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

Abstract

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. 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. 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. 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.