Presentation cardiac troponin and early computed tomography coronary angiography in patients with suspected acute coronary syndrome: a pre-specified secondary analysis of the RAPID-CTCA trial.

AIMS: To evaluate the potential associations between presentation cardiac troponin and the clinical impact of early computed tomography coronary angiography (CTCA) in intermediate-risk patients with suspected acute coronary syndrome. METHODS AND RESULTS: In a large multicentre randomized controlled trial of patients with intermediate-risk chest pain due to suspected acute coronary syndrome, early CTCA had no effect on the primary outcome-death or subsequent Type 1 or 4b myocardial infarction-but reduced the rate of invasive coronary angiography. In this pre-specified secondary analysis, cardiovascular testing and clinical outcomes were compared between those with or without cardiac troponin elevation at presentation. Of 1748 patients, 1004 (57%) had an elevated cardiac troponin concentration and 744 (43%) had a normal concentration. Patients with cardiac troponin elevation had a higher Global Registry of Acute Coronary Events score (132 vs. 91; P < 0.001) and were more likely to have obstructive coronary artery disease (59 vs. 33%; P < 0.001), non-invasive (72 vs. 52%; P < 0.001) and invasive (72 vs. 38%; P < 0.001) testing, coronary revascularization (47 vs. 15%; P < 0.001), and the primary outcome (8 vs. 3%; P = 0.007) at 1 year. However, there was no evidence that presentation cardiac troponin was associated with the relative effects of early CTCA on rates of non-invasive (Pinteraction = 0.33) and invasive (Pinteraction = 0.99) testing, coronary revascularization (Pinteraction = 0.57), or the primary outcome (Pinteraction = 0.41). CONCLUSION: Presentation cardiac troponin had no demonstrable associations between the effects of early CTCA on reductions in non-invasive and invasive testing, or the lack of effect on coronary revascularization or the primary outcome in intermediate-risk patients with suspected acute coronary syndrome.