Outcomes after ED visit for acute Chest Pain, with respect to negative but measurable troponin levels and CRP levels

Abstract

While chest pain is one of the most common chief complaints in the ED, the majority are discharged for ambulatory care. We explored outcomes of patients who presented to the ED with chest pain as chief compliant, and assessed whether an association exists with negative (but measurable) troponin levels or elevated CRP levels. The primary outcome was a percutaneous intervention (PCI) within 90 days from ED visit, and the secondary outcomes were 7-day revisit, 14-day ward admission, and 30-day mortality. Of 32,170 patients who presented with chest pain to the ED during the 5-year study period, 23,442 (73%) were discharged from the ED and 8,720 were admitted. Among the discharged 14,477 (61.8%) had very-low troponin, of whom only 70 (0.5%) had PCI withing 90 days, compared with 1.9% in patients with negative but measurable troponin levels (n = 169, p < 0.0001). All the secondary outcomes were higher among patients with negative but measurable troponin compared to very-low troponin: 7-days ED revisit rates were 5.3% compared with 3.3% respectively (p < 0.0001), 14-days admission rates were 3.2% and 0.9% respectively (p < 0.0001) and mortality rates were 0.3% compared to 0.01% (p < 0.0001). Troponin levels ≥ 3.5 ng/L were associated with 90-day PCI (aOR 2.0, [95% CI: 1.5–2.7], p < 0.001). An elevated CRP level was an independent protective factor against 90-day PCI (aOR 0.98, p = 0.03), but was associated with all the other outcomes. While nearly 3/4 of ED chest pain visits can be discharge safely, measurable troponin levels may suggest the need for imminent coronary intervention.