Ranolazine for Microvascular Angina
Guideline Recommendations
- The European Society of Cardiology recommends ranolazine as add-on therapy in patients with inadequate symptom control while on beta-blockers and/or calcium channel blockers, or as part of initial treatment in properly selected patients (Class IIa, Level B recommendation) 1, 2
Evidence Quality and Limitations
- A larger trial in microvascular angina patients did not show superiority of ranolazine compared with placebo on the frequency of angina or reduction in myocardial ischemia evaluated by single-photon emission computed tomography 3
Mechanism Supporting Use in Microvascular Disease
- Ranolazine inhibits the late sodium current, preventing intracellular calcium overload during ischemia—a key pathophysiologic mechanism in microvascular dysfunction 1, 2
- Ranolazine does not significantly affect heart rate or blood pressure, making it particularly useful when other antianginal agents are limited by bradycardia or hypotension 1, 2
Ideal Patient Selection
- Ranolazine is most appropriate for microvascular angina patients with bradycardia or hypotension preventing use of beta-blockers or calcium channel blockers 1, 2
- Ranolazine may be beneficial for patients with diabetes mellitus, as it reduces HbA1c levels 1, 3
- Ranolazine may be more effective than other agents in patients with left ventricular hypertrophy 1, 3
Critical Contraindications and Precautions
- Ranolazine is absolutely contraindicated in hepatic impairment or liver cirrhosis due to dose-dependent QT prolongation risk 1, 2, 3
- Ranolazine causes dose-related QTc prolongation, though torsades de pointes has not been observed at therapeutic doses 1
- Ranolazine increases digoxin concentrations—use with caution if co-administered 1, 2, 3
- Use caution with strong CYP3A inhibitors 1, 2