The superiority of high-power short-duration radiofrequency catheter ablation strategy for atrial fibrillation treatment: A systematic review and meta-analysis study

Comparative Analysis of Clinical Outcomes of High-power, Short-duration Ablation versus Low-power, Long-duration Ablation Strategy in Patients with Atrial Fibrillation: A Comprehensive Umbrella Review of Meta-analyses

Atrial fibrillation (AF) affects around 33 million people worldwide, rendering it a common cardiac arrhythmia. Catheter ablation (CA) has evolved as a leading therapeutic intervention for symptomatic AF. This umbrella review systematically evaluates existing systematic reviews and meta-analyses to assess the safety, efficacy, and potential of high-power, short-duration (HPSD) ablation as an alternative therapy option for AF. A thorough exploration was undertaken across PubMed, the Cochrane Library, and Embase to identify pertinent studies for inclusion in this umbrella review. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method was employed to assess the overall certainty of the evidence comprehensively, and the quality of the incorporated reviews was meticulously evaluated through use of the AMSTAR 2 tool, the Cochrane Collaboration tool, and the Newcastle-Ottawa scale. In this study, we initially identified 35 systematic reviews and meta-analyses, narrowing them down to a final selection of 11 studies, which collectively integrated data from 6 randomized controlled trials and 26 observational studies. For primary efficacy outcomes, the HPSD approach led to a non-significant decrease in the risk of atrial tachyarrhythmia recurrence (risk ratio [RR], 0.88; 95% confidence interval [CI], 0.70-1.12; I 2 = 90%; P = .31) and a significantly reduced risk of AF recurrence (RR, 0.53; 95% CI, 0.42-0.67; I 2 = 0%; P < .00001) compared to the low-power, long-duration (LPLD) approach. In terms of primary safety outcomes, the HPSD approach significantly reduced the risk of esophageal thermal injury (ETI) (RR, 0.71; 95% CI, 0.61-0.83; I 2 = 0%; P < .00001) and facilitated a non-significant decrease in the risk of other major complications (RR, 0.87; 95% CI, 0.73-1.03; I 2 = 0%; P = .10). In conclusion, HPSD therapy is safer and more effective than LPLD therapy, facilitating decreased AF recurrence rates along with reductions in ETI, total procedure duration, ablation number, ablation time, fluoroscopy time, and acute pulmonary vein reconnection.

Head-to-head comparison between left atrial appendage occlusion and non-vitamin K oral anticoagulants in non-valvular atrial fibrillation patients: A systematic review and meta-analysis study

Left atrial appendage occlusion (LAAO) was found to be non-inferior to warfarin. In non-valvular atrial fibrillation (AF), there is still a scarcity of data comparing LAAO versus non-vitamin K oral anticoagulants (NOACs). Our purpose was to compare the clinical benefits between LAAO and NOACs in non-valvular AF patients. The patient, intervention, comparison, and outcome principles were used to develop the research question in this systematic review and meta-analysis. Literature searches were conducted in online scientific databases such as ProQuest, PubMed, and ScienceDirect. All important information was extracted. The random-effect model was applied to estimate all pooled effects. The Mantel-Haenszel statistical method was used to determine the pooled risk ratio (RR) and 95% confidence interval (CI). A total of 4411 participants from 5 studies were involved. LAAO significantly decreased the cardiovascular mortality risk compared to NOACs (RR = 0.56; 95% CI = 0.42 to 0.75; p <0.01). Major bleeding risk in the LAAO group was significantly lower than in the NOACs group (RR = 0.66; RR = 0.53 to 0.82; p <0.01). A significantly lower risk of major bleeding or non-major bleeding in the patients receiving LAAO than NOACs was also observed in this meta-analysis (RR = 0.66; 95% CI = 0.54 to 0.81; p <0.01). LAAO was superior to the NOACs in reducing cardiovascular mortality, major bleeding, and major or non-major bleeding risks in non-valvular AF patients. In high-risk thromboembolism and bleeding patients, LAAO can be considered first as a long-term treatment strategy.

