Microwave ablation combined with percutaneous vertebroplasty for treating painful non-small cell lung cancer with spinal metastases under real-time temperature monitoring

PURPOSE

To retrospectively study the therapeutic effect and safety performance of the combination strategies of the computed tomography (CT)-guided microwave ablation (MWA) and percutaneous vertebroplasty (PVP) as a treatment for painful non-small cell lung cancer (NSCLC) with spinal metastases.

MATERIALS AND METHODS

A retrospective review included 71 patients with 109 vertebral metastases who underwent microwave ablation combined with percutaneous vertebroplasty by the image-guided and real-time temperature monitoring. Treatment efficacy was determined by comparing visual analog scale (VAS) scores, daily morphine equivalent opioid consumption, and Oswestry Disability Index (ODI) scores before treatment and during the follow-up period.

RESULTS

Technical success was achieved in all patients. The mean pre-procedure VAS score and morphine doses were 6.6 ± 1.8 (4-10) and 137.2 ± 38.7 (40-200) mg, respectively. The mean VAS scores and daily morphine doses at 24 h and 1, 4, 12, and 24 weeks postoperatively were 3.3 ± 1.9 and 73.5 ± 39.4 mg; 2.2 ± 1.5 and 40.2 ± 29.8 mg; 1.7 ± 1.2 and 31.3 ± 23.6 mg; 1.4 ± 1.1 and 27.3 ± 21.4 mg; and 1.3 ± 1.1 and 24.8 ± 21.0 mg, respectively (all P < 0.001). ODI scores significantly decreased (P < 0.05). Minor cement leakage occurred in 51 cases (46.8%), with one patient having a grade 3 neural injury. No local tumor progression was observed by follow-up imaging.

CONCLUSIONS

MWA combined with PVP can significantly relieve pain and improve patients' quality of life, which implied this is an effective treatment option for painful NSCLC with spinal metastases. Additionally, its efficacy should be further verified through the mid- and long-term studies.

Association of Atrial Fibrillation Recurrence with Right Coronary Atherosclerosis and Increased Left Arterial Epicardial Fat Following Catheter Ablation-Results of a Multimodality Study

BACKGROUND

Identification of predictors for atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) can lead to better long-term results. Our aim was to investigate the association between novel CT imaging markers reflecting the severity of coronary atherosclerosis and the risk of recurrence following PVI.

METHODS

This study included 80 patients with paroxysmal/persistent AF who underwent PVI. The patients were divided into two groups: Group 1-23 patients with recurrence and Group 2-57 patients without recurrence.

RESULTS

Patients with recurrence presented with a more enlarged left atrial diameter and reduced left ventricle EF, as assessed by echocardiography. Elevated calcium scores and right coronary artery (RCA) stenosis were correlated with a higher risk of AF recurrence (25.38 ± 4.1% vs. 9.76 ± 2.32%, p = 0.001). Patients with AF recurrence presented a higher left atrial volume index (LAVI) (61.38 ± 11.12 mm3/m2 vs. 46.34 ± 12.27 mm3/m2, p < 0.0001). The bi-atrial volume index (BAVI) was similarly higher in the AF recurrence group (98.23 ± 14.44 mm3/m2 vs. 76.48 ± 17.61 mm3/m2, p < 0.0001). Increased EAT volumes located around the LA (EAT-LA) were correlated with recurrence (25.55 ± 6.37 vs. 15.54 ± 8.44, p < 0.0001).

CONCLUSIONS

RCA stenosis, together with atrial volumes and EAT-AS evaluated by CCTA, is associated with the risk of AF recurrence following PVI.

Freedom from atrial arrhythmia and other clinical outcomes at 5 years and beyond after catheter ablation of atrial fibrillation: a systematic review and meta-analysis

AIMS

Catheter ablation of atrial fibrillation (AF) is now a mainstream procedure although long-term outcomes are uncertain. We performed a systematic review and meta-analysis of procedural outcomes at 5 years and beyond.

METHODS AND RESULTS

We searched PubMed and Embase and after the screening, identified 73 studies (67 159 patients) reporting freedom from atrial arrhythmia, all-cause death, stroke, and major bleeding at ≥5 years after AF ablation. The pooled mean age was 59.7y, 71.5% male, 62.2% paroxysmal AF, and radiofrequency was used in 78.1% of studies. Pooled incidence of freedom from atrial arrhythmia at 5 years was 50.6% (95%CI 45.5-55.7%) after a single ablation and 69.7% [95%CI (confidence interval) 63.8-75.3%) after multiple procedures. The incidence was higher among patients with paroxysmal compared with non-paroxysmal AF after single (59.7% vs. 33.3%, p = 0.002) and multiple (80.8% vs. 60.6%, p < 0.001) ablations but was comparable between radiofrequency and cryoablation. Pooled incidences of other outcomes were 6.0% (95%CI 3.2-9.7%) for death, 2.4% (95%CI 1.4-3.7%) for stroke, and 1.2% (95%CI 0.8-2.0%) for major bleeding at 5 years. Beyond 5 years, freedom from arrhythmia recurrence remained largely stable (52.3% and 64.7% after single and multiple procedures at 10 years), while the risk of stroke and bleeding increased over time.

CONCLUSION

Nearly 70% of patients having multiple ablations remained free from atrial arrhythmia at 5 years, with the incidence slightly decreasing beyond this period. Risk of death, stroke, and major bleeding at 5 years were low but increased over time, emphasizing the importance of long-term thromboembolism prevention and bleeding risk management.

High-Power, Short-Duration Ablation under the Guidance of Relatively Low Ablation Index Values for Paroxysmal Atrial Fibrillation: Long-Term Outcomes and Characteristics of Recurrent Atrial Arrhythmias

OBJECTIVE

The purpose of this study was to evaluate the difference in effectiveness and safety of high-power, short-duration (HPSD) radiofrequency catheter ablation (RFA) guided by relatively low ablation index (AI) values and conventional RFA in paroxysmal atrial fibrillation (PAF) patients.

