Surgery tops endovascular procedures in CLI, but only if saphenous vein conduit adequate
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CHICAGO — In patients with chronic limb-threatening ischemia, surgical revascularization was superior to endovascular revascularization if there was an adequate saphenous vein conduit, according to the results of the anticipated BEST-CLI trial.
However, in patients without an adequate saphenous vein conduit, there was no difference in death or major adverse limb events between surgical and endovascular revascularization, researchers reported at the American Heart Association Scientific Sessions.
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In addition, there were no meaningful differences in quality of life metrics between the two approaches.
Clinical outcomes
For BEST-CLI, researchers enrolled 1,830 patients with chronic limb-threatening ischemia (CLTI), also known as critical limb ischemia (CLI), and infrainguinal peripheral artery disease who were appropriate candidates for surgical or endovascular revascularization. “The treatment of CLTI depends on limb revascularization to improve limb perfusion and to prevent above-the-ankle amputation,” Alik Farber, MD, chief of vascular and endovascular surgery and associate chief medical officer for surgical services at Boston Medical Center and professor of surgery and radiology at Boston University Chobanian & Avedisian School of Medicine, said during a press conference. “There is tremendous variation in treatment strategy. So we asked the question, which strategy is the best in CLTI?”
The patients were split into two cohorts. Cohort 1 consisted of 1,434 patients (mean age, 67 years; 29% women) who had an adequate saphenous vein conduit for surgical bypass. Cohort 2 consisted of 396 patients (mean age, 69 years; 28% women) who did not have an adequate saphenous vein conduit for surgical bypass and who had an alternative bypass conduit used if assigned to the surgical group. The cohorts were analyzed separately and not pooled.
“Because the results of bypass are strongly influenced by the choice of conduit, and the single segment great saphenous vein is judged to be the best conduit for bypass, the patients were placed into two cohorts,” Farber said.
For the clinical outcome analysis, simultaneously published in The New England Journal of Medicine, the primary outcome was all-cause death or a major adverse limb event, defined as amputation above the ankle or a major limb reintervention including a new bypass graft or graft revision, thrombectomy or thrombolysis. Median follow-up was 2.7 years in cohort 1 and 1.6 years in cohort 2.
In cohort 1, the primary outcome occurred in 42.6% of the surgery group and 57.4% of the endovascular group (HR = 0.68; 95% CI, 0.59-0.79; P < .001), Farber said during the press conference.
The results were driven by major revascularization of the index limb (HR = 0.35; 95% CI, 0.27-0.47; P < .001) and to a lesser extent above-ankle amputation of the index limb (HR = 0.73; 95% CI, 0.54-0.98; P = .04), he said, noting there was no difference in all-cause death (P = .81).
The secondary endpoint of total number of major reinterventions over the duration of the study also favored the surgery group (incidence rate ratio = 0.48; 95% CI, 0.36-0.63; P < .001), according to the researchers.
MACE, defined as death, MI or stroke, did not differ between the groups (P = .27), nor did any serious adverse events.
In cohort 2, there was no difference between the groups in incidence of the primary outcome (surgery, 42.8%; endovascular, 47.7%; HR = 0.79; 95% CI, 0.58-1.06; P = .12), Farber said.
However, the surgery group had fewer major reinterventions in the index limb compared with the endovascular group (14.4% vs. 25.6%; HR = 0.47; 95% CI, 0.29-0.76; P = .002), according to the researchers.
“In CLTI, both surgical and endovascular revascularization are effective and safe,” Farber said during the press conference. “Bypass with an adequate saphenous vein is a more effective strategy for patients deemed suitable for both revascularization approaches. Patients who are candidates for limb salvage should undergo an evaluation of surgical risk and conduit availability. 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. Level 1 evidence from BEST-CLI does not support an endovascular-first approach to all patients with CLTI. BEST-CLI supports a complementary role for open and endovascular revascularization strategies.”
Quality of life outcomes
Matthew T. Menard, MD, co-director of the endovascular surgery program and director of the vascular and endovascular surgical fellowship at Brigham and Women’s Hospital and associate professor of surgery at Harvard Medical School, presented an analysis that assessed the impact surgical and endovascular revascularization of various quality of life metrics, both within each group and compared with each other. A minimal clinically important difference (MCID) was prespecified for each instrument.
