Risk, Clinical Features, and Outcomes of Thrombosis Associated With Pediatric Cardiac Surgery

Abstract

Background— Thrombosis, usually considered a serious but rare complication of pediatric cardiac surgery, has not been a major clinical and/or research focus in the past. Methods and Results— We noted 444 thrombi (66% occlusive, 60% symptomatic) in 171 of 1542 surgeries (11%). Factors associated with increased odds of thrombosis were age <31 days (odds ratio [OR], 2.0; P =0.002), baseline oxygen saturation <85% (OR, 2.0; P =0.001), previous thrombosis (OR, 2.6; P =0.001), heart transplantation (OR, 4.1; P <0.001), use of deep hypothermic circulatory arrest (OR, 1.9 P =0.01), longer cumulative time with central lines (OR, 1.2 per 5-day equivalent; P <0.001), and postoperative use of extracorporeal support (OR, 5.2; P <0.001). Serious complications of thrombosis occurred with 64 of 444 thrombi (14%) in 47 of 171 patients (28%), and were associated with thrombus location (intrathoracic, 45%; extrathoracic arterial, 19%; extrathoracic venous, 8%; P <0.001), symptomatic thrombi (OR, 8.0; P =0.02), and partially/fully occluding thrombi (OR, 14.3; P =0.001); indwelling access line in vessel (versus no access line) was associated with lower risk of serious complications (OR, 0.4; P =0.05). Thrombosis was associated with longer intensive care unit (+10.0 days; P <0.001) and hospital stay (+15.2 days; P <0.001); higher odds of cardiac arrest (OR, 4.9; P <0.001), catheter reintervention (OR, 3.3; P =0.002), and reoperation (OR, 2.5; P =0.003); and increased mortality (OR, 5.1; P <0.001). Long-term outcome assessment was possible for 316 thrombi in 129 patients. Of those, 197 (62%) had resolved at the last follow-up. Factors associated with increased odds of thrombus resolution were location (intrathoracic, 75%; extrathoracic arterial, 89%; extrathoracic venous, 60%; P <0.001), nonocclusive thrombi (OR, 2.2; P =0.01), older age at surgery (OR, 1.2 per year; P =0.04), higher white blood cell count (OR, 1.1/10 9 cells per 1 mL; P =0.002), and lower fibrinogen (OR, 1.4/g/L; P =0.02) after surgery. Conclusions— Thrombosis affects a high proportion of children undergoing cardiac surgery and is associated with suboptimal outcomes. Increased awareness and effective prevention and detection strategies are needed.

Incidence of Venous Thromboembolism and Benefits and Risks of Thromboprophylaxis After Cardiac Surgery: A Systematic Review and Meta‐Analysis

“…The majority of the studies were observational studies (n=49), 16 studies were RCTs, and 3 were meta‐analyses (Tables 1 and 2). 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84 Of the 16 RCTs identified,1...…”

Challenges and Priorities for Research

“…In a retrospective study of children undergoing surgery for congenital heart disease, clinically-evident thrombosis was noted in 11%, 53 whereas in single ventricle patients before Fontan, 25% to 40% of patients had clinically-evident thrombosis. 3 In both scenarios, clinically-evident thrombosis was associated with increased morbidity and mortality.…”

“…The identification of certain high-risk cardiac surgery subgroups that are expected to have a prolonged recovery 53 would provide a promising study scenario. Another scenario for clinical trials is the prevention and management of venous and arterial thrombosis related to vascular access associated with infant cardiac catheterization.…”

“…3 In both scenarios, clinically-evident thrombosis was associated with increased morbidity and mortality. 3,53 Hence, recognizing thrombosis immediately and instituting effective treatment is pivotal in preventing thrombosis-related conditions. However, thrombosis care pathways for children are largely based on adaptations of knowledge derived from adults, particularly for treatment modalities, laboratory monitoring, and antithrombotic intensity.…”

Pediatric transplantation: preventing thrombosis

“…The highest mortality period remains the first year post-transplant, most often a result of rejection or infection. It is recognized that clinically significant thrombosis occurs with increased frequency in patients wait-listed for heart transplant; however, the incidence of post-transplant thrombosis has not been well defined [31,32]. In a single-center study, Law et al [31] found a thrombosis prevalence of 12.2% in pediatric patients awaiting heart transplantation despite universal antithrombotic therapy in this population (various individualized regimens).…”