Delayed diagnosis of congenital heart diseases and associated factors in the largest tertiary hospital in Ethiopia

Introduction

Congenital heart disease (CHD), as proposed by Mitchell et al., is “a gross structural abnormality of the heart or intrathoracic great vessels that is actually or potentially of functional significance” (1). CHD accounts for nearly one-third of all congenital birth defects worldwide. However, these numbers vary greatly depending on geographic location, genetic background and the study methodologies implemented. In general, 8 per 1,000 live births is accepted as the best estimate of the incidence of CHDs (2). Twenty-eight percent of all major congenital anomalies are heart defects (3). Among all CHDs, critical congenital heart defects (CCHDs) are present in nearly 25% of cases (4). There are different schemes for classifying CHDs. Some cases are classified as simple defects, moderate complexity and complex lesions (5). Others classify depending on hemodynamic significance as significant or insignificant (6). The emphasis on earlier detection and management of CHD is integral to eliminating preventable child deaths and attaining Sustainable Development goals (7).

In Africa, 500,000 live newborns are born each year with CHDs (8). Sub-Saharan African countries contribute a larger portion of these numbers. The vast majority of these children receive suboptimal or no care at all (9). Ninety percent of these CHD-affected children reportedly lack access to high-quality healthcare (8). A third of newborns with moderate to severe CHD will not survive past the neonatal period if they are not given the appropriate treatment. Without interventions, nearly half of these patients die in early infancy (7). Without comprehensive care, survivors beyond infancy suffer from different complications (10).

Approximately 50% of all CHDs do not warrant interventions other than follow-up or simple medications. The remaining 50% of patients require timely surgical or transcatheter intervention to cure or achieve palliation (11). Delayed diagnosis of CHDs is common in low- and medium-income countries (12). A study by Rashid et al. demonstrated that the rate of delayed CHD diagnosis in low- and middle-income countries is 85.1% (13). Late presentation of CHD is more common in Africa (8,14). In contrast, the proportion of patients with delayed diagnoses in high-income countries was reported to be as low as 8.9% (15).

CHD treatment has been one of modern medicine’s greatest success stories in centers with comprehensive cardiac treatment facilities (16). In high-income countries, 85% of all children with CHD survive to adulthood. With appropriate care, 90% of children with complex CHD, such as tetralogy of Fallot or neonatal coarctation, and nearly 95% of children with simple CHD lesions, such as ventricular septal defects, survive to adulthood. Currently, approximately 80% of children with complex CHD, such as those with transposition of the great arteries or truncus arteriosus, survive to adulthood in high-income countries (17).

Despite the 34.5% reduction in global CHD mortality during the past decade, Africa’s CHD deaths have increased. This is attributed to poverty and limited care centers with appropriate treatment (8). In sub-Saharan African countries, there has been an increase in childhood mortality attributable to CHD, except in southern sub-Saharan Africa (18).

Prenatal CHD diagnosis has been made possible by technological advancements in diagnostic imaging. In a retrospective study conducted in Beijing, China, the majority (91.41%) of CHDs were identified through prenatal diagnosis. The remaining patients were diagnosed either before obstetric discharge/transfer (5.62%) or later through delayed diagnosis (2.97%) (19). Data concerning children with delayed CHD diagnosis in Ethiopia are lacking. Specifically, the magnitude of CHDs among cardiovascular diseases has also not been studied. However, there is a high burden of CHD cases in Tikur Anbessa Specialized Hospital (TASH), which is likely associated with delayed presentation and late diagnosis. Accordingly, this study aimed to determine the magnitude of delayed diagnosis of CHDs and its associated factors. We present this article in accordance with the STROBE reporting checklist (available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-186/rc).

