Most interventional cardiologists still rely solely upon angiography in making revascularization decisions about intermediate stenoses in the setting of stable coronary artery disease – and in doing so they end up making the wrong call nearly 40% of the time, according to the results of an international survey presented at the virtual annual meeting of the European Association of Percutaneous Cardiovascular Interventions.
“We saw a strong tendency to visually overestimate the percent diameter stenosis,” reported Gabor G. Toth, MD, an interventional cardiologist at the Medical University of Graz (Austria).
The same tendency has been highlighted in numerous randomized trials and observational studies. That’s why both European and U.S. guidelines now strongly recommend invasive functional assessment, such as fractional-flow reserve (FFR) testing, in evaluating the significance of intermediate stenoses in the absence of noninvasive evidence of ischemia. The new survey findings point to an important disconnect between these guideline recommendations and current clinical practice, he noted.
Dr. Toth presented the results of the second web-based, international survey on interventional decision-making strategy sponsored by the European Association of Percutaneous Cardiovascular Interventions. He contrasted the findings with those of the previously reported first international online survey, conducted 6 years earlier, for which he was first author (Circ Cardiovasc Interv. 2014 Dec;7[6]:751-9).
The two surveys were identically designed. In both, participants answered questions that enabled investigators to place them into one of four categories based upon the extent of their experience in interventional cardiology. The participants were also presented with 5 angiograms of focal intermediate stenoses and asked to determine the stenosis significance of each lesion. No information on the functional significance of the stenoses was included; however, the respondents could request additional diagnostic information by “ordering” adjunctive invasive functional assessment tests, including FFR, quantitative coronary angiography, intravascular ultrasound, or optical coherence tomography. Importantly, participating cardiologists were asked to make their decisions based upon best possible clinical practice in a hypothetical scenario where financial constraints had no role.
The second international survey was conducted during the latter half of 2019. The 334 interventional cardiologists who responded performed a total of 978 case evaluations including 2,054 coronary lesion assessments.
About 59% of all decisions were made solely on the basis of angiographic appearance without any information as to the functional significance of a given stenosis: Indeed, 13% of all stenoses were thereby declared to be “certainly” nonsignificant, and 46% were deemed “certainly” significant. In total, that figure was down significantly from the 71% rate in the first survey. In the first survey, 47% of decisions based upon angiographic appearance alone were discordant with FFR results known to the investigators, compared with a 39% discordance rate in the second survey.
Of the physician decisions made in the second survey, 10% involved a request for intravascular imaging, essentially unchanged from the 9% rate in the first survey. However, there was a significant increase over time in requests for invasive functional assessment tests: 25% in the first survey, rising to 31% in the second. This increase was entirely driven by additional requests for data on nonhyperemic pressure ratios; there was no difference in requests for FFR testing between the 2013 and 2019 surveys.
Clinician experience played an interesting role in decision-making: “Experience does not have an impact on the accuracy of angiographically based decisions, but experience does have an impact on understanding the need for adjunctive functional diagnostic testing,” Dr. Toth explained.
Indeed, 21% of decisions made by the least-experienced interventional cardiologists involved a request for adjunctive invasive functional assessment, compared with 24% of decisions by physicians in the third quartile of experience, 32% in the second, and 37% of decisions made by the most experienced clinicians.
Dr. Michael Haude
Discussant Michael Haude, MD, PhD, said that “these results clearly show that eyeball angioguidance is still the dominant tool used in decision-making, and that this eyeball angioguidance continuously overestimates the stenosis when you compare the results to quantitative coronary angiography.
“These results, surprisingly for me, show a quite low uptake of the invasive functional assessments despite overwhelming scientific data leading to clear guideline-based recommendations. Why is this the case, even after financial constraints are ruled out? Probably because FFR is still a complex invasive procedure. Maybe, in the future, quantitative flow-ratio angiography [which requires no pressure wire] or CT-based FFR will be more popular,” said Dr. Haude, an interventional cardiologist at the Rheinland Clinic in Neuss, Germany.
He reported receiving research grants from Biotronik and serving as a paid consultant to that company as well as Cardiac Dimensions, Orbus Neich, and Philips. Dr. Toth reported having no financial conflicts regarding the international survey.