Magnetic resonance imaging derived cardiac first pass perfusion in cryptogenic ischemic stroke in the young

Funding Acknowledgements Type of funding sources: None. Introduction Up to 50% of ischemic strokes in adults aged between 18 and 50 are cryptogenic by nature. Heart has been a hypothesised source. Purpose: Purpose of the study was to investigate the wash in and wash out of gadolinium based contrast agent in the left atrial appendage, and cardiac chambers in first pass cardiac magnetic resonance imaging. Methods The study comprised 30 patients with first-ever cryptogenic ischemic stroke and 30 age and gender matched stroke-free controls included in the prospective multicenter study Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers and Outcome (SECRETO; NCT01934725). Cardiac magnetic resonance imaging was performed on all participants with a 1.5T magnetic resonance system. Dynamic contrast enhanced T1 weighted first pass perfusion images were acquired in the superior vena cava, the left atrial appendage (Fig. 1), and the left ventricle. The images were analyzed for time-intensity curves (Fig. 2), and results were normalised to individual heart rate. Arrival times, peak times, areas under the curves, relative blood flows (defined as area under the curve/full width at half maximum), and maximum and minimum rates of bolus wash in / wash out were calculated. Results The wash in of the contrast agent bolus was similar in patients and controls. Arrival times and peak timings showed similar characteristics in patients and controls in the left atrial appendage (arrival time: 12.4 [2.3] vs. 13.5 [3.6] cardiac cycles, p = 0.657; peak time: 19.6 [5.1] vs. 19.8 [6.9] cardiac cycles, p = 0.929) and the left atrium (arrival time: 12.2 [2.8] vs. 13.0 [3.6] cardiac cycles, p = 0.535; peak time: 18.7 [5.5] vs. 18.1 [5.2] cardiac cycles, p = 0.790). Areas under under the curves and relative blood flows were similar in patients and controls. A significant difference between patients and controls was found in the wash out rate of gadolinium in the left ventricle (-28 [11] vs. -36 [13] 1/cardiac cycles, p = 0.012), indicating slightly slower wash out in the patients. Conclusions Cryptogenic ischemic stroke in the young is not associated with prolonged blood flow in the left atrial appendage or left atrium. There were no significant differences in the first pass perfusion between subjects and healthy controls. However, there might be a slight tendency for stagnation of blood flow in the left ventricles of cryptogenic stroke patients.