Increasing rates of thrombosis in children with congenital heart disease undergoing cardiac surgery

Objective: To determine thrombosis incidence, morbidities, and mortality of children with congenital heart disease who develop thrombosis after cardiac surgery.

Materials and methods: This retrospective study reviewed patients <18 years old within the Pediatric Health Information System (PHIS) database who underwent cardiac surgery from 2004-2012. Thrombosis rates were compared for each procedure. Mortality was modeled using proportional hazards, adjusting for important clinical and demographic factors.

Results: Of 91909 CHD patients who underwent surgery, 2655 (2.9%) developed thrombosis within the ensuing 12 months. The rate of thrombosis increased 253% (p<0.001), from 1.7% in 2004 to 4.4% in 2012. Systemic to pulmonary shunt placement (34.3%) and septostomy (26.1%) had the highest thrombosis percentages. Children <28 days had the highest prevalence (61%). Those with thrombosis had longer lengths of stay than those without [median 27 hospital days and 10 ICU days vs. 6 and 2 (p<0.001)]. Mean risk-adjusted cost was higher with thrombosis; $126,257 vs. $40,773 (p<0.001). Thrombosis was also associated with higher rates of bacteremia [8.3% vs. 3.4%, p<0.001], endocarditis [0.7% vs. 0.2%, p<0.001], and mortality [12.3% vs. 0.8%, p<0.001]. The adjusted hazard ratio for mortality in patients with thrombosis was 5.5 (95% CI: 4.6-6.5).

Conclusions: Thrombosis rates in CHD patients after cardiac surgery is increasing. Thrombosis is associated with longer hospital stay, increased ICU days, and cost. CHD patients with thrombosis also have increased bacteremia and mortality rates. More research is needed to understand contributors to thrombosis which may help develop strategies to mitigate morbidity and mortality.