Blogged by: Derya ULUDUZ, Prof. M.D. ,Istanbul University, Cerrahpasa School of Medicine

The Embolic causes of stroke session took place at 16.45-18.15 on 22.05.2019, chaired by Prof Danilo Toni and George Ntaios. The session was mainly focusing on Atrial fibrillation, ESUS trials and PFO patients.

The first speaker was Prof Timo Kohles with the topic ‘Screening for paroxysmal AF whom, when and how, which was very interesting. He mentioned that  recommendations  for screening duration and time for paroxysmal AF has changed over years. The evidence is AF increases risk of stroke 5 times and accounts approximately 15% of all ischemic strokes, which is predominantly asymptomatic, therefore it is big need of search for occult AF. Prolonged ECG-Monitoring during hospitalization increases AF detection. But automatic continuous ECG Monitoring (ACEM) is almost superior to all methods, 24 hour Holter monitoring can have 24% AF detection whereas ACEM can detect AF in 93% of the patients. ACEM identified 20% of newly diagnosed AF according to the study done by Kantonsspital Aarau Stroke Center in 2014. Prof Kohles also mentioned that AF detection rate decreases over time so it is important to start early. His conclusions were all stroke patients should be screened for AF (≥72 hours) in stroke unit and prolonged screening increases AF detection. Continuous monitoring should be preferred and automatic analysis fascilitate the allocation of resources.

The second speaker was Prof Mitsias from Greece explained the importance of the duration of paroxysmal AF.  The definition of AF burden was depending on the duration of longest AF episode, number of AF episodes during certain recording time, and there is an association between the AF duration, burden and stroke risk. The effect of very brief episodes less than 6 minutes on stroke risk has not been evaluated and still remains unknown. But longer AF durations hold higher stroke risk.

Prof Christopher Diener summarized the ESUS study results. He mentioned that they planned the studies with the idea that patients with undetermined stroke would have embolic stroke. RESPECT ESUS compared anticoagulation to aspirinin in those patients. RESPECT ESUS has many subgroup analysis, the subgroup analysis of PFO patients between OAC and Aspirin did not show any difference. But the subgroup analysis of disabling stroke result with the superiority of dabigatran. In NAVIGATE ESUS trial in subgroup analysis of PFO and left atrial diameter (>4.6 cm) OAC was found to be superior. Bu in general at present these two randomised trials failed to show superiority of OAC over Aspirin in secondary stroke prevention. Future is we have to wait ongoing results of ATTICUS and ARCADIA trials. ARCADIA trial is ongoing which is a multicenter randomised double blind Phase III study of apixaban versus Aspirin in patients with ESUS and cardiopathy. With the results of these two trials at least long term ECG monitoring returns to the agenda. The next speaker Prof Keith Muir also mentioned about the ESUS that ESUS is not a useful concept for therapeutic decision making. But we have no excuse to give up after a cursory investigation for stroke mechanism an done therapeutic approach does not fit all cases.

Last speaker Prof Sara Mazzucco give talked about PFO and patient selection for PFO closure. PFO closure compared to antithrombotic is effective however anticoagulant seems superior to antiplatelets. Patients in whom anticoagulation is contraindicated can benefit from PFO closure but PFO closure is superior in patients with a large shunt and atrial septal aneusysm. She concluded that as it is not enough evidence, future trials on secondary prevention in patients with cryptogenic stroke and PFO should be powered to include enough older patients and patients on anticoagulations including new anticoagulants.