[Bleeding in patients receiving dual antiplatelet therapy after acute coronary syndrome - significance, prevention and interdisciplinary management]

For secondary prevention of acute coronary syndrome, guidelines recommend dual antiplatelet therapy with acetylsalicylic acid and a P2Y12 receptor antagonist such as clopidogrel, prasugrel or ticagrelor for a period of 12 months. Premature discontinuation of dual antiplatelet therapy is associated with an increased risk of ischaemic events. However, antiplatelet therapy is also associated with an increased risk of bleeding that should not be under- or overestimated. To ensure an optimal care of patients receiving dual antiplatelet therapy after an acute coronary syndrome, an interdisciplinary group of experienced experts in the fields of cardiology, cardiac surgery, gastroenterology, anaesthesiology, intensive care and haemostaseology gathered bleeding-related information and developed recommendations relevant to daily clinical practice. These include the significance of bleeding events in the course of treatment, measures for bleeding prevention and the adequate care of patients with bleedings.

The emergence of cooperation from a single mutant during microbial life cycles

Cooperative behaviour is widespread in nature, even though cooperating individuals always run the risk of being exploited by free-riders. Population structure effectively promotes cooperation given that a threshold in the level of cooperation was already reached. However, the question how cooperation can emerge from a single mutant, which cannot rely on a benefit provided by other cooperators, is still puzzling. Here, we investigate this question for a well-defined but generic situation based on typical life cycles of microbial populations where individuals regularly form new colonies followed by growth phases. We analyse two evolutionary mechanisms favouring cooperative behaviour and study their strength depending on the inoculation size and the length of a life cycle. In particular, we find that population bottlenecks followed by exponential growth phases strongly increase the survival and fixation probabilities of a single cooperator in a free-riding population.