Bipolar ablation of heart arrhythmia safe, effective in lieu of failed unipolar approach
Use of bipolar radiofrequency ablation (BRFA) is both safe and effective in selected patients who have failed at least one standard unipolar approach, suggest the results of a systematic review and meta-analysis. However, the quality of the supporting evidence is low.
“BRFA emerged as a viable technique of radiofrequency ablation where the standard unipolar approach failed,” according to Dr Michal Farkowski from the National Institute of Cardiology in Warsaw, Poland, who presented the study at The Annual Meeting of the European Heart Rhythm Association (EHRA 2022).
“A number of studies describing BRFA were published recently suggesting high effectiveness and acceptable safety of this technology for ablation of ventricular tachycardia in structural heart disease (SHD), premature ventricular contractions, or atrial flutter,” he added.
Farkowski and his colleagues conducted a systematic review with meta-analysis to assess contemporary evidence of the effectiveness and safety of bipolar ablation of heart arrhythmia. They searched the databases of Medline, Embase, and Central from inception to 27 August 2022 for prospective and retrospective studies with or without a control group.
In addition, the team reached out to BRFA experts to draw information regarding the most up-to-date studies or conference presentations. Case studies and papers describing the technical aspects of BRFA instead of its clinical outcomes were excluded. The Newcastle‒Ottawa Scale was used to assess the quality of the studies.
A total of 1,919 studies were identified, of which 12 met the eligibility criteria: one good quality case-control study and 11 low-quality case series with no control group. [Farkowski M, et al, EHRA 2022]
Overall, 120 patients who received BRFA were analysed: mean age 61.9 years, 81 percent males, mean ejection fraction 43.2, SHD 62.6 percent, implantable cardioverter-defibrillator/cardiac resynchronization therapy with defibrillator 52.2 percent.
Almost all patients qualified for BRFA due to failure of at least one unipolar RFA. Follow-up period varied across studies, ranging between 1‒2 years in most cases.
BRFA demonstrated an overall acute effectiveness of 88.2 percent (95 percent confidence interval [CI], 82.5‒93.8; I2, 6.7 percent), while the overall effectiveness of a first BFRA at the end of follow-up period was 55 percent (95 percent CI, 46.2‒63.7; I2, 7.2 percent).
Of note, about one in five patients (21.2 percent, 95 percent CI, 11.2‒31.2; I2, 64 percent) required reablation. Similar results for ventricular tachycardia in SHD, premature ventricular contractions, and atrial flutter were noted in a subgroup analysis.
In terms of adverse events, 16 serious complications, including one surgical intervention, were recorded. No acute deaths occurred, but five patients died during the follow-up period, primarily due to heart failure progression.
A recent study in Canada involving 16 beating ex vivo human and swine hearts in a Langendorff setup suggested that BRFA at 20‒30 W delivered an ideal balance of safety and efficacy, while ≥40 W should be used with caution due to the high incidence of steam pops. [Heart Rhythm 2021;18:1772-1779]