METHODS

The HPSD RFA strategy (40-50 W, AI 350-400 for anterior, 320-350 for posterior wall; n = 547) was compared with the conventional RFA strategy (25-40 W, without AI; n = 396) in PAF patients who underwent their first ablation. Propensity-score matching analyses were used to compare the outcomes of the two groups while controlling for confounders.

RESULTS

After using propensity-score matching analysis, the HPSD group showed a higher early recurrence rate (22.727% vs. 13.636%, p = 0.003), similar late recurrence rate, and comparable safety (p = 0.604) compared with the conventional group. For late recurrent atrial arrhythmia types, the rate of regular atrial tachycardia was significantly higher in the HPSD group (p = 0.013). Additionally, the rate of chronic pulmonary vein reconnection and non-pulmonary vein triggers during repeat procedures was similar in both groups.

CONCLUSIONS

For PAF patients, compared with the conventional RFA strategy, the HPSD RFA strategy at relatively low AI settings had a higher early recurrence rate, similar long-term success rate, and comparable safety.

Targeted Atrial Fibrillation Therapy and Risk Stratification Using Atrial Alternans

Atrial fibrillation (AF) is the most persistent arrhythmia today, with its prevalence increasing exponentially with the rising age of the population. Particularly at elevated heart rates, a functional abnormality known as cardiac alternans can occur prior to the onset of lethal arrhythmias. Cardiac alternans are a beat-to-beat oscillation of electrical activity and the force of cardiac muscle contraction. Extensive evidence has demonstrated that microvolt T-wave alternans can predict ventricular fibrillation vulnerability and the risk of sudden cardiac death. The majority of our knowledge of the mechanisms of alternans stems from studies of ventricular electrophysiology, although recent studies offer promising evidence of the potential of atrial alternans in predicting the risk of AF. Exciting preclinical and clinical studies have demonstrated a link between atrial alternans and the onset of atrial tachyarrhythmias. Here, we provide a comprehensive review of the clinical utility of atrial alternans in identifying the risk and guiding treatment of AF.

Clinical outcome of a single procedure cryoballoon ablation for the treatment of atrial fibrillation: A real-world multicenter experience in Portugal

BACKGROUND

Cryoballoon ablation (CBA) for pulmonary vein isolation (PVI) has been growing as an alternative technique, not only in patients with paroxysmal atrial fibrillation (PAF) but also in persistent atrial fibrillation (AF). Cryoballoon ablation has demonstrated encouraging acute and mid-term results. However, data on long-term follow-up of CB-based PVI are scarce.

OBJECTIVE

We sought to examine efficacy, safety, and long-term outcomes of CBA in PAF and persistent AF in four Portuguese centers.

METHODS

All patients that were treated with the cryoballoon catheter according to routine practices with a second-generation 28-mm CB in four centers were included. This was a retrospective, non-randomized analysis. Patients were followed-up for >12 months and freedom from atrial arrhythmias (AA) was evaluated at the end of follow-up.

RESULTS

Four hundred and six patients (57.7±12.4 years, 66% men) participated. AF was paroxysmal in 326 patients (80.2%) and persistent in 80 (19.7%). The mean procedure time duration was 107.7±50.9 min, and the fluoroscopy time was 19.5±9.7 min. Procedural/periprocedural complications occurred in 30 cases (7.3%), being transient phrenic nerve palsy the most frequent incident (2 out of 3 complications). Anatomic variations of the PV were present in 16.1% of cases. At a mean follow-up of 22.0±15.0 months, 310 patients (76.3%) remained in stable sinus rhythm, with at least one AF episode recurrence documented in 98 cases (24.1%). The recurrence rate was 20.5% in the PAF group and 37.8% in the persistent AF group.

CONCLUSION

In this multicenter experience, a single CBA procedure resulted in 75.9% freedom from AF at a 22-month follow-up. This technique was demonstrated to be a safe and effective option in experienced centers for the treatment of PAF and PersAF.

Use of P wave indices to evaluate efficacy of catheter ablation and atrial fibrillation recurrence: a systematic review and meta-analysis

BACKGROUND

To investigate the changes of P wave indices in atrial fibrillation (AF) patients after catheter ablation and the association between P wave indices and AF recurrence.

METHODS

PubMed, Embase, and Cochrane Database were searched through September 15th 2021 for studies on the association between P wave indices and AF with catheter ablation. Heterogeneity was estimated using the I² statistic, the random effects model was used to calculate the pooled results, and summary receiver operating characteristic curve (SROC) was used to evaluate the predictive value.

RESULTS

Among included fourteen studies with 1674 AF patients, we found significantly decreased P wave dispersion (P_dis) (mean difference [MD]: - 6.5 ms, 95% confidence interval [95% CI]: - 11.81 to - 1.18, P = 0.02) after cryoballoon ablation (CBA) or radiofrequency ablation (RFA), and maximum P wave (P_max) (MD: - 8.57 ms, 95% CI: - 17.03 to - 0.10, P = 0.05) after RFA only, but increased minimum P wave (P_min) (MD: 3.43 ms, 95% CI: 1.07 to 5.79, P < 0.01) after CBA only. P_dis measured before ablation was remarkably higher (MD: 5.79 ms, 95% CI: 2.23 to 9.36, P < 0.01) in patients with recurrence than without; meanwhile, P_max was higher measured both before and after ablation (MD: 6.49 ms, 95% CI: 2.30 to 10.69, P < 0.01 and MD: 11.2 ms, 95% CI: 2.88 to 19.52, P < 0.01). Furthermore, SROC analysis showed acceptable predictive efficiencies of P_dis (AUC = 0.776) and P_max (AUC = 0.759) for AF recurrence.

