Persistence of Phrenic Nerve Palsy Following 28-mm Cryoballoon Ablation: A Four-Year Single Center Experience

Cryoballoon ablation for atrial fibrillation in octogenarians: a propensity score-based analysis with a younger cohort

BACKGROUND

In terms of safety and efficacy, cryoballoon ablation (CB-A) has become a valid option for achieving pulmonary vein isolation (PVI) in patients affected by symptomatic atrial fibrillation. However, CB-A data in octogenarians are still scarce and limited to single-centre experiences. The present multicentre study aimed to compare the outcomes and complications of index CB-A in patients older than 80 years with a cohort of younger patients.

METHODS AND RESULTS

We retrospectively enrolled 97 consecutive patients aged ≥80 years who underwent PVI using the second-generation CB-A. This group was compared with a younger cohort of patients using a 1:1 propensity score matching. After the matching, 70 patients from the elderly group were analysed and compared with 70 younger patients (control group). The mean age was 81.4 ± 1.9 years among octogenarians and 65.2 ± 10.2 years in the younger cohort. The global success rate after a median follow-up of 23 [18-32.5] months was 60.0% in the elderly group and 71.4% in the control group (P = 0.17). Phrenic nerve palsy was the most common complication occurring in a total of 11 patients (7.9%): in 6 (8.6%) patients in the elderly group and in 5 patients (7.1%) in the younger group (P = 0.51). Only two (1.4%) major complications occurred: one (1.4%) femoral artery pseudoaneurysm in the control group, which resolved with a tight groin bandage, and one (1.4%) case of urosepsis in the elderly group. Arrhythmia recurrence during the blanking period and the need for electrical cardioversion to restore sinus rhythm after PVI were found to be the only independent predictors of late arrhythmia relapses.

CONCLUSIONS

The present study showed that CB-A PVI is as feasible, safe and effective among appropriately selected octogenarians as it is in younger patients.

Persistent Phrenic Nerve Palsy after Atrial Fibrillation Ablation: Follow-up Data from the Netherlands Heart Registration

Background

Persistent phrenic nerve palsy (PNP) is an established complication of atrial fibrillation (AF) ablation, especially during cryoballoon and thoracoscopic ablation. Data on persistent PNP reversibility is limited because most patients recover <24 h. This study aims to investigate persistent PNP recovery, freedom of PNP‐related symptoms after AF ablation and identify baseline variables associated with the occurrence and early PNP recovery in a large nationwide registry study.

Methods

In this study, we used data from the Netherlands Heart Registration, comprising data from 9549 catheter and thoracoscopic AF ablations performed in 2016 and 2017. PNP data was available of 7433 procedures, and additional follow‐up data were collected for patients who developed persistent PNP.

Results

Overall, the mean age was 62 ± 10 years, and 67.7% were male. Fifty‐four (0.7%) patients developed persistent PNP and follow‐up was available in 44 (81.5%) patients. PNP incidence was 0.07%, 0.29%, 1.41%, and 1.25%, respectively for patients treated with conventional‐RF, phased‐RF, cryoballoon, and thoracoscopic ablation respectively. Seventy‐one percent of the patients fully recovered, and 86% were free of PNP‐related symptoms after a median follow‐up of 203 (113–351) and 184 (82–359) days, respectively. Female sex, cryoballoon, and thoracoscopic ablation were associated with a higher risk to develop PNP. Patients with PNP recovering ≤180 days had a larger left atrium volume index than those with late or no recovery.

Conclusion

After AF ablation, persistent PNP recovers in the majority of patients, and most are free of symptoms. Female patients and patients treated with cryoballoon or thoracoscopic ablation are more prone to develop PNP.

Acute Procedural Complications of Cryoballoon Ablation: A Comprehensive Review

Catheter ablation is increasingly performed for treatment of atrial fibrillation (AF). Balloon based procedures have been developed aiming at safer, easier and more effective treatment as compared to point to point ablation. In the present review article, we aimed to discuss acute procedural complications of cryoballoon ablation.

