Invasive findings in patients with angina equivalent symptoms but no coronary artery disease; results from the heart quest cohort study.

Background: The cause of angina in patients presenting at coronary angiography without significant coronary artery disease (CAD) has not been systematically assessed in a large prospective cohort. This study is aimed to identify the cause of angina in these patients.

Methods: This prospective cohort comprised 718 consecutive patients with angina equivalent symptoms and no CAD (defined as no coronary stenosis ≥ 50%) between January 1st 1997 and July 31st 2008. All patients underwent additional invasive testing (intracoronary acetylcholine administration, fast atrial pacing). Small vessel and vasospastic diseases were diagnosed according to symptoms and vessel reaction during testing.

Results: Mean age was 56.3 ± 11.0 years (range 15 to 81 years). A majority of 431 patients (60.0%) had small vessel and/or vasospastic disease (233 patients had small vessel disease, 145 vasospastic disease and 53 a combination of both). Additional 87 patients (12.1%) had another cardiac disease. Only in a minority of 200 study participants (27.9%) that the symptoms were attributed to an extracardiac problem. Patients with small vessel disease were more likely to be female, to have hypertension, to have a family history of CAD and to have effort-related symptoms. Patients with vasospastic disease were more likely to be current smokers, to have angina at rest or to present as myocardial infarction, and to have coronary sclerosis and/or endothelial dysfunction.

Conclusions: In a majority of patients with angina but no significant CAD, a cardiac cause of their symptoms can be found. Systematical invasive testing may help optimizing the medical management of these patients.