Conflicting data demonstrating worse outcomes in women after receiving drug-coated balloons raise questions about whether women with peripheral artery disease respond differently to the treatment than men, an expert said at the 2018 International Symposium on Endovascular Therapy (ISET).
In general, women with PAD present differently than men, according to Maureen Kohi, MD, chief of interventional radiology at the University of California, San Francisco.
Furthermore, although the prevalence of PAD may be similar between men and women, as the population ages and women outlive men, physicians are likely to see more women with PAD who are older and have more advanced disease than their male counterparts. That is why, Kohi said, it is essential that physicians know more about how women respond to the currently available interventions.
“If there are differences between men and women in treatment outcomes, knowledge of those will help us better understand how to optimize the management of patients with PAD whom we are going to encounter in the future,” she said.
At present, data indicate that short-term outcomes after routine peripheral transluminal angioplasty are similar for men and women, but long-term outcomes, such as reintervention rates at 12 months, are higher in women compared with men, according to Kohi.
Although DCBs appear to present a solution, with compelling evidence linking them to reduced reintervention rates in overall cohorts with PAD, several studies suggest these rates may vary according to sex, she said.
Results from the THUNDER trial, for example, demonstrated reduced target lesion revascularization rates after treatment with a paclitaxel-coated balloon (Paccocath, Bavaria Medizin Technologie GmbH) in the short term, without much difference between men and women. However, at 5 years, the rate of TLR was 17% for men vs. 38% for women. Additionally, 2-year results from a real-world registry showed that DCBs are effective in delaying rather than preventing restenosis in patients, but primary patency and freedom from TLR at 2 years were statistically significantly different between the men and women, with male sex actually being protective against restenosis, according to Kohi.
More current data from prospective, randomized controlled clinical trials also demonstrate potential differences between men and women in outcomes, she said. The LEVANT 2 trial showed that the Lutonix 035 DCB (Bard Peripheral Vascular) was superior to plain balloon angioplasty at 12 months for primary patency. However, according to the FDA executive summary, women who received plain balloon angioplasty outperformed those who received the Lutonix DCB, as compared with the male subgroup, where, as expected, men who received the Lutonix DCB outperformed those who received plain balloon angioplasty, Kohi said.
There may be some potential differences between men and women in response to DCB therapy based on device platform as well, according to Kohi. For instance, 3-year outcomes from the IN.PACT SFA randomized trial showed that the IN.PACT Admiral DCB (Medtronic) was associated with small, but not statistically significant, differences in freedom from TLR between men and women. Similarly, the Stellarex DCB (Spectranetics/Philips) was associated with a higher rate of clinically driven TLR at 12 months in women, but the difference was not statistically significant.
“Maybe we can’t demonstrate a statistically significant difference because there isn’t one, but it’s also possible that we can’t because the sample sizes are very small,” Kohi said.
In light of these data, Kohi said physicians and researchers cannot conclusively say whether women with PAD have worse outcomes with DCB than men.
“Ultimately, the challenge we’re facing is very small sample sizes. These trials are 30%, if even, female, which makes it very difficult to draw definitive conclusions,” she said. “The end-all point is we need a larger data set to really understand the role of DCBs for the treatment and management of women with PAD.” – by Melissa Foster