A combination of programmed parameters utilizing higher detection rate, longer detection intervals, empiric ATP, and optimized SVT discriminators reduced ICD therapies without increasing arrhythmic syncope and was associated with reduction in all-cause mortality among ICD patients.
VT is common in patients without a history of this arrhythmia who have received ICDs or CRT-Ds for primary prevention indications. Programming ICDs for ATP therapy at the time of implantation could potentially terminate most VT episodes and reduce the number of painful shocks for these patients.
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical Research Council Fellowship
Background
In DECAAF II, left atrial (LA) fibrosis ablation plus PVI did not improve AF outcome compared to PVI alone across the study cohort. We hypothesize that biatrial fibrosis ablation could improve AF ablation therapy outcome in a subset of patients with properties identified through a large virtual in silico trial.
Purpose
To investigate the effects of anatomy, fibrosis distribution, and LGE-MRI threshold on ablation outcome using a virtual cohort of 4000 patients.
Methods
We constructed 1000 biatrial models from a statistical shape model and we mapped pectinate muscles, Bachmann’s bundle and fibers from an atlas. For each of the 1000 anatomies we applied a randomly selected fibrosis map from a library of 100 clinical maps. We then created four versions of each case by assigning one of four randomly selected right atrial (RA) fibrosis distributions with Utah grades 1-4 (Fig 1A), giving 4000 virtual patients. Four ablation approaches were applied to each patient model after 5 seconds of AF: PVI, PVI & LA fibrosis, PVI & RA fibrosis, PVI & biatrial fibrosis. LGE-MRI was thresholded for fibrosis ablation at either 1.2 or 1.32 image intensity ratio (IIR). The outcome was classified 5 seconds post ablation.
Results
Biatrial fibrosis ablation is more effective than LA ablation. For patients with high (Utah 4) RA fibrosis, biatrial fibrosis ablation increases AF termination compared to LA fibrosis ablation (Figs 1B & 2A: 62% vs 14%), this compares to cases with low (Utah 1) RA fibrosis (21% vs 14%). For patients with high LA (Utah 4) fibrosis, biatrial ablation is more effective than LA ablation (Fig 2B: 52% vs 19%), this compares to patients with low (Utah 1) LA fibrosis (17% vs 7%). Increasing IIR threshold for ablation decreases termination (LA fibrosis ablation: 15.8% termination at IIR 1.2, 11.0% at IIR 1.32; biatrial: 41.5% at IIR1.2; 20.3% at IIR1.32). Anatomy has a larger effect on biatrial ablation outcome (31.2% of outcomes change between anatomies) than on PVI only ablation outcome (20.0% change).
Conclusion
Biatrial fibrosis ablation is superior to LA fibrosis ablation for cases with high RA fibrosis. Biatrial fibrosis distribution should be considered when targeting AF ablation therapy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.