Novel scoring system derived from meta-analysis and validated in cohort population for predicting 1-year atrial fibrillation recurrence after cryoballoon catheter ablation: The HeLPS-Cryo score

BACKGROUND

Atrial fibrillation (AF) recurrence rates in 1 year after cryoballoon ablation catheter (CBCA) are still high. We purposed to identify strong predictors for AF recurrence after the successful CBCA procedure and develop a new scoring system based only on pre-procedural parameters.

METHODS

In the derivation phase, a systematic review and meta-analysis identified the strong predictors of AF recurrence after the CBCA. The pooled hazard ratio (HR) was used to create the new scoring system. The second phase validated the new scoring system in the cohort population.

RESULTS

A meta-analysis including 29 cohort studies with 16196 participants confirmed that persistent AF, stroke, heart failure, and left atrial diameter (LAD) >40 mm were powerful predictors for AF recurrence after the CBCA procedure. The HeLPS-Cryo (heart failure [1], left atrial dilatation [1], persistent AF [2], and stroke [2]) was developed based on those pre-procedural predictors. It was validated in 140 patients receiving CBCA procedures and revealed excellent predictive performance for 1-year AF recurrence (AUC = 0.8877; 95% CI = 0.8208 to 0.9546). The HeLPS-Cryo score of ≥3 could predict 1-year AF recurrence with sensitivity and specificity of 78.9% and 87.9%, respectively. The positive predictive value was 66.7%, and the negative predictive value was 93.1%.

CONCLUSION

The HeLPS-Cryo score can help the physician estimate the probability of 1-year AF recurrence after the successful CBCA procedure. Patients with HeLPS-Cryo score <3 are good candidates for the CBCA procedure.

Impact of high-power short-duration atrial fibrillation ablation technique on the incidence of silent cerebral embolism: a prospective randomized controlled study

BACKGROUND

High-power short-duration (HPSD) ablation strategy has emerged as a popular approach for treating atrial fibrillation (AF), with shorter ablation time. The utilized Smart Touch Surround Flow (STSF) catheter, with 56 holes around the electrode, lowers electrode-tissue temperature and thrombus risk. Thus, we conducted this prospective, randomized study to investigate if the HPSD strategy with STSF catheter in AF ablation procedures reduces the silent cerebral embolism (SCE) risk compared to the conventional approach with the Smart Touch (ST) catheter.

METHODS

From June 2020 to September 2021, 100 AF patients were randomized 1:1 to the HPSD group using the STSF catheter (power set at 50 W) or the conventional group using the ST catheter (power set at 30 to 35 W). Pulmonary vein isolation was performed in all patients, with additional lesions at operator's discretion. High-resolution cerebral diffusion-weighted magnetic resonance imaging (hDWI) with slice thickness of 1 mm was performed before and 24-72 h after ablation. The incidence of new periprocedural SCE was defined as the primary outcome. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) test.

RESULTS

All enrolled AF patients (median age 63, 60% male, 59% paroxysmal AF) underwent successful ablation. Post-procedural hDWI identified 106 lesions in 42 enrolled patients (42%), with 55 lesions in 22 patients (44%) in the HPSD group and 51 lesions in 20 patients (40%) in the conventional group (p = 0.685). No significant differences were observed between two groups regarding the average number of lesions (p = 0.751), maximum lesion diameter (p = 0.405), and total lesion volume per patient (p = 0.669). Persistent AF and CHA2DS2-VASc score were identified as SCE determinants during AF ablation procedure by multivariable regression analysis. No significant differences in MoCA scores were observed between patients with SCE and those without, both immediately post-procedure (p = 0.572) and at the 3-month follow-up (p = 0.743).

CONCLUSIONS

Involving a small sample size of 100 AF patients, this study reveals a similar incidence of SCE in AF ablation procedures, comparing the HPSD strategy using the STSF catheter to the conventional approach with the ST catheter.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04408716. AF = Atrial fibrillation, DWI = Diffusion-weighted magnetic resonance imaging, HPSD = High-power short-duration, ST = Smart Touch, STSF = Smart Touch Surround Flow.