CONCLUSION

P_dis was significantly decreased after AF catheter ablation. Higher P_dis and P_max may have predictive values for AF recurrence.

Long-term outcomes of a time to isolation - based strategy for cryoballoon ablation compared to radiofrequency ablation in patients with symptomatic paroxysmal atrial fibrillation

BACKGROUND

Cryoballoon ablation (CBA) is one of the most commonly used technologies designed for pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF), although the dosing of CBA remains controversial. We evaluated the long-term efficacy and safety of a novel individualized strategy of CBA compared to radiofrequency ablation (RFA) for patients with PAF.

METHODS

In this observational study, symptomatic patients with drug-refractory paroxysmal AF were prospectively consented and enrolled in four centers, being assigned either to the CBA or RFA arm for ablation. In the CBA group, we used a time to isolation (TTI) - based dosing protocol. The primary endpoint was the recurrence of atrial arrhythmia >30 s following a 90-day blanking period. The secondary endpoint was procedure-related complications and procedure parameters.

RESULTS

A total of 500 patients were recruited in either the CBA group (n = 247) or the RFA group (n = 253) between January 2017 and July 2018. After a median follow-up of 778 days, the atrial tachyarrhythmia-free survival was 71.7% in the CBA group and 67.0% in the RFA group. CBA and RFA displayed similar major or minor complication occurrence, while the former had a significantly shorter procedure duration (82.5 min vs. 141.1 min, p < .001) and left atrial dwell time (60.1 min vs. 109.9 min, p < .001) but longer fluoroscopy exposure (13.8 min vs. 8.1 min, p < .001).

CONCLUSION

Compared to RFA, our TTI-based CBA dosing protocol showed comparable efficacy and safety, with a significantly reduced procedure duration in patients with PAF.

Frozen, Gone in 60 Seconds!

The field of electrophysiology has seen the development of a novel ultralow temperature cryoablation (ULTC) system. The data presented in this manuscript shows that the ULTC system is feasible, safe, and effective in acute PVI under sedation and by using angiography only This article is protected by copyright. All rights reserved.

Improved procedural workflow for catheter ablation of paroxysmal AF with high-density mapping system and advanced technology: Rationale and study design of a multicenter international study

BACKGROUND

The antral region of pulmonary veins (PV)s seems to play a key role in a strategy aimed at preventing atrial fibrillation (AF) recurrence. Particularly, low-voltage activity in tissue such as the PV antra and residual potential within the antral scar likely represent vulnerabilities in antral lesion sets, and ablation of these targets seems to improve freedom from AF. The aim of this study is to validate a structured application of an approach that includes the complete abolition of any antral potential achieving electrical quiescence in antral regions.

METHODS

The improveD procEdural workfLow for cathETEr ablation of paroxysmal AF with high density mapping system and advanced technology (DELETE AF) study is a prospective, single-arm, international post-market cohort study designed to demonstrate a low rate of clinical atrial arrhythmias recurrence with an improved procedural workflow for catheter ablation of paroxysmal AF, using the most advanced point-by-point RF ablation technology in a multicenter setting. About 300 consecutive patients with standard indications for AF ablation will be enrolled in this study. Post-ablation, all patients will be monitored with ambulatory event monitoring, starting within 30 days post-ablation to proactively detect and manage any recurrences within the 90-day blanking period, as well as Holter monitoring at 3, 6, 9, and 12 months post-ablation. Healthcare resource utilization, clinical data, complications, patients' medical complaints related to the ablation procedure and patient's reported outcome measures will be prospectively traced and evaluated.

DISCUSSION

The DELETE AF trial will provide additional knowledge on long-term outcome following a structured ablation workflow, with high density mapping, advanced algorithms and local impedance technology, in an international multicentric fashion. DELETE AF is registered at ClinicalTrials.gov (NCT05005143).

Institutional Variation in 30‐Day Complications Following Catheter Ablation of Atrial Fibrillation

Background

Complications are a measure of procedural quality, yet variation in complication rates following catheter ablation of atrial fibrillation (AF) among hospitals has not been systematically examined. We examined institutional variation in the risk‐standardized 30‐day complication rates (RSCRs) following AF ablation which may suggest variation in care quality.

Methods and Results

This cohort study included all patients >18 years old undergoing AF ablations from 2012 to 2017 in Australia and New Zealand. The primary outcome was procedure‐related complications occurring during the hospital stay and within 30 days of hospital discharge. We estimated the hospital‐specific risk‐standardized complication rates using a hierarchical generalized linear model. A total of 25 237 patients (mean age, 62.5±11.4 years; 30.2% women; median length of stay 1 day [interquartile range, 1–2 days]) were included. Overall, a complication occurred in 1400 (5.55%) patients (4.34% in hospital, 1.46% following discharge, and 0.25% experienced both). Bleeding (3.31%), pericardial effusion (0.74%), and infection (0.44%) were the most common complications while stroke/transient ischemic attack (0.24%), cardiorespiratory failure and shock (0.19%), and death (0.08%) occurred less frequently. Among 46 hospitals that performed ≥25 ablations during the study period, the crude complication rate varied from 0.00% to 21.43% (median, 5.74%). After adjustment for differences in patient and procedural characteristics, the median risk‐standardized complication rate was 5.50% (range, 2.89%–10.31%), with 10 hospitals being significantly different from the national average.

Conclusions

Procedure‐related complications occur in 5.55% of patients undergoing AF ablations, although the risk of complications varies 3‐fold among hospitals, which suggests potential disparities in care quality and the need for efforts to standardize AF ablation practices among hospitals.

