A German claims-based cohort study has revealed that—in 13,204 patients treated with a paclitaxel-coated device for peripheral arterial disease (PAD)—mortality differences were mostly attributable to a female subgroup treated above the knee, while no statistically-significant differences were observed in male patients. These findings were recently published in the Journal of Clinical Medicine (JCM).
Authors Christian-Alexander Behrendt (University Medical Center Hamburg-Eppendorf, Hamburg, Germany) and colleagues note that, while randomised controlled trials have reported excess mortality in patients treated with paclitaxel-coated devices versus uncoated devices, observational studies have reported the opposite. The researches aimed, therefore, to elucidate the underlying factors driving an observed improvement in mortality associated with paclitaxel exposure in patients with PAD.
Behrendt et al studied multicentre health insurance claims data from a large German insurance fund, BARMER. They detail that a homogenous sample of patients with an index of endovascular revascularisation for symptomatic peripheral arterial occlusive disease between 2013 and 2017 was included.
In total, 13,204 patients (54% females, mean age 74±11 years) were followed for a median of 3.5 years. The authors report that female patients were older (77 vs. 71 years), and had less frequent coronary artery disease (23% vs. 33%), dyslipidaemia (44% vs. 50%), and diabetes (29% vs. 41%), as well as being less likely to have a history of smoking (10% vs. 15%) compared with male patients.
In regard to mortality differences, Behrendt and colleagues relay that these were mostly attributable to the female subgroup who were revascularised above the knee (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.64–0.95), while no statistically significant differences were observed in male patients.
“This study found that female patients treated above the knee benefitted from paclitaxel-coated devices, while no differences were observed in male patients,” the authors conclude in JCM. In addition to this fact, which Behrendt et al state has not previously been reported, they found evidence once again for a female patient disadvantage in real-world data. They write: “It appears likely that previously underprivileged female patients benefit from treatment with paclitaxel-coated devices, an association that is moderated through improved optimal pharmacological treatment during follow-up.” However, they note that this subgroup seems to be excluded from previous trials (in Germany)—a fact that would explain a selection bias, they state.
Considering how their findings might impact further research in the area, the authors posit: “Ongoing and future trials should take sex disparities into account”.