Implementing the evidence base for the management of chronic disease is as challenging as discovering which interventions are effective. The HEARTS collaboration (Heart disease Evidence-based Audit and Research in Tayside Scotland) is achieving that goal for the secondary prevention of coronary heart disease (CHD by linking national databases to manually validated hospital and family practice electronic patient records. Specific data from the system is fed back to practices in a facilitated educational process and through the NHS intranet. This paper describes some of the key features of this strategic decision support system. All residents of the Tayside region of Scotland (n=484,013 mid year estimate 2002) are covered by the system. 9,828 patients who have suffered a myocardial infarction(MI) or who have undergone angioplasty or bypass surgery are registered on the system. Improvements in clinical status and prescribing of effective therapies are 5-10% greater than elsewhere in Scotland.