Po-05-090 local impedance and contact force for effective ablation of premature ventricular contractions

Contact force (CF) radiofrequency (RF) catheter ablation is a well-established approach to treating idiopathic premature ventricular contractions (PVCs) from the outflow tracts (OTs), and is associated with favorable outcomes, albeit with up to 30% recurrence rates even in very experienced hands. How the addition of local impedance (LI) feature may improve procedural outcome is unknown. We aimed to study whether the use of a catheter combining LI and CF information was associated with superior outcomes compared to other catheter technologies. We compared three groups of 40 propensity-matched patients with PVCs from the OTs, ablated by means of different catheter technologies: a CF- plus LI-featured catheter, an LI-featured catheter and a standard irrigated catheter. The three groups created by matching displayed no significant difference in baseline clinical variables. Median age was 56[40-63] years and 54% of the patients was female. Prior to ablation, median LVEF was 57[43-63] % and the daily PVC burden was 22[14-29] %. The sites of successful ablation were well balanced among the 3 groups, with 77 (64%) localized in the right outflow tract (RVOT), 24 (20%) in the coronary cusps, and 19 (16%) in the left outflow tract excluding the coronary cusps (LVOT). The CF+LI group displayed a significantly lower risk of PVC recurrence than the standard ablation group (HR, 0.22; 95%CI, 0.07-0.71; p=0.01). In the CF+LI group, LI drop and RF time were the only predictors of successful lesions (OR=1.19, CI: 1.13–1.26, p<0.001; OR=1.06 CI: 1.01-1.07, p=0.044, respectively). In the coronary cusps, unlike the RVOT/LVOT region, CF was not associated with LI drop (p=0.48), and RF duration showed a linear relationship with LI drop (p<0.001). LI drop is the most important predictor of effective lesions. The use of ablation catheters that combine CF and LI information is associated with increased success in RF ablation of PVCs from the OTs.