When history matters: the impact of prior coronary artery disease on chest pain evaluation and management in a brazilian cardiology center

In patients with known coronary artery disease (CAD), recurrent chest pain remains a diagnostic challenge due to overlapping chronic and acute ischemic patterns. The presence of prior CAD may modify risk profiles and influence biomarker interpretation, impacting risk assessment and treatment strategies in the emergency setting.

To evaluate the epidemiological characteristics, diagnostic classification, and management of chest pain patients according to prior CAD status in a tertiary cardiology emergency department (ED).

In this prospective cohort, 681 consecutive patients presenting with chest pain were evaluated at a tertiary cardiology hospital in Brazil. Participants were stratified according to known CAD (n = 433) or no CAD (n = 248). Demographics, cardiovascular risk factors, medication use, and 30-day outcomes (death, myocardial infarction, or revascularization) were assessed. Diagnostic classification followed the Rule-in/Rule-out protocol using high-sensitivity troponin I (hs-TnI) VITROS® assay performed at admission (0 h) and after 1 h.

Patients were classified as Rule-out when baseline hs-TnI values were below the 99th-percentile upper reference limit and the 1-h delta was below the analytical thresholds defined by the kit, and as Rule-in when hs-TnI exceeded high-risk thresholds or exhibited a significant 1-h delta, consistent with acute myocardial injury.

Comparisons used t-test, Mann–Whitney, or Chi-square tests. Logistic regression models adjusted for age and sex evaluated associations between prior CAD and 30-day outcomes.

Mean age was 64.2 ± 11 years; 63% were male. Patients with prior CAD were older (65.1 ± 10.2 vs 62.7 ± 12.3 years, p = 0.008), more often male (67% vs 56%, p = 0.007), and had more hypertension (90% vs 75%) and dyslipidemia (84% vs 49%). Statin (88% vs 47%) and beta-blocker (82% vs 42%) use were significantly higher among CAD patients (all p < 0.001).

Among rule-out patients, prior CAD was not associated with increased 30-day composite events (OR 1.17, 95% CI 0.82–1.65). In contrast, within the rule-in subgroup, those with prior CAD were significantly less likely to undergo revascularization (PCI or CABG) (OR 0.26, 95% CI 0.09–0.68; p = 0.008).

At 30 days, overall event rates were: death 1.8%, PCI 26%, myocardial infarction 27%, and composite outcome 48%.

Chest-pain patients with prior CAD present a distinct clinical and therapeutic profile, marked by a greater comorbidity burden and more frequent use of cardioprotective therapy. Despite comparable troponin dynamics, these patients underwent revascularization less often, suggesting a more conservative management approach possibly related to prior interventions or clinical bias. Incorporating prior CAD status into troponin-based rapid-assessment pathways may improve early risk stratification and guide individualized care in cardiology emergency settings.