Comparing Efficacy and Safety in Catheter Ablation Strategies for Paroxysmal Atrial Fibrillation: A Network Meta-Analysis of Randomized Controlled Trials

Although catheter ablation (CA) is an established treatment for paroxysmal atrial fibrillation (PAF), there is no consensus regarding the most efficient CA strategy. The objective of this network meta-analysis (NMA) was to compare the efficacy and safety of different CA strategies for PAF. A systematic search was performed in PubMed, Web of Science, and CENTRAL until the final search date, 5 October 2020. Randomised controlled trials (RCT) comparing different CA strategies and methods for pulmonary vein isolation (PVI) were included. Efficacy was defined as lack of arrhythmia recurrence after CA and safety as any reported complication related to the procedure during a minimum follow-up time of six months. In total, 43 RCTs comparing 11 different CA strategies involving 6701 patients were included. The risk of recurrence was significantly decreased in comparison with PVI with radiofrequency only for the following treatments: PVI with adjuvant ablation (RR: 0.79, CI: 0.65–0.97) and PVI with sympathetic modulation (RR: 0.64, CI: 0.46–0.88). However, PVI with radiofrequency was superior to non-PVI strategies (RR: 1.65, CI: 1.2–2.26). No statistically significant difference was found in safety between different CA strategies. Concerning different PVI strategies, no difference was observed either in efficacy or in safety between tested strategies. This NMA suggests that different PVI strategies are generally similar in terms of efficacy, while PVI with additional ablation or sympathetic modulation may be more effective than PVI alone. This study provides decision-makers with insights into the efficacy and safety of different CA strategies.

Medical, Interventional, and Surgical Treatment Strategies for Atrial Fibrillation

BACKGROUND

Atrial fibrillation is the most common type of cardiac arrhythmia; the lifetime risk for a 55-year-old person to develop atrial fibrillation is 37%. In recent years, years there have been various distinct changes in the clinical management of AF.

METHODS

This review is based on a selective search for literature on the treatment of AF and the prevention of thromboembolic complications. The updated guideline of the European Society of Cardiology (ESC) for the diagnosis and treatment of AF was also taken into consideration.

RESULTS

The main components of AF management are the comprehensive treatment of risk factors and concomitant diseases, as well as the prevention of thromboembolic complications, usually with non-vitamin-K-dependent oral anticoagulants or vitamin K antagonists, according to individual risk stratification. Beyond this, either rate or rhythm control are viable treatment concepts. Symptomatic patients in whom reversible causes have been ruled out should be offered rhythm-control therapy early in their course. In patients with risk factors and/or heart failure, an early rhythm control strategy has been found to be beneficial. As antiarrhythmic drugs often prove to be ineffective over the long term, catheter ablation is now becoming increasingly important in AF management.

CONCLUSION

The clinical management of atrial fibrillation consists of a multimodal approach with risk stratification, lifestyle modification, prevention of thromboembolism, and, if possible, early rhythm control therapy.

How effective is cryoablation in the treatment of atrial fibrillation?

Pulmonary vein isolation is the standard for atrial fibrillation ablation. Although the most commonly applied energy source is radiofrequency (RF), cryoablation has rapidly evolved as a powerful one-shot tool, particularly after the introduction of the second-generation catheter, gaining widespread use in recent years. The efficacy in maintaining sinus rhythm after a first ablative procedure is ∼70–80%, and the randomization studies comparing cryoablation to RF have not been able to reveal significant differences up to now. Although different baseline characteristics may influence the efficacy of cryoablation, we are not yet able to distinguish which patients may benefit from a personalized choice of ablative source. Regarding safety, cryoballoon ablation appears to be associated with a lower rate of pericardial effusion and cardiac tamponade, mainly due to the lack of risk of overheating. The other side of the coin is a higher incidence of phrenic nerve damage, which occurs in 1–2% of procedures. In conclusion, we do not yet have definitive data to affirm the superiority of the RF technique over that of cryoablation. The choice of energy source currently depends on the availability of the centre and on the experience of the operator.

Catheter ablation as first-line treatment for paroxysmal atrial fibrillation: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of catheter ablation (CA) compared with antiarrhythmic drugs (AADs) as first-line treatment for symptomatic paroxysmal atrial fibrillation (AF).

METHODS

Systematic review and meta-analysis of randomised controlled trials identified using MEDLINE, Cochrane Library and Embase published between 01/01/2000 and 19/03/2021. The primary efficacy endpoint was the first documented recurrence of atrial arrhythmias following the blanking period. The primary safety endpoint was a composite of all serious adverse events (SAEs).

RESULTS

From 441 records, 6 studies met the inclusion criteria. 609 patients received CA, while 603 received AAD therapy. 212/609 patients in the CA group had a recurrence of atrial arrhythmias as compared with 318/603 in the AADs group resulting in a 36% relative risk reduction (risk ratio: 0.64, 95% CI 0.51 to 0.80, p<0.01). The risk of all SAEs was not statistically different between CA and AAD (0.87, 0.58 to 1.30, p=0.49); 107/609 SAE in the CA group vs 126/603 in the AAD group. Both recurrence of symptomatic atrial arrhythmias (109/505 vs 186/504) and healthcare utilisation (126/397 vs 185/394) were significantly lower in the CA group (0.53, 0.35 to 0.79 and 0.65, 0.48 to 0.89, respectively). There was a 79% reduction in the crossover rate during follow-up among patients randomised to CA compared with AAD (0.21, 0.13 to 0.32, p<0.01).

CONCLUSIONS

First-line treatment with CA is superior to AAD therapy in patients with symptomatic paroxysmal AF, as it significantly reduces the recurrence of any atrial arrhythmias and symptomatic atrial arrhythmias, and healthcare resource utilisation with comparable safety profile.

Prediction of arrhythmia recurrence after atrial fibrillation ablation in patients with normal anatomy of the left atrium

BACKGROUND

Enlarged left atrium is an established predictor of atrial fibrillation recurrence after pulmonary vein isolation but arrhythmia recurrence is also observed in patients with normal anatomy of the left atrium. The aim of the study is to evaluate arrhythmia recurrence predictors in patients with normal anatomy of the left atrium.

