Assessment of Combined Left ventricular Function by Myocardial Performance Index in Children with Sickle Cell Anaemia in Steady State at a Nigerian Tertiary Hospital: A Comparative Study

Abstract

Background: Children with sickle cell anaemia (SCA) are at risk of early cardiac dysfunction due to chronic anaemia and volume overload. Conventional echocardiographic indices may underestimate myocardial impairment, as they are load-dependent. The myocardial performance index (MPI) provides a relatively load-independent assessment of combined ventricular function.

Objective: To assess combined (systolic and diastolic) left ventricular (LV) function using MPI in children with SCA in steady state and compare findings with age- and sex-matched controls.

Methods: This comparative cross-sectional study involved 340 children with SCA in steady state and 340 HbAA controls aged 2–15 years at Usmanu Danfodiyo University Teaching Hospital, Sokoto. All participants underwent clinical evaluation and transthoracic echocardiography. LV MPI was calculated as (IVCT + IVRT)/ET. Conventional systolic and diastolic indices were also assessed. Data were analysed using SPSS version 23. Statistical significance was set at p < 0.05.

Results: The mean LV MPI was significantly higher in subjects than controls (0.52 ± 0.20 vs 0.48 ± 0.10; p = 0.002). A higher proportion of subjects had combined LV dysfunction using MPI (65.6%) compared with EF (15.0%) and FS (23.8%). MPI showed a moderate positive correlation with IVRT (r = 0.652; p < 0.001) and weak negative correlations with EF, DT, and E/A ratio.

Conclusion: Children with SCA in steady state exhibit significant combined LV dysfunction detectable by MPI despite relatively preserved conventional systolic indices. MPI is a sensitive tool for early identification of myocardial dysfunction and should be incorporated into routine cardiac evaluation of children with SCA.

Keywords: Sickle cell anaemia; Myocardial performance index; Left ventricular function.