Methods

Study setting

The study was conducted at TASH, Department of Pediatrics and Child Health (PCH), from June 1 to October 30, 2023. The department has an emergency outpatient department (EOPD), a regular outpatient department (OPD), a follow-up clinic, inpatient wards, and an intensive care unit. TASH is the largest referral teaching hospital located in the capital city of the country, Ethiopia. It is the only government-owned hospital where pediatric cardiac surgery is being performed. Pediatric cardiac patients are referred from all corners of the country. Any pediatric patients suspected of having CHD with referral slips from any nearby governmental health facility are accepted. A suspected CHD patient is a patient whose clinical clue and echocardiography are performed by a radiologist, an adult cardiologist, or a non-staff pediatric cardiologist. An appropriate diagnosis of CHD is usually made after referral to the hospital. The pediatric cardiology unit is staffed with consultant pediatric cardiologists, pediatric cardiology fellows, and trained nurses. Pediatric residents and medical interns are assigned on a rotation basis. The unit offers inpatient and outpatient care, diagnostic tests, and mission-based interventional and cardiac surgeries. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by Department of Pediatric and Child Health, College of Health Sciences, Addis Ababa University (protocol No. REC-006/15) and informed verbal consent was obtained from all individual participants. The participants were notified that they had the right to refuse or withdraw from the study at any time, with no effect on their routine care. Study participants were encouraged to ask questions, and clarification was provided. Privacy and confidentiality were maintained by avoiding the use of identifiers and restricting data access.

Study design and population

A cross-sectional study design was employed. The study population included pediatric patients suspected of having structural CHD, who were confirmed by a staff pediatric cardiologist. Structural CHDs are defined by any structural abnormalities of the heart chambers or great arteries, excluding myocardial diseases. Direct caregivers to the children were approached. If the age of the child was 12 years or above, assent was obtained.

Inclusion & exclusion criteria

All children aged less than or equal to 18 years of age who were diagnosed with structural CHD and who visited a cardiac follow-up clinic were included. Children with secundum atrial septal defects (ASDs) less than 5 mm (20), patent ductus arteriosus (PDA) <2 mm in size (6), and PDA diagnosed in infants less than 3 months of age were excluded from the study. In this study, delayed diagnosis was defined in the following ways.

Sample size

The sample size was determined via the following assumption. To determine the magnitude of delayed diagnosis, a single proportion formula was used with a confidence interval (CI) of 95%, a proportion of delay to first diagnosis of 85% (13) and resulting in a sample size of 195. To assess the factors associated with delayed diagnosis, a double population formula was used. Considering residence [odds ratio (OR) =2.08] (12), 50.3% of the participants were unexposed, 69.8% were exposed, and the power 80% resulting in a sample size of 218. While considering cyanotic heart disease (OR =4.16), a total of 7% of the samples were unexposed, 26.9% were exposed and the power 80% (12), the sample size became 130. The largest calculated sample size [218] was selected. A 5% non-response rate was added, resulting in a final total sample size of 228.

Data collection

A structured interview-based questionnaire and record review using a checklist were used to collect data. The questionnaire and the checklist included socio-demographic and socio-economic characteristics (age, sex, residency, family’s occupational status, educational status and income), perinatal history, clinical characteristics and types of CHDs (acyanotic CHDs, cyanotic CHDs). A consecutive sampling method was employed to recruit study participants. Data collection was performed at the pediatric cardiac follow-up clinic by trained health care workers after obtaining verbal consent. Study participants fulfilling the inclusion criteria were included consecutively until the required sample size was reached. The data were collected online via the http://www.kobotoolbox.org/ software tool by the data collection form https://kf.kobotoolbox.org/#/forms/aQx4nzeMYou3oEL9SqoyVf.

In cyanotic heart diagnosis, newborns discharged from their birth clinic or hospital without a CHD diagnosis are labeled delayed diagnosis of CHD (21), whereas in an acyanotic heart diagnosis, delayed diagnosis is defined when immediate treatment, intervention, or cardiac surgery should have already been performed according to contemporary standards of pediatric cardiology (15,20,21). Procedurally, in acyanotic CHDs, a delayed diagnosis was assigned if the time passed according to the definition. If the referral was performed within a reasonable time, clinical or echocardiographic conditions were considered for the assignment.

