Methods
RECRUITMENT
The study was a two‐arm, randomized, controlled, outcome‐blinded trial involving older patients undergoing elective heart valve surgery with extracorporeal circulation (ECC). Recruitment took place at the Departments of Cardiac Surgery of the Kerckhoff Clinic in Bad Nauheim (Germany) and the University Hospital in Giessen (Germany). The patients were randomized (1:1 ratio) to either a paper‐and‐pencil–based cognitive training group or a control group. We applied the Short Form Health Survey (SF‐36) and the Cognitive Failures Questionnaire (CFQ) prior to surgery and 3 months after the cognitive training. Data were analyzed in a per‐protocol fashion.