Advanced technologies and improved patient selection have increased the rates of successful percutaneous revascularization of chronic total occlusions (CTOs). The biggest hurdle to offering more patients the option of PCI for CTOs is now more a matter of physician education, rather than of technique or technology.
PCI vs. CABG
Evidence is mounting, albeit from non-randomized studies, that patients who have their CTOs revascularized enjoy a better quality of life and a survival advantage compared with those who receive optimal medical therapy.
The choice of revascularization includes PCI or bypass surgery. In the last several years, interventional cardiologists have refined their catheter-based techniques for opening up CTOs. The most prolific practitioners, those performing up to 100-plus CTO PCIs per year on unselected patients, clock a 91 percent success rate, according to William Lombardi, MD, medical director of the cardiac cath labs at St. Joseph Hospital in Bellingham, Wash., and an adjunct clinical assistant professor of cardiovascular medicine at Stanford University in California. Vendors also have responded by designing CTO-specific guidewires and catheters that deliver better torquability and penetration power. Yet, one of the biggest predictors that patients will be referred for bypass surgery is if they have a CTO, says Lombardi.
Why aren’t more patients with CTOs being referred for PCI? The problem, says Lombardi, is multi-factorial. First, there are too few interventionalists with the experience to tackle all levels of CTO complexity. While a handful of U.S. interventionalists perform more than 100 CTO PCIs annually, many interventionalists average only 10 to 15 cases per year—and many of these cases are Level 1, or “simple,” lesions. “If you work only on easy cases, you won’t improve because only 15 percent of all CTOs are Level 1,” says Lombardi. “Our challenge is to educate and proctor physicians, to teach them how to achieve success so they can increase their volume and maintain their technical skills.”
Also, current guidelines do not support performing PCI for CTOs. There is no Class 1 indication for the procedure and the guidelines are not likely to change unless evidence to support the procedure emerges from randomized controlled trials. However, there are no such trials on the horizon because they would be too costly, says Aaron Grantham, MD, an interventional cardiologist at Saint Luke’s Mid-America Heart Institute in Kansas City, and an associate professor of medicine at the University of Missouri-Kansas City School of Medicine. “We have retrospective data from single-center studies that indicate percutaneous revascularization of CTOs is better than optimal medical therapy,” Grantham says. “I have no problem speaking to these data with my patients, but it is not enough for those who make recommendations about appropriateness and indications,” Grantham adds.
The only patients with CTOs in whom it is deemed appropriate to perform angioplasty are those who have symptoms despite maximum medical therapy. There are emerging data, however, from non-CTO patients, including from the COURAGE trial, that indicate ischemic burden is predictive of mortality and that PCI is better than medical therapy alone at relieving ischemia. The evidence also suggests that when the ischemic burden has been reduced by at least 5 percent, survival is better compared with no reduction, Grantham says.
A third confounding factor to the slow adoption of employing PCI for CTOs in the U.S. is reimbursement, which doesn’t equate to the time and effort involved. These complex procedures can last up to six hours, involve multiple stents and multiple wires and utilize much more contrast material and radiation than a non-CTO PCI. In 2006, Kirk Garratt, MD, from Lenox Hill Heart and Vascular Institute in New York City, testified before a CMS committee about the difficulty of CTO PCI and the inadequacy of reimbursement. The initiative was tabled. “There was no appetite for increasing reimbursement in 2006 and it’s even worse now,” Grantham says.
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