Abstracts

Rationale:
Children with congenital heart disease (CHD) may be at increased risk for epilepsy.  While the incidence of perioperative seizures after surgical repair of CHD has been well-described, the incidence of epilepsy is less well-defined.  Previous studies have estimated a 3.1-5.3% incidence of epilepsy in patients with CHD (1-3). However, risk factors for epilepsy in this population are not well-established. Our aim is to determine the incidence of epilepsy and associated risk factors in patients with CHD (4).
Method:
Retrospective cohort study of patients with CHD who underwent cardiopulmonary bypass (CBP) at < 1 year of age between January 2012 and December 2013 and had at least 2 years of follow-up. Clinical variables were extracted from a cardiac surgery database and hospital records. Seizures were classified based on time of occurrence after a possible inciting event, for example, cardiac arrest, cardiac surgery, or acute brain injury sustained during cardiac catheterization, as acute (≤ 7 days) or subacute (7 – 29 days). Epilepsy was defined based on International League Against Epilepsy criteria (4).
Results:
Two hundred eighty two patients underwent repair of CHD using CPB, 126 were excluded due to insufficient follow-up data. Four (2.5%) patients developed epilepsy. The median age of epilepsy diagnosis was 22.5 (IQR 13.9 – 31) months.  Acute seizures were present in 12 (7.7%) patients. Six patients had clinical seizures, four patients had electroclinical seizures, and two patients had electrographic-only seizures.  Patients with epilepsy had a longer length of hospital stay (median 129 [IQR 74-190] vs. 15 [7-45] days, p< 0.05) and a higher incidence of acute seizures (25% vs. 0.66%, p=0.05). Duration of CBP  (median 117.5  [IQR 93.7-148.7] vs. 127 [85.5 - 197] minutes, p=0.744) and deep hypothermic circulatory arrest (median 30  [IQR 30 - 30] vs. 33.5 [19.5 - 50] minutes, p=0.988), presence of a genetic syndrome (25% vs. 24%, p=0.054), number of cardiac surgeries (2 vs. 1.18, p=0.2070), catheterizations (0.75 vs. 1.3, p=0.4079), and cardiac arrests (0 vs. 0.05, p=0.67), number of postoperative cardiac complications (0 vs. 0.32, p=0.16), and presence of neurologic complications (25% vs 4%,  p=0.16) were similar in patients with and without epilepsy.  Brain MRI was obtained in 37% of patients prior to hospital discharge. No patient with epilepsy was diagnosed with an acute post-operative brain injury. However, two patients with epilepsy had encephalomalacia and one patient had hydrocephalus.  In addition, one patient had a cardiac arrest with anoxic brain injury prior to surgery.
Conclusion:
Infants with CHD undergoing surgical repair using CPB have a low incidence (2.5%) of epilepsy based on ILAE criteria. The presence of acute seizures and a prolonged length of hospital stay are associated with an increased risk of epilepsy. Further studies are needed to establish additional risk factors for epilepsy in patients with CHD.
Funding:
:None