Ischemic stroke associated with patent foramen ovale: hospital database analysis

Abstract

To analyze clinical and instrumental characteristics of patients with ischemic stroke (IS) due to paradoxical embolism according to the data of hospital registers of Moscow and Perm. A comprehensive study of 114 patients, aged 18 to 55 years, with IS by the mechanism of paradoxical embolism was carried out. All patients underwent clarification of the cause of IS (electrocardiography, ultrasound scanning of the brachiocephalic arteries, CT or MRI of the brain, CT or MR angiography, transthoracic and/or transesophageal echocardiography). The presence of right-left shunt blood flow (RLS) was confirmed by transcranial dopplerography with a bubble test. The clinical significance of patent foramen ovale (PFO) was assessed according to The PFO-Associated Stroke Causal Likelihood Classification System (PASCAL). Clinical and instrumental characteristics of patients with IS due to paradoxical embolism were obtained from two hospital registries. In both groups, the leading trigger for the development of IS was the Valsalva phenomen (>20%), the share of other provoking factors did not exceed 10%. Significant differences between the analyzed groups related to the ultrasonic characteristics of RLS/PFO: patients with a grade 4 shunt predominated in the Research Center of Neurology (RCN) population, while patients with a grade 3 shunt predominated in the City Clinical Hospital (CCH) №4 group. At the same time, there were twice as many patients with aneurysm of the interatrial septum in the CCH №4 group. In accordance with the PASCAL classification, in 93% of RCN patients, PFO can be considered as a probable cause of IS, while in the CCH No. 4 group, a probable causal relationship was traced only in 51% of cases, in 18% of patients, the role of an anomaly in the development of stroke was unlikely. The analysis showed that the primary screening of RLS in a regional vascular center allows classifying PFO as a probable cause of IS in only half of the patients. For a more accurate selection of patients for whom endovascular occlusion of the PFO will be most effective, an in-depth examination in a specialized hospital is recommended.