ANAHEIM, Calif., Nov. 14 (UPI) -- An experimental drug that influences metabolism in heart arteries appears to allow patients with chest pain exercise longer, researchers said Wednesday.
In addition, patients who took ranolazine experienced fewer episodes of angina during an average week than similar chest pain patients who were taking dummy medication, doctors told the annual scientific sessions of the American Heart Association.
Ranolazine represents a new class of drugs known as pFOX -- partial fatty acid oxidation -- inhibitors. The drugs maintain important metabolic functions within the blood vessels without accumulating toxic lactic acid. That translates into delay or prevention of angina pain.
All patients in the study were able to walk further on a treadmill test, said Dr. Bernard Chaitman, professor of medicine at the St. Louis University School of Medicine in Missouri. "But the patients on ranolazine were able to continue 24 seconds longer than placebo patients."
The placebo patients had showed a 92-second improvement from a starting point of 7.5 minutes. The patients on the drug were able to exercise 116 seconds longer than their starting point.
While the 24-second improvement may not appear significant, Dr. Rose Marie Robertson said that increase represents considerable effort. She explained the treadmill test used in the study increases in difficulty every three minutes, bumping up the speed and incline for the patient. She said patients reached Stage 3 at baseline and the placebo patients finished at Stage 3.
"To get even 30 seconds at Stage 4 -- accomplished by the patients on the drug -- is really quite impressive," Robertson said.
Chaitman said the extra time on the treadmill means patients should be able to better handle the activities of daily living.
At the start of the study, he said the average patient had four episodes of angina. Those taking the drug had about one episode less a week than the patients on placebo.
The improvements in exercise and decrease in anginal episodes both reached statistical significance, Chaitman said.
The Combination Assessment of Ranolazine in Stable Angina study enrolled 823 patients. Exercise testing was performed at two, six and 12 weeks.
Robertson said the study also was interesting because patients with stable angina are becoming more difficult to find since many of these patients undergo surgical treatment to relieve the condition.
