In young people with a stroke, it is crucial to identify the cause to optimize treatment. One possible cause is a small hole in the heart present in about 25% of people. Because it is common, it is not always clear when closing this connection is necessary. This thesis examines when this open connection actually contributes to a stroke. The results show that not only the shape or size of the hole matters: about 20% of patients have no risk features. Risk features appear linked to reduced function of the left atrium, and at the cellular level, clots seem to come from the arterial system, suggesting they may originate in the heart. Fever, illness, and intense exercise increase the risk. Ultimately, a multidisciplinary team is needed to decide whether closure of the patent foramen ovale is the appropriate treatment.
Maikel Immens obtained his medical degree from Radboud University in 2019. He is currently training to become a neurologist at Radboud University Medical Center and, in 2021, began his PhD research on patent foramen ovale–associated stroke under the supervision of Prof. Frank-Erik de Leeuw and Dr. Tim Ten Cate. Maikel hopes to complete his neurology training in 2029.