| Background:Atrial fibrillation(AF)is a major risk factor for thromboembolic events,and long-term anticoagulation therapy is recommended for patients with AF who are at risk for thromboembolism as assessed by the CHA2DS2-VASc score,regardless of whether the patient is in partial or prolonged normal sinus rhythm(NSR).Objective:To investigate the safety and feasibility of individualized anticoagulation protocols by continuous rhythm monitoring of paroxysmal AF patients after ablation with an implantable cardiac event monitor(ICM);to investigate the characteristics of AF recurrence after ablation and the risk factors for recurrence.Methods:To enroll patients with paroxysmal AF in the presence of anticoagulation indications,randomized to radiofrequency catheter ablation(RFCA)or cryoballon ablation(CBA)with ICM implantation,and daily thrombotic risk assessment based on ICM recording of AF events from 90 days after the procedure.Anticoagulation intervention was continued for patients who met(1)an AF burden of≥1 h in a single day in the last 30 days or(2)a cumulative AF burden of≥1 h in the last 30 days and an AF density of≥0.50,otherwise anticoagulation was discontinued.The primary endpoint events were the proportion of time spent on novel oral anticoagulants(NOAC),thromboembolic events,and serious bleeding events.All AF events were recorded and correlation analyses were performed to determine risk factors for recurrence rate and intensity of recurrence.Results:A total of 40 patients were included in the study,with mean CHA2DS2-VASc score of 2.6±1.4,45%were male(18/40),age 62.7±8.9 years and median follow-up of 805.5 days(IQR 632.75-941.75 days).15,448 AF events were recorded by ICM,with an accuracy rate of 96.37%,of which 97.48%had a duration<1 h,median annual mean AF burden of 1.16 h(IQR 0-4.58 h),median daily maximum AF burden of 0.70h(IQR 0-2.37 h),52.5%(21/40)no further NOAC after the blanking period,and interquartile ranges of anticoagulation duration and proportion of 0-69 days and 0-10.24%,respectively.There was no significant difference between the RFCA and CBA groups in terms of acute success rate,perioperative complications,recurrence rate and intensity of recurrence(P>0.05),and the length of surgery for CBA was less than that for RFCA(P<0.01).During follow-up,one patient had a possible transient ischemia attack(TIA),which was time-separated from AF,and one patient had a gastrointestinal bleed,which was not in the NOAC treatment period.Long-term AF recurrence was significantly positively associated with age(r_s=0.521),duration of AF(r_s=0.559),early first recurrence(r_s=0.548),and CHA2DS2-VASc score(r_s=0.351)(P<0.05),and was significantly negatively associated with early antiarrhythmic drugs(AAD)use(r_s=0.-356,P<0.05).AF recurrence intensity was significantly positively correlated(P<0.05)with age(r_s=0.493),duration of AF(r_s=0.418),early first recurrence(r_s=0.439),CHA2DS2-VASc score(rs=0.474),duration of left atrial operation(r_s=0.328),and LAD(r_s=0.362),and significantly negatively correlated(P<0.05)with early AAD use(r_s=0.-464,P<0.01).A Cox regression analysis was performed yielding a significantly higher risk of long-term relapse in patients with early relapse(HR 2.99,95%CI 1.01-8.82).Conclusions:In the paroxysmal AF population with short AF duration,individualized anticoagulation based on AF load and AF density under continuous ECG monitoring after ablation is safe and feasible,while substantially reducing the duration of NOAC use.The safety and efficacy of RFCA and CBA procedures are similar,and postoperative recurrence is mostly short-onset,with early postoperative recurrence being an independent risk factor for long-term recurrence. |
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