Index-Guided High-Power Radiofrequency Catheter Ablation for Atrial Fibrillation: A Systematic Review and Meta-Analysis Study

PURPOSE OF REVIEW

Studies have suggested the superiority of high-power compared to standard-power radiofrequency ablation ablation (RFCA). This study aimed to assess the efficacy and safety of high-power compared to standard-power RFCA guided by ablation index (AI) or lesion index (LSI).

RECENT FINDINGS

A systematic review and meta-analysis study comparing IGHP and IGLP approaches for AF ablation was conducted. The relevant published studies comparing IGHP and IGSP methods for RFCA in AF patients until October 2022 were collected from Cochrane, ProQuest, PubMed, and ScienceDirect. A total of 2579 AF patients from 11 studies were included, 1682 received IGHP RFCA, and 897 received IGSP RFCA. To achieve successful pulmonary vein isolation (PVI), the IGHP RFCA group had a significantly shorter procedure time than the IGHP RFCA group (mean difference (MD) -19.91 min; 95% CI -25.23 to -14.59 min; p < 0.01), radiofrequency (RF) application time (MD -10.92 min; 95% CI -14.70 to -7.13 min; p < 0.01), and fewer number of lesions (MD -10.90; 95% CI -18.77 to -3.02; p < 0.01) than the IGSP RFCA. First-pass PVI was significantly greater in the IGHP RFCA group than in the IGSP RFCA group (risk ratio (RR) 1.17; 95% CI 1.07 to 1.28; p < 0.01). The IGHP RFCA is an effective and efficient strategy for AF ablation. The superiority of IGHP RFCA includes the shorter procedure time, shorter RF application time, fewer number of lesions for complete PVI, and more excellent first-pass PVI.

Higher power achieves greater local impedance drop, shorter ablation time, and more transmural lesion formation in comparison to lower power in local impedance guided radiofrequency ablation of atrial fibrillation

BACKGROUND

Since the local impedance (LI) of the ablation catheter reflects tissue characteristics, the efficacy of higher power (HP) compared to lower power (LP) in LI-guided ablation may differ from other index-guided ablations.

OBJECTIVE

This study aimed to assess the efficacy of HP ablation in LI-guided ablation of atrial fibrillation (AF).

METHODS

A prospective observational study was conducted, enrolling patients undergoing de novo ablation for AF. Pulmonary vein isolation was performed using point-by-point ablation with a RHYTHMIA HDxTM Mapping System and an open-irrigated ablation catheter with mini-electrodes (IntellaNav MIFI OI). Ablation was stopped when the LI drop reached 30 ohms, three seconds after the LI plateaued, or when ablation time reached 30 s. To balance the baseline differences, a unique method was used in which the power was changed between HP (45 W to anterior wall/40 W to posterior wall) and LP (35 W/30 W) alternately for each adjacent point.

RESULTS

A total of 551 ablations in 10 patients were analyzed (HP, n = 276; LP, n = 275). The maximum LI drop was significantly larger (HP: 28.3 ± 5.4 vs. LP: 24.8 ± 6.3 ohm), and the time to minimum LI was significantly shorter (HP: 15.0 ± 6.3 vs. LP: 19.3 ± 6.6 s) in the HP setting. The unipolar electrogram analysis of three patients revealed that the electrogram indicating transmural lesion formation was observed more frequently in the HP setting.

CONCLUSION

In LI-guided ablation, the HP could achieve a larger LI drop and shorter time to minimum LI, which may result in more transmural lesion formation compared to a LP setting.