Comparison of Outcomes Using the First and Second Generation Cryoballoon to Treat Atrial Fibrillation

BACKGROUND

Pulmonary vein isolation using cryoballoon ablation is an effective treatment for patients with atrial fibrillation. We sought to compare outcomes with the first and second generation cryoballoon, with the second generation balloon incorporating the Achieve Lasso catheter, in terms of freedom from symptomatic recurrence and major complications.

METHODS

The first 200 patients who underwent cryoballoon ablation with the first generation balloon were compared with the first 200 patients using the second-generation balloon. All patients had symptomatic atrial fibrillation and had failed at least one antiarrhythmic drug. The primary efficacy endpoint was freedom from symptomatic recurrence of atrial fibrillation (AF) after a single pulmonary vein isolation (PVI) procedure using the cryoballoon. The primary safety endpoint was major procedural complications.

RESULTS

At 12 months, freedom from symptomatic AF after a single procedure in the first generation cohort was 64.3% compared with 78.6% in the second-generation cohort (p = 0.002). At 24 months, freedom from symptomatic AF in the first generation cohort was 51.3% compared with 72.6% in the second-generation cohort (p < 0.001). Procedural time (150 min vs 101 min; p < 0.001) and fluoroscopy time (32.5 min vs 21.4 min; p < 0.001) was lower in the second-generation group. The rate of major complications was comparably low in both groups.

CONCLUSIONS

The second-generation cryoballoon was associated with improved freedom from symptomatic AF with reduction in procedure and fluoroscopy time, with a similar low rate of major complications.

Towards a tailored cryo-pulmonary vein isolation. Lessons learned from second-generation cryoballoon ablation

Second-generation cryoballoon ablation has emerged as an effective and practical approach for the treatment of atrial fibrillation. It gained the overall interest of the electrophysiology community due to its excellent success rates, and reproducible clinical outcomes comparable to the point-by-point radiofrequency technique. This technology offers several advantages including a fast learning curve and shorter procedure times making this device widely adopted in many EP-laboratories as an alternative strategy to conventional point-by-point radiofrequency ablation. As compared to its predecessor, the improved technical performances of the second-generation cryoballoon translated into favorable clinical outcomes, which are maintained in long-term follow-up. However, the ideal cryo-application duration and the adequate number of freeze-thaw cycles are not well established and predictors of durable electrical isolation are poorly known. This review provides some practical advices for a successful ablation using the second-generation cryoballoon.

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.

Incidence and Predictors of Complications During Cryoballoon Pulmonary Vein Isolation for Atrial Fibrillation

BACKGROUND

Cryoballoon pulmonary vein isolation (PVI) has emerged as an alternative to radiofrequency PVI for atrial fibrillation (AF). Data are lacking to define the rates and predictors of complications, particularly phrenic nerve injury (PNI).

METHODS AND RESULTS

We evaluated a single-center prospective registry of 450 consecutive patients undergoing cryoballoon PVI between 2011 and 2015. Patients were 59±10 years old, 26% were women, 58% had hypertension, their mean CHA2DS2VASc score was 1.7±1.3, 30% had persistent atrial fibrillation, and 92% received a second-generation 28-mm balloon. Predefined major complications were persistent PNI, pericardial effusion, deep vein thrombosis, arteriovenous fistula, atrioesophageal fistula, bleeding requiring transfusion, stroke, and death. PNI was categorized as persistent if it persisted after discharge from the laboratory. Logistic regression was performed to identify predictors of complications and specifically PNI. We identified a major complication in 10 (2.2%) patients. In 49 (10.8%) patients, at least transient PNI was observed; only 5 persisted beyond the procedure (1.1%). All cases of PNI resolved eventually, with the longest time to resolution being 48 days. We also describe 2 cases of PNI manifesting after the index hospitalization. Regression analysis identified 23-mm balloon use (16.3% versus 5.2%, odds ratio 2.94, P=0.011) and increased age (62.8±7.7 versus 58.7±0.12 years, odds ratio 1.058, P=0.014) as independent significant predictors of PNI. There were no significant predictors of major complications.

