Background: Between 6-25% of patients undergoing coronary angiography for acute coronary syndrome (ACS) have non-obstructive coronary artery disease (NOCAD).
Methods: One-hundred and eighty patients presenting with an ACS who were taking part in a risk factor modification study and had undergone coronary angiography were examined. We compared baseline characteristics, medical treatment and 12-month outcome in patients with NOCAD (<50% lumen diameter stenosis at coronary angiography) and obstructive CAD (> or = 50% lumen diameter stenosis at coronary angiography).
Results: There were 29 (16%) patients with NOCAD and 151 (84%) with obstructive CAD (CAD). Patients with NOCAD were significantly younger, more likely to be female, had higher mean total cholesterol and LDL levels, and fewer received cardiac rehabilitation, treatment with statins, aspirin, ACE inhibitors, beta-blockers or clopidogrel. Over the next 12-months, there was no mortality or myocardial infarction in the NOCAD group compared to 2% in the CAD group, but 14% with NOCAD were readmitted for a cardiovascular cause including 2 patients (7%) who underwent percutaneous coronary intervention (PCI).
Conclusions: Patients presenting with ACS and NOCAD may not have a completely benign prognosis, and preventative strategies and therapies such as statins in this group of patients appear to be under-utilised.