REAL PTX Data Show Similar Outcomes for DES and DCB With Bailout Stenting at 1 Year, Trend Favoring DES at 3 Years
February 14, 2019—Recent data published from the REAL PTX trial showed that drug-eluting stents (DESs) and drug-coated balloons (DCBs) with bailout stenting had similar safety and effectiveness at 12 months in femoropopliteal interventions. Longer-term outcomes at 36 months indicated a trend in the favor of DESs, though the study was not powered to assess patency beyond the first year.
The data were published by Yvonne Bausback, MD, et al in the Journal of the American College of Cardiology (JACC; 2019;73:667–679). REAL PTX is a prospective randomized multicenter postmarket study investigating the effect of the paclitaxel-eluting stent Zilver PTX (Cook Medical) in comparison to that of paclitaxel-coated balloons (In.Pact Admiral/In.Pact Pacific DCB, Medtronic; or Lutonix DCB, BD Interventional) in the treatment of symptomatic femoropopliteal artery disease.
According to investigators in JACC, 150 patients with symptomatic femoropopliteal disease were randomly assigned to primary DES implantation (n = 75) or DCB angioplasty with bailout stenting (n = 75) after stratification for lesion length (≤ 10 cm, > 10 to ≤ 20 m, and > 20 to ≤ 30 cm). More than half the lesions in both groups were total occlusions (DES, n = 39; DCB, n = 40).
Primary patency rates at 12 months as assessed by Kaplan-Meier, which was the primary endpoint, were 79% for DESs and 80% for DCB with bailout stenting (P = .96). At 36 months, primary patency decreased to 54% and 38% (P = .17), respectively. Improvement in Rutherford class ≥ 1 was seen in 86.7% of the DES group and 82.3% in the DCB group at 12 months.
Secondary endpoints of the study included major adverse events (death, major amputations, and clinically driven target lesion revascularization [CD-TLR]), and clinical outcomes. Freedom from CD-TLR at 12 months was 90% for the DES group and 92.5% for the DCB group (confidence interval: 7.1%–12.1%; P = .34). These rates fell in both groups at 36 months to 68.9% and 71.3%, respectively.
Additional data of note found that among the DCB group, 19 (25.3%) cases required bailout stenting, with eight cases in each arm of the more complex mid- and long-length lesions. Investigators noted that 15 cases requiring bailout stenting were for treatment of chronic total occlusions. In a subgroup analysis of DCB plus bailout stenting, patency rates were 73.7% at 12 months and 33.8% at 36 months.
In JACC, the study authors explained that vessel preparation beyond standard balloon angioplasty was not used, which study investigator Sabine Steiner, MD, elaborated upon further in comments to Endovascular Today.
“The use of adjunctive devices could be particularly relevant in more complex lesions to tackle calcification and minimize dissections,” explained Dr. Steiner, who is a specialist in internal medicine/angiology at Universitätsklinikum Leipzig, in Leipzig, Germany. “Thus, lesion preparation could have the potential to improve patency after stenting, as we saw some early failures in the DES group where focal calcification with suboptimal stent deployment could have played a role. In the DCB group, we believe that vessel prep could reduce residual stenosis and minimize the need for bailout stenting.”
Regarding safety signals, the combined safety outcome of death, CD-TLR, and major target limb amputation within 12 months after the initial procedure occurred in 8% of patients in the DCB group and 7% in the DES group (P = .77). Through 36 months, 11 (7.3%) patients died, with only one procedure-related death in the DCB group. No deaths were determined to be device-related, including related to the use of paclitaxel across all devices.
In light of the recent Katsanos et al meta-analysis that suggested an increased risk for long-term mortality in patients treated with paclitaxel in the peripheral arteries (see our extended coverage here), Dr. Steiner noted that her team is planning to modify their ongoing trials evaluating drug-eluting devices that will allow for the collection of patient-relevant outcome data at longer follow-up periods.
“For REAL-PTX, we do not plan a longer-term follow-up as the number of patients left in the study after 3 years was small,” said Dr. Steiner. “In our experience, it’s very difficult to motivate patients to participate in a study extension after the clinical trial was already stopped.”
In fact, even at the scheduled 1-year follow-up, only 60/75 patients in the DES group and 62/75 patients in the DCB group were evaluated. “Relatively high dropout rates have become a major issue for all clinical trials we are performing," noted Dr. Steiner when asked about factors affecting follow-up compliance. "Patients often suffer from multiple comorbidities necessitating various doctor visits and negatively influencing retention within a clinical study, as this adds further appointments. In ongoing trials, we try to address this issue by contacting the patient in advance of the planned visit and offering coverage of travel expenses.”
The investigators noted that this was a pilot study, and larger long-term studies are needed to more thoroughly assess the safety and efficacy of DES and DCB technologies. Further research into comparing these various treatment strategies for complex superficial femoral artery (SFA) lesions is already in motion for Dr. Steiner and colleagues.
“We have designed BEST-SFA as a pilot study to evaluate patency rates comparing a stent-preferred (using DES) versus a stent-avoiding (using DCB) strategy in relatively complex SFA lesions without restricting the use of adjunctive devices. Vessel preparation using high-pressure/scoring balloons and debulking devices is encouraged reflecting the need for individualized approaches depending on the particular pathologies of each patient.
“We want to move forward from testing single devices against each other to actually compare different strategies for treatment of complex SFA lesions, as we believe we need a combination of devices for optimal results,” concluded Dr. Steiner. “Importantly, that’s also what we do in clinical routine.”