Novel Ischemia Measurement Strategies Show Potential vs. FFR

San Francisco, CA—The HeartFlowNXT study has shown the potential of a novel noninvasive strategy to accurately assess ischemia when compared with fractional flow reserve (FFR), while the ADVISE II study also showed similar promise of an adenosine-free pressure measurement to assess coronary stenoses. Results from both trials were presented at TCT 2013.

HeartFlowNXT

For the HeartFlowNXT trial, Bjarne L. Nørgaard, MD, PhD, of Aarhus University Hospital Skejby, Denmark, and colleagues compared FFR computed from coronary CT angiography images (FFR_CT) with coronary CT angiography (CTA) or invasive FFR in 254 patients with 484 vessels at 10 sites in Europe, Asia and Australia enrolled from September 2012 to August 2013.

Per-patient diagnostic performance was better for FFR_CT compared with both coronary CTA and invasive FFR without sacrificing specificity (see Figure 1). The area under the curve (AUC) for FFR_CT was 0.82 vs. 0.63 for coronary CTA (P<.001) with invasive FFR as the reference standard.

ADVISE II

Javier Escaned, MD, PhD, of Hospital Clinico San Carlos, Madrid, Spain, presented results from the ADVISE II trial which compared traditional FFR with instantaneous wave-free ratio (iFR), which does not require the administration of adenosine. It is based on the diastolic ‘wave-free period’ when intracoronary resistance is naturally constant and minimized.

Building off data presented at TCT 2011, ADVISE II is a prospective, global study including 40 sites that examined clinical applicability of iFR in the context of a hybrid iFR/FFR strategy. The study enrolled 797 patients with 919 stenoses. Patients had stable angina or ACS and were eligible for coronary angiography and/or PCI.

iFR performed well with regard to the primary endpoint (see Figure 2). The AUC was 0.90 (95% CI 0.88-0.92; P<.0001), specificity was 88% and sensitivity was 73%. Optimal iFR cutoff was ≤0.89. The hybrid iFR/FFR approach appropriately classified 94% of stenoses with a specificity of 96% and a sensitivity of 91%.

Speaking on both studies, James D. Joye, DO, of El Camino Hospital, Mountain View, Calif., commended the researchers because “we’re talking now about hundreds of patients in studies [when] we used to get excited about twenty-five. The world of trying to understand anatomy and physiology has tremendously evolved.” Both techniques are “taking FFR to a higher level,” he said, adding, however, that “we need to make these decisions before there is a wire down there and the patient is on the table.”

Disclosures:

The HeartFlowNXT study was funded by HeartFlow.

ADVISE was funded by Volcano Corporation.

Nørgaard reports no relevant conflicts of interest.

Escaned reports serving as a speaker for Boston Scientific, St. Jude Medical and Volcano Corporation.

Joye reports receiving consultant fees/honoraria from Abbott Vascular, Cook Medical, ev3, Medtronic CardioVascular and W.L. Gore & Associates, and royalties/intellectual property rights from PQ Bypass.