Assessment of Late Thromboembolic Complications Post–Fontan Procedure in Relation to Different Antithrombotic Regimens: 30-Years’ Follow-up Experience

Abstract

Background: The current CHEST guidelines recommend the use of antithrombotic therapy, either aspirin or warfarin, as a primary thromboembolic complications (TECs) prophylaxis in patients who undergo Fontan procedure, without specification on drug selection or duration of therapy. Objective: To investigate the incidence rate of late TECs, occurring after 1-year post–Fontan procedure and to assess the difference in rate of late TECs between warfarin and aspirin. Methods: A retrospective cohort study included patients who had Fontan procedures between 1985-2010 at our institution. Patients were stratified according to the antithrombotic regimen—warfarin, aspirin, or no therapy—at the time of TECs. Results: We screened 499 patients who underwent Fontan procedures; 431 procedures met the inclusion criteria. Over a median follow-up of 13.6 years (IQR= 8.7), freedom from late TECs at 5, 10, 15, and 20 years was 97.54%, 96.90%, 90.78%, and 88.07%, respectively. There was no difference in late TEC incidence rates per 1000 patient-years between warfarin and aspirin: 7.82 and 5.83 events, respectively; rate ratio= 1.34 (95% CI= 0.68-2.60). Warfarin was associated with a higher major bleeding incidence rate per 1000 patient-years: 3.70 versus 2.91 events with aspirin; rate ratio= 1.27 (95% CI= 0.49 to 3.29). Conclusion and Relevance: The incidence rate of late clinical TECs post–Fontan procedure in our population is low. Warfarin was not superior to aspirin for prevention of late TECs. Yet warfarin was associated with a higher rate of bleeding. This finding suggests a simpler antithrombotic regimen for prevention of TEC after 1-year post-Fontan procedure.

Thromboembolic Complications in Adult Patients Following Fontan Procedure—A Multicenter Study

“…Classically, the basis of antiplatelet or anticoagulant therapy is carried out with aspirin or VKA [24]. Recent reports showed that aspirin is generally not an inferior antithrombotic therapy to VKA (in our study, 53.8% vs. 22.1% used at baseline) [11,21]. Nevertheless, due to important limitations, i.e., high rate of aspirin resistance and difficulties in achieving a consistent international normalized ratio range with VKA among the FO population, the newest research tries to improve thromboprophylaxis through NOAC implementation, which provides easier use, e.g., no need of laboratory monitoring of its effectiveness and lower number of drug interactions [12,26].…”

“…Follow-up data in patients after an FO procedure have shown an overall TECs rate ranging between 8 and 33% and account for about 8% of all FO patients' deaths [4,10,11]. Incidence varies and can be attributed to different definitions and also distinct diagnostic methods of the TECs as well as insufficient follow-up data [12,13].…”