CONCLUSIONS

In a large contemporary cohort, cryoballoon PVI is associated with low procedural risk, including lower rates of PNI than previously reported. Older age and 23-mm balloon use were associated with PNI. Our low rate of PNI may reflect more sensitive detection methods, including compound motor action potential monitoring and forced double-deflation.

Femoral venous pressure waveform as indicator of phrenic nerve injury in the setting of second-generation cryoballoon ablation

AIMS

Femoral venous pressure waveform (VPW) analysis has been recently described as a novel method to assess phrenic nerve function during atrial fibrillation ablation procedures by means of the cryoballoon technique. In this study, we sought to evaluate the feasibility and effectiveness of this technique, with respect to the incidence of phrenic nerve injury (PNI), in comparison with the traditional abdominal palpation technique alone.

METHODS

Consecutive patients undergoing second-generation cryoballoon ablation (CB-A) from June 2014 to June 2015 were retrospectively analyzed. Diagnosis of PNI was made if any reduced motility or paralysis of the hemidiaphragm was detected on fluoroscopy.

RESULTS

During the study period, a total of 350 consecutive patients (man 67%, age 57.2 ± 12.9 years) were enrolled (200 using traditional phrenic nerve assessment and 150 using VPW monitoring). The incidence of PNI in the overall population was 8.0% (28/350); of these, eight were impending PNI (2.3%), 14 transient (4.0%), and six persistent (1.7%). Patients having undergone CB-A with traditional assessment experienced 18 phrenic nerve palsies (9.0%) vs two in 'VPW monitoring' group (1.3%; P = 0.002). Specifically, the former presented 12 transient (6.0%) and six persistent (3.0%) phrenic nerve palsies, and the latter exhibited two transient (1.3%; P = 0.03) and no persistent (0%; P = 0.04) phrenic nerve palsies.

CONCLUSION

In conclusion, this novel method assessing the VPW for predicting PNI is inexpensive, easily available, with reproducible measurements, and appears to be more effective than traditional assessment methods.

ECG-Guided Surveillance Technique in Cryoballoon Ablation for Paroxysmal and Persistent Atrial Fibrillation: A Strategy to Prevent From Phrenic Nerve Palsy

AIMS

Phrenic nerve palsy (PNP) is still a cause for concern in Cryoballoon ablation (CBA) procedures. New surveillance techniques, such as invasive registration of the compound motor action potential (CMAP), have been thought to prevent the occurrence of PNP. The present study investigates the impact of CMAP surveillance via an alternative and non-invasive ECG-conduction technique during CBA.

METHODS

PVI with CBA was performed in 166 patients suffering from AF. Diaphragmal contraction was monitored by abdominal hands-on observation in Observation Group I; Observation Group II was treated using additional ECG-conduction, as a means of modified CMAP surveillance method. During the ablation of the right superior and inferior pulmonary veins, the upper extremities lead I was newly adjusted between the inferior sternum and the right chest, thereby recording the maximum CMAP. The CMAP in the above-mentioned ECG leads was continuously observed in a semi-quantitative manner.

RESULTS

PNP was observed in 10 (6%) patients in total. In Observation Group I, 6 out of 61 (9.8%) demonstrated PNP. In Observation Group II a significant decrease of PNP could be demonstrated (p <0,001) and occurred in 4 out of 105 patients (3.8%). While three patients from Observation Group I left the EP lap with an ongoing PNP, none of the patients in Observation Group II had persistent PNP outside of the EP lab.

CONCLUSION

The present study demonstrates that additional ECG-conduction, used as modified CMAP surveillance, is an easy, effective and helpful additional safety measure to prevent PNP in CBA.

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.