Similar safety, efficacy with 90 W vs. 50 W radiofrequency ablation for AF
Very high-powered short-duration radiofrequency ablation for atrial fibrillation with 90 W using a next-generation catheter was safe and effective vs. high-powered short-duration 50 W radiofrequency ablation, researchers reported.
“Although point-by-point catheter ablation is the method of choice for flexible lesion sets for both pulmonary vein isolation and extra-pulmonary vein ablations, individual lesion generation can drive long ablation, fluoroscopy and procedure times,” Julian Müeller, MD, of the Clinic for Interventional Electrophysiology, Heart Centre Bad Neustadt, Germany, and colleagues wrote. “Application of the so-called high-power short-duration ablation strategy aims to minimize conductive heating and increase resistive heating in order to achieve atrial transmural lesion formation while reducing the risk of collateral tissue damage. Several studies show favorable safety and long-term results using this high-power short-duration strategy.”
In a retrospective study with a propensity score-matched cohort, Müeller and colleagues analyzed data from 42 patients undergoing a first AF ablation with very high-powered (90 W) very short-duration protocol using a specialized ablation catheter in conjunction with a novel radiofrequency generator, as well as 42 patients who underwent high-powered (50 W) short-duration ablation with a standard ablation catheter. The mean age of patients was 67 years; 58% were men and 47% had paroxysmal AF.
For patients undergoing 90 W radiofrequency ablation, there was a predefined ablation time of 3 seconds for posterior wall ablation and 4 seconds for anterior wall ablation. For patients undergoing 50 W radiofrequency ablation, radiofrequency energy was applied in an ablation index-guided manner.
The findings were published in the Journal of Cardiovascular Electrophysiology.
Researchers found that ablation times were shorter with 90 W vs. 50 W procedures (mean, 10.5 minutes vs. 17.4 minutes; P < .001); there were no major complications in either group. Researchers also observed lower first pass pulmonary vein isolation rates with 90 W vs. 50 W ablations (40% vs. 62%; P = .049) and higher AF recurrences during the blanking period with 90 W vs. 50 W ablations (38% vs. 12%; P = .007).
At 12 months, midterm outcomes were comparable for 90 W and 50 W ablation approaches (62% vs. 70%; log rank P = .452). In a multivariable Cox regression model, independent predictors of AF recurrence during follow-up included persistent AF (HR = 1.442; 95% CI, 1.035-2.01; P = .031) and increased procedural duration (HR = 1.011; 95% CI, 1.005-1.017; P = .001).
“Despite shorter ablation times in the 90 W group, total procedure time was comparable with the 50 W approach in a matched cohort,” the researchers wrote. “Shorter radiofrequency application times with 90 W seem to reveal fewer first pass pulmonary vein isolations, especially for the right pulmonary veins with increased need for touch up ablations. This decreased acute efficacy is also translated into more AF recurrences during the first 3 months post ablation; however, midterm ablation success after a follow-up of 12 months revealed comparable AF/atrial tachycardia recurrence rates.”
The researchers noted that larger studies with the updated ablation protocol investigating long-term follow-up of 90 W AF ablations are needed.
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