Abstract 19711: Thrombotic Complications and Thromboprophylaxis Effectiveness Across all 3 Stages of Univentricular Heart Palliation
Background: Thrombotic complications (TC) in pediatric cardiac patients are known to be associated with suboptimal outcomes and increased mortality. Risk of TCs for patients with univentricular defects is highest in the immediate post-operative periods but is also present between surgeries and after Fontan. The evidence base to guide thromboprophylaxis (TCP) at each stage is lacking, and use remains empiric.
Methods: A total of 257 children born between 1995-2008 with univentricular heart anatomy were reviewed. The proportions of patients at each stage who had TCs were calculated. The effectiveness of TCP after the immediate post-operative period was assessed in logistic and parametric survival models adjusted for age at surgery, ECMO and post-surgical TCs.
Results: Early TCs after stage 1 were seen in 37% of patients and 23% had TCs between hospital discharge and stage 2. After stage 2, prior to hospital discharge 27% experienced TCs and 16% had TCs between hospital discharge and Fontan. In the early post-Fontan period (prior to hospital discharge) 14% had TCs. Thereafter TC risk was constant over time at 2.1 events per 100 patient-years of follow-up. Between stages 1 and 2, most patients (82%) were on some form of TCP, with 50% of patients on TCP between stages 2 and 3. Almost all patients on TCP at these stages were receiving low molecular weight heparin. After Fontan, 69% of patients received TCP, almost all were on aspirin and/or warfarin. After stage 1, use of TCP (vs. no TCP) was associated with improved likelihood of survival to stage 2 without TCs (HR: 2.33, p=0.007). Similar benefit for TCP was noted for survival without TCs between stages 2 and 3 (HR: 3.17, p=0.02). After Fontan the use of ASA (vs. no TCP) had no effect on TCs (OR: 0.81, p=0.64) but the use of warfarin (vs. no TCP) was found to significantly decrease time-adjusted odds of TCs (OR: 0.22, p<0.001). No major bleeding episodes associated with TCP were reported prior to Fontan, and 1 major episode was noted in a patient on TCP warfarin after Fontan.
Conclusions: Given the impact of TCs on survival, the low risk of serious bleeding complications, and the effectiveness of TCP in preventing TCs across all 3 stages of univentricular palliation, the use of TCP from the initial stage onward in this population is reasonable.
- © 2010 by American Heart Association, Inc.