Background: Non-invasive limb hemodynamics may aid in diagnosis of critical limb ischemia (CLI), although the relationship with disease severity and response to endovascular therapy is unclear.
Methods and results: This prospective, single-center study enrolled 100 CLI patients (Rutherford class 4-6) who underwent infrapopliteal endovascular revascularization (175 lesions) in the Peripheral RegIstry of Endovascular Clinical OutcoMEs (PRIME) registry. Hemodynamic measures included ankle-brachial index (ABI), toe-brachial index (TBI), and toe pressure (TP). Procedure success following revascularization was defined as stenosis ≤30%. Hemodynamic success was defined as an increase >0.15 in ABI or TBI relative to baseline. Freedom from amputation was defined as no major or minor amputation during follow-up. Clinical success was defined as a decrease of at least one Rutherford class during follow-up. Treatment success was defined as procedure success, freedom from amputation, and clinical improvement. Median baseline hemodynamic values were 0.90 for ABI, 0.39 for TBI, and 54 mm Hg for TP. Twenty-nine patients (29%) did not meet the common hemodynamic diagnostic criterion for eligibility in CLI trials (ABI ≤0.5, TBI ≤0.5, or TP <50 mm Hg). Main outcomes included 96% procedure success, 95% freedom from amputation, 64% clinical success, and 62% treatment success. There was no relationship between baseline (or with the pretreatment to posttreatment change) limb hemodynamic values and the response to infrapopliteal endovascular therapy.
Conclusion: Non-invasive hemodynamic studies may have limited clinical usefulness in patients with CLI. The usefulness of these parameters to confirm eligibility and to assess response to therapy in interventional CLI clinical trials should be re-evaluated.