Open‐Irrigated Versus Non‐Irrigated Catheters in SVT Ablation: Substrate‐Specific Outcomes in AVRT and AVNRT

BACKGROUND: Open-irrigated catheters (OIC) provide improved cooling, deeper lesion formation, and enhanced safety during radiofrequency catheter ablation (RFCA). However, comparative evidence regarding substrate-specific outcomes with OIC versus non-irrigated catheters (NIC) for supraventricular tachycardia (SVT) remains limited. This study compared acute ablation success (AAS) and recurrence after first-time RFCA using OIC versus NIC, with particular emphasis on differential outcomes in atrioventricular re-entrant tachycardia (AVRT) and atrioventricular re-entrant tachycardia (AVNRT). METHODS: A retrospective cohort of consecutive patients undergoing first-time RFCA for AVNRT or AVRT between 2017 and 2023 was analyzed. Patients were categorized by catheter type (OIC vs. NIC). Primary outcomes were AAS and SVT recurrence during 24-month follow-up. Multivariate logistic regression and Cox proportional hazards models were used for adjusted analyses. Subgroup analyses were performed for AVNRT and AVRT. RESULTS: Among 302 procedures, OIC were used in 113 (37.4%). Overall AAS was achieved in 85.4% of cases (92.0% OIC vs. 81.5% NIC; p = 0.012). Recurrence occurred in 17.9% (7.1% OIC vs. 24.3% NIC; p < 0.001). In multivariable analyses, OIC use was independently associated with higher AAS (adjusted RR 1.12; 95% CI 1.05-1.20; p = 0.001) and lower recurrence (adjusted HR 0.24; 95% CI 0.12-0.52; p < 0.001). In the AVRT subgroup, OIC use was associated with higher AAS (89.9% vs. 76.6%; p = 0.014) and lower recurrence (adjusted HR 0.25; 95% CI 0.11-0.57; p < 0.001), whereas no significant differences were observed in AVNRT. CONCLUSIONS: In this cohort, OIC use was associated with higher AAS and lower recurrence, with the favorable association primarily observed in AVRT rather than AVNRT. These findings support further evaluation of substrate-specific catheter selection, particularly for accessory pathway ablation.