CCTA-based alternative to FFR may reduce costs

A new approach to compute fractional flow reserve (FFR) using coronary CT angiography (CCTA) appears to be cost-effective, according to results of a simulation study presented at the Society of Cardiovascular CT’s 2012 annual scientific meeting.

Mark Hlatky, MD, of the department of health research and policy at Stanford University in Stanford, Calif., and colleagues designed the simulation study to model the clinical and cost consequences of clinical management of intermediate-risk patients with suspected stable coronary artery disease (CAD) based on a novel strategy. The strategy uses CCTA plus FFR_CT, a technique that applies fluid dynamics theories to datasets from noninvasive CCTA to quantify FFR.

Previous research has shown that on a per-vessel basis, FFR_CT is more accurate and specific than CCTA (84.3 percent compared with 58.5 percent and 82.2 percent compared with 39.6 percent, respectively) and had better positive- and negative-predictive values. FFR and FFR_CT also were shown to be well correlated.

The researchers used clinical data collected from the DISCOVER-FLOW (Diagnosis of Ischemia-Causing Stenoses Obtained Via Noninvasive Fractional Flow Reserve) study as well as clinical and cost data in U.S. dollars from the literature. Their objective was to determine expected one-year death and MI rates and initial management costs associated with three diagnostic strategies. Those strategies were invasive coronary angiography (ICA) with PCI based on visual assessment; CCTA with ICA for lesions greater than 50 percent and PCI based on visual assessment; and CCTA with ICA and PCI for lesions with FFR_CT of less than 0.8.

They determined that CCTA with FFR_CT prior to invasive evaluation would reduce ICAs by 49 percent and PCIs by 39 percent, and consequently lower costs. They calculated that projected costs at one year were $7,940 for the CCTA plus FFR_CT strategy, compared with $11,500 for ICA and $10,393 for CCTA. That translated into a 31 percent reduction in initial per-patient treatment costs.

The use of CCTA with FFR_CT also would reduce death or MI compared with the ICA or CCTA-alone strategies, Hlatky and colleagues added. They concluded that using this tool may help evaluate and treat intermediate-risk patients with CAD while also lowering costs and improving outcomes. But the model needs to be tested in clinical practice to verify their results, they emphasized.

The study was sponsored by HeartFlow, a Redwood City, Calif.-based company that is developing the FFR_CT technology. The abstract was presented on July 20 at the meeting in Baltimore.

For more information on potential alternatives to FFR, read “FFR 2.0: A Calculated Run for Supremacy” in the August issue of Cardiovascular Business.