The purpose of this study in humans with stable coronary artery disease (CAD) treatable by percutaneous intervention (PCI) is to evaluate the efficacy of Enhanced External Counterpulsation (EECP) with regard to coronary collateral growth.

Inclusion Criteria:

• Age > 18 years, written informed consent to participate in the study

Exclusion Criteria:

• 1. Pregnancy (serum β-HCG<2 IU/l for all female volunteers)

Baseline History:

1. Endurance exercise 5 days before and the days between the exams
2. History of cardiovascular disease or surgery, including arterial hypertension, Raynaud phenomenon, recurrent migraine, or any cardiac rhythm disorder
3. History of metabolic disorder, particularly diabetes mellitus
4. History of respiratory, renal, hepatic or cerebral disease
5. Allergic reactions to Luminity or its components
6. Cardiovascular medication
7. Illness characterized by acute phase response
8. Anaemia with haemoglobin levels < 110 g/L

Baseline Physical Examination:

1. Peripheral artery disease

Baseline Echocardiogram:

1. Valvular heart disease
2. Aortic aneurysm (any abnormality of ascending aorta, aortic arch or descending aorta)
3. Intra- or extracardiac shunt
4. Systolic or diastolic left ventricular (LV) dysfunction
5. LV-hypertrophy
6. Pulmonary arterial hypertension