Cardiac CT Imaging in Acute stroke

Peter Sheeran¹, Prof. Joeseph Suttie^1,2, Prof. Martin Jude¹, Simeon Moore^1,2, Swazi Sharma^1,2
1. Wagga Wagga Base Hospital MLHD, 2. University of Notre Dame

Introduction:

This pilot and feasibility study would aim to assess whether cardiac computerised tomography (CT) has a higher yield for detecting cardiac sources of embolism (atrial thrombus) than transoesophageal echocardiography (TOE) in patients presenting with an acute cerebrovascular accident (CVA).

This proof of concept study could be used as the basis for larger repeat studies with the aim of providing evidence of improvement in standard diagnostic protocols for embolism diagnosis in CVA. Additionally, the proposed extended cardiac imaging could be utilised for assessment and screening of patients presenting with acute CVA without known coronary artery disease. Thereby aiding in risk factor management and allowing for the implementation of preventative care for those patients.

Wagga Wagga Base Hospital (WWBH) admitted 133 and 132 patients with ischaemic strokes in 2012 and 2013 respectively. This number increased to 252 in 2023 with 24% of those patients experiencing atrial fibrillation which is a known risk factor for atrial thrombus formation. There were 4075 ischaemic strokes nationally in 2023. This accounts for WWBH managing roughly 16% of ischaemic strokes while the Murrumbidgee Local Health District catchment area only accounts for roughly 9% of the population.

TTE and CT arch to COW are both currently performed as a standard part of the diagnostic work-up for acute CVA. TTE is often insufficient to rule-out cardiac sources of embolism, requiring patients to be assessed through transoesophageal echocardiography (TOE), which is a more invasive procedure requiring anaesthetics and cardiology physicians to be present while imaging is obtained. CT arch to COW could be extended to incorporate imaging of the entire heart with minimal impact on CT access or radiography personal. Previous studies have indicated an additional scan time of 6 mins when cardiac imaging is incorporated.

Objectives:

To assess whether cardiac computerised tomography (CT) has a higher yield for detecting cardiac sources of embolism (atrial thrombus) than transthoracic echocardiography (TTE) in patients presenting with an acute cerebrovascular accident (CVA).
Outcome measures: Number of participants for whom cardiac CT imaging would have negated the need for participants to undergo a transoesophageal echocardiography (TOE).

Methods:

 Pilot study to recruit approximately 15-20 participants from MLHD Wagga Wagga Base Hospital as ED or Medical Ward admitted patients. Participants to undergo TTE and CT arch to COW as per standard acute stroke protocol. TOEs to be utilised as required for patients with inadequate TTE imaging as per current standard practice. All participants will undergo the proposed extended cardiac CT to assess for atrial thrombus formation.
Outcome measures: Number of participants for whom cardiac CT imaging would have negated the need for participants to undergo a TOE. Post-analysis by expert cardiologist who is not a treating physician, to review cardiac CT and TTE imaging separately to determine whether TOE imaging would have been required.

Potential Outcomes:

1.            Reduced procedure time, freeing procedure room and staff for reallocation to other procedures

2.            Reduces unnecessary exposure to invasive procedures and anaesthetic risk

3.            Improved diagnosis accuracy and prevent delays in decision making for medical management of risk-factors, in particular anti-coagulants

4.            Potential reduced length of stay and earlier discharge

5.            There is potential for a cost benefit analysis can be conducted following trial completion

6.            There is a potential for a small increase in risk to renal function from minor increased contrast medium and a small increase in radiation exposure. However, these risks are likely outweighed by reduced invasive procedure and anaesthetic risks

References:

• 1.            Mohr, K. Has implementing a NSW Early Access to Stroke Thrombolysis program increased the rate of thrombolysis in the Murrumbidgee Local Health District (MLHD)?   https://www.heti.nsw.gov.au/__data/assets/pdf_file/0003/438807/Katherine-Mohr-Final-Report.pdf
• 2.            Wagga Wagga Base hospital (2023). Acute Stroke Unit ruault Stroke Database
• 3.            Stroke Foundation. (2023). National Stroke Audit – Acute Services Report   https://informme.org.au/stroke-data/acute-audits#:~:text=Download%20latest%20Acute%20Services%20National%20Report
• 4.            Stroke Foundation. (2025). The Australian and New Zealand Clinical Guidelines for Stroke Management   https://informme.org.au/guidelines/living-clinical-guidelines-for-stroke-management#
• 5.            Yu, S., Zhang, H., & Li, H. (2021). Cardiac computed tomography versus transesophageal echocardiography for the detection of left atrial appendage thrombus: a systemic review and meta‐analysis. Journal of the American Heart Association, 10(23), e022505. https://www.ahajournals.org/doi/pdf/10.1161/JAHA.121.022505?download=true
• 6.            Sun, C., Lv, J., Liu, M., & Ma, H. (2024). Different scanning protocol to assess left atrial appendage thrombus in patients with atrial fibrillation by cardiovascular computed tomography. Scientific Reports, 14(1), 30414. https://doi.org/10.1038/s41598-024-81708-0
• 7.            Ghozy, S., Liu, M., Kobeissi, H., Mortezaei, A., Amoukhteh, M., Abbas, A. S., Dmytriw, A. A., Kadirvel, R., Rabinstein, A. A., & Kallmes, D. F. (2024). Cardiac CT vs echocardiography for intracardiac thrombus detection in ischemic stroke: a systematic review and meta-analysis of 43 studies. Neurology, 103(7), e209771. https://www.neurology.org/doi/pdfdirect/10.1212/WNL.0000000000209771
• 8.            Rinkel, L. A., Guglielmi, V., Beemsterboer, C. F., Groeneveld, N.-S., Lobé, N. H., Boekholdt, S. M., Bouma, B. J., Muller, F. F., Beenen, L. F., & Marquering, H. A. (2022). Diagnostic Yield of ECG-Gated Cardiac CT in theAcute Phase of Ischemic Stroke vsTransthoracic Echocardiography. Neurology, 99(14), e1456-e1464. https://www.neurology.org/doi/10.1212/WNL.0000000000200995?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed