PFO closure for secondary stroke prevention: is the discussion closed?

Interventional prevention of paradoxical embolism as the gold standard: End of discussion?

Paradoxical embolism is one of the predominant causes of cryptogenic stroke and interventional secondary prevention, i.e., closure of the patent foramen ovale (PFO), is a much discussed issue. This review aims to provide a complex perspective on this topic, aggregates and comments on the available data and current guidelines. Several large trials were performed, some of which proved the superiority of PFO closure over pharmacotherapy while others have not. Studies detecting significant superiority of intervention worked with disproportionately high representation of large shunts compared to the general population. Other controversies also remain, such as the lack of comparison of the effect of modern anticoagulant/antiplatelet treatment to PFO closure or the risk of developing unwanted side effects after intervention, and these are discussed in detail. PFO closure is a suitable method for secondary prevention of paradoxical embolism and, therefore, cryptogenic stroke. However, this is only true for carefully selected patient populations and such selection is of the utmost importance in deciding on interventional or conservative treatment.

Stroke and presence of patent foramen ovale in sickle cell disease

Sickle cell disease (SCD) is an inherited monogenic hemoglobinopathy characterized by formation of sickle erythrocytes under conditions of deoxygenation. Sickle erythrocytes can lead to thrombus formation and vaso-occlusive episodes that may result in hemolytic anemia, pain crisis and multiple organ damage. Moreover, SCD is characterized by endothelial damage, increased inflammatory response, platelet activation and aggravation, and activation of both the intrinsic and the extrinsic coagulation pathways. Cerebrovascular events constitute an important clinical complication of SCD. Children with SCD have a 300-fold higher risk of acute stroke and by the age of 45 about 25% of patients have suffered an overt stoke. Management and prevention of stroke in patients with SCD is not well defined. Moreover, the presence of patent foramen ovale (PFO) increases the risk of the occurrence of an embolic cerebrovascular event. The role of PFO closure and antiplatelet or anticoagulation therapy has not been well investigated. Moreover, during COVID-19 pandemic and taking into account the increased rates of thrombotic events and the difficulties in blood transfusion, management of SCD patients is even more challenging and difficult, since data are scarce regarding stroke occurrence and management in this specific population in the COVID-19 era. This review focuses on pathophysiology of stroke in patients with SCD and possible treatment strategies in the presence of PFO.