5597164 BURDEN AND RISK FACTOR TO ACUTE MYOCARDIAL ISCHAEMIA IN CHILDREN WITH SICKLE CELL ANAEMIA

Abstract

Introduction: Sickle cell anaemia (SCA) is a genetic disorder of haemoglobin synthesis with multi-organ manifestations. Myocardial ischaemia (MI) and infarction as a result of sickling are not commonly reported, often overshadowed by the more dramatic presentation of musculoskeletal pain. Studies have postulated that sudden deaths during vaso-occlusive crisis (VOC) may be secondary to the arrhythmogenic effect of severe MI. Aim: This study compared the prevalence of MI and associated risk factor in children with SCA aged 6 months to 18 years in VOC and steady state at the Lagos University Teaching Hospital using both cardiac troponin T (cTnT) and electrocardiography (ECG) as recommended by the fourth universal definition of MI (2018). Methodology: A cross-sectional comparative study conducted over 10months (March and December 2019). The participants were 250 children (125 age and gender-matched children with SCA in VOC and steady state respectively). Informed consent was obtained from the parents or caregivers while assent was obtained from children 10 years and above. Socio-demographic data and relevant history were obtained using an interviewer-administered questionnaire. Targeted clinical examination with focus on the cardiovascular system was done. All study participants had ECG performed and blood samples taken for cTnT, full blood count, electrolyte, urea, and creatinine. Myocardial ischaemia was defined as cTnT level greater than 100ng/L which is the 99th percentile and abnormal ECG findings indicative of MI (wide Q wave, ST-segment elevation or prolonged QT interval corrected for heart rate with accompanying Q wave abnormalities). Statistical package for social sciences (SPSS) software version 20 was used for analysis, statistical association was declared significant if the p-value was <0.05. Results: The prevalence of MI using cTnT alone in children with SCA in VOC and steady state was 42.4% (53) and 23.2% (29) respectively while with ECG alone, the prevalence of MI in children with SCA in VOC and steady state was 40.8% (51) and 20.8% (26) respectively. The prevalence of MI using both cTnT and ECG in children with SCA in VOC and steady state was 38.4% and 20% respectively and this was statistically significant (p-valve 0.001). In relation to VOC, the mean age (10.0±4.1), mean WBC (20,131.2±7,268.0), mean platelet count (461,208.0±143,956.8) and pain score of children with MI was significantly higher compared to those without MI. Among the steady state children, higher mean age (11.6±3.5), lower mean PCV (22.3±3.7) and higher mean platelet count (446,240.0±140,841.0) was significant in children in steady state with MI compared to those without MI. Furthermore, on multivariate analysis, the mean age & mean platelet count; mean age & low PCV; were significantly associated with MI in children with VOC and steady state respectively. The older age group in both study participants had a higher prevalence of MI. Combining both cTnT and ECG in the diagnosis of MI gave similar prevalence compared to using either cTnT or ECG alone. Conclusion: Myocardial ischaemia (MI) is prevalent in children with SCA. Children with SCA should routinely be screened for MI during VOC and steady state especially adolescents with SCA for early intervention.