Comparative diagnostic yield and 3-month outcomes of “triple rule-out” and standard protocol coronary CT angiography in the evaluation of acute chest pain

Background“Triple rule-out” CT angiography simultaneously evaluates coronary artery disease, pulmonary embolism, and aortic dissection in a single imaging examination. However, the clinical outcomes of this approach are unknown.ObjectiveUsing standard cardiac CT angiography as a reference, this study was performed to describe the diagnostic yield and clinical outcomes of patients undergoing triple rule-out in clinical practice.MethodsWe identified consecutive patients at 2 institutions undergoing triple rule-out or cardiac CT angiography for acute chest pain. The primary outcome was a composite diagnostic yield consisting of coronary artery diameter stenosis >50%, pulmonary embolism, and aortic dissection. Other reported outcomes included radiation dose, downstream resource use, and 90-day clinical outcomes.ResultsAmong 2068 patients (272 triple rule-out and 1796 cardiac CT angiograms), the composite diagnostic yield was 14.3% with triple rule-out and 16.3% with cardiac CT (P = 0.41) and was driven by the diagnosis of obstructive coronary artery disease (13.2% triple rule-out versus 16.1% cardiac CT, P = 0.22). The diagnostic yield for pulmonary embolism was low (1.1% triple rule-out and 0.2% cardiac CT, P = 0.052) and no aortic dissections were found in either group. Compared with cardiac CT, the triple rule-out approach was associated with higher radiation exposure (12.0 ± 5.6 mSv versus 8.2 ± 4.0 mSv, P < 0.0001), a greater incidence of subsequent emergency center cardiac evaluations (5.9% versus 2.5%, P = 0.0017), and more downstream pulmonary embolism-protocol CT angiography (3.3% versus 0.9%, P = 0.0034).ConclusionsAmong patients with acute chest pain, a triple rule-out approach resulted in higher radiation exposure compared with cardiac CT, but was not associated with improved diagnostic yield, reduced clinical events, or diminished downstream resource use.