“CLTI is associated with very poor health-related quality of life,” Menard said during the press conference. “We also know that revascularization is effective at improving quality of life in CLTI patients. What’s not known is the comparative effectiveness of different revascularization strategies in regard to health-related quality of life.”
In cohort 1, revascularization improved the Vascular Quality of Life Questionnaire score within each group. At 4 years, the between-group difference was statistically significant in favor of the endovascular group (–0.14; 95% CI, –0.25 to –0.02; P = .02), but did not achieve the MCID of 0.36 to 1.19, Menard said.
For EQ-5D, SF-6D-R2, SF-12 physical composite score and SF-12 mental composite score, both groups had within-group improvement and no between-group differences achieved the MCID, he said.
Both groups improved in pain metrics.
The results for cohort 2 were similar except for any between-group differences achieving statistical significance, Menard said.
“Both revascularization strategies resulted in significant and meaningful improvement in quality of life over baseline,” he said. “This effect was achieved early and was sustained over all metrics utilized. In patients with an available single segment saphenous vein, endovascular therapy was statistically superior on some measures, but the differences were small and below the threshold of clinically meaningful difference.”
References:
- Farber A, et al. N Engl J Med. 2022;doi:10.1056/NEJMoa2207899.
- Menard M, et al. LBS.07: Preventing Limb Loss Through Vascular Interventions and Venous Therapies. Presented at: American Heart Association Scientific Sessions; Nov. 5-7, 2022; Chicago (hybrid meeting).
Perspective
Back to TopThe primary outcome trials are quite striking and important for clinical practice. When patients have a good saphenous vein conduit, that appears to be a better revascularization strategy than endovascular intervention. The benefit is driven primarily by the lower rate of repeat intervention or amputation. This echoes findings that we have seen in the coronary artery bypass arena, where the use of native vessels to bypass occluded coronary arteries is often associated with fewer repeat interventions compared with PCI.
The benefit found with saphenous vein revascularization in cohort 1 (as compared to endovascular intervention) was not seen when alternative revascularization conduits (eg, prosthetic, non-saphenous veins) were used. This suggests that a less-invasive approach of endovascular revascularization may be preferable for patients who do not have suitable saphenous veins.
Overall, this trial highlights the high rate of mortality and morbidity for patients with CLTI PAD. We need to invest more effort into identifying PAD at an earlier stage and initiating treatments to prevent CLTI from developing in the first place. Further studies on how best to implement ankle-brachial index screening for at-risk patients would be of high value, especially for patients most likely to be impacted by CLTI (eg, Black patients, those with diabetes, those at lower socioeconomic status). The disparities in PAD and CLTI treatments and outcomes are a major concern.
Of note is the high burden of hypertension, hyperlipidemia and diabetes in this population. Despite being in a clinical trial, only 70% were on a statin and only two-thirds were on aspirin. We need to improve the use of medical management for patients with PAD, no matter what stage of severity. We also need to develop more therapies targeted specifically for patients with PAD that have PAD-related outcome benefits (eg, prevention of progression to CLTI, prevention of amputation or revascularization).
With regard to the quality of life data, importantly, quality of life measures before the procedure are quite low, suggesting significant morbidity for patients. However, it’s good to know that these quality of life measures all improved dramatically after intervention. While the difference in cohort 1 was statistically significant, I do not believe that reaches a clinical threshold. So, I would not tell a patient that they are more or less likely to get a quality of life benefit with surgical vs. endovascular revascularization. Rather, any revascularization is likely to significantly improve their quality of life.
Vascular and Cardiovascular Medicine
Director, Vascular Medicine Fellowship
Frankel Cardiovascular Center
Co-Director, Michigan Program on Value Enhancement (MPrOVE)
Holder of the James O. Woolliscroft Early Career Endowment Award
University of Michigan
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Farber A, et al. LBS.07. Preventing Limb Loss Through Vascular Interventions and Venous Therapies. Presented at: American Heart Association Scientific Sessions; Nov. 5-7, 2022; Chicago (hybrid meeting).
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