The absence of radiological evidence of plaque on computed tomographic coronary angiography (CTCA) reliably excludes obstructive coronary artery disease.

We studied patients who presented to our emergency department with chest pain and were admitted to our chest pain assessment service. If they were free of pain and without high-risk features of myocardial ischaemia including elevation of serum biomarkers they underwent CTCA and performed a standard treadmill exercise test.

Eighty-nine patients aged 56.3±8.6 years were admitted. Eleven of them had selective angiography; CTCA identified all who had obstructive disease. More than half of the 85 patients who had normal values of cardiac troponin and of the 75 with a negative exercise test had radiological evidence of disease.

During follow-up for 355±72 days none died, suffered myocardial infarction or required coronary artery surgery: two with obstructive disease underwent percutaneous coronary intervention 1 and 7 days after the index study.

The CTCA findings were significantly correlated with those of selective angiography and with troponin status and increased the ascertainment of coronary artery disease in a cohort of patients at low risk for clinically significant ischaemic heart disease.