CT Angiography in Patients Referred for Invasive Coronary Angiography: A Single Large-Volume Tertiary Center Experience

<b>Background/Objectives:</b> Coronary artery disease (CAD) is a major cause of mortality worldwide, accounting for 7.3% of all deaths in Germany. Invasive coronary angiography (ICA) remains the gold standard for diagnosing CAD, yet coronary computed tomography angiography (CTCA) is gaining recognition as a non-invasive alternative. Recent clinical trials have confirmed CTCA's diagnostic accuracy, leading to its inclusion in the 2019 European Society of Cardiology (ESC) guidelines. Despite this, its adoption in Germany has been slow. <b>Methods:</b> This single-center, non-randomized study at the Heart and Diabetes Center North Rhine-Westphalia (HDZ NRW) evaluated CTCA's safety and diagnostic performance. We included patients with low to intermediate pre-test probability (PTP) referred for cardiac catheterization between 2019 and 2022. The primary outcome was the change in the Wall Motion Score Index (ΔWMSI), with a threshold of 0.37 indicating significant mortality risk. Secondary outcomes included cardiovascular mortality, myocardial infarction, angina at follow-up, and myocardial revascularization procedures. <b>Results:</b> A total of 100 patients were enrolled; 30 underwent CTCA, and 70 had ICA. The mean patient age was 63 years, with 33% female. Of the 63 patients who completed follow-up (41 ICA, 22 CTCA), no significant differences in cardiovascular outcomes or mortality were observed. CTCA effectively ruled out CAD in low-risk patients, with a sensitivity of 75% and specificity of 77%. CTCA was faster (4.7 vs. 20.2 h) but had a higher radiation dose (2.3 vs. 1.5 mSv). <b>Conclusions:</b> CTCA is a viable, non-invasive alternative for diagnosing low- to intermediate-risk CAD patients. Further studies are needed to confirm its clinical benefits.