There are limited treatment options for patients at high risk of ventricular arrhythmic events. Beta-blockers alone do not provide enough protection, sotalol has limited effectiveness, and amiodarone although effective in some groups of patients is used infrequently due to its side effects and limitations of a long-term use. Ischemia and cardiomyopathies are associated with a sodium overload of myocardial cells. Late sodium current plays a pivotal role in this process. Sodium overload leads to calcium overload of myocardial cells with consequent increased vulnerability of myocardium to ventricular tachyarrhythmias as well as increased impairment of diastolic relaxation of myocardium thereby augmenting the risk of ischemia and myocardial damage.
Ranolazine is a novel drug with anti-ischemic and antiarrhythmic properties that uniquely blocks late sodium current, decreases intracellular calcium overload, and improves diastolic relaxation of the ventricles. The antiischemic and antiarrhythmic properties of ranolazine might decrease the likelihood of arrhythmic events and improve the clinical course of patients with ventricular arrhythmias.
We designed a randomized double-blind placebo-controlled clinical trial enrolling 1,440 high-risk ICD patients who will be treated with ranolazine or placebo in addition to optimal medical therapy to test the hypothesis that late sodium current blockade contributes to significant reduction in the risk of arrhythmic events or death in high-risk ICD/cardiac resynchronization therapy-D patients.