Value of repeated troponin measurements to improve the safety of the HEART score for chest pain patients at the emergency department

OBJECTIVE: The HEART score is a clinical decision support tool for physicians to stratify the risk of major adverse cardiac events (MACE) in patients presenting with chest pain at the emergency department (ED). The score includes 5 elements, including troponin level. Our aim was to compare safety and efficiency of the HEART scores calculated by using the first representative troponin (i.e. based on time since symptom onset) compared to the original HEART score, where calculation was based on the first available troponin measurement, irrespective of duration of symptoms. METHODS: We performed a secondary analysis on patients from the HEART-Impact trial (2013-2014, the Netherlands). Two HEART scores were calculated for all patients: a HEART score with a T (troponin) element score based on the first available troponin (HEART-first) and one with a T element score based on the first representative troponin (i.e. at least 3 hours after symptom onset; HEART-representative). We compared all patients' scores and risk categories between HEART-first and HEART-representative. Furthermore, we compared safety (proportion of patients with MACE receiving a low score) and efficiency (proportion of patients with a low score) between HEART-first and HEART-representative. RESULTS: We included 1,222 patients. In 882 (72%) patients, the first troponin was representative, resulting in the same HEART-first and HEART-representative score. In the remaining 340 patients the use of HEART-representative led to a different score than HEART-first in 43 patients (3.5%). Out of the 222 patients with MACE, 11 patients (5.0%) received a low score by using HEART-first compared to 10 patients (4.5%) when using HEART-representative (p=0.83). The number of patients with a low score was similar (p=0.93) when using the HEART-first (464/1222; 38%) or HEART-representative score (462/1222; 38%). CONCLUSIONS: Using a representative troponin measurement changed the value of the HEART score in only 3.5% of patients and had no impact on safety and efficiency of the HEART score. These results suggest there is no need to wait for a representative troponin measurement and should encourage physicians to adhere to the original HEART score guidelines.