What is the clinical evidence from this study?

Study design: Observational. Population: Acute Coronary Syndrome (n=2185). Intervention: Symptom clusters (e.g., anginal, pleuritic, numbness, infectious). Primary outcome: Acute myocardial infarction (AMI) (RR 1.46, 95% CI 1.31-1.62).

What does this research mean for the field?

Symptom cluster patterns predictive of acute myocardial infarction are comparable between Aboriginal and Torres Strait Islander and non-Indigenous Australians, though no single symptom cluster provides sufficient discriminatory power to independently rule in or rule out the condition. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

June 1, 2026Open Access

Identifying Symptom Clusters Predictive of Acute Myocardial Infarction for Aboriginal and Torres Strait Islander and Non‐Indigenous Australians

Key Result

The anginal symptom cluster was most strongly associated with acute myocardial infarction (RR 1.46; 95% CI 1.31-1.62), but no cluster provided sufficient discriminatory power to rule in or out AMI.

Study Design

Type

Observational (n=2,185)

Structured PICO

Do specific symptom clusters predict acute myocardial infarction in patients investigated for ACS, and do these patterns differ between Aboriginal and Torres Strait Islander and non-Indigenous Australians?

Population

2,185 patients investigated for Acute Coronary Syndrome, including 22.7% who identified as Aboriginal and Torres Strait Islander.

Exposure

Symptom clusters (pleuritic, numbness, anginal, palpitations, epigastric, and infectious)

Outcome

Acute myocardial infarction (AMI)hard clinical

Symptom presentation in AMI is heterogeneous, and reliance on classic symptoms alone is insufficient to rule in or rule out AMI, with similar predictive performance across Indigenous and non-Indigenous Australians.

Main Result

Relative Risk: 1.46 (95% CI 1.31–1.62)

Abstract

OBJECTIVES: This study examines the symptoms experienced by patients investigated for Acute Coronary Syndrome (ACS). It aims to determine whether symptom clusters exist, whether these predict acute myocardial infarction (AMI), and whether symptom patterns differ between Aboriginal and Torres Strait Islander people and non-Indigenous Australians. METHODS: This analysis of the LEGEND trial included 2185 patients (22.7% of whom identified as Aboriginal and Torres Strait Islander). Data on presenting symptoms and outcomes were collected from patient medical records. Regression analyses examined whether individual symptoms predicted AMI for Aboriginal and Torres Strait Islander and non-Indigenous patients. Factor analysis identified symptom clusters. Regression analyses estimated the associations between each symptom cluster and AMI. RESULTS: Six symptom clusters were identified: pleuritic, numbness, anginal, palpitations, epigastric, and infectious. Anginal was most strongly associated with AMI (Risk ratio RR = 1.46; 95% CI: 1.31-1.62), while pleuritic was linked to a reduced risk (RR = 0.47; 95% CI: 0.35-0.62). Numbness (RR = 1.29; 95% CI: 1.11-1.49) and infectious (RR = 1.21; 95% CI: 1.05-1.41) were associated with an increased AMI risk. There were individual symptoms that differed for Aboriginal and Torres Strait Islander patients. However, cluster-level predictive performance was similar across groups. No symptom cluster provided sufficient discriminatory power to rule in or rule out AMI. CONCLUSIONS: Symptom presentation in AMI is heterogeneous, and reliance on "classic" symptoms alone may miss at-risk patients. While some differences in individual symptom associations were observed for Aboriginal and Torres Strait Islander patients, overall cluster patterns were comparable.