Limb Stress-Rest Perfusion Imaging With Contrast Ultrasound for the Assessment of Peripheral Arterial Disease Severity

• Published in: JACC. Cardiovascular imaging Vol. 1; no. 3; pp. 343 - 350
• Main Authors: Lindner, Jonathan R., Womack, Lisa, Barrett, Eugene J., Weltman, Judy, Price, Wendy, Harthun, Nancy L., Kaul, Sanjiv, Patrie, James T.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2008
• Subjects: Adult; Ankle - blood supply; Blood Pressure; Brachial Artery - physiopathology; Cardiovascular; Case-Control Studies; Contrast Media; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - diagnostic imaging; Diabetes Mellitus, Type 2 - physiopathology; Exercise Test; Female; Humans; Intermittent Claudication - diagnostic imaging; Intermittent Claudication - etiology; Intermittent Claudication - physiopathology; Lower Extremity; Male; Microcirculation; Middle Aged; Muscle, Skeletal - blood supply; Perfusion Imaging - methods; Peripheral Vascular Diseases - complications; Peripheral Vascular Diseases - diagnostic imaging; Peripheral Vascular Diseases - physiopathology; Predictive Value of Tests; Regional Blood Flow; Risk Assessment; Risk Factors; Severity of Illness Index; Ultrasonography, Doppler; ABI; DM; CEU; PAD; VI; PVR; video intensity; contrast-enhanced ultrasound; pulse volume recording; diabetes mellitus; peripheral arterial disease; ankle-brachial index
• ISSN: 1936-878X; 1876-7591; 1876-7591
• DOI: 10.1016/j.jcmg.2008.04.001

Limb Stress-Rest Perfusion Imaging With Contrast Ultrasound for the Assessment of Peripheral Arterial Disease Severity Jonathan R. Lindner, Lisa Womack, Eugene J. Barrett, Judy Weltman, Wendy Price, Nancy L. Harthun, Sanjiv Kaul, James T. Patrie Noninvasive methods to detect peripheral vascular disease are not yet optimal. A method looking at tissue perfusion would be useful. This study used lower extremity stress-rest perfusion imaging along with contrast-enhanced ultrasound to evaluate calf blood flow/flow reserve in patients with claudication. Calf perfusion during exercise as well as its perfusion reserve correlated with symptoms in peripheral vascular disease and was better than conventional tests in estimating severity of disease. Limb microvascular perfusion imaging during exercise, using contrast-enhanced ultrasound can evaluate muscle blood in patients with peripheral arterial disease. Abnormal perfusion and flow reserve may be useful for estimating the severity of peripheral vascular disease. We hypothesized that stress-rest perfusion imaging of skeletal muscle in the lower extremity with contrast-enhanced ultrasound (CEU) could evaluate the severity of peripheral arterial disease (PAD). Perfusion imaging may provide valuable quantitative information on PAD, particularly in patients with diabetes in whom microvascular functional abnormalities are common. Study subjects included 26 control subjects and 39 patients with symptomatic PAD, 19 of whom had type 2 diabetes mellitus. A modified treadmill exercise test was performed to determine exercise time to development of claudication. Multilevel pulse-volume recordings and ankle-brachial index (ABI) at rest and post-exercise ABI were measured in both extremities. Microvascular blood flow in the gastrocnemius and soleus muscles was measured at rest and after 2 min of calibrated plantar-flexion exercise. During exercise, claudication did not occur in normal subjects and occurred earlier in PAD patients with diabetes than without (median time 1.2 min [95% confidence interval (CI) 0.6 to 2.5] vs. 3.0 min [95% CI 2.1 to 6.0], p < 0.01). Compared to control subjects, patients with PAD had lower skeletal muscle blood flow during plantar-flexion exercise and lower flow reserve on CEU. After adjusting for diabetes, the only diagnostic tests that predicted severity of disease by claudication threshold were CEU exercise blood flow and flow reserve (odds ratios 0.67 [95% CI 0.51 to 0.88; p = 0.003] and 0.64 [95% CI 0.46 to 0.89, p = 0.008], respectively). A quasi-likelihood information analysis incorporating all non-invasive diagnostic tests indicated that the best models for predicting severity of disease were the combination of diabetes and either exercise blood flow or flow-reserve on CEU. Perfusion imaging of limb skeletal during exercise and measurement of absolute flow reserve can provide valuable information on the severity PAD. This strategy may be useful for evaluating the total impact of disease in patients with complex disease or those with coexisting functional abnormalities of flow regulation.