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The Take Home: VIVA
VIVA Physicians held its annual conference from Sept. 18 to Sept. 22 in Las Vegas. Cardiology Today’s Intervention attended the meeting and interviewed key opinion leaders on the most important science from the meeting. Interviewees included Mark W. Burket, MD, from University of Toledo Health, Ohio; Michael D. Dake, MD, from Stanford Health Care; Cardiology Today’s Intervention Editorial Board member Michael R. Jaff, DO, FSCAI, from Harvard Medical School and Newton-Wellesley Hospital, Newton, Massachusetts; and Krishna J. Rocha-Singh, MD, FACC, FAHA, FSCAI, FSVM, from Prairie Heart Institute of Illinois, Springfield.
DISRUPT PAD
Rocha-Singh: The 6-month results of DISRUPT PAD, which evaluated a lithoplasty device (Lithoplasty System, Shockwave Medical) in 95 patients with calcified femoropopliteal lesions, appear to be fairly substantial. Primary patency was 100% at 30 days and 76.7% at 6 months, while freedom from target lesion revascularization was 100% at 30 days and 96.8% at 6 months. Mean percent diameter stenosis fell from 78% at baseline to 24% at 6 months, and there were no serious adverse events reported.
The question is whether this is going to elevate other therapies. Usually, we use angioplasty not as a standalone treatment, but rather as an adjunct for vessel preparation. I think this device falls into a category, along with atherectomy, of use for vessel preparation prior to some type of drug therapy. What remains to be seen is whether CMS is going to value this and pay for it, and to what extent is it going to add cost to treating claudicants.
Yarrow Kraner, photographer; printed with permission.
This is a step forward, for which we have been waiting a long time. However, calcium is the Achilles’ heel of all therapies for treatment of lesions in patients with PAD, and questions remain about whether this technology addresses deep-wall calcium, which was not proven in this study.
DISSECTION
Jaff: I am overwhelmed by the success of a thoracic stent graft (Valiant Captiva, Medtronic) in treating such a morbid and mortal disease as acute complicated type B aortic dissection. In this study, among the 32 patients available for 3-year follow-up, there were no ruptures or conversions to open repair, freedom from all-cause mortality was 79.4% and freedom from dissection-related mortality was 90%.
The only other option we really have for these patients with acute complicated type B aortic dissection is an open surgical procedure with high morbidity and mortality. Patients did remarkably well with this therapy. It’s heartening to know that this technology is working out to such a huge advantage for these patients. It helps that the doctors are getting a lot better technically with the procedure. The results can be attributed to a combination of patient selection, physician expertise and experience, and technology improvement.
In the future, we should see procedures more proximal in the aortic arch, managing with the great vessels.
BOLSTER
Dake: BOLSTER was essentially an approval trial because the sponsor, Bard Peripheral Vascular, is trying to get its covered stent (Lifestream) approved for use in patients with occlusive iliac artery disease. The role of this stent in the iliac arteries may not be its only role, but it has to be approved before it can be tried elsewhere, so this is a necessary step.
The primary composite endpoint of device- or procedure-related death or MI at 30 days or any TLR, major limb amputation or restenosis occurred in 11.6% of 155 patients at 9 months, significantly lower than the 19.5% historical performance goal (P = .01).
I think this device will play a role in certain iliac artery lesions. As mentioned by presenter John R. Laird, MD, it might be close to the aortic bifurcation, in restenotic lesions or in other types of lesions. Given the breadth of the opportunities in terms of diameters and stent lengths, I’m sure when it’s approved, it will be used in many other places.
MAJESTIC
Jaff: It’s exciting to see that in this early study of a drug-eluting stent (Eluvia, Boston Scientific), with a relatively small number of patients with superficial femoral or proximal popliteal lesions (n = 57), the clinically driven TLR rates are remaining stable and quite good; 7.5% at 2 years. The patency rates took a dip from what we saw in year 1, and we’ll have to see if over time that correlates with recurrence of symptoms. That will predict the longer-term TLR rate.
I’m more interested in the IMPERIAL study, a head-to-head randomized trial of this DES with the only DES approved by the FDA for this indication (Zilver PTX, Cook Medical), which is enrolling right now. That will be much more important for us to understand the impact of this device.
SFA LONG
Burket: The 2-year results from the SFA LONG study of a paclitaxel-coated balloon (IN.PACT Admiral, Medtronic) in 93 patients with long femoropopliteal artery lesions are remarkably good. Primary patency was 74% in patients with stenotic lesions vs. 68% in patients with occlusive lesions (P = .42) and 75% in patients with long lesions vs. 66% in patients with very long lesions (P = .25). Freedom from TLR or > 50% restenosis was 71% at 720 days.
It’s surprising to me that there was no correlation between lesion length and outcome. Intuitively, one would think shorter lesions are at less risk for restenosis.
