Meta-analysis of high power short duration in atrial fibrillation ablation - a superior efficient ablation strategy

Focal Pulsed Field Ablation for Atrial Arrhythmias: Efficacy and Safety under Deep Sedation

Focal pulsed field ablation (PFA) is a novel technique for treating cardiac arrhythmias. It has demonstrated positive results in initial studies and has a good safety profile. In recent studies, PFA was often utilized for first-time pulmonary vein isolation (PVI) and was performed under general anesthesia. In our study, we assessed the feasibility, safety, acute procedural efficacy, and efficiency of focal PFA under deep sedation in patients, 80% of whom had undergone at least one left atrial ablation previously. We treated 30 patients (71 ± 7, 46% male) using the CENTAURI system for various atrial arrhythmias, including atrial fibrillation, typical and atypical atrial flutter, and focal atrial tachycardia. The average procedure and fluoroscopy times were 122 ± 43 min and 9 ± 7 min, respectively. A total of 83.33% of patients received additional line ablations beyond PVI, specifically targeting the posterior box and anterior mitral line. All ablations were successfully performed in deep sedation with only one major and one minor complication observed. The major complication was a vasospasm of the right coronary artery during ablation of the cavotricuspid isthmus, which was treated successfully with intracoronary nitroglycerin. All patients could be discharged in sinus rhythm. Moreover, adenosine appears effective in identifying dormant conduction in some patients after focal PFA. In conclusion, focal PFA is an effective approach for complex left atrial ablations under deep sedation, offering both high efficacy and efficiency with a reliable safety profile. Studies on long-term outcomes are needed.

Cardiac Radiofrequency Ablation Exacerbates Myocardial Injury through Pro-Inflammatory Response and Pro-Oxidative Stress in Elderly Patients with Persistent Atrial Fibrillation

BACKGROUND

There is a need to assess myocardial damage after radiofrequency ablation of the pulmonary veins (PV) for persistent atrial fibrillation (PAF) in elderly patients.

OBJECTIVE

To evaluate oxidative stress, inflammatory response and myocardial damage in elderly patients with PAF after radiofrequency ablation of the PV.

METHODS

High-sensitivity troponin T (hsTnT), malondialdehyde-modified low-density lipoprotein (MDA-LDL), acrolein (ACR), lipid hydroperoxide (LHP), toll-like receptor 4 (TLR4), soluble growth stimulation expressed gene 2 (sST2), angiotensin II (Ang II) and myocardial blood flow (MBF) were determined before ablation and at 1, 3 and 5 months after radiofrequency ablation.

RESULTS

The levels of hsTnT, MDA-LDL, ACR, LHP, TLR4, sST2 and Ang II were increased 3 months after ablations compared with before ablation and 1 month after ablation, respectively (P<0.001); they were further increased at 5 months after ablation compared with the 1- and 3-month groups, respectively (P<0.001). MBF was decreased in the 3 months group after ablations compared with before ablation and 1-month after ablation, respectively (P<0.001), and was further decreased in 5-months after ablations compared with 1-month and 3-month groups, respectively (P<0.001). Patients with epicardial monopolar radiofrequency ablation had higher levels of hsTnT, MDA-LDL, ACR, LHP, TLR4, sST2, Ang II and lower MBF than patients with endocardial monopolar and bipolar radiofrequency ablations, respectively (P<0.001).

CONCLUSION

Monopolar radiofrequency ablation method could result in more myocardial injury than bipolar radiofrequency ablation. Oxidative stress and inflammatory response may be involved in cardiac radiofrequency ablation-induced myocardial injury, resulting in myocardial ischemia in elderly patients with PAF.

Comparison of very high-power short-duration, high-power short-duration, and low-power long-duration radiofrequency ablation for atrial fibrillation: A systematic review and network meta-analysis

BACKGROUND

The optimal power and duration settings for radiofrequency (RF) atrial fibrillation (AF) ablation to improve efficacy and safety is unclear. We compared low-power long-duration (LPLD), high-power short-duration (HPSD), and very HPSD (vHPSD) RF settings for AF ablation.

