Does ranolazine have a place in the treatment of acute coronary syndromes?

Extended-release ranolazine: critical evaluation of its use in stable angina

Coronary heart disease is the major cause of morbidity and mortality throughout the world, and is responsible for approximately one of every six deaths in the US. Angina pectoris is a clinical syndrome characterized by discomfort, typically in the chest, neck, chin, or left arm, induced by physical exertion, emotional stress, or cold, and relieved by rest or nitroglycerin. The main goals of treatment of stable angina pectoris are to improve quality of life by reducing the severity and/or frequency of symptoms, to increase functional capacity, and to improve prognosis. Ranolazine is a recently developed antianginal with unique methods of action. In this paper, we review the pharmacology of ranolazine, clinical trials supporting its approval for clinical use, and studies of its quality of life benefits. We conclude that ranolazine has been shown to be a reasonable and safe option for patients who have refractory ischemic symptoms despite the use of standard medications (for example, nitrates, beta-adrenergic receptor antagonists, and calcium channel antagonists) for treatment of anginal symptoms, and also provides a modestly improved quality of life.

Recent advances in the management of chronic stable angina II. Anti-ischemic therapy, options for refractory angina, risk factor reduction, and revascularization

The objectives in treating angina are relief of pain and prevention of disease progression through risk reduction. Mechanisms, indications, clinical forms, doses, and side effects of the traditional antianginal agents - nitrates, β-blockers, and calcium channel blockers - are reviewed. A number of patients have contraindications or remain unrelieved from anginal discomfort with these drugs. Among newer alternatives, ranolazine, recently approved in the United States, indirectly prevents the intracellular calcium overload involved in cardiac ischemia and is a welcome addition to available treatments. None, however, are disease-modifying agents. Two options for refractory angina, enhanced external counterpulsation and spinal cord stimulation (SCS), are presented in detail. They are both well-studied and are effective means of treating at least some patients with this perplexing form of angina. Traditional modifiable risk factors for coronary artery disease (CAD) - smoking, hypertension, dyslipidemia, diabetes, and obesity - account for most of the population-attributable risk. Individual therapy of high-risk patients differs from population-wide efforts to prevent risk factors from appearing or reducing their severity, in order to lower the national burden of disease. Current American College of Cardiology/American Heart Association guidelines to lower risk in patients with chronic angina are reviewed. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial showed that in patients with stable angina, optimal medical therapy alone and percutaneous coronary intervention (PCI) with medical therapy were equal in preventing myocardial infarction and death. The integration of COURAGE results into current practice is discussed. For patients who are unstable, with very high risk, with left main coronary artery lesions, in whom medical therapy fails, and in those with acute coronary syndromes, PCI is indicated. Asymptomatic patients with CAD and those with stable angina may defer intervention without additional risk to see if they will improve on optimum medical therapy. For many patients, coronary artery bypass surgery offers the best opportunity for relieving angina, reducing the need for additional revascularization procedures and improving survival. Optimal medical therapy, percutaneous coronary intervention, and surgery are not competing therapies, but are complementary and form a continuum, each filling an important evidence-based need in modern comprehensive management.

Metabolic efficiency with ranolazine for less ischemia in non-ST elevation acute coronary syndromes (MERLIN TIMI-36) study

Ranolazine is a piperazine derivative believed to reduce anginal symptoms by preventing ischemia-mediated sodium and calcium overload in myocardial cells through inhibition of the late sodium current (late INa). Three small studies demonstrated the antianginal efficacy of ranolazine alone and in combination with betablockers or calcium channel blockers on conventional end points such as total exercise duration and time to ischemia/angina on a treadmill; however, questions of safety related to QT prolongation, efficacy in women and potential utility in higher risk populations remained. Metabolic Efficiency with Ranolazine for Less Ischemia in Non-ST Elevation Acute Coronary Syndromes-Thrombolysis in Myocardial Infarction (MERLIN-TIMI) 36 was a large randomized, double-blind, placebo-controlled trial, which evaluated the efficacy and safety of ranolazine initiated acutely and continued as chronic therapy following a non-ST-segment elevation acute coronary syndrome event. A total of 6560 patients were randomized 1:1 to ranolazine or placebo; the primary efficacy end point of the trial was a composite of cardiovascular death, myocardial infarction or recurrent ischemia. The key safety end points were death from any cause and symptomatic documented arrhythmia. Although statistically significant differences between the ranolazine and placebo groups were not reached in the primary efficacy analysis or in the major secondary outcome end point analyses (cardiovascular death, myocardial infarction or severe recurrent ischemia), the individual component of recurrent ischemia was significantly reduced by ranolazine, and ranolazine was demonstrated to be safe.