Real world data on SVT ablation in Denmark Higher risk of need for reablation in todays patient population a Nationwide registry based Danish study

Abstract Introduction Supraventricular tachycardias (SVTs) are a common reason for healthcare contacts and can have significant impact on patient’s quality of life. Today, ablation therapy is considered the treatment of choice for many cardiac tachyarrhythmias, and it is increasingly utilized to treat SVT-patients with chronic symptoms. Ablation therapy for SVTs is considered a safe procedure with high periprocedural success rates. However, recent studies on today’s patient population have shown a tendency towards higher age and more comorbidity, which might affect these success rates. Therefore, there is a need to explore more real-world data on long-term outcomes of catheter ablations in today’s population. Purpose To examine the long-term success rates of ablation therapy by investigating risk of reablation in patients treated for either an accessory pathway (AP), atrioventricular nodal re-entry tachycardia (AVNRT) or ectopic atrial tachycardia (EAT). Methods Using Danish nationwide registries, patients of 18 years or older who underwent RFA for AP, AVNRT or EAT between January 1st 2010 and January 1st 2019 were included. Comorbidities and use of antiarrhythmic drugs were analyzed. The cumulative incidences of reablation for either AP, AVNRT or EAT were estimated at 5-year follow-up. Results Figure 1 shows the baseline characteristics of the study population. A total of 5.905 patients were included in the study, with a median age of 52 [38, 65], and 47% were male. Among them, the AP group comprised 1.575 patients, with a mean age of 42 [29, 55], and 61% were male. The AVNRT group consisted of 3.598 patients, with a mean age of 56 [43, 67], and 42% were male. In the EAT group, there were 732 patients, with a mean age of 57 [42, 67], and 44% were male. The comorbidity burden was generelly higher in EAT patients, who also had the highest use of antiarrhythmic drugs. Figure 2 shows the 5-year cumulative incidence of reablation for AP, AVNRT or EAT-patients. Risk of reablation after 5 years was 12%, 5% and 12% for AP-, AVNRT- and EAT patients respectively. After 1 year the risk was 9%, 3% and 9% for AP-, AVNRT- and EAT patients respectively. Conclusion Despite the generally safe nature of ablation therapy with high periprocedural success rates, our findings highlight a notable risk of reablation, particularly for AP and EAT patients, after 5 years of follow-up.Baseline Characteristics5year cumulative incidence of reablation