METHODS

This network meta-analysis (NMA) was structured according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Medline, Scopus and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Observational and randomized studies were included. Eligible studies compared outcomes in AF patients who underwent first-time RF ablation with the following settings: vHPSD (70-90 W, 3-10 s), HPSD (45-60 W, 5-10 s), or LPLD (20-40 W, 20-60 s).

RESULTS

Thirty-six studies comprising 10,375 patients were included (33% female). Frequentist NMA showed LPLD tended toward a lower odds of freedom from arrhythmia (FFA) versus HPSD (OR 0.93, 95% CI 0.86-1.00). There was no difference in FFA between vHPSD versus HPSD. Splitwise interval estimates showed a lower odds of FFA in LPLD versus vHPSD on direct (OR 0.78, 95% CI 0.65-0.93) and network estimates (OR 0.85, 95% CI 0.73-0.98). Frequentist NMA showed less total procedural (TP) time with HPSD versus LPLD (generic variance 1.06, 95% CI 0.83 to 1.29) and no difference between HPSD versus vHPSD.

CONCLUSION

This NMA shows improved procedural times in HPSD and vHPSD versus LPLD. Although HPSD tended toward improved odds of FFA compared to LPLD, the overall result was not statistically significant. The odds of FFA in LPLD was lower versus vHPSD on direct and network estimates on splitwise interval analysis. Large prospective head-to-head randomized trials are needed to validate HPSD and vHPSD settings.

Safety and effectiveness of the first contact force ablation catheter with a flexible tip

Background

Catheter ablation is an established therapy for paroxysmal atrial fibrillation (PAF). The TactiFlex Ablation Catheter, Sensor Enabled (TactiFlex SE) is a next-generation radiofrequency ablation catheter incorporating fiber optics-based contact force-sensing technology with a flexible, laser-cut tip.

Objective

The study sought to evaluate the safety and effectiveness of the TactiFlex SE ablation catheter for treatment of drug-refractory PAF.

Methods

The TactiFlex AF investigational device exemption was a prospective, nonrandomized, multicenter clinical study. Enrollment began on June 26, 2020 and completed June 18, 2021. Subjects with PAF underwent de novo pulmonary vein isolation and, if indicated, ablation for typical atrial flutter. Subjects were followed for 12 months.

Results

Of the 355 subjects enrolled at 37 sites worldwide, 334 underwent ablation with the TactiFlex SE catheter. The Kaplan-Meier estimate of 12-month freedom from AF/atrial flutter (AFL)/atrial tachycardia recurrence was 72.9% (95% confidence interval [CI] 95% CI 67.2%-77.8%) and clinical success was 83.6% (95% CI 95% CI 78.1%-87.2%). As-treated analyses compared subjects treated at high power (left atrium time-averaged power setting 40-50 W; n = 222) vs low power (<40 W; n = 97). The Kaplan-Meier estimate of 12-month freedom from AF/AFL/atrial tachycardia recurrence was 76.4% (95% CI 69.3%-82.0%) and clinical success was 83.9% (95% CI 77.5%-88.6%) in the high-power group compared with 66.8% (95% CI 56.1%-75.5%) and 80.7% (95% CI 70.8%- 87.5%), respectively, in the low-power group. The primary safety event rate in all treated subjects was 4.3%; 4.1% in the HP group and 5.2% in the LP group (P = .7671).

Conclusion

TactiFlex SE is safe and effective for treatment of drug-refractory PAF and concomitant AFL and enables more efficient procedures than previous generation catheters.

50-W vs 40-W During High-Power Short-Duration Ablation for Paroxysmal Atrial Fibrillation: A Multicenter Prospective Study

BACKGROUND

High-power short-duration (HPSD) radiofrequency ablation of atrial fibrillation (AF) increases first-pass pulmonary vein isolation (PVI) and freedom from atrial arrhythmias while decreasing procedural time. However, the optimal power setting in terms of safety and efficacy has not been determined.

