A low (0–3) History, Electrocardiogram, Age, Risk factors and Troponin (HEART) score reliably identifies ED chest pain patients who are low risk for near-term major adverse cardiac events (MACE). To optimize sensitivity, many clinicians employ a modified HEART score by repeating troponin measurements and excluding patients with abnormal troponin values or ischemic electrocardiograms (ECGs). The residual MACE risk among patients with otherwise non-low (≥4) modified HEART scores is thus likely much lower than with non-low original HEART scores.

To explore residual 60-day MACE risks among patients with non-low modified HEART scores.

Secondary analysis of a retrospective cohort of ED patients presenting with chest pain to an integrated healthcare system between 2013 and 2015. Patients with serial troponin measurements within 6 h of ED arrival were considered for inclusion. Exclusions included an ischemic ECG, troponin values above the 99th percentile or a lack of continuous health plan coverage through the 60-day follow-up period. MACE was defined as a composite of myocardial infarction, cardiac arrest, cardiogenic shock or death.

There were 22,976 study eligible patients encounters, 13,521 (59%) of which had non-low (≥4) modified HEART scores. The observed 60-day MACE risk among non-low HEART score patients was 2.0% (95% CI 1.8–2.3). When including all coronary revascularizations (MACE-R), the risk was 4.4% (95% CI 4.1–4.4).

Risk of near-term MACE among patients with non-low modified HEART scores (excluding those with abnormal troponin or ischemic ECGs) appears to be much lower than in the original HEART score validation studies.