Impact of Ranolazine on Coronary Microcirculatory Resistance

Inclusion criteria

• - Patients with subjective symptoms of ischemia without flow limiting angiographic CAD (<50% epicardial coronary stenosis) and abnormal IMR (>20 U).
• Definition of ischemia (any one):

• chest pain with dynamic ischemic ECG changes (t wave inversions or > 1 mm ST depressions
• Exercise treadmill testing induced chest pain with ≥1 mm of downsloping or flat ST segment depression during exercise or recovery; ≥2 mm of ischemic ST depression at a low workload (stage 2 or less or ≤130 beats/min); early onset (stage 1) or prolonged duration (>5 min) of ST depression; multiple leads (>5) with ST depression
• Nuclear stress perfusion defect > 10%
• Stress echocardiogram with stress induced wall motion abnormality

Exclusion criteria

• - Age < 18 yrs
• Flow Limiting epicardial CAD >50%
• Life expectancy < 6 months
• Recent (<1 week) myocardial infarction or positive biomarkers
• Severe aortic stenosis
• Contraindications to IMR testing including inability to utilize antithrombotic therapy and/or intravenous adenosine
• Contraindications to Ranolazine therapy:
• Patients with known hepatic insufficiency, prolonged QT or renal failure (GFR < 60)
• use of drugs that inhibit CYP3A such as diltiazem, verapamil, ketoconazole, macrolides and HIV protease inhibitors
• Pregnancy, breastfeeding
• Patients taking drugs which prolong QT interval