FDA Clears Volcano's iFR Modality for Lesion-Specific Assessment

March 19, 2014—Volcano Corporation (San Diego, CA) announced US Food and Drug Administration (FDA) clearance of the company’s instant wave-Free Ratio (iFR) modality, which is a physiologic measurement tool that uses the same pressure wires and equipment utilized in catheterization labs for fractional flow reserve (FFR), but avoids injection of hyperemic agents into the patient that induce stress to the heart. This allows for lesion-specific assessment in seconds by amplifying the resting pressure waveform. 

Volcano advised that the iFR modality is used most efficiently with Volcano's recently introduced Verrata pressure guidewire, which is designed for simple disconnection and reattachment during a procedure and facilitates making quick measurements multiple times during a procedure without injecting hyperemic agents each time.

The company noted that the iFR modality has been available internationally, with most installed in Europe and Japan. With FDA clearance, more than 90% of Volcano’s worldwide installed base of multimodality systems can be upgraded.

ADVISE II, the Adenosine Vasodilator Independent Stenosis Evaluation II study, is investigating the diagnostic utility of iFR in assessing coronary stenosis relevance. The study prospectively tested the performance of the iFR modality in approximately 800 patients. The trial data were presented in October at the TCT 2013: Transcatheter Cardiovascular Therapeutics conference in San Francisco, California. 

The iFR Hybrid Approach Analysis performed on the independently held ADVISE II dataset was the first prospective, real-world registry comparing iFR and FFR, and it demonstrated a statistically high correlation (sensitivity, 90.7% for FFR ≤ 0.8; specificity, 96.2% for FFR > 0.8). The hybrid method would have avoided the use of a hyperemic agent in 65.1% of this patient population. Patients in ADVISE II were recruited from more than 40 centers in the United States and Europe, and all procedures were performed with operators blinded to the iFR values, which were calculated offline at an independent core lab in Rotterdam, the Netherlands.

Amir Lerman, MD, Professor of Medicine at the Mayo Clinic in Rochester, Minnesota, served as Coprincipal Investigator of ADVISE II. Dr. Lerman commented in Volcano’s press release, “As cardiologists today we are concerned not only with the well being of our patients, but also about the efficiency with which we deliver appropriate and individualized care for a very complex problem. Stents have proven beneficial when used selectively in patients that demonstrate a functional deficiency, and FFR is a terrific tool to identify the specific lesion causing the problem. iFR will further increase efficiency by reducing the time, cost, and complexity required to properly identify lesions causing this functional deficiency and then confirming the problem is resolved by the stent.”

Dr. Lerman continued, “As physicians, we routinely ask for tools that make these valuable measurements faster, easier, and less expensive to put into practice. The fewer barriers there are to use, the more patients that will benefit from guidance tools that measure live physiology during a procedure. In an environment where cost, efficiency, and personalized medicine workflows are endpoints of major clinical trials, the hybrid iFR/FFR workflow’s 94% match with FFR and 65% patient reduction in the time and cost of a hyperemic drug infusion seem to address a couple of very significant barriers and is worth pursuing. If iFR is enough to get nonusers off the fence to embrace physiology, then this can only benefit patients by moving away from angiography alone.