Comparative Efficacy and Safety Profiles of High-power, Short-duration and Low-power, Long-duration Radiofrequency Ablation in Atrial Fibrillation: A Systematic Review and Meta-analysis

High-power, short-duration (HPSD) radiofrequency (RF) ablation is expected to be more effective and safer than low-power, long-duration (LPLD) RF ablation in treating atrial fibrillation (AF). Given the limited data available, the findings are controversial. This meta-analysis evaluated whether the clinical effects of HPSD outweigh those of LPLD. A systematic search of PubMed, Embase, and Google Scholar databases identified studies comparing HPSD to LPLD ablation. All the analyses used the random-effects model. This analysis included 21 studies with a total of 4,169 patients. Pooled analyses revealed that HPSD was associated with a lower recurrence of atrial tachyarrhythmias (ATAs) at 1 year (relative risk [RR], 0.62; 95% confidence interval [CI], 0.50-0.78; P = .00001; I² = 0%). Furthermore, the HPSD approach reduced the risk of AF recurrence (RR, 0.64; 95% CI, 0.40-1.01; P = .06; I² = 86%). The HPSD approach was associated with a lower risk of esophageal thermal injury (ETI) (RR, 0.78; 95% CI, 0.58-1.04; P = .09; I² = 73%). The HPSD strategy increased first-pass pulmonary vein (PV) isolation (PVI) and decreased acute PV reconnection (PVR), both of which were predominantly manifested in bilateral and left PVs. HPSD facilitated a reduction in procedural time, number of lesions created during PVI, and fluoroscopy time. The HPSD method reduces ETI, PVR, and recurrent AF. The HPSD approach also reduced the procedural time, number of lesions created during PVI, fluoroscopy time, and post-ablation AF relapse in 1 year, improving patient outcomes and safety.

Atrial fibrillatory wave amplitude revisited: A predictor of recurrence after catheter ablation independent of the degree of left atrial structural remodeling

BACKGROUND

The fibrillatory wave amplitude (FWA) during atrial fibrillation (AF) is thought to reflect structural atrial remodeling, but it remains unclear what determines the FWA.

METHODS

114 consecutive patients were prospectively studied who underwent catheter ablation of AF. The mean FWA was computed by automated surface ECG analyses. The extent of the left atrial (LA) voltage-defined atrial fibrosis and conduction properties were estimated by a three-dimensional high-density electroanatomical mapping system. The LA size was evaluated by transthoracic echocardiography. The study patients were divided into 2 groups according to an FWA in lead V1 above the median value of 46 µV (high FWA group, n=57) or below 46 µV (low FWA group, n=57).

RESULTS

There were no differences in the age, gender, CHADS2 score, prevalence of paroxysmal AF, medications, ablation strategy, and LA volume index between the two groups. The LA low voltage areas in the low FWA group were not different from those in the high FWA group. The total LA activation time and local LA conduction velocity did not differ between the two groups. During a median follow-up of 710 days, the recurrence rate after ablation was significantly higher in patients with a low FWA than a high FWA (log-rank P=0.02). In a multivariate analysis, non-paroxysmal AF, the LA volume index, and FWA were independent predictors of recurrence after　ablation.

CONCLUSIONS

The FWA was not correlated with the markers of atrial structural remodeling. Nevertheless, the FWA could still provide information for predicting the clinical outcome after AF ablation.

Procedural Efficiency, Efficacy, and Safety of High-Power, Short-Duration Radiofrequency Ablation Delivered by STSF Catheter for Paroxysmal Atrial Fibrillation

Objectives

To investigate the procedural efficiency, efficacy, and safety of high-power, short-term radiofrequency ablation delivered by the SmartTouch Surround Flow (STSF) catheter for paroxysmal atrial fibrillation (AF).

Methods

We retrospectively analyzed a total of 72 patients who were admitted with paroxysmal AF, and who underwent radiofrequency catheter ablation (RFCA) for the first time. Of these patients, 36 cases underwent low-power, long-duration (LPLD, (30–35 W/20–40 s) pulmonary vein isolation (PVI) delivered by an SmartTouch (ST) catheter (control group), and the other 36 cases underwent high-power, short-duration (HPSD, (45–50 W/10–20 s) PVI delivered by a STSF catheter (study group). The baseline data, duration of PVI, procedural time, fluoroscopy time, the rate of first-pass isolation, irrigation perfusion, eschar and steam pop occurrences, intraoperative complications, and the rate of stable sinus rhythm maintenance following a blanking period of three months were analyzed between the two groups.

