Coronary CT Angiography in Non ST-elevation Myocardial Infarction (NSTEMI) - a Way to Reduce Unnecessary Invasive Investigations

Non ST-elevation myocardial infarction (NSTEMI) represents 70-75% of all myocardial infarctions. Current guidelines recommend invasive angiography and this patient group represents a major burden on the invasive catheterization laboratories and the health care system.

The coronary pathology found in NSTEMI-patients varies substantially, ranging from structurally normal vessels, non-obstructive atherosclerosis to severe multivessel disease. 30-40 % of patients with NSTEMI undergoing invasive coronary angiography do not undergo revascularization. If these patients could be identified by a non-invasive method like coronary CT angiography (CCTA), an invasive procedure with the potential risk for complications could be avoided. Furthermore, less patients would need transfer to an invasive center. Both for patients and for health care costs this would be of major benefit.

The quality of CCTA images has improved during the years, and radiation dose has decreased. Due to technological development it is now possible to perform high quality coronary CCTA with a very low radiation dose (1-1.5 mSv) compared to a radiation dose of 3-4 mSv for invasive coronary angiography.

The overall aim of the project is to define a subpopulation of NSTEMI patients that preferably should undergo CCTA as the first step in imaging of the coronary arteries and thus potentially be saved from an unnecessary invasive investigation. This would result in less patient discomfort, less patient risk and reduced health care costs. Patients with a clinical indication for invasive angiography according to current guidelines will undergo CCTA prior to the invasive investigation. The ability of CCTA to identify those with no need for revascularization will be assessed using invasive angiography as the gold standard.