Statistical analysis

The data from the KoboToolbox software were exported to SPSS version 29 for analysis. Initially, data exploration was performed for data clearing, ensuring that the underlying assumptions of the statistical analyses were satisfied. Descriptive statistics were used to examine participants’ sociodemographic, socioeconomic, and clinical characteristics. The Chi-square test was used to assess the relationships between independent and dependent variables. Binary and multivariate logistic regression analyses were used to assess associations between variables. A binary logistic regression model was fitted for each explanatory variable. If P value is ≤0.25 in the binary regression, it is considered significant and included in the multivariate analysis. Confidence levels at the 95% CI were used, and statistical significance was considered at P<0.05. Tables were employed to present the results.

Results

Sociodemographic and clinical characteristics

A total of 228 study participants were recruited. Among these, 63.6% were female. Most of the study participants (62.3%) were from Addis Ababa. The maternal age at delivery was less than 35 years in 56.6% of the patients. More than three-fourths of the parents had at least one formal school (Table 1).

Nearly all the mothers reported at least one antenatal care (ANC) follow-up visit, with the majority having more than four visits. An obstetric ultrasound was performed for most patients. Larger proportions of deliveries were at government hospitals, which were attended largely by nurses, midwives, or health officers (Table 2).

Most of the patients referred to the cardiac clinic were from public hospitals. Nearly one-third of patients have clinical syndromes, mainly Down Syndrome. By the time of diagnosis, 67.5% (n=154) had at least one symptom that might suggest cardiac illness. Fast breathing, breast feeding interruption and poor growth were the most common symptoms. Almost half of the study participants had a history of admission to a health care facility. Pneumonia was the most common reason for hospital admission. The percentage of first-degree families with a history of CHD was reported to be 6.6% (Table 3).

Nearly 80% of the study participants had acyanotic heart diseases. Isolated VSD is the most common CHD, with a frequency of 25.8% and an additional 10.5% in combination with other shunt lesions. Nearly half of cyanotic CHDs are tetralogy of Fallot (ToF) cases. It constitutes 9.6% of the overall CHDs. The other complex lesions combined account for 11% of all CHDs. The prevalence of obstructive CHD is 8.8%. Generally, septal defects constitute approximately 70% of all CHDs (Table 4).

The median age at diagnosis for all CHD patients was 7 months, with an interquartile range (IQR) of 1.5–24 months. The median age at diagnosis for acute CHD was 6 months (IQR, 1.5–24 months), whereas the median age at diagnosis for cyanotic CHD was 9 months (IQR, 1.5–29 months) (Table 4).

Proportion of patients with delayed diagnosis

Overall, more than half of the study participants (53.1%) had delayed diagnosis. The proportion of patients with delayed diagnoses among those with acyanotic CHDs was 45.4%. The majority of patients (83%) with cyanotic CHDs had delayed diagnoses. Among shunt lesions, atrioventricular septal defect (AVSD) is the most common (60.7%) heart defect with delayed diagnosis, followed by PDA (54.05%). Among the patients with cyanotic CHDs, 90.91% of the ToF patients were diagnosed late. For the remaining cyanotic CHD patients, the prevalence of delayed diagnosis was 76% (Table 5).

Factors affecting delayed diagnosis

The number of ANC visits, obstetric ultrasound, mode of delivery, birth attendants, place of delivery, CHD type, shunt size and degree of pulmonary hypertension (PHTN) were found to be associated with delayed CHD diagnosis. Fewer than four ANC visits increased the likelihood of delayed CHD diagnosis [adjusted odds ratio (AOR) 2.34, 95% CI: 1.05–5.25; P=0.04]. The probability of a delayed diagnosis of CHD was 4.47 times greater in children whose mothers did not have an ultrasound performed during pregnancy (AOR 4.47, 95% CI: 1.29–17.59; P=0.02). Patients who were delivered by nonphysicians were at increased risk of delayed diagnosis (AOR 2.79, 95% CI: 1.49–5.19; P<0.001). There was a significant delay in the diagnosis of cyanotic lesions compared with that of acyanotic lesions (AOR 6.84, 95% CI: 2.86–16.34; P<0.001) (Table 6).

