Correction Reverses Zilver PTX Paclitaxel-Eluting Stent's Reported Late Survival Advantage in PAD

February 21, 2019

Arguably the fastest-moving topic in interventional cardiology now isn't in the coronaries but the periphery, as paclitaxel-delivering devices for femoropopliteal disease appear to lose a bit more luster.

Researchers from the Zilver PTX Randomized Trial, which compared the paclitaxel-eluting Zilver PTX stent (Cook Medical) with a Zilver bare-metal stent (BMS) in 236 and 238 patients, respectively, have issued a correction to their 2016 publication of the trial's 5-year outcomes.

Updated, the report now shows significantly higher all-cause mortality with the paclitaxel device. It is unclear whether the trial was statistically powered for all-cause mortality, which was not a primary end point.

In the last week, Medtronic announced that it had incorrectly omitted some mortality data from safety-outcomes tables it assembled on the company's IN.PACT Admiral paclitaxel-coated balloon used in femoropopliteal disease.

The faulty numbers, | Medscape Cardiology recently reported, had made their way into several publications and meeting presentations, including a recent meta-analysis of Medtronic's IN.PACT SFA trial series.

That publication was part of broad-based response to a controversial December 2018 meta-analysis that has led to a re-examination of paclitaxel-delivering balloons and stents in peripheral interventions. It found a significant excess 2-year mortality risk with the devices in the femoropopliteal artery.

In the original 5-year outcomes report from the Zilver PTX Randomized Trial, all-cause mortality for patients treated with the Zilver PTX or Zilver BMS had been incorrectly reported as 10.2% and 16.9%, respectively (= .03). Those numbers, the correction explains, had been inadvertently switched during the editorial production process.

The corrected figures are 16.9% for Zilver PTX and 10.2% for the BMS; the P value did not change.

A corresponding error in the publication's Figure 1, a patient-disposition flow chart, was also revised, notes the correction, published online February 19 in Circulation. No author is listed; lead author on the original 2016 report was Michael D. Dake, Stanford University Medical Center, California.

The erratum makes no mention of the correction's effects on end points other than all-cause mortality. The study's primary end points were 12-month event-free survival and event-free primary patency.

In the original 5-year outcomes publication, a number of other reported 5-year outcomes significantly favored the Zilver PTX, including event-free survival (81.4% vs 70.1%; < .01), primary patency (66.4% vs 43.4%; < .01), and freedom from clinically driven target-lesion revascularization (83.1% vs 67.6%; < .01).

The Zilver PTX Randomized Trial was sponsored by the Cook Group.

Circulation. 2016;133:1472-1483. Full text

Circulation. 2019;139:e42. Correction

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