Philips et al wrote that the aim of their study included determining whether catheter ablation outcomes for ARVD/C have improved with the use of electroanatomic mapping systems and epidcardial ventricular tachycardia ablation and investigating the impact of catheter ablation on the burden of ventricualr tachycardia.
They found, in a matched cohort (for age, 3D mapping technique, repetition of procedure, and centre performing catheter ablation) involving 10 epdicardial procedures and eight endocardial procedures, that ventricular tachycardia free survival was significantly longer with epicardial catheter ablation compared with endocardial catheter ablation (p=0.003). Additionally, ventricular tachycardia free survival was significantly longer in patients in whom 3D electroanatomic mapping system was used for the ablation procedure. Philips et al reported: “Freedom from ventricular tachycardia following a single ablation procedure facilitated by 3D electroanatomical mapping was 50%, 34%, and 24% compared to 36%, 16%, and 8% following a single ablation procedure not facilitated by 3D electroanatomical mapping at one, two, and five years, respectively (p=0.016).”
However, whichever technique was used and whether or not a 3D-electroanatimocal mapping system was used, the rate of ventricular tachycardia reccurrence was high. Philips et al wrote: “Recurrence of ventricular tachycardia after catheter ablation is not uncommon in ARVD/C and emphasises the fact that catheter ablation cannot be considered to be ‘curative’ in the long term and should not be viewed an alternative to placement of an implantable cardioverter defibrillator.”
Despite the high rate of recurrence of ventricular tachycardia following an ablation procedure, according to Philips et al, catheter ablation should still be “viewed as an important treatment option” for patients with ARVD/C because it reduces ventricular tachycardia burden. They reported: “The mean frequency of ventricular tachycardia was significantly lower after ventricular tachycardia ablation [0.2±0.4 (median 0.08) ventricular tachycardia episodes/month] as compared with ventricular tachycardia frequency prior to ablation [0.4±0.5 (median 0.16) ventricular tachycardia episodes/month].” They added that with epicardial catheter ablation, mean ventricular tachycardia burden was reduced from 0.42±0.4 (median 0.2) episodes per month prior to the ablation procedure to 0.05±0.1 (median 0) episodes per month after the procedure.
Philips et al wrote that catheter ablation was also an important treatment option for patients who “experience intolerant side effects to antiarrhythmic medications or prefer not to take antiarrhythmic medications.” They added that while epicardial ablation was more efficacious than endocardial procedures, “it should generally be considered after a prior failed endocardial procedure given the higher complication rates associated with pericardial access, mapping, and ablation.”
Harikrishna Tandri, Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, USA, told Cardiac Rhythm News: “The main highlight of our study is that overall the outlook for catheter ablation in ARVD related ventricular tachycardia has significantly improved over the last five years. This is due to multiple factors including improved understanding of the disease process, use of advanced imaging techniques, substrate based ablation, epicardial ablation approach and improved operator experience with complex ventricular tachycardia ablations. An initial conservative endocardial ablation is probably appropriate for low volume centres that routinely do not perform epicardial ablations. However, to achieve best results and to minimise procedural complications, we believe that ARVD patients should be dealt with at high volume ventricular tachycardia ablation centres with particular expertise in epicardial ablation procedures".