If a Saphenous Graft Is Available, Treat Limb Threatening Ischemia Surgically

Ted Bosworth

November 09, 2022

CHICAGO – In patients with chronic limb-threatening ischemia (CLTI) and a usable saphenous vein segment, a surgical procedure leads to better outcomes than an endovascular approach, according results of the multinational randomized BEST-CLI trial.

In that study, conducted with two cohorts, the advantage of surgery was limited to the group with an available saphenous vein, but in this group the advantage over an endovascular approach was substantial, according to Alik Farber, MD, chief of vascular and endovascular surgery at Boston University.

"Bypass with adequate saphenous vein should be offered as a first-line treatment option for suitable candidates with CLTI as part of fully informed, shared decision-making," Farber stated in presenting the results at the annual scientific sessions of the American Heart Association.

The study pursued two hypotheses, which is why CLTI patients were divided into two cohorts. For cohort 1, which was limited to CLTI patients with an available saphenous vein, it was predicted that surgery would be better than an endovascular approach. For cohort 2, which enrolled patients who needed an alternative conduit, the hypothesis was that endovascular procedures would prove superior.

The study confirmed the first hypothesis, but there was no difference between the two approaches for the composite primary outcome of major adverse limb events (MALE) in the second cohort.

Saphenous Vein Availability Determined Cohort

Candidates for the BEST-CLI (Best Endovascular versus Best Surgical Therapy in Patients with CLTI) trial had to have CLTI producing severe ischemia and to be judged by both surgeons and cardiovascular specialists to be candidates for both types of interventions. Eligible patients were then enrolled in cohort 1 if the saphenous vein was considered the best conduit on imaging. If not, they were enrolled in cohort 2.

Patients were randomized to undergo surgical or endovascular repair only after the cohort was assigned. The primary composite MALE endpoint consisted of an adjudicated first major reintervention, such as new bypass or thrombectomy, an above-the-ankle amputation, or death from any cause.

In cohort 1, the primary composite MALE endpoint was reached in 42.6% of those in surgical arm and 57.4% in the endovascular arm, translating into a 32% relative risk reduction (hazard ratio, 0.68; P < .001) in favor of surgery at the end of a median of 2.7 years of follow-up.

The main advantage was the difference in reinterventions. The lower rate in the surgical group (9.2% vs. 23.5%), translated into a 65% relative risk reduction for this endpoint (HR, 035; P < .001).

The reduction in above-ankle amputations in the surgical group (10.4% vs. 14.9%) was also significant (HR, 0.73; P = .04), but the reduction in all-cause mortality (33.0% vs. 37.6%) was not (HR, 0.98; P = .81).

BEST-CLI involved 150 sites in North America, Europe, and New Zealand. Cohort 1, which randomized 1,434 patients, was the larger of the two. In the second cohort, only 396 patients were randomized, which Farber said "might have been underpowered."

The results were published in the New England Journal of Medicine simultaneously with presentation of the results at the meeting.

After a median follow-up of 1.6 years in cohort 2, the slightly lower proportion of patients who reached the composite MALE endpoint in the surgical group relative to the endovascular group (42.8% vs. 47.7%) did not translate into a significant advantage (HR, 0.79; P = .12).

For the individual components, the lower rate of reinterventions in the surgical arm (14.4% vs. 25.6%) did reach statistical significance (HR, 0.47; P = .002), but both amputation (14.9% vs. 14.1%) and all-cause death (26.3% vs. 24.1%) were numerically but not significantly higher in the surgical group.

The primary safety endpoint was major adverse cardiovascular events (MACE). This was not significantly different in either cohort. There were also no major differences between groups in the risk of perioperative complications.

Level 1 Evidence Provided For Intervention Choice

Overall, BEST-CLI showed that both surgical and endovascular revascularizations are effective and safe, according to Farber. As a result, he suggested that both can be considered even if a saphenous vein is available when specific patient characteristics make one more attractive than another.

Yet, in a general population with an available saphenous vein, these data provide "level 1 evidence" that a surgical approach should be the dominant choice, he added.

A quality of life (QOL) substudy of BEST-CLI did not challenge this conclusion. Rather, the main finding was that restoring circulation by either approach has a major favorable impact on patient well-being, according to Matthew Menard, MD, codirector of endovascular surgery at Brigham and Women's Hospital, Boston.

In this substudy, presented separately from the primary BEST-CLI results, that analysis confirmed that baseline QOL was extremely poor, whether measured with a disease specific instrument such as VascuQol, or generic instruments, such as SF-12.

Surgical or endovascular treatment produced clinically meaningful and sustained improvements in every QOL measure employed, according to Menard, and this was true in either cohort.

Results Not Necessarily Relevant to All

These data are likely relevant to the patients evaluated, but "it is important to consider who made it into this trial," according to Naomi M. Hamburg, MD, section chief of vascular biology at Boston University.

Not least, patients had to be candidates for either surgical or endovascular repair to get into the study, omitting those patients not deemed by the investigators to be suited for either.

In addition, Hamburg pointed out that there was a low enrollment of Blacks (20%) and women (28%), two groups for whom CTLI is a common condition.

Lastly, Hamburg questioned whether specific types of anatomy might be better suited to one procedure relative to another, a variable not considered in this study. Reassured by Farber that this will be explored in subsequent analyses of BEST-CLI data, Hamburg expressed interest in learning the results.

Hamburg was among those who spoke about the growing urgency to optimize strategies for early diagnosis and treatment of CTLI. She plugged the PAD National Action Plan as one of the efforts to thwart the coming wave of CTLI expected from the steep climb in the prevalence of diabetes in the United States.

Farber reported a financial relationship with Sanifit Therapeutics. The study was funded by the National Heart, Lung, and Blood Institute, but received additional support from multiple pharmaceutical companies. Menard reported a financial relationship with Janssen Pharmaceuticals. Hamburg reported financial relationships with Acceleron Pharma, Merck, NovoNordisk, and Sanifit.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.


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