Evaluation of a Preparatory eHealth Intervention to Support Cardiac Patients During Their Waiting Period.

The goal of this pilot study is to evaluate the feasibility of an eHealth intervention for cardiac patients during their waiting period before their rehabilitation. The main questions it aims to answer are: * What is the feasibility of an eHealth intervention designed for cardiac patients with a low socio-economic position during the waiting period before their cardiac rehabilitation. * What is the potential effect of this intervention on patient activation and feelings of certainty and guidance. Participants will: * Be randomised in either intervention or control group * Fill in a questionnaire at the start of their waiting period (after release from the hospital) * Use the eHealth intervention during their waiting period (usually 2 to 6 weeks)(intervention group only) * Fill in a questionnaire at the start of their rehabilitation Researchers will compare intervention and control group to see if the intervention has improved patient activation and feelings of certainty and guidance.