Predictors of major adverse cardiac events among patients with chest pain and low HEART score in the emergency department

Aim: For patients who present to the emergency departments (ED) with undifferentiated chest pain, the risk of major adverse cardiac events (MACE) may be underestimated in low-HEART score patients. We aimed to identify characteristics of patients who were classified as low risk by HEART score but subsequently developed MACE at 6 weeks. Methods: We studied a multiethnic cohort of patients who presented with chest pain arousing suspicion of acute coronary syndrome to EDs in the Netherlands and Singapore. Patients were risk-stratified using HEART score and followed up for MACE at 6 weeks. Risk factors of developing MACE despite low HEART scores (scores 0-3) were identified using logistic and Cox regression models. Results: Among 1376 (39.8%) patients with low HEART scores, 63 (4.6%) developed MACE at 6 weeks. More males (53/806, 6.6%) than females (10/570, 2.8%) with low HEART score developed MACE. There was no difference in outcomes between ethnic groups. Among low-HEART score patients with 2 points for history, 21% developed MACE. Among low-HEART score patients with 1 point for troponin, 50% developed MACE, while 100% of those with 2 points for troponin developed MACE. After adjusting for HEART score and potential confounders, male sex was independently associated with increased odds (OR 4.12, 95%CI 2.14-8.78) and hazards (HR 3.93, 95%CI 1.98-7.79) of developing MACE despite low HEART score. Conclusion: Male sex, highly suspicious history and elevated troponin were disproportionately associated with MACE. These characteristics should prompt clinicians to consider further investigation before discharge.