Complications in children with ventricular assist devices: systematic review and meta-analyses

Heart failure is a significant cause of mortality in children with cardiovascular diseases. Treatment of heart failure depends on patients' symptoms, age, and severity of their condition, with heart transplantation required when other treatments are unsuccessful. However, due to lack of fitting donor organs, many patients are left untreated, or their transplant is delayed. In these patients, ventricular assist devices (VADs) are used to bridge to heart transplant. However, VAD support presents various complications in patients. The aim of this study was to compile, review, and analyse the studies reporting risk factors and aetiologies of complications of VAD support in children. Random effect risk ratios (RR) with 95% confidence intervals were calculated to analyse relative risk of thrombosis (RR = 3.53 [1.04, 12.06] I 2 = 0% P = 0.04), neurological problems (RR = 0.95 [0.29, 3.15] I 2 = 53% P = 0.93), infection (RR = 0.31 [0.05, 2.03] I 2 = 86% P = 0.22), bleeding (RR = 2.57 [0.76, 8.66] I 2 = 0% P = 0.13), and mortality (RR = 2.20 [1.36, 3.55] I 2 = 0% P = 0.001) under pulsatile-flow and continuous-flow VAD support, relative risk of mortality (RR = 0.45 [0.15, 1.37] I 2 = 36% P = 0.16) under left VAD and biVAD support, relative risk of thrombosis (RR = 1.72 [0.46, 6.44] I 2 = 0% P = 0.42), infection (RR = 1.77 [0.10, 32.24] I 2 = 46% P = 0.70) and mortality (RR = 0.92 [0.14, 6.28] I 2 = 45% P = 0.93) in children with body surface area < 1.2 m 2 and > 1.2 m 2 under VAD support, relative risk of mortality in children supported with VAD and diagnosed with cardiomyopathy and congenital heart diseases (RR = 1.31 [0.10, 16.61] I 2 = 73% P = 0.84), and cardiomyopathy and myocarditis (RR = 0.91 [0.13, 6.24] I 2 = 58% P = 0.92). Meta-analyses results show that further research is necessary to reduce complications under VAD support.