METHODS

The study included 182 patients with normal anatomy of the left atrium who underwent pulmonary vein isolation using catheter ablation. Various parameters were also compared, including age, gender, history of arrhythmia, arterial hypertension, concomitant coronary pathology, echocardiography findings, such as mitral valve and tricuspid valve regurgitation and procedure parameters, between patients with and without relapses. Statistical analysis was performed using the IBM SPSS Statistics-19 software.

RESULTS

Transthoracic echocardiography was performed by independent specialists with extensive experience. Trans-esophageal echocardiography was performed before each ablation procedure. Standard trans-septal puncture was performed under fluoroscopic control. Radiofrequency ablation was performed in the ipsilateral pulmonary vein antrum with a wide capture of nearby lung tissue.

CONCLUSIONS

It was concluded that the tricuspid valve regurgitation and arterial hypertension correlate with atrial fibrillation recurrence after pulmonary vein isolation in patients with normal left atrial anatomy.

Pulmonary vein isolation in atrial fibrillation patients guided by a novel local impedance algorithm: 1-year outcome from the CHARISMA study

BACKGROUND

Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have recently emerged as a viable real-time indicator of tissue characteristics and durability of the lesions created. We report the outcomes of acute and long-term clinical evaluation of the new DirectSense algorithm in AF ablation.

METHODS

Consecutive patients undergoing AF ablation were included in the CHARISMA registry. RF delivery was guided by the DirectSense algorithm, which records the magnitude and time-course of the impedance drop. The ablation endpoint was pulmonary vein isolation (PVI), as assessed by the entrance and exit block.

RESULTS

3556 point-by-point first-pass RF applications of >10 s duration were analyzed in 153 patients (mean age=59 ± 10 years, 70% men, 61% paroxysmal AF, 39% persistent AF). The mean baseline LI was 105 ± 15 Ω before ablation and 92 ± 12 Ω after ablation (p < .0001). Both absolute drops in LI and the time to LI drop (LI drop/τ) were greater at successful ablation sites (n = 3122, 88%) than at ineffective ablation sites (n = 434, 12%) (14 ± 8 Ω vs 6 ± 4 Ω, p < .0001 for LI; 0.73 [0.41-1.25] Ω/s vs. 0.35[0.22-0.59 Ω/s, p < .0001 for LI drop/τ). No major complications occurred during or after the procedures. All PVs had been successfully isolated. During a mean follow-up of 366 ± 130 days, 18 patients (11.8%) suffered an AF/atrial tachycardia recurrence after the 90-day blanking period.

CONCLUSION

The magnitude and time-course of the LI drop during RF delivery were associated with effective lesion formation. This ablation strategy for PVI guided by LI technology proved safe and effective and resulted in a very low rate of AF recurrence over 1-year follow-up.

The effect of left atrial remodeling after cryoballoon ablation and radiofrequency ablation for paroxysmal atrial fibrillation

Background

Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the most common procedures used to treat refractory atrial fibrillation (AF) and are performed through pulmonary vein isolation (PVI). Studies have shown that CBA can approximately match the therapeutic effects of RFA against AF. However, few studies have investigated the difference between CBA and RFA of the effects on left atrial remodeling for paroxysmal AF.

Objective

Atrial remodeling is considered pivotal to the occurrence and development of AF, therefore we sought to assess the influence of atrial remodeling in patients with paroxysmal AF after CBA and RFA in this study.

Methods

In this nonrandomized retrospective observational study, we enrolled 328 consecutive patients who underwent CBA or RFA for refractory paroxysmal AF in May 2014 to May 2017 in our hospital. After propensity score matching, 96 patients were included in the CBA group, and 96 were included in the RFA group. Patients were asked to undergo a 12‐lead electrocardiogram, a 24‐h Holter monitor, and an echocardiogram and to provide their clinical history and symptoms at 6 months and 1, 2, and 3 years postprocedurally. Electrical remodeling of the left atrium was assessed by P wave dispersion (Pdis); structural remodeling was assessed by the left atrium diameter (LAD) and left atrial volume index (LAVI) during scheduled visits.

Results

As of January 2020, compared with baseline, at 1 year, 2 years, and 3 years after ablation, the average changes in Pdis (∆Pdis), LAD (∆LAD), and LAVI (∆LAVI) were significant in both the CBA and RFA groups. Six months after ablation, ∆Pdis, ∆LAD, and ∆LAVI were greater in the CBA group than in the RFA group. There was no significant difference between the two groups in AF/flutter recurrence, but the AF/flutter‐free survival time of CBA group may be longer than RFA group after 2 years after ablation. A higher ∆Pdis, ∆LAD, or ∆LAVI at 1 year after ablation may increase AF/flutter‐free survival.

Conclusions

Although CBA and RFA are both effective in left atrial electrical and structural reverse‐remodeling in paroxysmal AF, CBA may outperform RFA for both purposes 6 months after ablation. However, during long‐term follow‐up, there was no significant intergroup difference.

A systematic review and meta-analysis comparing second-generation cryoballoon and contact force radiofrequency ablation for initial ablation of paroxysmal and persistent atrial fibrillation

INTRODUCTION

Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the preferred modalities for catheter ablation of atrial fibrillation (AF). Technological advances have improved procedural outcomes, warranting an updated comparison. We sought to evaluate the efficacy and safety of CBA-2nd generation (CBA-2G) in comparison to RFA-contact force (RFA-CF) in patients with AF.

METHODS

MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched until 03/01/2020 for relevant studies comparing CBA-2G versus RFA-CF in patients undergoing initial catheter ablation for AF.

