Apples and oranges? A comparison of BEST-CLI to BASIL-2

Predictors of major adverse lower limb events in patients with tissue loss secondary to critical limb-threatening ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is the end-stage of peripheral arterial disease (PAD) posing a high risk for limb loss and mortality. This study aims to evaluate and list possible predictors of major adverse limb events (MALEs) in CLTI patients with tissue loss.

METHODS

This retrospective study included all Rutherford-Becker stage 5 or 6 patients who required foot debridement and revascularization in our department from January 2016 to December 2018. The limbs were classified according to the TASC II, GLASS and WiFI grading systems. The primary composite outcome was MALEs at 2 years. The secondary outcomes included all-cause mortality, primary patency, freedom from reintervention, and major amputation. Kaplan-Meier estimates were used to determine the event rates, and Cox proportional hazards model with the index MALE as a time-dependent covariate was used to search for MALEs predictors.

RESULTS

Of 241 included patients, 19 underwent open surgeries (7.9 %) 207 had endovascular interventions (85.9 %) and 15 required a hybrid approach (6.2 %). On univariate analysis, patients who experienced MALEs (n = 111) more often required hemodialysis (25 vs 15; p = .02), presented with more complex lesions (TASC D on femoropopliteal (p = .05) or below the knee (BTK) arteries (p = .006) with increasing infra-inguinal GLASS Stage (p < .0001)), a history of index limb open (p = .009) or endovascular (p = .049) revascularization, an occluded tibial artery (p = .002 for the posterior tibial and p = .052 for the anterior tibial), or a "desert foot" (p = .02). The CRP level was also higher at admission (p = .001). Technical success of BTK revascularization significantly reduced MALEs (p < .0001) along with the number of patent BTK vessels (p = .0007). Independent predictors of MALEs included hemodialysis (HR = 2.00; 95%CI: 1.14 to 3.39), pulsatile arterial pressure (HR = 1.01; 95%CI: 1.00 to 1.03) and the infra-inguinal GLASS Stage (HR = 2.50; 95%CI: 1.17 to 5.82). We could not correlate our results with the WiFI scores for amputation risk and revascularization benefit.

CONCLUSION

For patients with CLTI at the stage of trophic disorders, with or without a history of index limb revascularization, the GLASS successfully predicted MALEs. Hemodialysis and high pulsatile arterial pressure increased the risk of MALEs. The WiFI score did not demonstrate its interest in this subgroup of patients.

Surgery or endovascular therapy for patients with chronic limb-threatening ischemia requiring infrapopliteal interventions

OBJECTIVE

The recent publication of randomized trials comparing open bypass surgery to endovascular therapy in patients with chronic limb-threatening ischemia, namely, Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) and Bypass versus Angioplasty in Severe Ischaemia of the Leg-2 (BASIL-2), has resulted in potentially contradictory findings. The trials differed significantly with respect to anatomical disease patterns and primary end points. We performed an analysis of patients in BEST-CLI with significant infrapopliteal disease undergoing open tibial bypass or endovascular tibial interventions to formulate a relevant comparator with the outcomes reported from BASIL-2.

METHODS

The study population consisted of patients in BEST-CLI with adequate single segment saphenous vein conduit randomized to open bypass or endovascular intervention (cohort 1) who additionally had significant infrapopliteal disease and underwent tibial level intervention. The primary outcome was major adverse limb event (MALE) or all-cause death. MALE included any major limb amputation or major reintervention. Outcomes were evaluated using Cox proportional regression models.

RESULTS

The analyzed subgroup included a total of 665 patients with 326 in the open tibial bypass group and 339 in the tibial endovascular intervention group. The primary outcome of MALE or all-cause death at 3 years was significantly lower in the surgical group at 48.5% compared with 56.7% in the endovascular group (P = .0018). Mortality was similar between groups (35.5% open vs 35.8% endovascular; P = .94), whereas MALE events were lower in the surgical group (23.3% vs 35.0%; P<.0001). This difference included a lower rate of major reinterventions in the surgical group (10.9%) compared with the endovascular group (20.2%; P = .0006). Freedom from above ankle amputation or all-cause death was similar between treatment arms at 43.6% in the surgical group compared with 45.3% the endovascular group (P = .30); however, there were fewer above ankle amputations in the surgical group (13.5%) compared with the endovascular group (19.3%; P = .0205). Perioperative (30-day) death rates were similar between treatment groups (2.5% open vs 2.4% endovascular; P = .93), as was 30-day major adverse cardiovascular events (5.3% open vs 2.7% endovascular; P = .12).

CONCLUSIONS

Among patients with suitable single segment great saphenous vein who underwent infrapopliteal revascularization for chronic limb-threatening ischemia, open bypass surgery was associated with a lower incidence of MALE or death and fewer major amputation compared with endovascular intervention. Amputation-free survival was similar between the groups. Further investigations into differences in comorbidities, anatomical extent, and lesion complexity are needed to explain differences between the BEST-CLI and BASIL-2 reported outcomes.

Network Meta-analysis of Randomised Controlled Trials Comparing the Outcomes of Different Endovascular Revascularisation Treatments for Infra-inguinal Peripheral Arterial Disease Causing Chronic Limb Threatening Ischaemia

OBJECTIVE

The aim of this study was to compare the efficacy of different endovascular revascularisation procedures for treating chronic limb threatening ischaemia (CLTI) using network meta-analysis (NMA).

DATA SOURCES

The databases PubMed and Cochrane Central Register for Controlled Trials were searched on 14 March 2023.

REVIEW METHODS

A NMA of randomised controlled trials (RCTs) reporting the efficacy of different endovascular revascularisation techniques for treating CLTI was performed according to PRISMA guidelines. The primary and secondary outcomes were major amputation and death, respectively. Random effects models were developed and the results were presented using surface under the cumulative ranking curve plots and forest plots. A p value of ≤ .050 was considered statistically significant. The Cochrane collaborative tool was used to assess risk of bias.

RESULTS

A total of 2 655 participants of whom 94.8% had CLTI were included. Eleven trials compared plain balloon angioplasty (PBA) vs. drug coated balloon (DCB) angioplasty (n = 1 771), five trials compared bare metal stent (BMS) vs. drug coated stent (DCS) (n = 466), three trials compared atherectomy vs. DCB (n = 194), two trials compared PBA vs. BMS (n = 70), one trial compared PBA vs. atherectomy (n = 50), and one trial compared BMS vs. DCB (n = 104). None of the revascularisation strategies significantly reduced the risk of major amputation or death compared with PBA. Using the network estimates, GRADE certainty of evidence for improvement in major amputation outcomes for DCB was moderate, for atherectomy and BMS was low, and for DCS was very low compared with PBA. Risk of bias was low in 16 trials, of some concerns in six trials, and high in one trial, respectively.

CONCLUSION

There is no current evidence from RCTs to reliably conclude that BMS, DCB, DCS, or atherectomy are superior to PBA in preventing major amputation and death in patients with CLTI. Larger comparative RCTs are needed to identify the best endovascular revascularisation strategy.