In this study, we found that 1.3% of adult patients presenting to the EMD-MNH had a primary complaint of non-traumatic chest pain (NTCP). Nearly half of patients were admitted, and mortality was 9.6%, higher than in many high income countries (HICs). Most patients presenting with NTCP were young, while the majority of those admitted were > 50 years. Strengths of this study were that patients were enrolled prospectively and consecutively, with 24-h enrolment during the study period. No admitted patients were lost to follow up and aetiology was based on hospital rather than ED diagnoses. MNH is a referral hospital, and patients are referred to the ED from all over the country.
The frequency of chest pain complaints in our study is lower than that in HICs; studies from EDs in the United states, Europe and United kingdom report that from 2 to 5% of patients present with NTCP [5, 15,16,17]. However, our data are consistent with a study done in Pretoria, South Africa, where 1.66% of patients presented with NTCP .
Our findings are also in contrast to studies done in HICs where the majority of patients presenting to the EMD with NTCP were elderly . In our study, the median age was 45 years. Studies in low and middle income countries (LMICs) have reported a similar age range . This can be partly explained by the differences in etiologies of NTCP, in our study, pulmonary TB was one of the two leading causes of NTCP among those admitted, and patients of any age are at risk, while TB is far less common in HICs. Additionally, hypertension and hypertensive heart disease have an early age of onset in our population, and many patients do not receive timely preventive treatment [19, 20].
Previous studies in LMICs reported that respiratory disease is the leading cause of NTCP presentations to emergency departments . However, in this study, heart failure and PTB were equally common as the primary etiologies, followed by CKD and then ACS. The current study also highlights the prevalence of cardiovascular risk factors and the increasing prominence of cardiovascular causes for NTCP in LMICs [3, 21] If one includes both heart failure and ACS, cardiovascular disease was among the leading causes of non-traumatic chest pain presentation at EMD (25%) higher than the reported 8–18% in the United Kingdom . Although the proportion of patients presenting with NTCP was lower than in other countries, the admission rate was substantially higher than seen in prior studies [14, 15]. This could be partly due to the lack of alternative sites for evaluation for patients who might have cardiac disease.
One quarter of patients were referred from other hospitals; however, only few arrived by an ambulance. The proportion of patients arriving by ambulance is considerably lower than in the study conducted by Knocker et.al in Belgium . But similar to a study in Pakistan where < 3% of such patients arrived by ambulance . This difference likely reflects the deficiency of a well-established ambulance system and pre-hospital care currently in the most LMICs. The lack of a prehospital care system, as well as generally poor access to care, might also contribute to the delayed presentation as evidenced by the median duration of current illness (7 days) and poor outcomes.
Electrocardiography was performed in more than 50% of patients, which is similar to findings in other studies in LMICs . This is far lower than would be considered appropriate in HICs and is likely due to generally low suspicion for cardiac disease. Serial ECGs were very rarely performed in our patients. Many patients were discharged home with a single initial ECG and point of care troponin, despite recommendations to perform seserial ECGs to detect acute coronary syndrome, [4, 21]. Troponin was performed in less than half of patients in this cohort, which is higher than frequency of troponin testing in another LMICs study reported < 5% , but lower than in HICs . Thus it is possible, that a number of the patients who were discharged from the ED also had CVD but were not fully evaluated.
In our study, we found a number of factors that predicted cardiovascular aetiologies that can be used by emergency physicians in our setting to guide evaluation. Most of these risk factors have been found in prior studies. However, heart beat awareness is not usually mentioned in evaluation of chest pain but is a common presentation in our setting. Notably, unlike prior studies, we did not find that males had a higher risk of having cardiovascular disease and thus physicians must be equally alert to chest pain in women as in men .
Overall, mortality rate of patients presenting with NTCP in our cohort was 9.6%, higher than reported study in USA 0.8%  and in LMICs < 1% . Acute coronary syndrome was the most common single cause of death, accounting for nearly 40% of all deaths, which is comparable with a prior study from LMICs (46%)  but higher than HICs (14.9%).(1, 23) The higher mortality rate in our population might also be due to a combination of several factors including delayed presentation (median length of NTCP was 7 days), delayed recognition in the EMD, (particularly of ACS, as only few patients received serial ECG and troponin) or limitations in resources, (as only 2 patients were placed in an ICU).
This was a single centre study, which limits generalizability. The information from patient’s proxy was used when the patient was too sick to remember, the proxy information might not have been as accurate or as complete as if the patient had given it. Diagnosis was based on the hospital treating physician’s diagnosis, rather than adjudicated by a panel of experts. Given the many limitations in our setting for follow-up, we were only able to determine aetiologies for admitted patients and thus the prevalence of serious disease may be higher.