Atrial anatomy in non-cardioembolic stroke patients: effect of medical therapy.

OBJECTIVES The purpose of the study was to assess the mechanism responsible for increased stroke risk in patients with atrial septal aneurysm (SA) and patent foramen ovale (PFO), and to determine the efficacy of medical therapy for preventing stroke recurrence or death. BACKGROUND Atrial septal aneurysm and PFO are associated with stroke. However, the mechanism for this association is undefined, and the efficacy of medical therapy has not been investigated in a randomized fashion. METHODS The Patent foramen ovale In Cryptogenic Stroke Study (PICSS) evaluated transesophageal echocardiography findings in patients enrolled in the Warfarin-Aspirin Recurrent Stroke Study, a randomized double-blind trial to evaluate the efficacy of warfarin compared with aspirin. RESULTS Large PFO and prominent eustachian valve (EV) or right atrial (RA) filamentous strands were found more frequently in patients with SA compared with those without SA (37.7% vs. 10.9%, p < 0.001 and 59.4% vs. 43.1%, p = 0.02). Patients with SA and PFO had no significant difference in time to recurrent stroke or death compared with those having neither (hazard ratio [HR] 1.08, 95% confidence interval [CI] 0.49 to 2.38, p = 0.84; two-year event rates 15.9% vs. 14.5%). Patients with SA, PFO, and RA anatomy predisposing to paradoxical embolization also had no difference compared with those without these findings (HR 1.22, 95% CI 0.43 to 3.47, p = 0.71; two-year event rates 18.2% vs. 14.2%). There was no significant difference in time to recurrent stroke or death between the patients treated with warfarin or aspirin (HR 1.00, 95% CI 0.22 to 4.47, p = 1.0; two-year event rates 16.0% vs. 15.8%). CONCLUSIONS Atrial septal aneurysm is associated with the presence of large PFO and prominent EV or RA filamentous strands. On medical therapy, patients with SA and PFO did not experience increased risk of adverse events, and there was no difference between treatment results for warfarin and for aspirin.