Incidence and Follow-Up of Extracardiac Findings on Cardiac Computed Tomography: A Single Tertiary Centre Experience.

Abstract

Background: Extracardiac findings (ECF) are frequently detected on cardiac computed tomography (CT), yet their clinical follow-up in contemporary practice is variable. We sought to describe their incidence and assess whether clinically significant findings were associated with documented follow-up or further investigation.

Method: We conducted a retrospective observational study of consecutive patients undergoing cardiac CT, including CT coronary angiograms (CTCA) and CT left atrial mapping (CTLA), at a single tertiary centre between January 2021 and December 2022. ECF data were extracted from formal reports. For patients with clinically significant findings, electronic medical records were reviewed to determine whether findings were documented as acknowledged and whether further investigation or follow-up was recorded.

Results: A total of 402 patients underwent cardiac CT. Most ECF were low risk, including hiatus hernia (39.8%) and small pulmonary nodules <6 mm (13.4%). Clinically significant ECF were identified in 41 patients (10.2%), including pulmonary nodules measuring 6-8 mm (2.7%), pulmonary nodules >8 mm (2.5%), indeterminate liver lesions (1.5%), other mass lesions (1.5%), and pulmonary emboli (1.2%). Twenty-two patients (5.5%) met criteria for Fleischner guideline-directed surveillance, of whom 15 had documented follow-up, including one subsequent diagnosis of malignancy. Overall, 12 patients (29.2%) with clinically significant ECF had no documented follow-up. Clinically significant ECF were more frequently observed in patients undergoing CTLA (odds ratio 2.4; 95% confidence interval 1.1-5.1; p=0.03) and were associated with higher odds of lacking documented follow-up compared with CTCA (odds ratio 4.8; 95% confidence interval 1.1-21.2; p=0.05). Missed clinically significant ECF predominantly occurred in the outpatient setting.

Conclusions: ECF on cardiac CT are common, and approximately 10% represent clinically significant abnormalities. In this cohort, clinically significant findings identified on CT left atrial mapping were associated with lower rates of documented follow-up compared with CTCA. These findings suggest a potential vulnerability in outpatient CTLA mapping pathways and support consideration of strategies to reduce unacknowledged ECF.