Paclitaxel exposure and long-term mortality of patients treated with the Zilver PTX drug-eluting stent.

OBJECTIVES

Paclitaxel-eluting stents have demonstrated improved patency over balloon angioplasty and bare metal stenting for endovascular interventions in the femoral-popliteal segment. Recently, concerns have arisen regarding the safety of paclitaxel use and its association with mortality. This study aims to examine real-world, long-term mortality, and patency of patients treated with the Zilver PTX drug-eluting stent.

METHODS

Patients treated with the PTX stent after FDA approval between 2013 and 2015 were identified from an institutional database. Demographic, procedural, and device information was collected and initial- and lifetime-exposure dose of paclitaxel was calculated. The primary outcome was all-cause mortality and its association with paclitaxel exposure. Long-term patency was also evaluated.

RESULTS

Seventy-nine procedures involving PTX placement were performed on 64 individual patients during the study period, with 15 (23.4%) having bilateral procedures. Average age was 70 years, and 71.9% were male. Forty-five patients (70.3%) were claudicants, and 19 (29.7%) had chronic, limb-threatening ischemia. An average of 2.3 PTX stents, totaling 203 mm in length, were placed per procedure. Paclitaxel exposure was 1.87 mg/procedure initially (range 0.38-4.03 mg), and average lifetime exposure was 4.65 mg/patient (range 0.38-27.91 mg). Average follow-up was 59.6 months. Kaplan-Meier estimated survival was 96.9%, 81.2% and 71.7% at one , three, and five years. On multivariate analysis, no specific factors were associated with overall morality including initial paclitaxel dose (HR 0.99, 95% CI 0.99-1.00) and lifetime paclitaxel exposure (HR 0.98, 95% CI 0.89-1.08). Kaplan-Meier primary patency was 76.2%, 60.1%, and 29.3% at one, two, and five years, respectively. Secondary patency was 92.2%, 85.4%, and 75.2% at the same intervals.

CONCLUSIONS

At a mean follow-up of five years, exposure to higher doses of paclitaxel from Zilver PTX does not appear to be associated with increased mortality compared to lower doses in real-world patients. Long-term patency rates confirm the efficacy of Zilver PTX, and further investigation may be warranted before abandoning paclitaxel use altogether.