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

TY - JOUR

T1 - Blood Oxygenation Level-Dependent CMR-Derived Measures in Critical Limb Ischemia and Changes with Revascularization

AU - Bajwa, Adnan

AU - Wesolowski, Roman

AU - Patel, Ashish

AU - Saha, Prakash

AU - Ludwinski, Francesca

AU - Ikram, Mohammed

AU - Albayati, Mostafa

AU - Smith, Alberto

AU - Nagel, Eike

AU - Modarai, Bijan

PY - 2016/2/2

Y1 - 2016/2/2

N2 - 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.

AB - 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.

KW - angioplasty

KW - cardiovascular magnetic resonance

KW - perfusion

KW - surgery

UR - http://www.scopus.com/inward/record.url?scp=84959386475&partnerID=8YFLogxK

U2 - 10.1016/j.jacc.2015.10.085

DO - 10.1016/j.jacc.2015.10.085

M3 - Article

C2 - 26821631

AN - SCOPUS:84959386475

SN - 0735-1097

VL - 67

SP - 420

EP - 431

JO - Journal of the American College of Cardiology

JF - Journal of the American College of Cardiology

IS - 4

ER -