Most patients come to the catheterization laboratory without prior functional tests, which makes the cost-effective treatment of patients with intermediate coronary lesions a practical challenge.

We developed a decision model to compare the long-term costs and benefits of 3 strategies for treating patients with an intermediate coronary lesion and no prior functional study: 1) deferring the decision for percutaneous coronary intervention (PCI) to obtain a nuclear stress imaging study (NUC strategy); 2) measuring fractional flow reserve (FFR) at the time of angiography to help guide the decision for PCI (FFR strategy); and 3) stenting all intermediate lesions (STENT strategy). On the basis of the literature, we estimated that 40% of intermediate lesions would produce ischemia, 70% of patients treated with PCI and 30% of patients treated medically would be free of angina after 4 years, and the quality-of-life adjustment for living with angina was 0.9 (1.0 = perfect health). We estimated the cost of FFR to be $761, the cost of nuclear stress imaging to be $1093, and the cost of medical treatment for angina to be $1775 per year. The extra cost of splitting the angiogram and PCI as dictated by the NUC strategy was $3886 by use of hospital cost-accounting data. Sensitivity and threshold analyses were performed to determine which variables affected our results.

The FFR strategy saved $1795 per patient compared with the NUC strategy and $3830 compared with the STENT strategy. Quality-adjusted life expectancy was similar among the 3 strategies (NUC-FFR = 0.8 quality-adjusted days, FFR-STENT = 6 quality-adjusted life days). Compared with the FFR strategy, the NUC strategy was expensive (>$800,000 per quality-adjusted life year gained). Both screening strategies were superior to (less cost, better outcomes) the STENT strategy. Sensitivity analysis indicated that the NUC strategy would only become attractive (<$50,000/quality-adjusted life years compared with FFR) if the specificity of nuclear stress imaging was >25% better than FFR. Our results were not altered significantly by changing the other assumptions.

In patients with an intermediate coronary lesion and no prior functional study, measuring FFR to guide the decision to perform PCI may lead to significant cost savings compared with performing nuclear stress imaging or with simply stenting lesions in all patients.