OBJECTIVES

This study compared the procedural characteristics and clinical outcomes of 50-W vs 40-W during HPSD ablation of paroxysmal AF.

METHODS

Patients from the REAL-AF prospective multicenter registry (Real-World Experience of Catheter Ablation for Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation) undergoing HPSD ablation of paroxysmal AF, either using 50-W or 40-W, were included. The primary efficacy outcome was freedom from all-atrial arrhythmias. The primary safety outcome was the occurrence of any procedural complication at 12 months. Secondary outcomes included procedural characteristics, AF-related symptoms, and the occurrence of transient ischemic attack or stroke at 12 months.

RESULTS

A total of 383 patients were included. Freedom from all-atrial arrhythmias at 12 months was 80.7% in the 50-W group and 77.3% in the 40-W group (Log-rank P = 0.387). The primary safety outcome occurred in 3.7% of patients in the 50-W group vs 2.8% in the 40-W group (P = 0.646). The 50-W group had a higher rate of first-pass PVI (82.3% vs 76.2%; P = 0.040) as well as shorter procedural (67 minutes [IQR: 54-87.5 minutes] vs 93 minutes [IQR: 80.5-111 minutes]; P < 0.001) and radiofrequency ablation times (15 minutes [IQR: 11.4-20 minutes] vs 27 minutes [IQR: 21.5-34.6 minutes]; P < 0.001) than the 40-W group.

CONCLUSIONS

There was no significant difference in freedom from all-atrial arrhythmias or procedural safety outcomes between 50-W and 40-W during HPSD ablation of paroxysmal AF. The use of 50-W was associated with a higher rate of first-pass PVI as well as shorter procedural times.

Multicenter prospective comparison of conventional and high-power short duration radiofrequency application for pulmonary vein isolation: the high-power short-duration radiofrequency application for faster and safer pulmonary vein ablation (POWER FAST III) trial

BACKGROUND

Electrical isolation of pulmonary veins (PV) with high-power short-duration (HPSD) radiofrequency application (RFa) may reduce the duration of atrial fibrillation (AF) ablation, without compromising the procedural efficacy and safety in comparison with the conventional approach. This hypothesis has been generated in several observational studies; the POWER FAST III will test it in a randomized multicenter clinical trial.

METHODS

It is a multicenter randomized, open-label and non-inferiority clinical trial with two parallel groups. AF ablation using 70 W and 9-10 s RFa is compared with the conventional technique using 25-40 W RFa guided by numerical lesion indexes. The main efficacy objective is the incidence of atrial arrhythmia recurrences electrocardiographically documented during 1-year follow-up. The main safety objective is the incidence of endoscopically detected esophageal thermal lesions (EDEL). This trial includes a substudy of incidence of asymptomatic cerebral lesions detected by magnetic resonance imaging (MRI) after ablation.

RESULTS

A randomized clinical trial compares for the first time high-power short-duration and conventional ablation in order to obtain data about the efficacy and safety of the high-power technique in an adequate methodological context.

CONCLUSIONS

The results of the POWER FAST III could support the use of the high-power short-duration ablation in clinical practice.

REGISTRATION

ClinicalTrials.gov: NTC04153747.

High power short duration versus low power long duration ablation in patients with atrial fibrillation: A meta-analysis of randomized trials

BACKGROUND

High-power-short-duration (HPSD) radiofrequency (RF) ablation is a viable alternative to low-power-long-duration (LPLD) RF for pulmonary vein isolation (PVI). Nevertheless, trials showed conflicting results regarding atrial fibrillation (AF) recurrences and few data concerning complications. Therefore, we conducted a meta-analysis of randomized trials comparing HPSD versus LPLD.

METHODS

We systematically searched the electronic databases for studies published from inception to March 31, 2023 focusing on HPSD versus LPLD. The study endpoints were AF recurrence, procedural times and overall complications.

