Utility of adenosine 5'-triphosphate in predicting early recurrence after successful ablation of manifest accessory pathways.

Objectives: The purpose of this study was to determine whether administration of adenosine 5'-triphosphate (ATP; 20-40 mg) after successful ablation of accessory pathway (AP) with manifest preexcitation is useful for detecting residual conduction and predicting early recurrences.

Background: The reported incidence of recurrence of AP conduction after an initially successful procedure is 5% to 10%. Little information on the variables related to early recurrence has been reported.

Methods: We prospectively used 108 ATP tests on 100 consecutive patients (66 men, mean age 36 +/- 15 years) with manifest preexcitation. Five minutes after successful ablation, intravenous boluses of ATP at increasing doses were injected until the target effect of second- or third-degree AV block or AP conduction was observed.

Results: The effect of ATP was AV block (negative test) in 82 cases (76%), conduction over previously ablated AP (positive test) in 9 cases (8.3%), and no achievement of target effect (nondiagnostic test) in 17 cases (15.7%). Thirteen early recurrences were observed in 12 patients. In all 9 (100%) patients with positive ATP test and in 4 (4.9%) of the 82 patients with negative ATP test, conduction over the AP recurred (relative risk 20; 95% confidence interval 8-53; P < .000001). The diagnostic accuracy of the test (analyzing the target effect) was 95%, sensitivity 69%, specificity 100%, and positive and negative predictive values 100% and 95%, respectively.

Conclusions: ATP administration after successful ablation of APs has a high predictive value for early recurrence and may help optimize the duration of the ablation procedure.