Cath Lab Digest

Well the conundrum of the SFA got “clearer” —— the Zilver PTX data were released at the TCT in Washington, D.C. this past week. Given the high anticipation, the data presented initially suggested that the critical concern of in-stent restenosis in the superficial femoral artery (SFA) has been solved. Fantastic results at 12 months between the PTA and Zilver PTX groups of 236 patients (251 lesions) and 235 patients (247 lesions), respectively. The Zilver stent with a paclitaxel coating without a carrier/polymer came in at 83% vs. 65% (optimal PTA). If we compare the Zilver group with the suboptimal PTA vs. bare-metal stenting group, the 12-month patency was 89.9% vs. 73%, respectively. The stent fracture rate was 0.9% in the entire cohort.

An amazing study. Now let’s get to the specifics. The reported patency is listed on a Kaplan-Meier curve at 83.1%, then 76.7%, which reflects the total number of patients known at the time of the 12-month visit, then the entire cohort at the 13-month endpoint. This was bit of statistical manipulation of results from the “window” of assessments of the 12-month endpoint ± 30 days. Moreover, the study used a PSV of only 2.0 (compared with other studies using 2.4 or 2.5). This very conservative measure still allowed a remarkable patency rate for both the paclitaxel stent and optimal balloon angioplasty.

Even more important to the above quandary, where the data truly lie is in the fact that the lesion length as tested was only 53 mm. Again, not a real-world experience and, more importantly, we have, as has the FDA, accepted that the PTA arm of any trial would sit at 33% (OPC-Rocha-Singh CCI 2007), but the “optimal” angioplasty arm resulted in a primary patency of 65% —— a far cry from the accepted 33%, and if driven by the OPC data, an acceptable outcome for any “stent” arm in a current trial.

I truly commend Dr. Dake and his team for this presentation and the efforts of so many to show one of the first “true” scientific outcomes in the SFA. Critically, this study does not answer the daunting question of primary patency in patients we see every day with longer lesions than 5 cm. Moreover, it will be critical to see the outcome of these results at 2 years in both groups —— stent and angioplasty. However, this is a great first step to the ultimate question of drug elution in the SFA.

Let’s see where the discussion goes from here and pick it up next month.

Lawrence A. Garcia, MD

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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.