Acute myocardial infarction under-diagnosis and mortality in a Tanzanian emergency department: A prospective observational study

Abstract

Background: Growing evidence suggests that under-diagnosis of acute myocardial infarction (AMI) may be common in sub-Saharan Africa. Prospective studies of routine AMI screening among patients presenting to emergency departments in sub-Saharan Africa are lacking. Our objective was to determine the prevalence of AMI among patients in a Tanzanian emergency department.

Methods: In a prospective observational study, consecutive adult patients presenting with chest pain or shortness of breath to a referral hospital emergency department in northern Tanzania were enrolled. Electrocardiogram (ECG) and troponin testing were performed for all participants to diagnose AMI types according to the Fourth Universal Definition. All ECGs were interpreted by two independent physician judges. ECGs suggesting ST-elevation myocardial infarction (STEMI) were further reviewed by additional judges. Mortality was assessed 30 days following enrollment.

Results: Of 681 enrolled participants, 152 (22.3%) had AMI, including 61 STEMIs and 91 non-STEMIS (NSTEMIs). Of AMI patients, 91 (59.9%) were male, mean (SD) age was 61.2 (18.5) years, and mean (SD) duration of symptoms prior to presentation was 6.6 (12.2) days. In the emergency department, 35 (23.0%) AMI patients received aspirin and none received thrombolytics. Of 150 (98.7%) AMI patients completing 30-day follow-up, 65 (43.3%) had died.

Conclusions: In a northern Tanzanian emergency department, AMI is common, rarely treated with evidence-based therapies, and associated with high mortality. Interventions are needed to improve AMI diagnosis, care, and outcomes.

Figure 1.

Flow of study participants from screening through 30-day follow-up.

Figure 2.

Diagnoses of adult patients presenting to the KCMC emergency department with chest pain or shortness of breath, 2018–2019. Panel A: The proportion of patients found to have STEMI, NSTEMI, acute ischemic ECG findings, and ECG evidence of prior infarct when all patients underwent AMI testing in 2019 (N=681). Panel B: The proportion of patients who were diagnosed with AMI in 2018 when AMI testing was driven by physician discretion, as previously reported (N=339).

Figure 3.

All-cause thirty-day mortality among adults presenting to the emergency department with chest pain or shortness of breath, northern Tanzania, 2019 (N=669)