Background: About one third of ischemic strokes are caused by cardioembolism. Early determination of stroke etiology is essential for three reasons: 
1. Detection of etiology is more likely to succeed directly after the stroke (‘smoking gun’). For instance, an intracardiac thrombus may vanish after intravenous thrombolysis. 
2. The risk of recurrence is highest early after the initial stroke. 
3. The choice of secondary prevention depends on the etiology. Cardioembolic stroke generally requires treatment with oral anticoagulation.

We hypothesize that a CTA of the heart and entire aortic arch, performed in the acute phase (before reperfusion therapy) in patients with ischemic stroke, is superior to echocardiography in detecting cardio-aortic sources of ischemic stroke.

Methods: International prospective cohort study in two high-volume stroke centers:  Academic Medical Center in Amsterdam and Toronto Western Hospital. Four-hundred and seven consecutive patients with acute ischemic stroke who are eligible for reperfusion therapy (intravenous thrombolysis or intra-arterial thrombectomy) will be included. Patients will undergo an ECG-triggered CTA in the acute setting, including the heart, entire aortic arch, cervical and intracranial arteries. Patients will also receive routine work-up for cardioembolism (ECG, Holter, echocardiography). Predefined relevant sources of embolism from the heart and aortic arch will be systematically scored.   

Results: First enrollment expected in May 2018. Results expected in 2021.

Conclusions: The study will generate the best available evidence regarding the diagnostic yield of heart and aortic arch CTA in the acute phase of ischemic stroke. If CTA is superior to echocardiography, this will likely become the new standard-of-care.

MIND THE HEART: CARDIAC CT-ANGIOGRAPHY IN THE ACUTE PHASE OF ISCHEMIC STROKE