Author + information
- Andrew J. Feiring, MD⁎ ()
- ↵⁎Cardiology, Columbia-St. Mary's Medical Center, Suite 600, Milwaukee, Wisconsin 53211-1643
We appreciate the comments of Dr. Dieter and colleagues regarding our paper (1) and thank them for the opportunity to expand on their insightful observations.
1. Although the biologic effect of drug-eluting stents (DES) in crural arteries needs further investigation, current data suggests that below-the-knee arterial lesions respond to coronary DES in a similar fashion. This is not surprising because these 2 arteries are similar in both dimensions and histology. However, drawing parallels between self-expanding superficial femoral artery (SFA) DES trials and crural DES implants is unwarranted. The SFA has 4 times the cross-sectional atherosclerotic burden compared to crural lesions. Additionally, SFA lesions are far more diffuse and the dynamic stresses are more severe than for tibial arteries. Compared with coronary DES, self-expanding struts are thicker, the drug-free interstices are wider, and the dosimetry per volume of plaque is lower. Thus, predicting the effectiveness of below-the-knee DES based on previous SFA trials may be deceptive.
2. Although limb salvage and relief of rest pain are the primary goals of critical limb ischemia therapy, we propose that extended arterial patency is an additional end point that deserves consideration. The mantra that “patency need only be maintained long enough to affect healing” is derived from observation that long-term bypass patency is suboptimal. Previous studies (referenced in the PaRADISE [Preventing Amputations Using Drug Eluting Stents] trial), demonstrated excellent short-term DES patency. Recently, Balzer et al. (2) reported that 83% of Cypher stents (Cordis Corp., Bridgewater, New Jersey) (n = 341) were patent at 18 months. Whereas bypass surgery demonstrates time-dependent decremental graft patency and limb salvage, data from the PaRADISE trial and Balzer et al. (2) suggests that stent patency and limb salvage remain nearly constant after the first 6 months. Thus, DES may facilitate long-term patency translating into fewer repeat interventions and reduced health care costs.
3. Reducing mortality in critical limb ischemia remains a significant challenge. However, a DES-centered endovascular strategy may offer significant improvement over current therapy. The 1-year mortality in the PaRADISE trial was 11%. The median age of death was 80 years (95% confidence interval: 74 to 86 years), which is comparable to expected actuarial survival. In comparison, first-year mortality in the BASIL (Bypass Versus Angioplasty in Severe Ischaemia of the Leg) trial (3) was 20%, and in the PREVENT III trial (4), mortality was 15% even though patients were a mean of 7 years younger. We postulate that PaRADISE's apparent survival advantage is related to reduction in deaths from surgery, amputation, procedural complications, and more aggressive secondary prevention.
Contemporary evidence indicates that the time is right for an industry-sponsored U.S. Food and Drug Administration independent developmental evaluation designed to investigate the impact of DES on limb salvage, cost-effectiveness, and quality of life in patients with critical limb ischemia.
- American College of Cardiology Foundation
- Feiring A.J.,
- Krahn M.,
- Nelson L.,
- Wesolowski A.,
- Eastwood D.,
- Szabo A.
- Balzer J.O.,
- Zeller T.,
- Rastan A.,
- et al.