Safety and Cost-efficiëncy of New Imaging Techniques in Patients Suspected of Coronary Artery Disease

Yearly, 180 000 patients in the Netherlands are referred to a cardiologist with symptoms suspected of coronary artery disease (CAD). To assess this, multiple diagnostic tests are available. Non-invasive imaging tests, such as coronary CT-scan, are safe, relatively cheap and can effectively rule-out CAD. However, when CAD is present, coronary CT-scan cannot assess the restriction in blood flow caused by the stenosis. Cardiac angiography with invasive blood flow measurements is required to assess this restriction in blood flow. This is an invasive test, more expensive than CT and it is accompanied by certain risks. Most patients in whom CAD is present do not need treatment, and would therefore benefit from non-invasive diagnostic tests. To reduce the number of unnecessary cardiac angiography with flow measurements, new imaging techniques have been developed. These techniques use CT- or angiographic images to calculate the restriction in coronary blood flow and determine the need for treatment. This study is designed to assess the safety and efficacy of these techniques when used as an addition to coronary CT-scan. Subjects are eligible if their CT-scan indicates possibly significant CAD. To determine need for treatment of a subject's CAD, the investigators will randomize subjects in three arms. One arm consists of additional CT-derived calculation of coronary blood flow, one arm consists of angiography-derived calculation of coronary blood flow and one arm consists of standard care, coronary angiography and invasive coronary blood flow measurements. After these tests, subjects are treated and followed according to routine care guidelines. Additionally, subjects are requested to complete 5 questionnaires in a 12 month follow-up period. The investigators expect that the total number of invasive cardiac angiographies with additional blood flow measurements can be reduced by half with the use of new imaging techniques. The investigators expect that this will lead to a reduction in healthcare costs, complications and a lower burden of diagnostic tests for patients. The investigators do not expect a difference in primary endpoints between the study groups.