We are now at the point where we need a randomized trial between DES and drug-coated balloons. The issue of course is who will fund such a trial. It is revolutionary that there will be a head-to-head trial between two DES, though it’s logical that the maker of a new entrant into the field would be willing to sponsor a trial. It’s hard to say who would be willing to do that for a DES vs. a DCB.
IN.PACT GLOBAL
Rocha-Singh: The 12-month results of the IN.PACT Global study of a DCB in a real-world population of 1,406 patients with symptomatic femoropopliteal PAD are exceptional. Freedom from clinically driven TLR occurred in 92.6% of patients at 12 months. The primary safety endpoint of freedom from device- and procedure-related mortality at 30 days and freedom from major target limb amputation and clinically driven target vessel revascularization at 12 months was met in 92.1% of patients.
It is important to realize that while the data may support this therapy (IN.PACT Admiral, Medtronic) as a first-line treatment for patients with superficial femoral and popliteal disease, we should not assume it is “the” first-line treatment. Vessel preparation is important for these procedures, and we need to learn more about what was used in this cohort.
Provisional stenting was required in almost one of every four patients, so what we need to understand from those data is where we can anticipate provisional stenting, and whether in those cases it is more cost-effective to use a DES first. That is a substantial question that will need an answer down the line.
ESPRIT I
Dake: The results of ESPRIT I, albeit in a small number of patients, are incredibly good and encouraging. An everolimus-eluting bioresorbable vascular scaffold (Esprit BVS, Abbott Vascular) was tested in 35 patients with symptomatic claudication from PAD involving the superficial femoral or iliac arteries. At 3 years, the rate of all-cause mortality was 3.4%, the rate of TLR was 13.8%, the rate of scaffold thrombosis was 3.4% and there were no amputations or bypasses of the treated limb.
The results open the door to moving to the next step of evaluation of these bioresorbable technologies, studying them in more patients and in patients with longer lesions. The biggest benefit is likely to be in patients with longer lesions, but if it works in the shorter lesions presented in this study, and it is financially reasonable to consider, why not take advantage of its benefits in short- or moderate-length lesions. This is the natural extension of the paradigm of leave nothing behind.
MOBILE
Jaff: I keep hoping that a cell therapy or gene therapy trial will work, and every time I wait with bated breath, I am disappointed.
For the MOBILE study, patients with critical limb ischemia were assigned to receive bone marrow-derived progenitor cell therapy (n = 119) or a placebo-controlled sham procedure (n = 36). Patients in the cell-therapy group were more likely to have amputation-free survival at 52 weeks compared with those in the placebo group (HR = 0.64; 95% CI, 0.31-1.31), but the difference was not statistically significant. When patients with Rutherford category 4 (rest pain) with and without diabetes and Rutherford category 5 (tissue loss) without diabetes were analyzed collectively, amputation-free survival rates were significantly higher in the treatment group (treatment group, 86.17%; placebo group, 66.67%; P = .018). Patients with diabetes and Rutherford category 5 demonstrated no benefit from bone marrow cell therapy.
I understand that the researchers potentially found a signal in a subgroup analysis. But the truth of the matter is, Rutherford category 5 patients with diabetes are the patients who present with the worst clinical manifestations of their disease. It’s hard for me to justify excluding them to find a silver lining in the data.
I think we are picking the wrong patient populations for these trials. We should be looking for ways to speed up wound healing after successful revascularization. Patients would love that. Currently, sometimes the procedure restores blood flow but it takes many months for the wound to heal. If there were a therapy to speed that up, it would be hugely impactful. The researchers suggested they will look at that.
LIFE
Burket: This study included 250 patients from the LIFE registry who underwent endovascular aneurysm repair with a “fast-track” protocol including bilateral percutaneous access, no use of general anesthesia, performance of the procedure in the cath lab, no ICU admission and next-day discharge. The rate of major adverse events at 30 days was 0.4% (95% CI, 0-1.8; P vs. historical performance goal of 10.4% < .001). The mean procedure costs for the patients in the fast-track protocol were $8,200 compared with $29,300 for 8,306 patients from an inpatient discharge database.
Reducing costs for procedures performed by experienced operators very comfortable with percutaneous delivery by this much is a major achievement. The protocol is very safe and the results are remarkable. Whether a center should adopt this protocol probably depends not so much on center size but on dedication. In other words, if there are people who are really committed to this fast-track approach, they should have the opportunity to participate in it.
Disclosure: Jaff reports consulting for Cardinal Health and Volcano; receiving research funding from Novella; and holding equity in AccessClosure, Embolitech, Janacare, Micell Technologies, Northpoint Domain, Northwind Medical, PQ Bypass, Primacea, Valiant and Vascular Therapies. Jaff also is a non-compensated adviser to Boston Scientific Corp. Rocha-Singh reports consulting for Alumend, Medtronic, Rex Medical and Zimmer/Biomet and receiving research funding from and holding equity in PQ Bypass. Burket and Dake report no relevant financial disclosures.