Doing a cardiac CT scan in the acute phase of stroke along with head CT scan was superior to Transthoracic echocardiography (TTE) in detecting high-risk cardioaortic sources of embolism, according to the results of the "Mind the Heart" study from The Netherlands recently published in the journal Neurology.¹

The single-centre prospective observational cohort study carried out at the Amsterdam University Medical Center included 452 consecutive patients with a suspected acute ischaemic stroke from May 2018 through November 2020. All 452 patients underwent ECG-gated cardiac CT in the hyperacute stroke phase i.e., within 6 hours of stroke onset, which took an extra scan time of 6 minutes (median). TTE was done in 350 (77.4%) patients one day later (median);99 of the TTEs were done in an outpatient setting. In 15.3% TTE was too burdensome to perform in the outpatient setting and therefore was not done, while 7.3% participants died. All routine stroke workup was done. The study aimed to explore the utility of cardiac CT as part of the initial imaging protocol for stroke in detecting high-risk cardioaortic sources of embolism vis-à-vis TTE. The median age of the patients was 72 years and nearly 60% of the study population was male.

Out of the 350 patients in whom TTE was also done, 11.4% (n = 40) patients were found to have a high-risk cardioaortic source of embolism on cardiac CT done within 6 hours versus only around 5% (n = 17) such cases on TTE done later with odds ratio (OR) of 5.60. Slightly over 7% patients had a cardiac thrombus on cardiac CT compared to 0.6% with TTE. The diagnostic yield of cardiac CT in the entire study population, including those who did not undergo TTE was 12.2% (55/452). A cause of stroke could be identified in 6.3% among 175 patients who had a cryptogenic stroke.

By demonstrating the feasibility of cardiac CT simultaneously as a head CT scan when the patient first presents to the ER, this study may be practice changing. A gated CT scan added just 6 minutes to the imaging protocol. It was also able to detect high-risk sources of cardioembolism in 40 patients compared to less than 20 patients with TTE.  

Cardiac CT could therefore be made a part of the initial stroke imaging protocol and “may be considered as an alternative to TTE to screen for cardioembolism”. TTE is routinely done in patients with stroke, but not in the acute phase of presentation. It is usually carried out within a week of the acute event or even later. While a TTE cannot be entirely written off, a thorough clinical history and examination could identify patients in whom TTE may still indicated.

An accompanying editorial on this in the same issue of the journal has a very apt subheading “Dont Leave the CT Scanner Without Imaging the Heart”.²

References

1. Rinkel LA, et al. Diagnostic yield of ECG-gated cardiac CT in the acute phase of ischemic stroke vs transthoracic echocardiography. Neurology. 2022 Oct 4;99(14):e1456-e1464. doi: 10.1212/WNL.0000000000200995.

2. Parsons MW, et al. Adding Cardiac CT to the hyperacute stroke CT Protocol: Dont Leave the CT Scanner Without Imaging the Heart. Neurology. 2022 Oct 4;99(14):595-596. doi: 10.1212/WNL.0000000000201082.