Inadvertent inversion of late mortality data reverses the advantage of the Paclitaxel Zilver PTX stent in PADs to PTAs

A serious error in data reporting in the Zilver PTX trial reverses the finding that there was a long-term mortality benefit for the paclitaxel-based stent compared to percutaneous transluminal angioplasty (PTA) in patients with of MAP. The newspaper circulation says that the authors reversed the all-cause mortality data for the study groups, inadvertently, in their original manuscript and that they were corrected, as well as an additional error.

This trial has the longest follow-up of randomized patients in an endovascular device for the treatment of femoro-popliteal arterial disease and has been cited repeatedly in recent months as strong evidence to refute claims linking increased mortality to Paclitaxel-based devices controversial meta-analysis Konstantinos Katsanos, MD, PhD (University Hospital of Patras, Rion, Greece).

In their article published in circulation in 2016, Zilver PTX researchers led by Michael D. Dake, MD (University of Arizona, Tucson), reported that the all-cause mortality rate in the 474-patient trial was 10 , 2% for the DES group and 16.9% for the PTA group (P = 0.03). The correction, published on February 19, 2019 on the journal's website, reverses these numbers, giving the mortality benefit to the PTA group.

This is the second time in less than a week that a major trial of a paclitaxel coating device for PAD has recognized a serious data error. February 15, 2019, Medtronic revealed that some mortality data for patients treated in the IN.PACT global study were not included in two recent publications.

A PAD researcher who spoke with TCTMD on condition of anonymity was speechless at the news of the circulation correction, noting that the Zilver PTX data have been repeatedly seen as solid evidence of the long-term safety of paclitaxel coated devices and adding that "it's really a shame."

Indeed, the Zilver PTX trial has been a focal point in a recent special session at LINC 2019 Researchers in various studies of paclitaxel-based devices for PAD have presented patient-level meta-analyzes that consistently showed no mortality signal compared to an uncoated device. At that time, Dake presented additional data from Zilver PTX on cross-patients who had not been included in the Katsanos meta-analysis. It is unclear when Dake and his colleagues discovered the transposed data and reported it to circulation. In addition to this error, the log indicates that there was also an error in a figure.

"When high-resolution files were requested during production, an incorrect version of Figure 1 was provided in error," says the correction. "Subsequently, the published version of the flowchart in Figure 1 contained incorrect numbers."

In an interview with TCTMD, William A. Gray, MD (Lankenau Heart Institute, Wynnewood, PA), said the errors were "unfortunate" and needed to be taken into account in efforts to consolidate analyzes at the patient in all areas. The trials of DCB and paclitaxel-based stents are progressing. VIVA Physicians will oversee the collection of data from the sponsors of the trial, and the FDA said It evaluates long-term follow-up data from all studies supporting the approval of balloons or stents coated with paclitaxel for the treatment of femoropopliteal artery disease.

"I do not think that, by itself, changes much of the current activity or perspective. We are still solving this problem, "Gray said. "We have to remember that differences seen at 5 years of age in a relatively small number of patients can be problematic because they are too small to see a mortality effect."

Requests for comments from Cook Medical, sponsor of the Zilver PTX trial, were not returned until this story was posted.