RESULTS

Five studies enrolling 424 patients met the inclusion criteria (mean age 61.1 years; 54.3% paroxysmal AF; mean LVEF 58.2%). Compared to LPLD, HPSD showed a significantly lower AF recurrence rate [16.3% vs. 30,1%; RR: 0.54 (95% CI: 0.38-0.79); p = 0.001] at a mean 10.9 months follow-up. Moreover, HPSD led to a significant reduction in total procedural time [MD: -26.25 min (95%CI: -42.89 to -9.61); p = 0.002], PVI time [MD: -26.44 min (95%CI: -38.32 to -14.55); p < 0.0001], RF application time [MD: -8.69 min (95%CI: -11.37 to -6.01); p < 0.00001] and RF lesion number [MD: -7.60 (95%CI: -10.15 to -5.05); p < 0.00001]. No difference was found in either right [80.4% vs. 78.2%; RR: 1.04 (95% CI: 0.81-1.32); p = 0.77] or left [92.3% vs. 90.2%; RR: 1.02 (95% CI: 0.94-1.11); p = 0.58] first-pass isolation and overall complications [6% vs. 3.7%; RR: 1.45 (95%CI: 0.53-3.99); p = 0.47] between groups.

CONCLUSION

In our metanalysis of randomized trials, HPSD ablation appeared to be associated to a significantly improved freedom from AF and shorter procedures, without increasing the risk of complications.

QDOT MICRO™ versus THERMOCOOL® SMARTTOUCH™ and THERMOCOOL SMARTTOUCH® Surround Flow in radiofrequency ablation of paroxysmal atrial fibrillation

Aim: The objective of this study was to indirectly compare QDOT MICRO™ (QDOT), Thermocool® SmartTouch™ (ST) and Thermocool® SmartTouch® Surround Flow (STSF) to treat paroxysmal atrial fibrillation. Methods: Differences in baseline characteristics between study cohorts were reduced by reweighting patients using inverse probability of treatment weighting. The primary outcome was procedure time. Secondary outcomes were fluoroscopy time, clinical success at 12 months, and rhythm monitoring-adjusted recurrence. Results: QDOT was associated with significantly faster mean procedure and fluoroscopy time, and significant improvement in the rate of recurrence compared with pooled ST/STSF. No difference was observed for clinical success at 12 months. Conclusion: QDOT was associated with greater efficiency, greater effectiveness in rhythm monitoring-adjusted recurrence and similar effectiveness in clinical success at 12 months compared with pooled ST/STSF.

Zero fluoroscopy catheter ablation for atrial fibrillation: a systematic review and meta-analysis

Introduction

Catheter ablation for atrial fibrillation (AF) is the most frequently performed cardiac ablation procedure worldwide. The majority of ablations can now be performed safely with minimal radiation exposure or even without the use of fluoroscopy, thanks to advances in 3-dimensional electroanatomical mapping systems and/or intracardiac echocardiography. The aim of this study was to conduct a meta-analysis to compare the effectiveness of zero fluoroscopy (ZF) versus non-zero fluoroscopy (NZF) strategies for AF ablation procedures.

Methods

Electronic databases were searched and systematically reviewed for studies comparing procedural parameters and outcomes of ZF vs. NZF approaches in patients undergoing catheter ablation for AF. We used a random-effects model to derive the mean difference (MD) and risk ratios (RR) with a 95% confidence interval (CI).

Results

Our meta-analysis included seven studies comprising 1,593 patients. The ZF approach was found to be feasible in 95.1% of patients. Compared to the NZF approach, the ZF approach significantly reduced procedure time [mean difference (MD): -9.11 min (95% CI: -12.93 to -5.30 min; p < 0.01)], fluoroscopy time [MD: -5.21 min (95% CI: -5.51 to -4.91 min; p < 0.01)], and fluoroscopy dose [MD: -3.96 mGy (95% CI: -4.27 to -3.64; p < 0.01)]. However, there was no significant difference between the two groups in terms of total ablation time [MD: -104.26 s (95% CI: -183.37 to -25.14; p = 0.12)]. Furthermore, there was no significant difference in the acute [risk ratio (RR): 1.01, 95% CI: 1.00-1.02; p = 0.72] and long-term success rates (RR: 0.96, 95% CI: 0.90-1.03; p = 0.56) between the ZF and NZF methods. The complication rate was 2.76% in the entire study population and did not differ between the groups (RR: 0.94, 95% CI: 0.41-2.15; p = 0.89).

