FAQ for FFR
- Volume 18 - Issue 12 - December 2010
- Posted on: 12/30/10
- 1 Comments
- 33479 reads
A: IC and IV adenosine induce equivalent hyperemia. There have been a couple of studies suggesting higher FFRs with IV than IC adenosine, but the differences were very small.14 In general, and in my lab, I recommend IV adenosine at 140mcg/kg/min for several reasons. It is weight-based. It is hands-free, i.e., the operator does not need to switch stop cocks and flush. It measures FFR at a steady state. IV adenosine is the standard everywhere in the world and was used by the developers of the technique, Drs. Pijls and DeBruyne. Central venous infusion is optimal, but a large peripheral arm vein (not hand vein) is adequate.7
It is curious that some FFR operators want to use very high IC bolus doses of adenosine (100, 200mcg etc). It seems to me that those who insist on using multiple higher doses when the FFR is 0.84 and unchanging are non-believers who want to treat the stenosis despite the non-ischemic value and keep raising the dose in hopes of lowering the FFR. The same might be said for IV adenosine at 170mcg/min/kg, which does not produce lower FFRs, but more side effects.
Q: I have not seen Lexiscan (regadenoson) in a comparative trial with adenosine. Do you have any experience with this drug in assessing FFR?
A: I have not seen the results of the ongoing trials of regadenoson and adenosine for FFR. Although our lab contributed to the flow velocity comparison studies of several A2A receptor blockers, we did not perform FFR in these patients, since they did not have significant coronary artery disease.16
One concern was that multiple A2A agonist dosing could minimize subsequent hyperemia. This issue has not yet been resolved. For the moment, I cannot recommend regadenoson replace adenosine.
I hope this discussion on FFR is helpful. I’ll look for more of your questions on this or any important cath lab topic in the coming year.
1. Pijls NHJ, Fearon WF, Tonino PAL, et al. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention in patients with multivessel coronary artery disease: 2-year follow-up of the FAME (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) study. J Am Coll Cardiol 2010;56:177-184.
2. Tonino PAL, DeBruyne B, Pijls NHJ, et al. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention. (FAME). New Engl J Med 2009;360:3:213-224.
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12. Fearon WF, Shah M, Ng M, et al. Predictive value of the index of microcirculatory resistance in patients with ST-segment elevation myocardial infarction. J Am Coll Cardiol 2008;51:560-565.
13. Sahinarslan A, Kocaman SA, Olgun H, et al. The reliability of fractional flow reserve measurement in patients with diabetes mellitus. Coron Artery Dis 2009;20(5):317-321.
14. Jeremias A, Whitbourn RJ, Filardo SD, et al. Adequacy of intracoronary versus intravenous adenosine-induced maximal coronary hyperemia for fractional flow reserve measurements. Am Heart J 2000;140(4):651-657.
15. Parham WA, Bouhasin A, Ciaramita JP, et al. Coronary hyperemic dose responses to intracoronary sodium nitroprusside. Circulation 2004; 109:1236-1243.
16. Hodgson JMcB, Dib N, Kern MJ, et al. Coronary circulation responses to binodenoson, a selective adenosine A2a receptor agonist. Am J Cardiol 2007;99:1507-1512.
Disclosure: Dr. Kern reports that he is a speaker for Volcano Therapeutics and St. Jude Medical, and is a consultant for Merit Medical and InfraReDx, Inc.
Check out Dr. Kern’s latest book, “Notes from the Editor’s Corner of Cath Lab Digest” at www.mortonkernmd.com