Diagnostic algorithms. Diagnostic algorithms for patients (Pt) presenting with suspected coronary artery disease (CAD). In algorithm A, cardiovascular magnetic resonance (CMR) was performed first and patients were referred for invasive coronary angiography (Angio) only if CMR was positive or non-diagnostic (NDx). Patients with false-negative test results were at risk for myocardial (MI) or death from undetected CAD. Diagnostic algorithm B had the same basic structure as algorithm A, but involved single-photon emission computed tomography (SPECT) instead of CMR. Algorithm C used invasive coronary angiography as the first and only test to diagnose CAD.