RESULTS

A total of 17 studies, involving 11 793 patients were included. There was no difference between the two groups in the outcomes of freedom from atrial arrhythmia (p = .67) and total procedural complications (p = .65). There was a higher incidence of phrenic nerve palsy in CBA-2G (odds ratio: 10.7; 95% confidence interval [CI]: 5.85 to 19.55; p < .001). Procedure duration was shorter (mean difference: -31.32 min; 95% CI: -40.73 to -21.92; p < .001) and fluoroscopy duration was longer (+3.21 min; 95% CI: 1.09 to 5.33; p = .003) in CBA-2G compared to RFA-CF. In the subgroup analyses of patients with persistent AF and >1 freeze lesion delivered per vein, there was no difference in freedom from atrial arrhythmia.

CONCLUSIONS

In AF patients undergoing initial ablation, CBA-2G and RFA-CF were equally efficacious. The procedure duration was shorter, but with a higher incidence of phrenic nerve palsy in CBA-2G. In patients with persistent AF, there was no difference in the efficacy between CBA-2G or RFA-CF techniques.

Emerging Technologies for Pulmonary Vein Isolation

Atrial fibrillation is the most common sustained cardiac arrhythmia and is associated with considerable morbidity and mortality. Electrically isolating the pulmonary veins from the left atrium by catheter ablation is superior to antiarrhythmic drug therapy for maintaining sinus rhythm, but its success varies depending on multiple factors, including arrhythmic burden. Although procedural outcomes have improved over the years, further gains are limited by a seemingly zero-sum relationship between effectiveness and safety, which is largely a product of the available technologies. Current energies used to create contiguous, transmural, and durable atrial lesions can result in serious complications if they reach the esophagus or phrenic nerve, for instance—structures that can be adjacent to the atrial myocardium, often within millimeters of the energy source. Consequently, high rates of pulmonary vein-left atrium reconnections are consistently seen in clinical studies and in clinical practice as operators appropriately forgo ablation effectiveness to protect patients from harm. However, as ablative technologies evolve to circumvent this stalemate, safer, and more effective pulmonary vein isolation seems increasingly realistic. Furthermore, the innovative nature of these technologies raises the prospect of markedly improved procedural efficiency, which could increase patient comfort, reduce operator occupational injuries, and enhance the use of health resources—all of which are increasingly important considerations particularly as the demand for catheter ablation for atrial fibrillation continues to rise. We herein review 3 promising candidate ablation technologies with the potential to revolutionize the management of patients with atrial fibrillation: electroporation (pulsed-field ablation), expandable lattice-tip radiofrequency ablation/electroporation, and ultra-low temperature cryoablation.

Atrial arrhythmias in chronic lung disease-associated pulmonary hypertension

Atrial arrhythmias are common during episodes of acute respiratory failure in patients with chronic lung disease-associated pulmonary hypertension. Expert opinion suggests that management of atrial arrhythmias in patients with pulmonary hypertension should aim to restore sinus rhythm. This is clinically challenging in pulmonary hypertension patients with coexisting chronic lung disease, as there is controversy on the use of rhythm control agents; generally, in regard to either their pulmonary toxicity profile or the lack of evidence supporting their use. Rate control methods are largely focused on the use of beta blockers and calcium channel blockers. Concerns regarding their use involve their negative inotropic properties in cor pulmonale, the risk of bronchospasm associated with beta blockers, and the potential for ventilation/perfusion mismatching associated with calcium channel blockers. While digoxin has been associated with promising outcomes during acute right ventricular failure, there is limited evidence to suggest its routine use. Electrical cardioversion is associated with a high failure rate and it frequently requires multiple attempts. Radiofrequency catheter ablation is a more definitive approach, but concerns surrounding mechanical ventilation and sedation limit its applicability in decompensated pulmonary hypertension. Individual approaches are needed to address atrial arrhythmia management during acute episodes of respiratory failure.

Ablation of persistent atrial fibrillation: Challenges and solutions

Catheter ablation is commonly used for treatment of persistent atrial fibrillation (AF). Pulmonary vein isolation (PVI) is still the cornerstone for the procedure, however, outcomes are consistently lower compared to paroxysmal AF. It is hypothesized that it could be due to lack of durable lesions or the presence of non-PV targets that remain after PVI. Numerous advances in ablation catheter technologies and mapping systems may potentially achieve lower recurrence rates in the future. Ongoing research is required to discover the best technique for persistent AF ablation. The purpose of this review is to describe the new, developing technologies that may improve the outcome of this procedure in the persistent AF population.

Budget Impact of Cryoablation Versus Radiofrequency Ablation of Atrial Fibrillation in the Brazilian Public Healthcare System

BACKGROUND

Cryoablation is a new technology for ablation of atrial fibrillation (AF), effective and safe when compared with standard radiofrequency (RF) ablation. Nevertheless, the economic impact of its incorporation is unknown, especially considering the public health system of a developing country. This study analyzed the budget impact of cryoablation incorporation for treatment of paroxysmal AF in the Brazilian public health system.

METHODS

The budget impact was calculated as the cost difference between the current scenario (RF ablation guided by electroanatomic mapping) and the new scenario (cryoablation). The cost of each intervention was obtained by multiplying the price of a single procedure by the number of candidates for it. Other technologies (RF ablation guided by intracardiac echocardiography or with a nonirrigated catheter) were considered in a sensitivity analysis.

RESULTS

The budget impact showed savings of $43 097 096.84 with cryoablation. In the sensitivity analysis, cryoablation resulted in cost savings compared with RF ablation guided by intracardiac echocardiography, whereas in comparison to RF ablation with the nonirrigated catheter, cryoablation was more expensive. A market share assessment, performed using an incorporation rate of 3% per year, indicated savings of approximately $800 000 per 5 years.

CONCLUSIONS

Cryoablation of AF resulted in cost savings compared with the current scenario (RF ablation guided by electroanatomic mapping). When alternative technologies were considered, cryoablation was more expensive than RF ablation with a nonirrigated catheter, but it also resulted in savings compared with RF ablation guided by intracardiac echocardiography. Overall, cryoablation of AF may reduce expenditures in the Brazilian public health system.

