Inclusion Criteria:

1. Single-vessel disease of the proximal LAD with a stenosis > 50% (multivessel disease only if further coronary vessel stenoses do not require treatment)
2. Patients with angina pectoris (CCS 1-4)
3. Asymptomatic patients if clear signs of ischemia in the segments supplied by the LAD as assessed by bicycle ergometry or treadmill and/or scintigraphically and/or stress echo
4. Patients for whom both methods of treatment are equally possible
5. Consensus between the cardiac surgeon and the cardiologist that both inclusion and exclusion criteria are met in the selected case
6. Informed consent of the patient.

Exclusion Criteria:

1. Patients < 18 years
2. Pregnancy
3. Previous coronary artery bypass surgery
4. Concomitant diseases that lead to a greater risk for each of the treatment strategies
5. Significant peripheral arterial occlusive disease
6. Concomitant disease with limited life expectancy (e.g. malignant tumours that have not been curatively treated)
7. Objective follow-up examination not possible due to physical or mental handicap
8. Participation in another study.

Angiographical exclusion criteria:

1. Left main stem stenosis
2. Multivessel disease for which surgical or interventional therapy on other vessel areas is required.
3. Diagonal/septal branch > 1.5 mm, which might be compromised by a stent
4. Need for acute intervention (e.g. acute myocardial infarction)
5. Total occlusion of the LAD