Objective: Recent trials of patent foramen ovale (PFO) closure to prevent recurrent stroke found overall stroke reduction in the PFO closure group compared with antiplatelet therapy alone. However several aspects in the
management of patients with embolic stroke of undetermined source (ESUS) and PFO remain unclear.
Methods: An interdisciplinary cardioneurological treatment algorithm was
developed to standardize the management of patients with ESUS
(see figure). All patients were aimed to receive long-term cardiac monitoring
(e.g. implantable cardiac monitor, ICM). Depending on the age (cut off ≥
60 years) and the transesophageal detection of a relevant PFO there was
an assignment to different treatment regimens including antiplatelet
therapy, oral anticoagulation (OAC) and PFO-closure. Follow-up period
will be at least 36 months. The study was approved by local authorities and
patients gave informed consent.
Results: The algorithm has been implemented in January 1, 2018. Since then, 114 patients with a mean age of 66 years (26y-87y) have been included. An event recorder was implanted in 68 patients, for different reasons, e.g. due
to patient wishes, this was not done in the other cases. As secondary stroke prevention 96 patients received antiplatelet therapy and 18 (N)OAC.
Conclusions: Due to this new treatment algorithm 59% of stroke patients with ESUS received an ICM. About 50% of patients under 60 years showed a PFO, which after 6 months of cardiac monitoring has already been closed in two patients. In view of the small number of cases to date, the rate of recurrence of stroke (3% in 3 months) is approximately comparable to that of the NAVIGATE-ESUS trial (5% in 1,5 years). Also the rate of new atrial fibrillation with 7% is comparable to the FIND-AF study, in which the patients had 3x10 days long-term ECG within 6 months and an atrial fibrillation risk of 14%.
Overall, this open-label prospective observational study will help to resolve various unanswered questions regarding the treatment regimen of ESUS patients with and without PFO and might help identifying patients best suited for PFO closure.

Follow up in embolic stroke of undetermined source: new clinical treatment algorithm including long-term cardial monitoring and PFO closure in a prospective open-label observational study