Sunnybrook Health Sciences Centre says it has conducted the world's first clinical trial of a new treatment for patients with blocked coronary arteries.
What's more, the study has shown the new treatment to be safe with promising success rates, the hospital said.The findings "are poised to change the way patients with blocked arteries are treated throughout the world," a statement from the hospital said.Twenty patients with a coronary artery completely blocked by plaque, a condition known as chronic total occlusion (CTO), received an injection of an experimental drug called MZ-004.The drug contains an enzyme that softens the plaque over a 24-hour period.That allows the patient to then undergo a traditional angioplasty, which involves advancing a guide-wire through the otherwise impenetrable blockage and having a stent inserted to re-open the artery and restore blood flow.Fifteen patients, or 75 per cent of those on the study, received a successful angioplasty after receiving the drug, even though previous attempts had failed. Results of the study, which was funded by the Canadian Institutes of Health Research, are being published in a medical journal called Circulation.Dr. Bradley Strauss, chief of Sunnybrook's Schulich Heart Centre and the founder of Matrizyme Pharma Corporation, which developed the drug, said the study indicates promising results for many coronary patients."Due to the traditionally low success rate of angioplasty in patients with completely blocked arteries, many patients turn to bypass surgery or treatment with medications alone," said Strauss, also a professor of medicine at the University of Toronto."This treatment provides patients with the option of receiving angioplasty rather than having more invasive treatment with bypass surgery or living with pain and discomfort."About 20 per cent of patients who have an angiogram, a test to look at heart flow in an artery, are diagnosed with CTO. Of that number, fewer than 10 per cent have an angioplasty. About 25 per cent have a bypass operation and the rest are likely treated with medication alone, Sunnybrook said.Louis Waldman, a 49-year-old police officer and father of five, said receiving the drug followed by angioplasty helped him."I was feeling tired and worn out and a trip to my family doctor revealed that I had a clogged right artery. After one angioplasty attempt didn't work, I found Dr. Strauss," he said."My discomfort went away almost immediately after the successful angioplasty. I could breathe and had no chest pains. It's a vast improvement. I'm pretty much back to normal."