire.

RESULTS

A majority of 131 centers (57%) responded. EP (ablation procedures and device therapy) was mainly part of a cardiology department (89%) and only independent (with its own budget) in 11%. The proportion of female physicians in EP training increased from 26% in 2010 to 38% in 2015. In total, 49,356 catheter ablations (i.e., 81% of reported ablations in 2015) were performed by the responding centers, resulting in a 44% increase compared with 2010 (the median number increased from 180 to 297 per center). Atrial fibrillation (AF) was the most common arrhythmia interventionally treated (47%). At 66% of the centers, (at least) 2 physicians were present during most catheter ablations. A minimum of 50 (75) AF ablations were performed at 80% (70%) of the centers. Pulmonary vein isolation with radiofrequency point-by-point ablation (62%) and cryoablation (33%) were the preferred ablation strategies. About one-third of centers reported surgical AF ablations, with 11 centers (8%) performing stand-alone surgical AF ablations. Only one-third of the responding 131 centers fulfilled all requirements for training center accreditation.

CONCLUSIONS

Comparing 2010 with 2015, an increasing number of EP centers and procedures in Germany are registered. In 2015, almost every second ablation was for therapy for AF. Thus, an increasing demand for catheter ablation is likely, but training opportunities are still limited, and most centers do not fulfil recommended requirements for ablation centers.

How safe are NOACs compared with phenprocoumon after pulmonary vein isolation with the cryoballoon technique using purse-string suture closure?

INTRODUCTION

The aim of this observational study was to compare the postprocedural incidence of bleeding and thromboembolic complications associated with novel oral anticoagulants (NOACs) with that of interrupted and continuous phenprocoumon after pulmonary vein isolation (PVI) using a purse-string suture (PSS) closure of the puncture site.

METHODS AND RESULTS

Consecutive patients who had undergone PVI via cryoballoon ablation were divided into the following groups: (1) interrupted phenprocoumon with heparin bridging (n=101), (2) continuous phenprocoumon targeting an internationally normalized ratio>2 (n=70), and (3) NOACs without bridging that were restarted 2-4h after the procedure (n=185). Protamine was not administered after venous closure with PSS at the end of the procedure. The total complication rate was significantly lower in group 3 than in groups 1 and 2 (1.62% vs. 6.93% vs. 7.14%, p=0.04). The hospital costs were lower and the hospital stay length was significantly shorter (4484±3742 vs. 6082±4044 Euro vs. 4908±2925, p=0.03; 1.94±1.67 vs. 2.70±1.80 vs. 2.19±1.30days, p<0.01). No thromboembolic event occurred. Vascular complications were the most common complications noted (80%). The occurrence of any complication led to a significantly longer hospital stay (5 vs. 2days, p<0.01) and higher costs (10,052±6241 Euro vs. 4747±3447, p<0.01). The vascular complication rate after PSS was independent of intraprocedural heparin dosage and activated clotting time.

CONCLUSIONS

NOACs have a lower complication rate and appear to be safer in this setting than phenprocoumon. The hospital costs and hospital stay length after PVI was significantly reduced in patients treated with NOACs compared with phenprocoumon.