Risk of Recurrent Neurologic Stroke or Transient Ischemic Attack in Patients with Cryptogenic Stroke and Intrapulmonary Shunt

Background and Purpose Cardio-embolic phenomenon is believed to underlie a significant proportion of cryptogenic strokes. We recently showed that intrapulmonary shunt (IPS) was associated with cryptogenic stroke and transient ischemic attack (TIA). We hypothesized that patients with prior cryptogenic stroke or TIA that had an IPS were at a higher risk for recurrent ischemic events. Methods The population included subjects with cryptogenic cerebrovascular accident (CVA) or TIA. Inclusion criteria were age ≥18 years, sinus rhythm, and clinically indicated transesophageal echocardiography (TEE). Exclusion criteria were hemorrhagic CVA, septal defect, and patent foramen. Patients were followed from index TEE. Results Of 71 patients, 8 were lost to follow-up. A total of 23 patients had and 40 were without IPS. Average follow-up duration was 38.3 ± 19.2 months. Groups were similar at baseline. There was no significant difference in the recurrence of ischemic CVA or TIA in the IPS versus non-IPS groups (0% vs. 7.5%; P = NS). There was no difference between the incidence of hemorrhagic CVA in the IPS and non-IPS groups (4.3% vs. 5.0%; P = NS). The proportion of patients on warfarin in the IPS group was significantly higher compared to the non-IPS group (17.4% vs. 0%; P < 0.05). Conclusions Patients with IPS and cryptogenic stroke or TIA did not have a higher recurrence of ischemic cerebral events. Warfarin was significantly higher at follow-up in the IPS compared to the non-IPS group, which may explain these findings. A study randomizing patients with IPS and cryptogenic stroke or TIA to warfarin or no warfarin would be of great interest.