Impact of Ranalozine on Coronary Microcirculatory Resistance- A Prospective Single Center Study to Evaluate the Effect of Ranalozine in Microcirculatory Resistance (MICRO Study)

Study start date: May 1, 2012

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