A total of consecutive patients in the CAS registry of the Cardiovascular Center at Korea University Guro Hospital and who had resting chest pain without significant coronary lesions (luminal narrowing <50%) underwent a provocation test with Ach infusion during coronary angiography from November 2004 to May 2012 will be reviewed. Among them, patients with documented cardiovascular disease and/or any other serious medical condition, such as an increased serum creatinine level (>2mg/dl), will be excluded. Patients will be excluded due to incomplete data. The investigators will register hypertensive patients who are currently using antihypertensive medications. The study population will be divided into quartiles based on rising systolic BP, diastolic BP, and pulse pressure. CAS+chest pain(CP) means>70% luminal narrowing on Ach provocation test. and/or concurrent typical chest pain.