Dataset Information

Blood Oxygenation Level-Dependent CMR-Derived Measures in Critical Limb Ischemia and Changes With Revascularization.

ABSTRACT:

Background

Use of blood oxygenation level-dependent cardiovascular magnetic resonance (BOLD-CMR) to assess perfusion in the lower limb has been hampered by poor reproducibility and a failure to reliably detect post-revascularization improvements in patients with critical limb ischemia (CLI).

Objectives

This study sought to develop BOLD-CMR as an objective, reliable clinical tool for measuring calf muscle perfusion in patients with CLI.

Methods

The calf was imaged at 3-T in young healthy control subjects (n = 12), age-matched control subjects (n = 10), and patients with CLI (n = 34). Signal intensity time curves were generated for each muscle group and curve parameters, including signal reduction during ischemia (SRi) and gradient during reactive hyperemia (Grad). BOLD-CMR was used to assess changes in perfusion following revascularization in 12 CLI patients. Muscle biopsies (n = 28), obtained at the level of BOLD-CMR measurement and from healthy proximal muscle of patients undergoing lower limb amputation (n = 3), were analyzed for capillary-fiber ratio.

Results

There was good interuser and interscan reproducibility for Grad and SRi (all p < 0.0001). The ischemic limb had lower Grad and SRi compared with the contralateral asymptomatic limb, age-matched control subjects, and young control subjects (p < 0.001 for all comparisons). Successful revascularization resulted in improvement in Grad (p < 0.0001) and SRi (p < 0.0005). There was a significant correlation between capillary-fiber ratio (p < 0.01) in muscle biopsies from amputated limbs and Grad measured pre-operatively at the corresponding level.

Conclusions

BOLD-CMR showed promise as a reliable tool for assessing perfusion in the lower limb musculature and merits further investigation in a clinical trial.

SUBMITTER: Bajwa A

PROVIDER: S-EPMC4728170 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ImportanceThe Bypass Versus Angioplasty for Severe Ischemia of the Leg randomized controlled trial showed comparable outcomes between endovascular revascularization (ER) and surgical revascularization (SR) for patients with critical limb ischemia (CLI). However, several observational studies showed mixed results. Most of these studies were conducted before advanced endovascular technologies were available.ObjectiveTo compare ER and SR treatment strategies for 6-month outcomes among patients with CLI.Design, setting, and participantsThis retrospective, population-based cohort study used the Nationwide Readmissions Database to identify 66 277 patients with CLI who underwent ER or SR from January 1, 2016, to December 31, 2018. Data analyses were conducted from January 1, 2022, to February 8, 2022. A propensity score with 1:1 matching was applied. Patients with CLI who underwent ER or SR were identified, and those with missing information on the length of stay and/or younger than 18 years were excluded.ExposuresEndovascular or surgical revascularization.Main outcomes and measuresThe primary outcome was a major amputation at 6 months. Significant secondary outcomes were in-hospital and 6-month mortality and an in-hospital safety composite of acute kidney injury, major bleeding, and vascular complication. Subgroup analysis was conducted for major amputation in high-volume centers.ResultsA total of 66 277 patients were identified between 2016 and 2018 who underwent ER or SR for CLI. The Nationwide Readmissions Database does not provide racial and ethnic categories. The mean (SD) age of the cohort was 69.3 (12) years, and 62.5% of patients were male. A total of 54 546 patients (82.3%) underwent ER and 11 731 (17.7%) underwent SR. After propensity score matching, 11 106 matched pairs were found. Endovascular revascularization was associated with an 18% higher risk of major amputation compared with SR (997 of 10 090 [9.9%] vs 869 of 10 318 [8.4%]; hazard ratio, 1.18; 95% CI, 1.08-1.29; P = .001). However, no difference was observed in major amputation risk when both procedures were performed in high-volume centers. Endovascular revascularization and SR had similar mortality rates (517 of 11 106 [4.7%] vs 490 of 11 106 [4.4%]; hazard ratio, 1.06; 95% CI, 0.93-1.20; P = .39). However, the ER group had a 17% lower risk of in-hospital safety outcomes compared with the SR group (2584 of 11 106 [23.3%] vs 2979 of 11 106 [26.8%]; odds ratio, 0.83; 95% CI, 0.78-0.88; P < .001).Conclusions and relevanceThe results of this study suggest that ER was safer, without any difference in mortality, but ER was associated with an increased risk of major amputation compared with SR. However, the risk of major amputation was similar when both procedures were performed at high-volume centers.