BP was measured with a noninvasive BP monitoring device with the patient lying on the angiographic table after a five-minute rest (Patient monitoring system, NP 30:Philips, Amsterdam, The Netherlands). The first reading was discarded, and the mean of the next two consecutive readings was used. Next, coronary angiography was performed. Hypertension is defined as systolic BP ≥140mmHg and/or diastolic BP ≥90mmHg on at least two consecutive readings in the outpatient clinic. Patients taking antihypertensive medications are also categorized as hypertensives. Other Risk factors for CAS examined in this study include hyperlipidemia (total cholesterol level ≥200mg /dl or current medication with lipid-lowering drugs), diabetes (fasting blood glucose≥126mg /dl, and/or glycated Hemoglobin A1c level more than 6.5% or current use of medications), current smoker (active smoking within the past 12 months), and current alcohol user (at least 1 alcohol drinking a week).