Many patients undergoing coronary angiography are found to have no significant coronary artery disease (CAD) despite angina equivalent symptoms and/or electrocardiographic abnormalities suggestive of myocardial ischemia. The aim of this study is to systematically assess patients with angina equivalent symptoms despite normal coronary angiograms and to evaluate their symptoms according to a defined algorithm.

All consecutive patients who had coronary angiography at the Luzerner Kantonsspital between July 1st 1996 and July 31st 2008 and who had no significant coronary stenoses (no coronary stenoses ≥ 50%) were recruited for this study. Patients are extensively examined during angiography using acetylcholine infusion and fast atrial pacing. According to the result of the additional invasive examination (vasospasm, vasoconstriction, vasodilation; symptoms during examination) a distinct diagnosis is attributed to the patients (small vessel disease, vasospastic disease, hypertensive heart disease, rhythm disorder, or extracardiac thoracic pain including pulmonary hypertension). Patients are followed-up after 10 years and prognosis of these patients is assessed (including mortality, cardiovascular events, re-angiography, functional status after 10 years).

Inclusion Criteria:

• Coronary angiography at the Luzerner Kantonsspital between July 1st 1996 and July 31st 2008
• No significant coronary stenoses (no coronary stenoses ≥ 50%)

Exclusion Criteria:

• Severe valvular heart disease
• Severe congestive heart failure

All consecutive patients who had coronary angiography at the Luzerner Kantonsspital between July 1st 1996 and July 31st 2008 and who had no significant coronary stenoses (no coronary stenoses ≥ 50%) were recruited for this study.