Philips Volcano's iFR Modality Studied in Three Trials, Enrolling More Than 5,000 Patients

April 1, 2016—Royal Philips announced that a combined total of more than 5,000 patients have been enrolled in three prospective clinical studies to assess the safety of deferring cardiovascular interventions using Philips Volcano’s instant wave-free ratio (iFR) pressure measurement technology versus conventional fractional flow reserve (FFR) measurements.

According to the company, the combination of these three studies—with more than 5,000 patients studied, all with physiologic guidance—creates one of the largest intracoronary physiologic data sets ever collected. With approximately 40% of the patients in these studies presenting with acute coronary syndrome (ACS), these studies have the potential to expand the use of physiology above its predominant use today.

DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularization) and iFR SWEDEHEART will assess whether patient outcomes at 1 year differ when guided by iFR or FFR. SYTNAX II will evaluate the relative treatment outcomes of a hybrid iFR/FFR strategy coupled with intravascular ultrasound (IVUS) guidance, to compare the clinical utility of percutaneous coronary intervention (PCI) versus bypass surgery for three-vessel coronary disease.

Philips noted that iFR is able to synchronize pressure measurements to a wave-free period in the patient’s heartbeat, so no hyperemic agent is needed. FFR measurements require the injection of a hyperemic agent to dilate the artery. By eliminating the need for hyperemic agents, iFR offers the benefits of reduced procedure time, cost, and complexity.

Professor Patrick W.J.C. Serruys, MD, who is the DEFINE-FLAIR Study Chairman and SYNTAX II Steering Committee Chairman, commented in the company’s press release, “We are all really excited about completing enrollment for the DEFINE-FLAIR, iFR SWEDEHEART, and SYNTAX II studies. Together, these three major clinical outcome studies will more than double the randomized published physiology data, and have the potential to reshape revascularization guidelines and help physicians perform PCI procedures more likely to benefit their patients.” Prof. Serruys is from Erasmus Medical Center in Rotterdam, the Netherlands.

The 2,500 DEFINE-FLAIR patients were recruited at more than 47 centers located across Europe, Asia, North America, and Africa. DEFINE-FLAIR is sponsored by Imperial College London in London, United Kingdom. The DEFINE-FLAIR and iFR SWEDEHEART studies have harmonized endpoints.

The 2,043 patients enrolled in iFR SWEDEHEART were selected from 15 sites in Sweden, Denmark, and Iceland. The investigators expect to present the 12-month primary outcome data on myocardial infarction, unplanned revascularization, and death during spring 2017. Uppsala Clinical Research Center in Uppsala, Sweden, is the sponsor for iFR SWEDEHEART.

SYTNAX II will evaluate the relative treatment outcomes of a hybrid iFR/FFR strategy, along with IVUS guidance, to compare the clinical utility of PCI versus bypass surgery for three-vessel coronary disease using a clinical Syntax scoring methodology. SYNTAX II has enrolled 453 multivessel disease patients at 22 European sites, and uses contemporary interventional practice combining ischemia-driven revascularization using physiological guidance, the Synergy stent (Boston Scientific), and IVUS guidance. ECRI, the European Cardiovascular Research Institute, sponsors SYNTAX II.

Philips contributes funding and other support for these pivotal studies, advised the company.