Significant Contribution of Aortogenic Mechanism in Ischemic Stroke: In Vivo Observation of Aortic Plaque Rupture Dynamics by Angioscopy

Background: Although aortogenic stroke is recognized as one of the embolic strokes, examinations to identify the embolic source has been insufficient. Recently, non-obstructive general angioscopy (NOGA) has developed to be applied to observe atheromatous change of aorta. NOGA can help visualize the in vivo surface of aorta and plaques in detail. Methods: We examined the 114 consecutive patients whose aorta was observed by NOGA and ischemic stroke lesions were searched by brain MRI. The evaluation of the aortic observation by NOGA was defined as the presence and location of spontaneous ruptured aortic plaque (SRAP). The ascending aorta and arch were defined as proximal aorta (PAo), which ranges from the origin of the aorta to the left subclavian artery. The segment from the left subclavian artery to the height of the 5th thoracic vertebra was defined as the proximal descending aorta (DAo). Findings: Forty-nine of 114 patients included in the study had SRAP observed by NOGA. Of those, 24 patients had SRAP in PAo, and 43 had SRAP in DAo. Patients with ischemic stroke had a significantly higher frequency of SRAP detection than those without ischemic stroke (69% vs. 33%, p<0.01). In 49 patients with SRAP, ischemic stroke lesions were found in 23 patients, with a positive predictive value of 47%. In patients with SRAP in PAo, the positive predictive value for ischemic stroke was 75%. In 65 patients without SRAP, ischemic stroke lesions were observed in 10 patients, and the negative predictive value was 85%. The presence of SRAP in PAo was significantly correlated with the detection of ischemic stroke lesions (Odds ratio was 14.3, p<0.001). Interpretation: Attention should be paid to SRAP, especially that in PAo, in the treatment of ischemic stroke. Funding Statement: None. Declaration of Interests: Komatsu S. is a technical consultant for Nemoto Kyorin-do Co. Ltd., Kodama K. is the president of Inter-tec Medicals, Co. Ltd., All other authors have no relationships relevant to the contents of this paper to disclose. Ethics Approval Statement: This study was approved by the ethical committee of Osaka Police Hospital. Trial Registration: This study was registered in the UMIN-CTR (STROKE-NOGA Study, UMI34588).