Inclusion Criteria:

   - Males and females, age 18 to 80 years

   - Diagnosis of chronic angina due to obstructive coronary artery disease that is
   refractory to drug therapy and unsuitable for revascularization via coronary artery
   bypass graft or percutaneous coronary intervention

   - Angina class II-IV based on Canadian Cardiovascular Society Classification of Angina
   Pectoris

   - Adequate hematologic (hemoglobin ≥ 10 g/dL, absolute neutrophil count > 1.2 × 10^3 per
   μL and platelet count ≥ 75,000 per μL), hepatic (alanine aminotransferase and
   aspartate aminotransferase ≤ 3 x ULN; total bilirubin ≤ 2 x ULN), and renal function
   (glomerular filtration rate > 29 mL/minute/1.73 m2)

   - Adequate birth control if of child-bearing potential

   - Must be willing and able to provide informed consent

Exclusion Criteria:

   - ST elevation myocardial infarction (STEMI) or non-ST elevation myocardial infarction
   (NSTEMI) not requiring revascularization, transmural myocardial infarction or cerebral
   vascular accident within the past 30 days

   - New York Heart Association Function Class III or IV or left ventricular ejection
   fraction < 25% within the 6 weeks prior to the screening visit

   - HbA1c ≥ 8.5%, SBP <90 or >180 mmHg, DBP >100 mmHg

   - Other concurrent medical conditions that could jeopardize the safety of the subject or
   objectives of the study