Where OPTIMA fell short
Gregg W. Stone, MD, who moderated the session, said a big problem with the study was that, even though all subjects had angiographically severe stenoses, it has been clear for years that angiography alone is inadequate to identify clinically significant coronary lesions. It’s imperative to also show physiologic evidence of clinically important impairment of blood flow before intervening. Yet 29% of subjects had a preprocedural fractional flow reserve (FFR) measurement greater than 0.80 in their stenotic vessel, which indicates normal blood flow.Angiography vs. functional testing
“Twenty-nine percent of patients, we’d all agree, should not have had angioplasty because they had no ischemia,” said Dr. Stone, professor of medicine at Columbia University, New York, and director of the TCT conference.
All subjects in ORBITA did indeed undergo measurement of both FFR and instant Wave-Free Ratio (iFR) while on the table immediately before and after their real or sham PCI. The mean stenosis severity was 0.69 by FFR and 0.76 by iFR, readings indicative of significantly impaired flow. However, the operators were blinded as to those results. The rationale for withholding that information was that, even though it has been shown to be clinically useful, studies show that 80% of angioplasties are done based upon angiography alone, and the ORBITA investigators wanted the study to reflect routine clinical practice, Dr. Al-Lamee explained.
“I think one of the many lessons coming out of this trial is to see the discrepancy between the angiogram and functional testing. We cannot guide our therapy solely by the angiogram. We have to get physiologic data and consider that together with symptoms in the patient’s clinical context,” said panelist Allen Jeremias, MD, director of interventional cardiology research at St. Francis Hospital in Rosyln, N.Y.
Commentary goes too far
The “last-nail-in-the-coffin” Lancet commentary (2017 Nov 2. doi: 10.1016/S0140-6736[17]32757-5) penned by David L. Brown, MD, of Washington University in St. Louis and Rita F. Redberg, MD, of the University of California, San Francisco, emphatically declared that the ORBITA results mean all cardiology guidelines should be revised to downgrade the recommendation for PCI in patients with angina despite medical therapy. Dr. Al-Lamee was one of many at TCT 2017 who took strong exception to that.
“This is the first trial of its kind. I think it would be very easy to take the results of this trial and overextrapolate. To downgrade the guideline recommendations based on this study would be an incredibly large overreach,” she said.
Ajay J. Kirtane, MD, who chaired a press conference in which Dr. Al-Lamee presented the ORBITA results, had a further criticism of the editorial.
“Some of the risks of PCI as described in the editorial are just factually inaccurate. An MI rate of 15%, an acute kidney injury rate of 13% – those are simply factually incorrect,” said Dr. Kirtane, director of the cardiac catheterization laboratories at New York-Presbyterian/Columbia University Medical Center.
The ORBITA trial was sponsored by Imperial College London and funded by grants from the National Institute of Health Research Imperial Biomedical Research Center and charity organizations. Dr. Al-Lamee reported serving as a paid consultant to Philips Volcano, which supplied the coronary pressure wires for physiologic testing.
bjancin@frontlinemedcom.com