Results

The isolation time of bilateral PVI and procedural time in the study group were markedly less than in controls (p < 0.01). The rate of first-pass isolation in the study group was significantly higher than in the control group (95.8% vs. 84.7%, p = 0.023), while the fluid perfusion in the study group was approximately 20% less than that in the control group (767 ± 171 vs. 966 ± 227 ml, p < 0.001). We observed no severe complications in any patients. The rate of freedom from AF recurrences following a blanking period of three months showed a tendency to be higher than in controls (93.9% vs. 87.1%, p = 0.348).

Conclusions

The HPSD strategy delivered by the STSF catheter was superior to conventional LPLD ablation through the ST catheter with respect to efficiency, acute procedural effectiveness, short-term safety, and the risk of heart failure in patients with paroxysmal AF.

Prophylactic Cavotricuspid Isthmus Ablation in Atrial Fibrillation without Documented Typical Atrial Flutter: A Systematic Review and Meta-analysis

Background: The advantage of prophylactic cavotricuspid isthmus (CTI) ablation for AF patients without documented atrial flutter is still unclear. The present study aimed to evaluate the role of prophylactic CTI ablation in this population. Methods: A systematic review and meta-analysis study was conducted. The overall effects estimation was conducted using random effects models. The pooled effects were presented as the risk difference and standardised mean difference for dichotomous and continuous outcomes, respectively. Results: A total of 1,476 patients from four studies were included. The risk of atrial tachyarrhythmias following a successful catheter ablation procedure was greater in the pulmonary vein isolation + CTI ablation group than pulmonary vein isolation alone group (34.8% versus 28.2%; risk difference 0.08; 95% CI [0.00–0.17]; p=0.04). Prophylactic CTI ablation was associated with a higher recurrent AF rate (33.8% versus 27.1%; risk difference 0.07; 95% CI [0.01–0.13]; p=0.02). Additional prophylactic CTI ablation to pulmonary vein isolation significantly increased the radio frequency application time (standardised mean difference 0.52; 95% CI [0.04–1.01]; p=0.03). Conclusion: This study suggested that prophylactic CTI ablation was an ineffective and inefficient approach in AF without documented typical atrial flutter patients.

A Systematic Review and Meta-Analysis of the Direct Comparison of Second-Generation Cryoballoon Ablation and Contact Force-Sensing Radiofrequency Ablation in Patients with Paroxysmal Atrial Fibrillation

The superiority of second-generation cryoballoon (2G-CB) ablation versus contact force-sensing radiofrequency (CF-RF) ablation in patients with paroxysmal atrial fibrillation (AF) was assessed in this systematic review and meta-analysis. Freedom from atrial tachyarrhythmias (ATAs) (OR = 0.89; 95% confidence interval [CI] = 0.68 to 1.17; p = 0.41), freedom from AF (OR = 0.93; 95% CI = 0.65 to 1.35; p = 0.72), and acute pulmonary vein isolation (PVI) (OR = 1.17; 95% CI = 0.54 to 2.53; p = 0.70) between 2G-CB ablation and CF-RF ablation were not different. The procedure time for the 2G-CB ablation was shorter (MD = −18.78 min; 95% CI = −27.72 to −9.85 min; p < 0.01), while the fluoroscopy time was similar (MD = 2.66 min; 95% CI = −0.52 to 5.83 min; p = 0.10). In the 2G-CB ablation group, phrenic nerve paralysis was more common (OR = 5.74; 95% CI = 1.80 to 18.31; p = < 0.01). Regarding freedom from ATAs, freedom from AF, and acute PVI, these findings imply that 2G-CB ablation is not superior to CF-RF ablation in paroxysmal AF. Although faster than CF-RF ablation, 2G-CB ablation has a greater risk of phrenic nerve paralysis.