Cryoballoon pulmonary vein ablation and left atrial appendage closure combined procedure: A long-term follow-up analysis

BACKGROUND

The combined left atrial appendage closure (LAAC) and cryoenergy pulmonary vein isolation (PVI) procedure has been proven safe and effective in managing stroke in patients with nonvalvular atrial fibrillation (AF), although most data refer to procedures performed using radiofrequency as the main energy source.

OBJECTIVE

The purpose of this study was to evaluate long-term follow-up of patients with AF undergoing concomitant LAAC and cryoenergy PVI.

METHODS

Patients undergoing LAAC and cryoballoon PVI at our institution were enrolled. At 3, 6, and 24 months from the index procedure, we determined the atrial arrhythmia recurrence rate, the extent of LAAC, and the rate of cerebrovascular/bleeding events.

RESULTS

Forty-nine patients (mean age 69 ± 8 years; 32/49 (67%) men; CHA₂DS₂-VASc score 2.8 ± 1.2; HAS-BLED score 3 ± 1) with a guideline-recommended LAAC indication were included. Acute PVI and complete LAAC were achieved in 100% of patients. All patients completed at least 24 months of follow-up. At 8 weeks and 6 months, complete or satisfactory (<5 mm leak) LAAC rates were achieved in 40 (82%) and 9 (18%) and in 42 (86%) and 7 (14%) of patients, respectively. The overall freedom from atrial arrhythmia rate at 24 months was 29 (60%), and 45 (92%) of patients were off antithrombotic drugs. The observed annualized stroke and bleeding rates were 1% and 2%, respectively, a 71% and 60% risk reduction in comparison to event rates predicted from CHA₂DS₂-VASc and HAS-BLED scores.

CONCLUSION

Concomitant cryoballoon ablation and LAAC procedures appear safe and effective at long-term follow-up, with high antithrombotic drug withdrawal rates at 24 months.

Is epicardial fat tissue associated with atrial fibrillation recurrence after ablation? A systematic review and meta-analysis

INTRODUCTION

Although an undoubted association between epicardial fat tissue (EFT) and atrial fibrillation (AF) has been recently approved, the association between EFT and post-ablation AF recurrence is not evident yet. This study aimed to assess the association between EFT and AF recurrence after ablation.

METHODS

The present study was a systematic review and meta-analysis using related literature available in electronic databases until July 2018 via "atrial fibrillation" and "epicardial fat" as the main keywords. Considering the different methods of EFT measurement, three different pooled meta-analyses were conducted in this study including: 1) comparison of total EFT volume, 2) left atrium (LA)-EFT volume, and 3) EFT thickness between two groups with and without AF recurrence estimating standardized mean difference (SMD) through a random and non-random effect meta-analysis. Statistical analysis was also performed using Comprehensive Meta-analysis (CMA) Software.

RESULTS

Following a search into a total number of 518 articles, the findings of 12 studies published in 10 articles were enrolled in this meta-analysis. Accordingly, the results of meta-analysis showed that LA-EFT and total EFT volumes were higher in recurrent subjects (LA-EFT: SMD = 0.862 ml; I2 = 0.00, 95% confidence interval (CI) = 0.567-1.156; total EFT: SMD = 1.017 ml, I2 = 0.00, 95% CI = 0.748-1.286). Besides, a significant higher EFT thickness in patients with AF recurrence compared to those with no AF recurrence was observed (SMD = 0.808 mm, I2 = 91.07, 95% CI = 0.215-1401).

CONCLUSION

The total EFT and LA-EFT volumes, as well as EFT thickness, seemed to be associated with AF recurrence in patients undergoing AF ablation.

Low voltage areas in paroxysmal atrial fibrillation: The prevalence, risk factors and impact on the effectiveness of catheter ablation

BACKGROUND

The prevalence, risk factors of left atrial low voltage areas (LVA) in paroxysmal atrial fibrillation (PAF) and the impact of LVA on the effectiveness of circumferential pulmonary vein isolation (CPVI) were not fully clarified.

METHODS

One hundred fifty patients (mean age 64.7 years, 89 males) with PAF were consecutively enrolled to undergo CPVI. Prior to ablation a contact force sensing ablation catheter was utilized for LVA mapping in sinus rhythm. The patients were graded based on the proportion of LVA (LVA%): non LVA, mild (LVA% ≤ 10%), moderate (LVA% 10%-<20%) and severe (LVA% ≥ 20%), and were followed up for 12 months after initial CPVI.

RESULTS

There were 56 in non LVA, 54 in mild LVA, 22 in moderate LVA and 18 in severe LVA. The prevalence of LVA was 62.7% in this PAF cohort, with the most frequent localization at anterior free wall (35.3%), PV antrum (22%) and septum (14.7%). Female gender (OR 3.634, 95% CI 1.704-7.751, P = 0.001) and left atrial surface area (LASA) (OR 1.024, 95% CI 1.000-1.048, P = 0.048) were risk factors of LVA. LVA% exceeding10% was associated with poor effectiveness of CPVI. LVA grade (HR 1.633, 95% CI 1.122-2.378, P = 0.011) was an independent predictor for AF recurrence after initial ablation.

CONCLUSIONS

LVA affected >60% of patients with PAF. Female gender and LASA were two risk factors of LVA. LVA grade was an independent predictor for AF recurrence following CPVI.