Conclusion

The ZF approach is a feasible method for AF ablation procedures. It significantly reduces procedure time and radiation exposure without compromising the acute and long-term success rates or complication rates.

Network meta-analysis and systematic review comparing efficacy and safety between very high power short duration, high power short duration, and conventional radiofrequency ablation of atrial fibrillation

BACKGROUND

High-power short-duration (HPSD) atrial fibrillation (AF) ablation with a power of 40-50 W was proved to be safe and effective. Very high-power short-duration (vHPSD) AF ablation is a novel method using >50 W to obtain more durable AF ablation. This study aimed to evaluate the efficacy and safety of vHPSD ablation compared with HPSD ablation and conventional power ablation.

METHODS

A literature search for studies that reported AF ablation outcomes, including short-term freedom from atrial arrhythmia, first-pass isolation (FPI) rate, procedure time, and major complications, was conducted utilizing MEDLINE, EMBASE, and Cochrane databases. All relevant studies were included in this analysis. A random-effects model of network meta-analysis and surface under cumulative ranking curve (SUCRA) were used to rank the treatment for all outcomes.

RESULTS

A total of 29 studies with 9721 patients were included in the analysis. According to the SUCRA analysis, HPSD ablation had the highest probability of maintaining sinus rhythm. Point estimation showed an odds ratio of 1.5 (95% confidence interval [CI]: 1.2-1.9) between HPSD ablation and conventional power ablation and an odds ratio of 1.3 (95% CI: 0.78-2.2) between vHPSD ablation and conventional power ablation. While the odds ratio of FPI between HPSD ablation and conventional power ablation was 3.6 (95% CI: 1.5-8.9), the odds ratio between vHPSD ablation and conventional power ablation was 2.2 (95% CI: 0.61-8.6). The procedure times of vHPSD and HPSD ablations were comparable and, therefore, shorter than that of conventional power ablation. Major complications were low in all techniques.

CONCLUSION

vHPSD ablation did not yield higher efficacy than HPSD ablation and conventional power ablation. With the safety concern, vHPSD ablation outcomes were comparable with those of other techniques.

Effect of Left Atrial Pulmonary Vein Angiography on Safety and Efficacy for High-Power, Short-Duration Pulmonary Vein Isolation in Patients with Atrial Fibrillation

Imaging of pulmonary vein (PV) anatomy by angiography before pulmonary vein isolation (PVI) for atrial fibrillation (AF) has long been standard practice in many centers. Nowadays, very accurate anatomical maps can be generated by the use of high-resolution mapping catheters, and very effective ablation lesions can be generated by the use of the high-power, short-duration (HPSD) technique. In our center, PV angiography was routinely performed before PVI. However, since there is no clear evidence for this, we refrained from performing PV angiography. This study aimed to investigate whether PV angiography is still necessary when using high-resolution mapping catheters after ablation in the high-power, short-duration (HPSD) technique. A total of 139 consecutive patients with atrial fibrillation (66.25 ± 11.68 years old, 62.39% male) undergoing radiofrequency PVI were included in the study. Ablation was performed with the HPSD technique using a fixed protocol for energy delivery of 50 watts (contact force 3-20 g). We observed no significant effect on the efficacy, efficiency and complications of the ablation procedure if pulmonary vein angiography was omitted before HPSD PVI. Thus, using our protocol, it may be useful that PV angiography is avoided, especially in young patients and those with chronic renal disease.