PURPOSE: The purpose of this clinical trial is to study the cost-effectiveness ratios of diagnostic strategies for the imaging assessment of symptomatic carotid stenosis.

MATERIALS AND METHODS: The diagnostic accuracies of Doppler ultrasound (DUS), contrast-enhanced magnetic resonance angiography (CEMRA) and computed tomography angiography (CTA) were compared with digital subtraction angiography (DSA) in a multicenter study (CARMEDAS; 206 patients assessable) and in a meta-analysis (for CEMRA and CTA). The direct costs of each imaging method were calculated in 2 university medical centers. Eight hypothetical models were studied with DUS considered as the first-line imaging method and either CEMRA or CTA or DSA as the second or third line method. The effectiveness criterion was the number of potential avoided strokes for each strategy and for 1000 patients.

RESULTS: DUS alone has the best cost-effectiveness ratio (1109 Euros for one avoided stroke) but the number of avoided strokes is significantly lower in comparison with other strategies including 2 or 3 imaging methods. A combination of DUS and CTA is the best strategy with 2 techniques (1450 Euros for one avoided stroke) compared with DUS-DSA (3635 Euros for one avoided stroke) or DUS-CEMRA (1914 Euros for one avoided stroke). DSA is not justified, neither for effectiveness nor for costs.

CONCLUSION: Considering that a combination of methods is better than only one modality, the best cost-effectiveness strategy for the assessment of symptomatic carotid stenosis is the combination of DUS and CTA. CEMRA, performed as the third line technique when DUS and CTA are discordant, allows for one more avoided stroke for 2000 patients.