Drug-Coated Balloons Beat Angioplasty for SFA In-Stent Restenosis, but Long-Term Solutions Needed
Patients with symptomatic in-stent restenosis (ISR) of the superficial femoral artery (SFA) or proximal popliteal artery have better primary patency at 1 year if they received a drug-coated balloon (DCB) versus an uncoated balloon, results from the PACUBA trial show. Still, fully half of the DCB-treated patients required clinically driven target lesion revascularization.
The findings, published in the July 11 issue of JACC: Cardiovascular Interventions, were previously reported this February at the 2016 International Symposium for Endovascular Therapy in Hollywood, FL.
There are myriad approaches to addressing in-stent restenosis, and the body of literature is conflicting on how well each of them works, according to lead author Christian M. Kinstner, MD (Medical University of Vienna, Austria), and colleagues. When the numerous “studies are put into perspective, it is evident that ISR is a difficult problem that requires new treatment concepts.”
Standard balloon angioplasty—the comparator in PACUBA—has shown primary patency rates in the range of 13% to 28% and freedom from clinically driven TLR rates of 22% to 42% by 1 year, With other options available, it “should not be offered to our patients,” Kinstner et al advise.
Indeed, as an accompanying editorial notes, there are currently only two therapies specifically approved by the US Food and Drug Administration for SFA-ISR: excimer laser-assisted angioplasty and the Viabahn endoprosthesis (WL Gore). Then, beyond standard balloon angioplasty, two other treatments are sometimes used off-label: DES and DCB.
Advocates and Naysayers
In their editorial, Bruce H. Gray, DO and Jack A. Buchan (Greenville Health System, Greenville, SC), point out that lesion length, the likelihood of compliance with antiplatelet/anticoagulant therapy, and variations among device characteristics within the same category can influence outcomes, thus muddying the waters for clinicians trying to make a treatment decision.
DCB “advocates” cite several reasons why this option is best for treating SFA-ISR, Gray and Buchan note. DCBs offer “local delivery of a target-specific drug with the theoretical application to the entire arterial surface,” and often involve prolonged balloon inflation, which could enhance outcomes, they write. Moreover, they say, the devices avoid the downsides of excimer lasers (eg, potential embolization, acoustic trauma, and thermal injury), layered stents, and covered stents (which carry “increased thrombotic potential”) while being less risky than surgical bypass.
But DCB “naysayers” have their own counterpoints, the editorialists observe. Among them are the frequency of recurrent restenosis, the expense involved in often needing multiple DCB to fully treat SFA-ISR, and the fact that “each DCB is unique (different manufacturer, drug dose, carrier, balloon) and may not have the same clinical effect, necessitating individual study and comparison.”
Half of DCB Patients Needed TLR by 1 Year
PACUBA specifically looked at the Freeway 0.035-inch balloon (Eurocor/Opto Eurocor Healthcare), which has a shellac coating as a spacer and a paclitaxel concentration of 3 µg/mm2. In the comparator arm, angioplasty was performed for 2 minutes with a standard balloon.
For the single-center study, Kinstner and colleagues prospectively enrolled 74 patients, randomizing them to receive either the paclitaxel-coated balloon or standard angioplasty. Mean lesion lengths were 17.3 cm and 18.4 cm, respectively.
Primary patency at 12 months (primary endpoint) was 40.7% in the DCB group and 13.4% in the uncoated balloon group (log-rank P = 0.02), though the rates of freedom from clinically driven TLR were statistically similar at 49.0% and 22.1%, respectively (log-rank P = 0.11). Moreover, there was no difference between the two study arms in the likelihood of patients improving by at least one Rutherford-Becker category by 12 months.
Overall, the editorialists conclude, growing evidence shows that “paclitaxel-coated balloons do provide benefit at 6 months, but this benefit may not last.”
Standard balloons are also ineffective for SFA-ISR, especially in longer lesions, they add. “Furthermore, these data suggest that [angioplasty with uncoated balloons] has outrun its usefulness as a comparator for SFA-ISR trials from an ethical standpoint. Any further studies should use a Food and Drug Administration-approved device as the comparator.”
For now, they say, “There is no single ‘default strategy’ for the treatment of SFA-ISR, allowing the practitioner to use their best judgment to make this on-table decision.”
Kinstner CM, Lammer J, Willfort-Ehringer A, et al. Paclitaxel-eluting balloon versus standard balloon angioplasty in in-stent restenosis of the superficial femoral and proximal popliteal artery: 1-year results of the PACUBA trial. J Am Coll Cardiol Intv. 2016;9:1386-1392.
Gray BH, Buchan JA, The treatment of superficial femoral artery in-stent restenosis: the jury is still out. J Am Coll Cardiol Intv. 2016;9:1393-1396.
- Kinstner and Buchan report no relevant conflicts of interest.
- Gray reports having served as a committee member for the National Cardiovascular Data Registry.