Polycythemia and its determinants among children with unoperated cyanotic congenital heart disease at Tikur Anbessa specialized hospital, Ethiopia: observational cross-sectional study.

BACKGROUND

Polycythemia is a physiologic adaptive response to hypoxia seen in children with cyanotic congenital heart disease (Cyanotic CHD). Globally, due to timely cyanotic CHD interventions, polycythemia is underreported or understudied. Timely identification and treatment of polycythemia among unoperated cyanotic CHDs avoids serious hematologic and related complications. This study aimed to determine the burden and factors associated with polycythemia among patients with cyanotic CHD enrolled in chronic care.

METHODS

This observational cross-sectional study used a semi-structured questionnaire to collect relevant sociodemographic and clinical data. Children with cyanotic CHD aged 1 month to 18 years were included. Polycythemia was considered when the hemoglobin was ≥ 17 g/dl on the complete blood count report of an automated hematology analyzer. Bivariate and multivariable binary logistic regression models were used to identify associated variables.

RESULTS

In this study, 384 patients with cyanotic CHD were included, 55.2% males. The median age of study participants was 42 months (Interquartile range/IQR: 20.3-91.5). The median altitude of residence and age at cyanotic CHD diagnosis were 2355 m (IQR: 1826-2470) and 4 months (IQR: 1-12), respectively. Polycythemia was documented in 38% (146) [95% CI: 33.1-43.1] of participants. Males had almost doubled odds of polycythemia, aOR = 1.66 (95% CI: 1.01-2.70). Children with oxygen saturation < 70 and 70-90 had almost tripled odds of polycythemia, aOR 2.71 (95% CI: 1.25-5.88) and aOR 2.79 (1.46-5.33), respectively. Moreover, children with tricuspid atresia had tripled odds of polycythemia, aOR 3.20 (95% CI: 1.19-8.55). Additionally, children who had no phlebotomies in the last six months had reduced odds of polycythemia, aOR 0.07(0.02-0.22).

CONCLUSION

The burden of polycythemia among patients with cyanotic CHD is huge. Male sex, saturation level, diagnosis of tricuspid atresia and phlebotomy frequency were associated with polycythemia among patients with cyanotic CHD. Males with cyanotic heart disease, children with tricuspid atresia, and cyanotic CHDs with saturation of oxygen below ninety should receive targeted screening for polycythemia during chronic follow-up.