Prevalence, Severity, and Hematological Profile of Anemia in Children with Cyanotic Congenital Heart Disease Presenting with Cyanotic Spells: A Cross-Sectional Study.

Abstract

Background: To determine the prevalence and severity of anemia, characterize the associated hematological profile, and examine its association with recurrent cyanotic spells among children with cyanotic congenital heart disease (CCHD) admitted to a tertiary-care hospital in Pakistan.

Methodology: This observational cross-sectional study included 387 children, from neonates to 12 years, with echocardiographically confirmed CCHD admitted for cyanotic spells at Lady Reading Hospital, Peshawar, Pakistan, from May to October 2025. Data were retrospectively retrieved from the Hospital Management Information System. Anemia was defined as hemoglobin (Hb) <15 g/dL and classified as mild (12–<15 g/dL), moderate (9–<12 g/dL), or severe (<9 g/dL). Demographics, CCHD subtype, hematological indices, and documented cyanotic spells were analyzed.

Results: Mean age was 28.4 ± 22.6 months, and 228 (58.9%) participants were male. Tetralogy of Fallot was the most common lesion (51.2%; n=198). Anemia was present in 58.2% (n=225; 95% CI: 53.2–63.1%), including mild in 35.9%, moderate in 16.0%, and severe in 6.2%. Compared with non-anemic patients, anemic patients had lower MCV (70.2 ± 6.4 vs. 78.5 ± 7.2 fL; p<0.001) and higher RDW (17.8 ± 2.4% vs. 14.2 ± 1.8%; p<0.001), indicating a predominantly microcytic pattern. Recurrent cyanotic spells occurred in 42.2% of anemic versus 31.5% of non-anemic patients (p=0.038; OR=1.59, 95% CI: 1.03–2.46). Among those with severe anemia, 58.3% experienced recurrent spells.

Conclusion: Anemia affected nearly three-fifths of children with CCHD and was associated with a microcytic hematological pattern and greater odds of recurrent cyanotic spells. These findings support routine hematological assessment in CCHD. Prospective studies incorporating ferritin, transferrin saturation, and other iron-status markers are needed to determine the contribution of iron deficiency and its relationship with cyanotic spell burden.