Early computed tomography coronary angiography in patients with suspected acute coronary syndrome: randomised controlled trial

Abstract

Objectives: To establish if the use of early computed tomography (CT) coronary angiography improves one year clinical outcomes in patients presenting to the emergency department with acute chest pain and at intermediate risk of acute coronary syndrome and subsequent clinical events.

Design: Randomised controlled trial.

Setting: 37 hospitals in the UK.

Participants: Adults with suspected or a provisional diagnosis of acute coronary syndrome and one or more of previous coronary heart disease, raised levels of cardiac troponin, or abnormal electrocardiogram.

Interventions: Early CT coronary angiography and standard of care compared with standard of care only.

Main outcome measures: Primary endpoint was all cause death or subsequent type 1 or 4b myocardial infarction at one year.

Results: Between 23 March 2015 and 27 June 2019, 1748 participants (mean age 62 years (standard deviation 13), 64% men, mean global registry of acute coronary events (GRACE) score 115 (standard deviation 35)) were randomised to receive early CT coronary angiography (n=877) or standard of care only (n=871). Median time from randomisation to CT coronary angiography was 4.2 (interquartile range 1.6-21.6) hours. The primary endpoint occurred in 51 (5.8%) participants randomised to CT coronary angiography and 53 (6.1%) participants who received standard of care only (adjusted hazard ratio 0.91 (95% confidence interval 0.62 to 1.35), P=0.65). Invasive coronary angiography was performed in 474 (54.0%) participants randomised to CT coronary angiography and 530 (60.8%) participants who received standard of care only (adjusted hazard ratio 0.81 (0.72 to 0.92), P=0.001). There were no overall differences in coronary revascularisation, use of drug treatment for acute coronary syndrome, or subsequent preventive treatments between the two groups. Early CT coronary angiography was associated with a slightly longer time in hospital (median increase 0.21 (95% confidence interval 0.05 to 0.40) days from a median hospital stay of 2.0 to 2.2 days).

Conclusions: In intermediate risk patients with acute chest pain and suspected acute coronary syndrome, early CT coronary angiography did not alter overall coronary therapeutic interventions or one year clinical outcomes, but reduced rates of invasive angiography while modestly increasing length of hospital stay. These findings do not support the routine use of early CT coronary angiography in intermediate risk patients with acute chest pain and suspected acute coronary syndrome.

Trial registration: ISRCTN19102565, NCT02284191.

Fig 1

Flowchart of recruitment and participants. CT=computed tomography; CTCA=computed tomography coronary angiography

Fig 2

Cumulative incidence of primary endpoint of one year all cause death or non-fatal myocardial infarction (type 1 or 4b). CTCA=computed tomography coronary angiography

Fig 3

Prespecified subgroup analyses of one year all cause death or non-fatal myocardial infarction (type 1 or 4b). GRACE=global registry of acute coronary events; CTCA=computed tomography coronary angiography

Fig 4

Cumulative incidence of invasive coronary angiography (top) and coronary revascularisation (bottom). One participant in each of the treatment arms had unknown date of invasive coronary angiography and one participant in CTCA + standard of care arm had unknown date of coronary revascularisation and therefore these participants were not included in the time-to-event analyses. CTCA=computed tomography coronary angiography

Fig 5

Cumulative incidence of non-invasive coronary artery disease or myocardial ischaemia testing (top) and other non-invasive cardiac investigations (bottom) from post hoc analysis. Evidence of non-proportional hazards for non-invasive coronary artery disease or myocardial ischaemia testing was found, and adjusted hazard ratio was reported as an estimate indicative of the average effect. One participant in CTCA + standard of care arm had unknown date of exercise electrocardiogram and one participant in each treatment arm had unknown date of cardiac magnetic resonance angiogram and therefore these participants were not included in the time-to-event analysis for non-invasive coronary artery disease or myocardial ischaemia testing. One participant in standard of care only arm had unknown date of echocardiogram and therefore this participant was not included in the time-to-event analysis for other non-invasive cardiac investigations. CTCA=computed tomography coronary angiography