Atrial fibrillation ablation using cryoballoon technology: Recent advances and practical techniques

Atrial fibrillation (AF) affects 1-2% of the population, and its prevalence is estimated to double in the next 50 years as the population ages. AF results in impaired patients' life quality, deteriorated cardiac function, and even increased mortality. Antiarrhythmic drugs frequently fail to restore sinus rhythm. Catheter ablation is a valuable treatment approach for AF, even as a first-line therapy strategy in selected patients. Effective electrical pulmonary vein isolation (PVI) is the cornerstone of all AF ablation strategies. Use of radiofrequency (RF) catheter in combination of a three-dimensional electroanatomical mapping system is the most established ablation approach. However, catheter ablation of AF is challenging even sometimes for experienced operators. To facilitate catheter ablation of AF without compromising the durability of the pulmonary vein isolation, "single shot" ablation devices have been developed; of them, cryoballoon ablation, is by far the most widely investigated. In this report, we review the current knowledge of AF and discuss the recent evidence in catheter ablation of AF, particularly cryoballoon ablation. Moreover, we review relevant data from the literature as well as our own experience and summarize the key procedural practical techniques in PVI using cryoballoon technology, aiming to shorten the learning curve of the ablation technique and to contribute further to reduction of the disease burden.

Efficacy and safety of uninterrupted low-intensity warfarin for cryoballoon ablation of atrial fibrillation in the elderly: A pilot study

WHAT IS KNOWN AND OBJECTIVE

Uninterrupted warfarin during cryoballoon ablation (CB-A) of atrial fibrillation (AF) has been widely accepted. However, to our knowledge, no previous studies exist investigating the optimal intensity of anticoagulation with warfarin for CB-A. This study aimed to evaluate the efficacy and safety of uninterrupted low-intensity warfarin for CB-A of AF in the elderly.

METHODS

Paroxysmal AF patients (age ≥ 70 years) who underwent CB-A were enrolled prospectively. The participants were stratified into 2 groups based on international normalized ratio (INR) before ablation (INR in group A: 1.5 to 2.0; INR in group B: 2.0-2.5). Primary endpoints included periprocedural thromboembolic complications and major bleeding. Secondary endpoints were new asymptomatic cerebral emboli (ACE) and minor bleeding.

RESULTS AND DISCUSSION

A total of 144 patients were enrolled (group A: 65; group B: 79). In group A, the use of concomitant antiplatelet drugs was more common. Also, the mean HAS-BLED score was significantly higher (2.4 ± 0.8 vs 2.0 ± 0.6, P < .01) and the mean activated clotting time (ACT) during the procedure was significantly lower (302 ± 14 s vs 311 ± 11 s, P < .01). Other clinical characteristics were balanced between the 2 groups. No thromboembolic complications and major bleeding occurred in either group. The incidence of periprocedural ACE was comparable between the 2 groups (9.2% vs 6.3%, P = .74). The incidence of minor bleeding in group A and group B was 4.6% and 11.4%, respectively (P = .14).

WHAT IS NEW AND CONCLUSION

Compared with standard-intensity warfarin, uninterrupted low-intensity warfarin might not increase the incidence of thromboembolic complications and might be associated with less bleeding risk during the perioperative period of cryoballoon ablation in the elderly. Large trials are needed to confirm these results.

Efficacy and Safety of Uninterrupted Low-Intensity Warfarin for Radiofrequency Catheter Ablation of Atrial Fibrillation in the Elderly

Background: No previous studies exist investigating the optimal intensity of uninterrupted anticoagulation with warfarin during radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in the elderly. Objective: Evaluate the efficacy and safety of continuous low-intensity warfarin therapy throughout the periprocedural period of RFCA for AF in the elderly. Methods: This is a prospective randomized study. We enrolled AF patients (age ≥ 70 years) who underwent first-time RFCA for AF. Enrolled patients were randomized to group A and group B. The international normalized ratios before ablation were maintained at 1.5 to 2.0 and 2.0 to 2.5 in group A and B, respectively. Primary end points were periprocedural thromboembolic complications and major bleeding. Secondary end points included periprocedural asymptomatic cerebral emboli (ACE) and minor bleeding. Results: A total of 101 patients were enrolled in our study (group A: 52; group B: 49). Baseline characteristics were well balanced between the 2 groups. Only 1 patient suffered from stroke in group B. No major bleeding events occurred in either group. The incidence of new ACE lesions was comparable between the 2 groups (11.5% vs 8.2%, P = 0.82). Minor bleeding occurred in 1 of 52 (1.9%) patients in group A and in 5 of 49 (10.2%) patients in group B ( P = 0.10). Conclusions: Uninterrupted low-intensity warfarin for RFCA of AF might be as effective as standard-intensity warfarin in preventing periprocedural thromboembolic complications and might be associated with fewer bleeding events in the elderly.

Ablation of atrial fibrillation: single-shot techniques poised to dominate rhythm control strategies/the future is here

Over the recent years, the advent of single-shot techniques, such as circular catheter and cryoballoon ablation, has ushered in a new era in the catheter ablation approach and rhythm control strategies of patients with atrial fibrillation (AF). These techniques make it easier to navigate the heart and have the potential to decrease the threshold for, expand the access to, and increase patient and physician acceptance of rhythm-control therapies, that may lead to reduction of the AF disease burden and its socioeconomic impact. Due to technical issues the circular catheter technique is lagging behind, however the cryoballoon approach is progressing at a faster pace both in the field of technical advancements and clinical studies, all contributing to its rapid penetration in the electrophysiological community and rhythm management approaches toward the commonest cardiac arrhythmia. Comparative studies of the conventional point-by-point radiofrequency (RF) ablation technique and the cryoablation approach to pulmonary vein isolation (PVI), which constitutes the cornerstone of all ablation methods, seem to favor the cryoablation technique in certain aspects. The results of current studies converge in their conclusion that cryoablation employing current generation cryoballoons is a simplified and faster method compared to the conventional technique in achieving effective and durable PVI. Furthermore, investigators have recently proposed particular tips and parameters to serve as reliable predictors of successful and durable PVI that may enhance the clinical success of this single-shot ablation technique. These issues will be discussed in this overview and placed into perspective.