Cost-effectiveness of Fractional Flow Reserve Versus Intravascular Ultrasound to Guide Percutaneous Coronary Intervention: Results From the FLAVOUR Study

Abstract

Background and objectives: The Fractional Flow Reserve and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients with Intermediate Stenosis (FLAVOUR) trial demonstrated non-inferiority of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) compared with intravascular ultrasound (IVUS)-guided PCI. We sought to investigate the cost-effectiveness of FFR-guided PCI compared to IVUS-guided PCI in Korea.

Methods: A 2-part cost-effectiveness model, composed of a short-term decision tree model and a long-term Markov model, was developed for patients who underwent PCI to treat intermediate stenosis (40% to 70% stenosis by visual estimation on coronary angiography). The lifetime healthcare costs and quality-adjusted life-years (QALYs) were estimated from the healthcare system perspective. Transition probabilities were mainly referred from the FLAVOUR trial, and healthcare costs were mainly obtained through analysis of Korean National Health Insurance claims data. Health utilities were mainly obtained from the Seattle Angina Questionnaire responses of FLAVOUR trial participants mapped to EQ-5D.

Results: From the Korean healthcare system perspective, the base-case analysis showed that FFR-guided PCI was 2,451 U.S. dollar lower in lifetime healthcare costs and 0.178 higher in QALYs compared to IVUS-guided PCI. FFR-guided PCI remained more likely to be cost-effective over a wide range of willingness-to-pay thresholds in the probabilistic sensitivity analysis.

Conclusions: Based on the results from the FLAVOUR trial, FFR-guided PCI is projected to decrease lifetime healthcare costs and increase QALYs compared with IVUS-guided PCI in intermediate coronary lesion, and it is a dominant strategy in Korea.

Trial registration: ClinicalTrials.gov Identifier: NCT02673424.

Keywords: Coronary artery disease; Cost; Percutaneous coronary intervention; Quality-adjusted life year.

Figure 1. Model structure. A 2-part cost-effectiveness model, composed of a short-term decision tree (A) and a long-term Markov model (B), is shown. In the decision tree, a decision was made on FFR or IVUS, and PCI was decided based on the results of the chosen test. Thereafter, non-fatal MI, revascularization, cardiac death, and non-cardiac death could occur within one year. Patients who survived in the one-year decision tree entered into the Markov model, and the entering health state was determined according to the events that occurred in the decision tree. Yearly, patients were at risk of non-fatal MI, revascularization, cardiac death, and non-cardiac death. Non-cardiac death can occur at every state but not shown.

DES = drug-eluting stent; FFR = fractional flow reserve; IVUS = intravascular ultrasound; MI = myocardial infarction; MLA = minimal lumen area; PCI = percutaneous coronary intervention.

Figure 2. Selected results of one-way sensitivity analysis. A tornado diagram for FFR- vs. IVUS-guided PCI is presented to visualize the one-way sensitivity analysis. The top 10 variables with considerable INMB variation are shown. The vertical line represents the base-case INMB. The x-axis represented the ranges of INMB when the parameter values were varied over plausible ranges. A value of INMB greater than 0 indicates that IVUS-guided PCI is more cost-effective than FFR-guided PCI under the WTP threshold. Blue color indicates when each parameter has values lower than the base-case value within the range, and orange color indicates when each parameter has higher values.

EV = expected value; FFR = fractional flow reserve; INMB = incremental net monetary benefit; IVUS = intravascular ultrasound; MLA = minimal lumen area; PCI = percutaneous coronary intervention; USD = U.S. dollar; WTP = willingness-to-pay.

Figure 3. Cost-effectiveness acceptability curves. The results of the probabilistic sensitivity analysis are shown. The curves show the probabilities that each strategy is cost-effective at varying cost-effectiveness threshold ratios. Even as the willingness-to-pay threshold increased, the higher probability that FFR-guided percutaneous coronary intervention would be cost-effective was maintained.

FFR = fractional flow reserve; IVUS = intravascular ultrasound; QALY = quality-adjusted life-year; USD = U.S. dollar.