It is well documented that participation in cardiac rehabilitation (CR) programs improves risk factor control and therapy adherence, enhances quality of life and reduces recurrent events. However, the current incomplete fulfilment of guideline recommended CR targets is a matter of concern. Also, while international recommendations advocate program flexibility and individual tailoring, most of the current CR programs are rigid, time-limited and demand substantial health care resources. Therefore, all main international heart associations have claimed for the reengineering of CR to enhance access, adherence, and effectiveness. The general call is for the development of innovative and cost-effective CR programs oriented to modify lifestyle and behaviour with sustainable results and that may be easily integrated in the pre-existing health care structures.eHealth i.e. the use of electronic communication and information technologies in health care, offers a whole new array of possibilities to provide clinical care. These include for example distance monitoring via telecommunication and sensors, interactive computer programs and smart phone applications. While there are thousands of available eHealth applications on the market, only a small minority have been tested in a controlled manner with proper guidance from health care personnel. The study will assess the efficacy of a web-based patient support application as a complement to traditional exercise-based CR for improvement of secondary prevention outcomes in post-MI patients, compared with usual care. The hypothesis is that the intervention enhances patient adherence to lifestyle advice (exercise training, daily physical activity, healthy diet and tobacco abstinence) and medication, resulting in better risk factor control and prognosis as well as increased self-rated health. A secondary hypothesis is that complementing the application with an activity tracker (accelerometer in a smart bracelet) will enhance the effect of the intervention.