Popliteal Interventions Linked to Higher Long-term Amputation Risk Than SFA

PAD patients with claudication undergoing peripheral vascular interventions (PVIs) in contemporary practice have a 4% risk of amputation within 4 years, with higher risk seen among those revascularized in a femoropopliteal segment compared with a superficial femoral artery (SFA) segment, a new analysis of prospectively collected data shows.

“I think the takeaway is that when we have discussions with our patients about the best way to treat their claudication, we need to be very sure that we've optimized them medically and exhausted their structured exercise program,” S. Elissa Altin, MD (Yale School of Medicine, New Haven, CT), the study’s lead author, told TCTMD. “When we have discussions about whether to intervene on their fem-pop segment, we can have informed decision-making with them around these data, knowing that up to one in 25 patients may end up having an amputation in the 4 years following PVI.”

Altin said in the case of patients with severe popliteal disease who haven’t applied themselves to exercise, for example, the new results may be an incentive to make a serious attempt before undergoing a procedure since some retrospective studies have also supported a conservative approach.

The reason for the increased risk in the popliteal artery is unclear, but in the paper, published in JACC: Cardiovascular Interventions, Altin and colleagues say it “may be related to mechanical stress caused by compression, torsion, and bending, making it overall more susceptible to stent fracture, restenosis, and occlusion.” Another possibility is that popliteal outflow into diseased tibial vessels may impact long-term patency.

Compared with earlier reports, the current analysis does suggest that the repeat revascularization rate in contemporary PVI in this population is lower than expected, however.

“It’s hard for me to speculate why that is, but it’s probably some combination of not capturing everybody who had a repeat revascularization because they're not showing up in this database, or it could be that the devices are working better, or it could be that the people who have return of claudication don't want to [go through] that again,” Altin added.

In an accompanying editorial, Debabrata Mukherjee, MD (Texas Tech University Health Sciences Center, El Paso), notes that while the analysis gives real-world insights into long-term outcomes, it’s not clear how many patients had truly lifestyle-limiting claudication despite optimal guideline-directed medical therapy (GDMT).

“At this time, given concerns for increased amputations after PVI for [intermittent claudication] and the availability of effective lifestyle and medical therapies, PVI should be restricted in stable PAD only for those with persistent lifestyle-limiting claudication despite GDMT and structured exercise therapy,” Mukherjee writes.

Insights By Revascularization Location

Altin and colleagues analyzed data on 19,324 patients (41% female; 14% Black) from the PINC AI Healthcare Database who underwent PVI between 2016 and 2020. Of those: 13,425 were revascularizations of the SFA, 2,340 of the popliteal artery, and 3,559 of both arteries.

Index limb amputations were more common among patients who were younger, Black or Hispanic, past or present smokers and in those who had diabetes, chronic kidney disease, or chronic obstructive pulmonary disease. Patients undergoing both SFA and popliteal interventions tended to be older, while those undergoing popliteal-only interventions were more often men than women (63.8% vs 36.2%; P < 0.001).

Amputation of the index limb occurred in 4.3% of the entire cohort at 4 years, with rates of 7.5% in the popliteal patients versus 3.4% in the SFA-only group and 5.5% in the combined SFA and popliteal group (log-rank P < 0.0001). 

The rate of major amputation of the index limb at 4 years was 3.2% in the entire cohort—with the lowest rate (2.5%) in the SFA-only group and the highest (5.2%) in the popliteal-only group.

We know that popliteal stenting is fraught with issues. S. Elissa Altin

The rate of repeat index limb revascularization at 4 years was 16.7% in the entire cohort, and it was highest in patients undergoing revascularization of both the SFA and the popliteal artery (20.1%). The target-vessel revascularization rate was 15.2% in the entire cohort, and again was highest in patients undergoing both SFA and popliteal interventions (18.7%).

In multivariate analysis, popliteal interventions were associated with greater risk of 4-year index limb amputation than isolated revascularization of the SFA (HR 2.10; 95% CI 1.52-2.91), as well as with higher risk of index limb major amputation (HR 1.98; 95% CI 1.32-2.95).

In sensitivity analyses assessing use of atherectomy during the index procedure, the 4-year rate of index limb amputation with versus without atherectomy was 3.8% vs 4.8% (log-rank P = 0.0042). In multivariate adjustment, the rate of any index limb amputation was lower with atherectomy (adjusted HR: 0.76; 95% CI 0.59-0.99) but the rate of index limb major amputation was not.

Rivaroxaban and Other Options

As far as optimizing these patients medically, Mukherjee says on the basis of available data from VOYAGER PAD and the PAD subgroup of the COMPASS trial, “it is reasonable to consider adding rivaroxaban to aspirin for 1 year in patients with PAD and [intermittent claudication], especially after lower extremity revascularization, with reassessment and estimation of patient-specific risks and benefits beyond 1 year.”

Other newer options may include the PCSK9 inhibitor evolocumab (Repatha; Amgen), which was shown in the FOURIER trial to reduce the risk of CV events and risk for major adverse limb events in patients with PAD.

“The data from VOYAGER PAD and COMPASS are compelling,” agreed Altin, adding that using rivaroxaban to move the needle on outcomes is progressing slowly. “I think we need to identify whether there have there been changes in prescribing habits from the publication of these studies to now, and understand what the barriers are to getting patients on these medications long-term, both before and after an intervention,” she added.

Another insight from the data is that SFA lesions were more likely to be treated with stenting than were popliteal lesions, raising the question of whether more popliteal stenting might be helpful in preventing repeat revascularization and/or amputation.

“We know that popliteal stenting is fraught with issues and popliteal disease, depending on how distal it is, often means that you have more distal tibial disease,” Altin noted. “So, these patients may just be different because their outflow is worse, but we can't know from this study. I think one thing this is showing us is that we need to think about lower extremity peripheral artery disease not as a single disease entity, but by level of disease. Broad strokes of understanding are not sufficient to prognosticate how people would do with different devices.”