Efficacy Study of Oral Nicorandil on Improving Microvascular Function in Female Non-obstructive Coronary Artery Disease (CAD) Participants

Exclusion Criteria

• •Severe or uncontrolled hypertension (resting Systolic blood pressure \[SBP\] \>=160 millimeter of mercury (mmHg), or resting Diastolic blood pressure \[DBP\] \>=100mmHg at screening period)
• •Participants with shock (including cardiogenic shock), or hypovolemia
• •Severe hypotension (resting SBP\<90mmHg，or resting DBP\<60mmHg)
• •Significant valvular heart disease, congenital heart disease or cardiomyopathy
• •Congestive heart failure(New York Heart Association \[NYHA\] III-IV), echocardiographic ejection fraction\<45%
• •Acute pulmonary edema;
• •Hepatic or renal dysfunction, defined as:
• •* Serum Alanine Aminotransferase (ALT) \> triple of the normal value upper limit;
• •* Serum Aspartate Aminotransferase (AST) \> triple of the normal value upper limit
• •* Serum creatinine \> twice of the normal value upper limit
• •Glaucoma
• •Active peptic ulcer or active skin ulcer
• •Taking glyburide, phosphodiesterase type 5 (PDE-5) inhibitor, soluble guanylate cyclase stimulator(s)
• •Known to be hypersensitivity to nicorandil, nitrates, niacin, or any of the excipient
• •With contraindication to complete stress PET test
• •No legal ability and legal ability is limited
• •Participants unlikely to cooperate in the study or with inability or unwillingness to give informed consent
• •Child-bearing period women without effective contraceptive measures, pregnancy and lactation
• •Participation in another clinical trial within the past 30 days
• •Other significant disease that in the Investigator's opinion would exclude the participant from the trial