High‐power short‐duration ablation: Better, safer, and faster?

Safety and efficacy of high power shorter duration ablation for atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Radiofrequency ablation in patients with atrial fibrillation (AF) is effective but hampered by pulmonary veins reconnection because of insufficient lesions. High power shorter duration ablation (HPSD) was seen to increase efficacy and safety. This analysis aimed to evaluate the clinical benefits of HPSD in patients with AF.

METHODS

The Medline, PubMed, Embase, and the Cochrane Library databases were searched for studies comparing HPSD and Low power longer duration (LPLD) ablation.

RESULTS

A total of seven trials with 2023 patients were included in the analysis. Pooled analyses demonstrated that HPSD showed a benefit of first-pass pulmonary vein isolation (PVI) [risk ratio (RR): 1.27; 95% confidence interval (CI): 1.18-1.37, P < .001]. HPSD could reduce recurrence of atrial arrhythmias (RR: 0.70; 95% CI: 0.50-0.98, P = .04). Additionally, HPSD was more beneficial in terms of procedural time [Weighted Mean Difference, (WMD): -44.62; 95% CI, -63.00 to -26.23, P < .001], ablation time (WMD: -21.25; 95% CI: -25.36 to -17.13, P < .001), and fluoroscopy time (WMD: -4.13; 95% CI: -7.52 to -0.74, P < .001). Moreover, major complications and esophageal thermal injury (ETI) were similar between two groups (RR: 0.75; 95% CI: 0.44-1.30, P = .31) and (RR: 0.64; 95% CI: 0.17-2.39, P = .51).

CONCLUSION

HPSD was safe and efficient for treating AF with clear advantages of procedural features, it also showed benefits of higher first-pass PVI and reducing recurrence of atrial arrhythmias compared with the LPLD. Moreover, major complications and ETI were similar between two groups.

Lesion size and adjacent tissue damage assessment with high power and short duration radiofrequency ablation: comparison to conventional radiofrequency ablation power setting

There is increased interest in creating high-power short duration (HPSD) ablation lesions in the field of atrial fibrillation (AF) radiofrequency ablation (RFA). We evaluated the lesion characteristics and collateral damage using two separate RFA protocols setting (HPSD: 50 W and 7 s vs control: 25 W and 30 s) in vitro model. Sixteen freshly killed porcine hearts were obtained, and the atrium and ventricle slabs were harvested for ablation. The each slabs were placed in a tissue bath with circulating 0.9% NaCl at maintained temperature 37 °C. RFA was performed with 4 mm tip irrigated force sensing catheter. All lesions were ablated under recording the electrical parameters using with Ensite Navx system (St. Jude Medical, St. Paul, Minnesota). After RFA, lesion characteristics were assessed for each lesion. Thirty-five lesions were made for each ablation protocol (total 70 lesions for analysis). Ablation parameters were similar between two groups (HPSD vs control; impedance drop (Ω): 34.2 ± 13.1 vs 36.1 ± 8.65 P = 0.49, contact force (g): 13.9 ± 4.37 vs 14.6 ± 5.09, P = 0.51, lesion size index: 4.8 ± 0.52 vs 4.73 ± 0.59, P = 0.62). Although the lesion volume was similar, the HPSD ablation creates wider but more shallower lesions compared to control group (HPSD vs control; lesion volume: 29.6 ± 18.1 mm³ vs 35.5 ± 17.1 mm³ P = 0.16, lesion diameter: 4.98 ± 0.91 mm vs 4.45 ± 0.74 mm P = 0.0095, lesion depth: 2.2 ± 0.76 mm vs 2.8 ± 1.56 mm P = 0.046). Of these, 38 lesions were assessed for adjacent tissue damage and adjacent tissue damages were more frequent seen in control group (HPSD vs control; 1/19 (5.26%) vs 6/19 (31.5%), P = 0.036). Effective lesions were made with HPSD, thereby reducing RFA procedure time. Although the lesion volume was similar between two groups, collateral damage was less seen in HPSD group attributed by lesion characteristics.

Comparison of higher-power and conventional power ablation of atrial fibrillation using contact force-sensing catheters: a systematic review and meta-analysis

BACKGROUND

Contact force-sensing catheters have been widely used in catheter ablation. During the past few decades, more attention has been paid on the technique of high-power ablation. The purpose of this meta-analysis is to compare the efficacy and safety of conventional power and high power on atrial fibrillation radiofrequency ablation by contact force-sensing catheters.

METHODS

We identified studies through searching MEDLINE, Embase, the Web of Science, Scopus, and the Cochrane Library from inception up until July 2020. The primary outcomes were defined as recurrence of atrial tachyarrhythmia and complications. The secondary outcomes were acute reconnections of pulmonary veins (PVs), ablation time, and the total procedural time.

RESULTS

Four nonrandomized, observational studies (nROS) were selected involving 231 patients with high-power ablation and 239 patients with conventional power ablation. There were insignificant differences in the recurrence rate of atrial tachyarrhythmia (14.2% versus 20.5%, OR: 0.64, 95%CI: 0.39 to 1.04, Z = 1.82, P = 0.07) and clinical complications (1.7% versus 2.5%, OR: 0.72, 95%CI: 0.21 to 2.47, Z = 0.51, P = 0.61) between high-power and conventional power ablation. However, compared with conventional power group, the high-power group had fewer acute PVs reconnections (P = 0.0001), shorter in ablation time (P < 0.0001), and the total procedural time (P < 0.0001).

CONCLUSIONS

High-power ablation could not only ablate safely and efficiently but also reduce focal ablation time and total procedural time significantly.

Efficiency, Safety, and Efficacy of High-Power Short-Duration Radiofrequency Ablation in Patients with Atrial Fibrillation

Pulmonary vein isolation (PVI) is the cornerstone therapy of atrial fibrillation (AF). Radiofrequency catheter ablation (RFCA) is performed using a point-by-point method to achieve durable PVI. However, this procedure remains complex and time-consuming, and the long-term clinical outcomes are still not satisfactory. Recently, there has been increasing interest in the clinical application of high-power short-duration (HPSD) approaches in the field of RFCA. HPSD ablation, distinguishing it from the conventional ablation strategy, delivers RF energy at a high power and saves the dwell time at each site. It is unknown whether the HPSD approach can bring some gratifying changes in the field of RF energy ablation. A number of experimental studies and clinical studies have been conducted regarding this topic. The review aimed to summarize the research findings and evaluate the procedural efficiency, safety, and clinical outcomes of the HPSD approach based on the evidence available to date.

High-power, Short-duration Radiofrequency Ablation for the Treatment of AF

High-power, short-duration (HPSD) ablation for the treatment of AF is emerging as an alternative to ablation using conventional ablation generator settings characterised by lower power and longer duration. Although the reported potential advantages of HPSD ablation include less tissue oedema and collateral tissue damage, a reduction in procedural time and superior ablation lesion formation, clinical studies of HPSD ablation validating these observations are limited. One of the main challenges for HPSD ablation has been the inability to adequately assess temperature and lesion formation in real time. Novel catheter designs may improve the accuracy of intra-ablation temperature recording and correspondingly may improve the safety profile of HPSD ablation. Clinical studies of HPSD ablation are on-going and interpretation of the data from these and other studies will be required to ascertain the clinical value of HPSD ablation.