Background

CAD is the main cause of death in industrialised countries [6]. For that reason, an early detection as well as an appropriate method to rule out the presence of CAD is very important. In addition, a reliable and noninvasive test would offer big advantages for the patient.
Conventional coronary angiography (CCA) represents the gold standard when the presence of CAD is suspected, although in almost 60% of the cases no revascularisation is necessary and the invasive examination only serves a diagnostic purpose [5]. CT has become the most frequently used alternative imaging modality to CCA and offers two important advantages: First, the examination is noninvasive, which considerably reduces the risk for the patient and, secondly, from an economical point of view, the examination is more cost-effective [9].
A meta-analysis by our group pooling the results of several studies has shown that the accuracy of CT in patients with a low to intermediate pretest likelihood of CAD is quite high (97% sensitivity, 87% specificity) [8]. These patients are most likely to benefit from a CT examination and a negative CT result excludes the presence of CAD with very high certainty [4, 7]. Nevertheless, previous studies and meta-analyses had to rely on limited summary patient data. By performing an IPD meta-analysis, we will be able to carry out a more detailed and powerful analysis and thus increase the generalisability of the results.