Cost-Effectiveness of Different Diagnostic Strategies in Suspected Stable Coronary Artery Disease in Portugal

Background

Cost-effectiveness is an increasingly important factor in the choice of atest or therapy.

Objective

To assess the cost-effectiveness of various methods routinely used for thediagnosis of stable coronary disease in Portugal.

Methods

Seven diagnostic strategies were assessed. The cost-effectiveness of eachstrategy was defined as the cost per correct diagnosis (inclusion orexclusion of obstructive coronary artery disease) in a symptomatic patient.The cost and effectiveness of each method were assessed using Bayesianinference and decision-making tree analyses, with the pretest likelihood ofdisease ranging from 10% to 90%.

Results

The cost-effectiveness of diagnostic strategies was strongly dependent on thepretest likelihood of disease. In patients with a pretest likelihood ofdisease of ≤50%, the diagnostic algorithms, which include cardiac computedtomography angiography, were the most cost-effective. In these patients,depending on the pretest likelihood of disease and the willingness to payfor an additional correct diagnosis, computed tomography angiography may beused as a frontline test or reserved for patients with positive/inconclusiveergometric test results or a calcium score of >0. In patients with apretest likelihood of disease of ≥ 60%, up-front invasive coronaryangiography appears to be the most cost-effective strategy.

Conclusions

Diagnostic algorithms that include cardiac computed tomography angiographyare the most cost-effective in symptomatic patients with suspected stablecoronary artery disease and a pretest likelihood of disease of ≤50%. Inhigh-risk patients (pretest likelihood of disease ≥ 60%), up-front invasivecoronary angiography appears to be the most cost-effective strategy. In allpretest likelihoods of disease, strategies based on ischemia appear to bemore expensive and less effective compared with those based on anatomicaltests.