Peripheral arterial disease: clinical and cost comparisons between duplex US and contrast- enhanced MR angiography-a multicenter randomized trial

PURPOSE To prospectively determine the clinical and economic consequences of replacing duplex ultrasonography (US) with contrast material-enhanced magnetic resonance (MR) angiography for the initial imaging work-up of patients with peripheral arterial disease (PAD). MATERIALS AND METHODS This randomized multicenter study was approved by the institutional review board of each hospital, and all patients signed written informed consent prior to randomization. Patients with PAD who needed to undergo imaging work-up and who had an ankle-brachial pressure index (ABPI) of less than 0.90 were recruited by vascular surgeons between January 2002 and September 2003. Patients were randomly assigned to undergo contrast-enhanced MR angiography or duplex US. The primary outcome measure was cost. Secondary outcome measures included therapeutic confidence, changes in disease severity, and changes in quality of life (QOL) assessed during 6 months of follow-up. Indicators for disease severity were based on the Rutherford classification, treadmill walking distance, ABPI at rest, and ABPI after exercise. QOL was assessed with the Rating Scale, Short Form 36, EuroQol-5D, and VascuQol questionnaires. The cost of (additional) imaging procedures, therapeutic interventions, and outpatient visits were calculated from a hospital perspective (ie, all costs incurred inside the hospital were estimated, including physician costs). Data were evaluated by using the Student t test and a multivariable linear regression analysis. RESULTS At 6 months, 352 patients (239 [68%] men, 113 [32%] women; mean age, 65 years) were analyzed. The use of contrast-enhanced MR angiography versus duplex US reduced the number of additional vascular imaging procedures by 42%; contrast-enhanced MR angiography was also associated with higher therapeutic confidence. Diagnostic costs for contrast-enhanced MR angiography were 167 euros (186 dollars) higher than those for duplex US (P < .001). No statistically significant differences were found for total cost, changes in disease severity, or changes in QOL between patients examined with duplex US and those examined with contrast-enhanced MR angiography (P > .05). CONCLUSION Replacing duplex US with contrast-enhanced MR angiography for the initial imaging work-up of patients with PAD reduces the need for additional imaging, although diagnostic costs are higher.