In patients with coronary artery disease scheduled for a percutaneous intervention (PCI), fractional flow reserve (FFR) assessment at the time of angiography significantly improves outcome, but it has no apparent value as a routine study in all CAD patients, according to the randomized RIPCORD 2 trial.
When compared to angiography alone in an all comer-strategy, the addition of FFR did not significantly change management or lower costs, but it was associated with a longer time for diagnostic assessment and more complications, Nicholas P. Curzen, BM, PhD, reported at the annual congress of the European Society of Cardiology.
As a tool for evaluating stenotic lesions in diseased vessels, FFR, also known as pressure wire assessment, allows interventionalists to target those vessels that induce ischemia without unnecessarily treating vessels with lesions that are hemodynamically nonsignificant. It is guideline recommended for patients with scheduled PCI on the basis of several randomized trials, including the landmark FAME trial.
“The results of these trials were spectacular. The clinical outcomes were significantly better in the FFR group despite less stents being placed and fewer vessels being stented. And there was significantly less resource utilization in the FFR group,” said Dr. Curzen, professor of interventional cardiology, University of Southampton, England.
Hypothesis: All-comers benefit from FFR
This prompted the new trial, called RIPCORD 2. The hypothesis was that systematic FFR early in the diagnosis of CAD would reduce resource utilization and improve quality of life relative to angiography alone. Both were addressed as primary endpoints. A reduction in clinical events at 12 months was a secondary endpoint.
The 1,136 participants, all scheduled for angiographic evaluation for stable angina or non-ST elevated myocardial infarction (NSTEMI), were randomized at 17 participating centers in the United Kingdom. All underwent angiography, but the experimental arm also underwent FFR for all arteries of a size suitable for revascularization.
Resource utilization evaluated through hospital costs at 12 months was somewhat higher in the FFR group, but the difference was not significant (P =.137). There was also no significant difference (P = 0.88) between the groups in quality of life, which was measured with EQ-5D-5L, an instrument for expressing five dimensions of health on a visual analog scale.
No impact from FFR on clinical events
Furthermore, there was no difference in the rate of clinical events, whether measured by a composite endpoint of major adverse cardiac events (MACE) (P = .64) or by the components of death, stroke, myocardial infarction, and unplanned revascularization, according to Dr. Curzen.
Finally, FFR did not appear to influence subsequent management. When the intervention and control groups were compared, the proportions triaged to optimal medical therapy, optimal medical therapy plus PCI, or optimal medical therapy plus bypass grafting did not differ significantly.
Given the lack of significant differences for FFR plus angiography relative to angiography alone for any clinically relevant outcome, the addition of FFR provides "no overall advantage" in this all comer study population, Dr. Curzen concluded.
However, FFR was associated with some relative disadvantages. These included significantly longer mean procedure times (69 vs. 42.4 minutes; P < .001), significantly greater mean use of contrast (206 vs. 146.3 mL; P < .001), and a significantly higher mean radiation dose (6608.7 vs. 5029.7 cGY/cm2; P < .001). There were 10 complications (1.8%) associated with FFR.