Follow-up Data: Personnel unaware of the stress testing results contacts each subject or an immediate family member and the date of this contact was used for calculating the follow-up time duration. Outcome data is collected from a standardized questionnaire and determined from patient interviews at the outpatient clinic or by telephone interviews. Reported clinical events are confirmed by review of the corresponding medical records in our electronic Hospital Information System (HIS), contact with the general practitioner, referring cardiologist or the treating hospital. Cardiac death and nonfatal myocardial infarction are registered as major cardiac events. Cardiac death is defined as death from any cardiac cause (lethal arrhythmia, myocardial infarction, or congestive heart failure) or sudden unexpected death occurring without another explanation. Myocardial infarction is defined by angina of >30 minutes duration and either ST segment elevation of ≥2mm in 2 consecutive ECG leads or a rise in troponin T of ≥0.03µg/l.