Summit Highlights Advances in Cardiac Research
By Eleni Kanavas
Researchers, clinician-scientists, staff and students filled the seats inside Harrison Hall for the fifth annual Canadian CTO Summit hosted by Sunnybrook Research Institute on June 11, 2012.
The full-day research conference, Translating Science to the Clinic, focused on the clinical and research aspects of chronic total occlusions (CTOs). The annual event is organized by the Canadian Institutes of Health Research (CIHR) team in occlusive vascular disease, co-led by Dr. Graham Wright, director of the Schulich Heart Research Program and senior scientist in physical sciences at SRI.
"We've come to the end of our CIHR funding for the team, and in the past year, we've seen a lot of exciting publications and productivity. This is our opportunity to get together to discuss some of the advances and directions we want to take, and brainstorm new opportunities for advancing the state-of-the-art in management of patients with chronic total occlusions," said Wright, who holds the Canada Research Chair in Imaging for Cardiovascular Therapeutics. He is also a professor at the University of Toronto.
Chronic total occlusions are blocked coronary arteries that affect about 20% of patients with coronary artery disease. Studies have shown that revascularization, a surgical procedure that restores blood supply to an organ, of coronary CTOs can significantly improve angina and left ventricular function.
The day was divided into three sessions: state-of-the-art cardiovascular treatments and therapies, the benefits of cardiac revascularization and advances in new imaging techniques to treat CTOs.
The summit also featured keynote lectures from interventional cardiologists Dr. Antonio Micari from Villa Maria Eleonora Hospital in Palermo, Italy, and Dr. Marc Jolicoeur from Montreal Heart Institute in Montreal, Canada. Micari spoke about the advanced techniques for below-the-knee CTO recanalization, and Jolicoeur presented a review of the evidence for and against CTO intervention, and what studies are needed to further the field.
Dr. Bradley Strauss, chief of the Schulich Heart Centre at Sunnybrook and senior scientist in biological sciences at SRI, moderated the second session on the outcomes of chronic total occlusion and who to treat. He discussed the importance of translating an idea into a therapy by using the collagenase trial as an example. Strauss, who is a co-principal investigator of the CIHR team and a professor at the University of Toronto, developed collagenase, an enzyme-based therapy, more than a decade ago. Results since then have shown progress in treating patients with blocked coronary arteries.
In January 2012, Strauss and colleagues published results from the world's first clinical trial using his novel approach in the journal Circulation. The study evaluated four dose levels of collagenase and looked at safety and efficacy of the therapy to facilitate guide wire crossings in the blocked arteries. Strauss used a microcatheter to inject collagenase into the occlusion to soften plaque buildup in the artery and allow for insertion of a stent—a small, expandable stainless steel tube used to improve blood flood—the next day. Twenty male patients who had previous failed attempts participated in the study, a collaboration between Sunnybrook and St. Michael's Hospital. Strauss reported a 75% success rate in crossing and stenting 15 out of the 20 patients with soft-tip guide wires.
Next, Strauss is leading a large, multisite clinical trial in Canada and the U.S., expected to begin later this year. An estimated 200 to 250 patients will participate. "The primary point will be guide wire crossing, as well as quality of life," he said. "Hopefully this will be the trial that will allow us to move forward and actually use this product in everyday life."
