Study: iFR-guided heart disease treatments are quicker, more cost-effective

iFR-guided procedures for coronary artery disease use the same guidewires and equipment as FFR-guided procedures, but don't require drugs that increase blood flow.

Philips presented data from two clinical trials pitting its instant wave-free ratio (iFR) against fractional flow reserve (FFR) in the diagnosis and treatment of heart disease. Using iFR, a pressure-derived index, could lead to quicker, more cost-effective diagnoses and treatments.

Physicians use FFR—the ratio between the maximum blood flow in a diseased artery and the theoretical maximum flow in a normal artery—alongside angiography in image-guided treatments for coronary artery disease. This method requires giving the patient a hyperemic agent, one that increases blood flow to the target area.

iFR-guided procedures use the same guidewires and equipment that FFR-guided procedures do, but avoid the administration of hyperemic agents, cutting down on patient discomfort. Hyperemic drugs can ramp up heart rate and cause pounding of the heart, flushing and a heightened temperature, Philips said in a statement.

“The outcomes of these clinical studies underpin the value of iFR and its benefits for patient safety and effective diagnoses. It is our hope that the results advance the adoption of iFR to help physicians improve patient care,” said Christopher Barys, Business Leader at Philips Volcano, in the statement.

Philips unveiled data from a pair of trials involving more than 4,500 patients. The randomized, blind DEFINE FLAIR trial compared the clinical outcomes and cost efficiencies of iFR and FFR interventions of patients in Europe, North America, Europe and Asia, while the randomized iFR Swedeheart trial evaluated outcomes of using iFR or FFR with equipment from Philips.

One-year outcome data from the trials showed that iFR had shorter procedure times and lower costs than FFR, while keeping the same rate of major adverse cardiac events, Philips said in the statement. Because iFR doesn’t need a hyperemic drug, the method had a 10% shorter procedure time and cut down on patient discomfort by 90%, Philips said.

“Findings from these two major clinical outcome studies have the potential to significantly improve the use of coronary physiological assessment,” said Manesh Patel, M.D., chief of the Division of Cardiology at Duke University School of Medicine, in the statement. “One of the barriers to iFR adoption has been the lack of outcome data, however now we have evidence that an iFR-guided treatment strategy is as reliable as an FFR-guided strategy with regard to future cardiovascular events.”