Discussion

The magnitude of overall delayed diagnosis in this study was 53.1%. This percentage is higher than that reported by Massin and Dessy in Belgium, which was 10% (15). However, this rate is lower than that reported in a study performed in Pakistan, which reported that the rate of delayed diagnosis among CHD patients was 85.1% (13). This magnitude varies depending on the socioeconomic status of a country with a prevalence as low as 10% (15) in high-income countries, and delay is more common than an exception in Africa (14).

In our study, delayed diagnosis was more common in cyanotic heart disease patients (84.4%) than in acyanotic heart disease patients (45.4%). This is in line with the studies of Murni et al. and Massin and Dessy (12,15). However, other studies have demonstrated that patients with acyanotic heart diseases are more likely to be diagnosed late (13,21). These studies hypothesized that cyanosis could be obvious to families and help them seek medical advice. However, the contemporary definition of delay in cyanotic heart diseases is stricter and could be the reason for the greater prevalence of delays in our study. These assumptions also hold true in our findings. The median age at presentation of cyanotic CHDs is 9 months, whereas it is 6 months for acyanotic CHDs. Our proposed explanations are as follows. First, the majority of cases are seen by lower health professionals, including nurses, where cyanosis might be missed. Second, most of our cyanotic cases were ToF or ToF physiology, where acute presentation is less common and survival beyond infancy is prevalent. Third, more critical cyanotic patients might have died early before referral.

In addition to the type of congenital heart lesions, children whose mothers had fewer than four ANC visits were at increased risk of being diagnosed late. Nonsyndromic patients were not found to be delayed in comparison to those with clinical syndromes in our study. This is in contrast to the study by Murni et al., where nonsyndromic patient diagnosis was delayed by 1.7-fold (12). Family income, gestational age at delivery and parental education were not found to be predictors of delayed diagnosis, unlike studies in other parts of the world (12,13,22,23). In our study, the prevalence of preterm delivery was less than 5%, which could explain the absence of a significant association.

Children born to mothers whose deliveries were attended by nonphysicians were also diagnosed later than those whose deliveries were attended by physicians. Mothers who underwent obstetric ultrasonography (US) were associated with a decreased risk of their children being diagnosed late with CHD. However, none of the obstetric ultrasound studies reported any CHD. The significant relationships between delayed diagnosis and frequent ANC visits, obstetric US examinations and physician attendance may be explained simply by the better health-seeking behavior of the family. In addition, awareness of CHD among health workers is critical for the early detection of CHD. Healthcare workers stationed at health centers in Ethiopia’s context are fewer health professionals, usually nurses. Availing appropriate physicians and equipping them with knowledge, tools, and referral pathways can result in the timely detection of children with CHD, especially in underserved regions.

Limitations of the study

This study is limited in that it was conducted at a single center, although the center is the largest referral hospital in the country.

Conclusions

In conclusion, the magnitude of delayed diagnosis of CHD was unacceptably high (53.1%). The factors associated with delayed diagnosis were ANC visits, obstetric ultrasound, place of delivery, type of birth attendant and type of CHD. To prevent the delayed diagnosis of CHDs, improving ANC, increasing healthcare workers’ awareness and performing perinatal screening are recommended.

Acknowledgments

We are grateful to Addis Ababa University College of Health Science School of Medicine and the Department of PCH for providing the opportunity to conduct this research project. We also thank all the data collectors who participated in the data collection. The manuscript of this work was submitted to the repository of the Addis Ababa University (AAU). AAU college of health science requires submission of original research document after completion of the study.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-186/rc

Data Sharing Statement: Available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-186/dss

Peer Review File: Available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-186/prf

Funding: This study was funded by Addis Ababa University (protocol No. REC-006/15).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-186/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by Department of Pediatric and Child Health, College of Health Sciences, Addis Ababa University (protocol No. REC-006/15) and informed verbal consent was obtained from all individual participants.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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