A low threshold to ECG-gated repeat CTA reduces the risk of false-positive diagnosis of type A dissection in interhospital referrals: a case series study

Abstract

Angela Kornberger,1 Iris Burck,2 Hazem El Beyrouti,1 Nancy Halloum,1 Andres Beiras-Fernandez,1 Christian-Friedrich Vahl1 1Department of Cardiothoracic and Vascular Surgery, University Hospital of Johannes Gutenberg University, Mainz, Germany; 2Department of Diagnostic and Interventional Radiology, University Hospital of Johann Wolfgang Goethe University, Frankfurt am Main, Germany Background: False-positive diagnosis of acute Stanford type A aortic dissection (AAD) on computed tomography angiography (CTA) is still an issue and may lead to substantial consequences. Given that electrocardiography (ECG)-gated CTA provides greater diagnostic safety, it may be assumed that interhospital referrals with a diagnosis of AAD based on non-ECG-gated pre-referral CTA carry an elevated risk of false-positive diagnosis.Patients and methods: We reviewed a series of patients in whom a diagnosis of AAD based on non-ECG-gated pre-referral CTA was subsequently proven false by ECG-gated CTA. The artifacts that gave rise to the misdiagnosis, as well as the diagnostic pathways followed and the consequences of false-positive diagnosis were investigated.Results: In 5 patients, ECG-gated repeat CTA revealed artifacts in the pre-referral scans that had led to false-positive diagnosis and referral for emergent surgery. In the first case, the patient proceeded to surgery. In 4 subsequent cases, ECG-gated CTA was ordered because a false-positive diagnosis was suspected. We found that ECG-gated CTA rather than echocardiography provided sufficient information to rule out AAD in each of these cases. Comparison between pre-referral non-ECG-gated scans and ECG-gated repeat CTA demonstrated the wide range of artifacts that may give rise to a diagnosis of AAD.Conclusion: Patient condition permitting, the threshold to ECG-gated repeat CTA should be low when doubt arises with regard to a diagnosis of AAD based on non-ECG-gated CTA in interhospital referrals. Keywords: Stanford type A dissection, false-positive diagnosis, ECG-gated CTA

Keywords

• Stanford type A dissection
• false-positive diagnosis
• ECG-gated CTA