Shelley Wood

May 23, 2013

PARIS, France — In what may prove a wake-up call for noninvasive cardiologists routinely performing diagnostic angiograms, a small proof-of-concept study suggests that angiography alone may lead one in four stable CAD patients toward the wrong treatment plan.

According to Dr Nick Curzen (University Hospital Southampton, UK) who presented the study here at EuroPCR 2013 , diagnostic angiography may be the next frontier for fractional flow reserve (FFR), now used exclusively to guide angioplasty procedures.

In the study, dubbed Does Routine Pressure Wire Assessment Influence Management Strategy at Coronary Angiography for Diagnosis of Chest Pain? (RIPCORD), FFR was performed as an adjunct to the diagnostic angiography.

"This is at an earlier stage of the patient's pathway," he explained to heartwire . "The previous studies [DEFER, FAME , and FAME II ] were all at a later stage of the patient's pathway; those were all studies where the patients were already committed to an intervention. RIPCORD is a study where patients were at the stage where [their doctors] were deciding whether they needed medical therapy, PCI, or CABG. And if you can alter their management with FFR, it would affect many more patients."

Pulling the Cord

Dr Nick Curzen

Designed as a small proof-of-concept trial, RIPCORD enrolled 200 patients at 10 UK centers.

All were patients being evaluated for chest pain who underwent a diagnostic angiogram by their cardiologist, more often than not a noninterventional cardiologist, Curzen noted.

Those cardiologists then drew up their treatment plans for their patients and left the room, at which time patients underwent FFR assessment of all stentable (>2.25 mm-diameter) vessels by a second cardiologist. The treating cardiologist was then provided with the FFR results and invited to draw up "treatment plan 2."

The primary end point for the study was the difference between treatment plans 1 and 2.

As Curzen showed during today's hot-line session, a full 26% of patients had their treatment plans changed following the FFR results.

For example, in their initial treatment plan based on angiography alone, cardiologists intended to send 72 patients for medical management, 90 for PCI, 23 for CABG, and 15 for additional testing.

After reviewing the FFR, however, the plans were changed such that 89 patients were directed toward medical therapy, 80 toward PCI, and 30 toward CABG; only one patient was deemed to need further tests.

After seeing the FFR findings, cardiologists also upgraded or downgraded their views on the seriousness of the vascular disease. For example, based on angiography alone, cardiologists had estimated that 81 patients had no significant lesions in any vessel, but that number actually increased to 89 following FFR. Similarly, they initially stated that two patients had left main disease, but that number increased to five after seeing the FFR findings. In all, the judgment as to whether disease was "significant" or not changed following the FFR test in a full third of patients.

Important Clinical/Economic Implications

These results have potentially important implications for clinical practice, Curzen observed.

"Management of patients with stable angina by angiogram alone is probably flawed, and management of patients would probably be improved by routine use of FFR at the diagnostic stage."

Warranted now, he continues, is a large randomized trial comparing angiographic- vs FFR-guided assessment and management of patients with stable angina, he added. Such a trial would provide information not only on clinical outcomes, but also on costs," he added to heartwire .

The perception is that adding an FFR wire in every patient might not prove cost-effective, but Curzen is not convinced that's how it would work out.

"It's very clear that the more pressure wire you do, the less stenting you do. And in fact, one of the reasons FFR hasn't spread more widely around the world is that doctors don't want the FFR results, because it might tell them they shouldn't put a stent in, and that's a disincentive."

He continued: "There was a question in one of the sessions yesterday from a cardiologist . . . who said, but if I do this FFR, I'll do less stenting, and I'll be making less money. And I said, yes, but you'll be treating patients better."

Beyond the Diagnostic Cath

Following Curzen's presentation, an audience member asked him whether the difference in treatment plans before and after seeing FFR was more or less than the difference that might be seen simply between two cardiologists. Curzen acknowledged that noninvasive cardiologists, interventionalists, and surgeons often see things very differently, but he believes having FFR information will actually bring the three perspectives much more closely into alignment.

Curzen envisions a future where FFR obviates the need for much of the other adjunct noninvasive tests, but also for cardiologists who perform angiograms yet do not have the catheter skills to perform FFR.

"If a randomized trial shows the same results as RIPCORD, that may well be the end of noninterventional cardiologists doing diagnostic angiography," Curzen said.

Commenting on RIPCORD for heartwire , Dr Anthony Gershlick(University of Leicester, UK) called the study "elegantly undertaken" and "thought-provoking."

"This addresses the concerns we have about the coronary angiogram and estimating severity of lesions by eye, and it clearly shows that if you used FFR you get better management decisions in a third of the patients."

Whether it is, in fact, feasible to do FFR in every stable patient, particularly given the need for a catheter change-out, use of heparin, etc, remains to be seen. Also, he noted, "it may be that undertaking quantitative coronary angiography would increase the match between the FFR and the visual estimate of the coronary angiogram."

The trial was funded by St Jude Medical. Curzen disclosed receiving speaker fees from St Jude Medical but no personal financial reimbursement in relation to the RIPCORD trial. He has also received an unrestricted educational grant from Volcano. Gershlick has previously disclosed having served as an advisor or consultant for Medtronic, Boston Scientific, and Abbott and as a speaker or a member of a speaker's bureau for Medtronic, Boston Scientific, and Abbott. He has also received grants for clinical research from Abbott.

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