Influence of Timing of Cardiac Computed Tomography on Emergency Department Length of Stay in Acute Chest Pain Investigation

Abstract

Background: Whilst cardiac CT angiography (CCTA) is used in Emergency Departments (ED) for assessing low-to-intermediate risk chest pain, current strategies utilise CCTA following serial troponin measurements. We sought to assess ED length of stay (LOS) of a CCTA-guided strategy where patients had CCTA after a single troponin and compared this to a CCTA-guided strategy whereby patients had CCTA after serial troponin measurements. Methods: We prospectively evaluated 335 consecutive patients who underwent 320-detector CCTA after presenting to ED with low-to-intermediate risk chest pain (TIMI 0-4), normal electrocardiogram and no known coronary disease. Two hundred and three patients underwent CCTA after a single negative troponin (Group 1) and 132 after serial negative troponin (Group 2). Patients in Group 1 without plaque or stenoses on CCTA were immediately discharged, whilst patients with mild or moderate stenoses were discharged after repeat 6-h troponin. Patients with severe stenoses were admitted and excluded from LOS analysis. Results: Mean age of Group 1 vs. Group 2 was 56 ± 12 years (60% male) vs. 59 ± 11 years (58% male) (P = 0.04). Disposition of Group 1 patients was: 65 (32%) discharged after a single troponin, 99 (49%) discharged after repeat troponin and 39 (19%) admitted. Disposition of Group 2 patients was: 116 (88%) had at most moderate stenoses and were discharged after CCTA and 16 (12%) had severe stenoses and were admitted. Mean ED LOS for Group 1 vs. Group 2 was 8.2 ± 0.95 h compared to 16.2 ± 4.4 h (P < 0.001). Conclusion: Considerable reduction in ED LOS is achievable when CCTA is performed after a single negative troponin compared to when CCTA is performed after serial troponin measurements.