Microcardia and cardiomegaly screening using postero-anterior chest X-ray (PA CXR) across university students in Ghana - a retrospective study

Background: Microcardia and cardiomegaly are good diagnostic and prognostic tools for several diseases. This study investigated the distribution of microcardia and cardiomegaly among students of the University of Health and Allied Sciences (UHAS) in Ghana to determine the prevalence of microcardia and cardiomegaly across gender, and to evaluate the correlation between the presence of these heart conditions and age.

Methods: This retrospective study involved a review of 4519 postero-anterior (PA) chest X-rays (CXRs) between 2020 and 2023. The CXRs were taken using a digital radiography machine. The CXRs were obtained on PA projection, with the students upright, on arrested inspiration and a source-to-detector distance of 180 cm. Only CXR images with no significant rotation (assessed using the distance between the medial ends of the clavicles and the vertebral spinous processes) and lung abnormalities were included in the study. The transverse cardiac diameter (TCD) and transverse thoracic diameter (TTD) were measured and cardiothoracic ratio (CTR) calculated for each CXR. The CTR was calculated as a ratio of TCD/TTD and categorised as microcardia (CTR < 0.42), normal heart size (0.42 < CTR ≤ 0.50) and cardiomegaly (0.50 < CTR ≤ 0.60). The data was analysed using the Statistical Package for the Social Sciences (SPSS) version 26 and descriptive and inferential statistics were conducted. The Mann-Whitney U Test was conducted to determine statistically significant differences in TCD, TTD and CTR across female and male students. Spearman's rho correlation was conducted to investigate the relationships between age and TCD, TTD and CTR.

Results: The students were aged 15-37 years (mean = 19.60 ± 2.20) with a modal age of 18 years. The study included 2930 (64.84%) females and 1589 (35.16%) males. Most of the students [3384 (74.88%)] had normal heart sizes. However, 647 (14.32%) had microcardia whereas 488 (10.80%) had cardiomegaly. Out of the students suffering from cardiomegaly, 478 (97.95%) and 10 (2.05%) had mild/moderate and severe cardiomegaly respectively. Cardiomegaly was more common among the female students (p < 0.05) and those aged 15-22 years [418 (85.66%)]. There was no correlation between TCD, TTD and CTR and age [ r = 0.01, p = 0.42; r = 0.02, p = 0.17; r = 0.01, p = 0.66, respectively].

Conclusion: The majority of the students had normal heart sizes, but a few had microcardia and cardiomegaly. Cardiomegaly was more common among the female students. The presence of microcardia and cardiomegaly could have health implications for the students and increase their risks of cardiovascular diseases hence these students should be further screened medically for the underlying causes though they may be asymptomatic. Stakeholders in higher education and public health may find this study useful in developing strategies to minimise the prevalence of cardiac diseases and also improve treatment.