Heated saline needle catheter eliminates ventricular tachycardia during radiofrequency ablation
Radiofrequency ablation with a heated saline needle catheter was effective in eliminating clinical ventricular tachycardia in patients who did not respond to prior treatments, according to data from the SERF study presented at the virtual Heart Rhythm Society Annual Scientific Sessions.
Patients unresponsive to prior treatment
In this early feasibility study, researchers analyzed data from 32 patients (mean age, 67 years; 91% men) with implantable cardioverter defibrillators, refractory monomorphic ventricular tachycardia, an ejection fraction between 20% and 60% and at least one prior failed ablation. All patients underwent radiofrequency ablation with a heated saline needle catheter, which created transmural lesions.
“The SERF trial used saline-enhanced radiofrequency ablation delivered through needles placed into the myocardium in order to ablate ventricular tachycardia,” Douglas L. Packer, MD, professor of medicine and consultant in the division of heart rhythm services in the department of cardiovascular medicine at Mayo Clinic, said during the press conference.
Follow-up was conducted at 30 days, 3 and 6 months, during which the ICD was interrogated to determine the recurrence of ventricular tachycardia. The efficacy endpoint was noninducibility of targeted clinical ventricular tachycardia at the end of radiofrequency ablation. The safety endpoint was defined as the absence of serious adverse events probably or definitely related to the device within 30 days.
In the 3 to 6 months before ablation, patients had a median of 40 ICD therapies for ventricular tachycardia.
“Some had as much as 400 and some had as few as five to 10,” Packer said during the press conference.
The catheter used in the study delivered an average of 10 lesions per patient with a median of 6.5 minutes of radiofrequency ablation time. The median duration of the total procedure was 4 hours, 42 minutes.
“[This duration] tends to be less than what we would typically see with standard ablation catheters,” Packer said during the press conference.
Regarding acute efficacy, 100% of patients were acutely noninducible for clinical ventricular tachycardia. During a median follow-up of 5 months, 61% of patients had their ICD therapy reduced by 90%, and 78% of patients had their therapy reduced by 75%.
There were two deaths and two strokes, all of which were possibly related to the device and probably related to the procedure.
“The bottom line from the study is that this is a different catheter design that creates larger lesions yet controllable, but it appears to be highly effective in eliminating the clinical [ventricular tachycardias] in the subjects who have already been treated with antiarrhythmic drugs or treated with prior ablation,” Packer said during the press conference.
Events before, after 30 days
Serious adverse events were probably or definitely related to the device in 6% of patients within the first 30 days after the procedure. After 30 days, 0% of serious adverse events were probably or definitely related to the device.
“As we obtain the remaining information on 50 patients, we feel that the data are going to demonstrate a high feasibility for eliminating ventricular tachycardia in difficult patients,” Packer said during the press conference. – by Darlene Dobkowski
Reference:
Packer DL, et al. LBCT04-04. Presented at: Heart Rhythm Society Annual Scientific Sessions; May 6-9, 2020 (virtual meeting).
Disclosures: The study was sponsored by Thermedical. Packer reports he consulted for Biosense Webster, Boston Scientific, CyberHeart, Medtronic, nContact, Sanofi Aventis, St. Jude Medical and Toray Industries; received research funding from Biosense Webster, Boston Scientific, Cryo Cath, Medtronic, Minnesota Partnership for Biotechnology and Medical Genomics/University of Minnesota, the NIH, Siemens AG, Thermedical, and has a financial interest in mapping technology used in this pilot research that is licensed to Mayo Clinic and St. Jude Medical.
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Packer DL, et al. LBCT04-04. Presented at: Heart Rhythm Society Annual Scientific Sessions; May 6-9, 2020 (virtual meeting).
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