Cath Lab Digest

For this month’s discussion, I wanted to continue with the SFA revascularization conundrum. Where do we think the SFA interventional data are going? Do we still believe that the data will “prove” that a durable patency is possible in many if not all our “real-world” patients with claudication and present with SFA disease to include long total occlusions?

Currently, the data suggest that the answer is No. The “plumbers” of the group will disagree, but clearly, the benefit from endovascular therapies seems to be primarily clinical (“doctor, my leg feels better”) without the anatomic durability of patency.

That being “true”, the critical question remains: What is restenosis? The current level of restenosis that most trials have used comes from surgical sonographic surveillance data and runs between 2.4–2.5 x baseline. In the surgical literature this corresponds to a 50% restenosis. The level of ≥ 3.5 has suggested a more critical > 70% stenosis. Unfortunately, the data for these numbers have not been published or are not widely available; however, one could surmise that the actual critical restenosis is much smaller than the perceived number currently in the literature. This would also correlate with the fact that the “clinical” patency of patients with isolated SFA disease is far better, despite the “anatomic” patency being nearly 50/50 at 2 years. One such study, called DEFINITIVE, which I am leading with my esteemed colleagues James McKinsey, MD, from Columbia, NYC, and Thomas Zeller, MD, from Bad Krozinger, Germany, evaluates atherectomy in “real-world” patients with either claudication or critical limb ischemia. DEFINITIVE is enrolling patients with lesions up to 20 cm in length and will number 800 total patients. This trial, the largest ever to date, will use the 3.5 surrogate sonographic endpoint as a critical restenosis metric, however, it will still report the 2.5 level as well. I would bet that the numbers for critical restenosis will be much more in line with the clinical patency that we have seen with most modalities of endovascular therapy. The correlation with the clinical benefit from a walking test will likely be in line with recent information published as well.

Ultimately, the best metric would be to have a trial that measures walking tests before and after with the duplex data to correlate these numbers to “clinical” and “anatomic” to a much better degree. Many trials, recently, DURABILITY and others, have attempted to have walking tests as part of the trial, but have had enrollment problems because of the difficulties from investigators to obtain pre and post studies.

Let me know what you think and we will reconvene next month.

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Dr. Garcia received his B.A. and M.D. degrees from the University of Arizona. He was an Intern and Resident at Parkland Memorial Hospital, University of Texas at Southwestern in Dallas, Texas. He received his training in Cardiology at the University of Iowa Hospitals and Clinics in Iowa City, Iowa, and as an interventional cardiologist at the Beth Israel Deaconess Medical Center, Harvard Medical School. Further, he received his peripheral vascular training at St. Elizabeth’s Medical Center, Tuft’s University, Boston, Massachusetts. He then served as the Chief of Vascular Medicine and Peripheral Vascular Interventions for the Florida Heart Group in Orlando, Florida. Dr. Garcia returned to Harvard’s Beth Israel Hospital as a full-time interventional cardiologist and Director of the Peripheral Cardiovascular Program and Peripheral Interventions at the Beth Israel Deaconess Medical Center as well as the Director of the Interventional Fellowship Program. This program developed into one of the busiest in the city of Boston, performing over 600 peripheral procedures per year.

Dr. Garcia has now returned to St. Elizabeth’s Medical Center as Chief of the Section of Interventional Cardiology and as Associate Director of the Vascular Medicine Program. Dr. Garcia’s work has largely focused on arterial occlusion-reperfusion models and the efficacy of therapeutic modalities or interventions with regard to free radical generation or endovascular stenting outcomes. Dr. Garcia continues his research interests in a wide variety of studies including acute MI studies, unstable angina studies, interventional trials, peripheral interventional trials, angiogenesis trials, imaging modality studies, and numerous device trials for both the coronary and peripheral circulations. His work has been presented in numerous manuscripts, abstracts, textbooks and textbook chapters.