While a drug commonly used to treat chest pain is safe for people with certain implantable defibrillators, it doesn’t significantly decrease the likelihood of the first occurrence of an irregular heart beat or death, according to a new clinical trial.
Researchers launched the trial in 2011 after previous studies suggested the drug, called ranolazine, might cut the incidence of ventricular tachycardia, ventricular fibrillation, or death in this high-risk population.
A limited number of anti-arrhythmic therapies have been developed and tested over the last 25 years, leaving doctors and patients with older treatment options that often come with substantial side effects.
Some good news
The trial, which researchers conducted at 95 centers in the United States and Canada, revealed a bright spot for ranolazine, however: the drug lowered the number of recurring episodes of ventricular tachycardia, a fast, abnormal heart rate that begins in the ventricles (lower chambers of the heart) and can cause dizziness, lightheadedness, palpitations, or loss of consciousness.
The results suggest there could be a potential role for ranolazine in patients with implantable cardioverter defibrillators (ICDs) who can’t tolerate other drugs or aren’t eligible for ablation, a procedure that attempts to correct faulty heart rhythms.
“This drug is already on the market to treat chest pain, and while it didn’t provide the revolutionary results we had hoped for, I think there’s a place for it in the toolbox of treatments for select patients,” says Wojciech Zareba, professor of cardiology at the University of Rochester Medical Center and lead author of the study, which appears in the Journal of the American College of Cardiology.
“Ventricular tachycardia is the most common arrhythmia that individuals with ICDs experience,” Zareba says. “This drug could be an option for patients who haven’t had success with other therapies.”
Safe option
The double-blind, placebo-controlled randomized trial included 1,012 people with cardiomyopathy, a disease of the heart muscle that makes it difficult for the heart to pump blood throughout the body. All participants had ICDs and were at high risk for ventricular tachycardia (VT) and ventricular fibrillation (VF), irregular heart rhythms that are associated with increased hospitalizations and death.
The average age of participants was 64 years and 18 percent were women. Half received 1,000 mg of ranolazine orally twice daily and half received a placebo pill. Approximately 34 percent of patients who took ranolazine experienced ventricular tachycardia, ventricular fibrillation, or death, compared to 39 percent of individuals in the placebo group.
Though the number in the ranolazine group was lower, the difference between groups was not large enough to be considered “significant” or meaningful.
Upon further analysis, researchers found that the risk for recurrent ventricular tachycardia was 30 percent lower in patients randomized to receive ranolazine compared with placebo.
“This trial provides clinicians with one more treatment option… which is huge given that this is a very sick population for which we often have limited therapies.”
Mehmet Aktas, associate professor of cardiology and a member of the UR Medicine Heart & Vascular team enrolled 20 patients at the University of Rochester Medical Center.
“Through this trial we learned that ranalozine can be administered safely in patients with life threatening abnormal heart rhythms and that it can be given concomitantly with other commonly used antiarrhythmic drugs,” he says.
“This trial provides clinicians with one more treatment option for patients who have recurrent lethal arrhythmias, which is huge given that this is a very sick population for which we often have limited therapies.”
A major limitation of the study was that nearly half of the study participants discontinued the study drugs (both ranolazine and placebo).
The National Heart, Lung, and Blood Institute at the National Institutes of Health funded the work. Gilead Sciences, Inc., the biopharmaceutical company that markets ranolazine, donated the drug and placebo needed for the trial.
Source: University of Rochester
