Author + information
- Received September 18, 2012
- Revision received November 18, 2012
- Accepted December 10, 2012
- Published online March 5, 2013.
- Ron Waksman, MD*,* (, )
- Jacek Legutko, MD†,
- Jasvindar Singh, MD‡,
- Quentin Orlando, DO§,
- Steven Marso, MD∥,
- Timothy Schloss, MD¶,
- John Tugaoen, MD#,
- James DeVries, MD**,
- Nicholas Palmer, MD††,
- Michael Haude, MD‡‡,
- Stacy Swymelar, BS* and
- Rebecca Torguson, MPH*
- ↵*Reprint requests and correspondence:
Dr. Ron Waksman, MedStar Washington Hospital Center, 110 Irving Street, NW, Suite 4B-1, Washington, DC 20010
Objectives FIRST (Fractional Flow Reserve and Intravascular Ultrasound Relationship Study) aimed to determine the optimal minimum lumen area (MLA) by intravascular ultrasound (IVUS) that correlates with fractional flow reserve (FFR) and to assess the correlation between virtual histology IVUS and FFR for intermediate coronary lesions.
Background FFR is considered the gold standard for assessing intermediate coronary lesions. Measurements of ≤0.8 are considered clinically significant and indicative of physiological ischemia.
Methods FIRST is a multicenter, prospective, international registry of patients with intermediate coronary lesions, defined as 40% to 80% stenosis by angiography. In total, 350 patients (367 lesions) were enrolled at 10 U.S. and European sites. Patients were followed through hospital discharge.
Results Overall, an MLA <3.07 mm2 (64.0% sensitivity, 64.9% specificity, area under curve [AUC] = 0.65) was the best threshold value for identifying FFR <0.8. The accuracy improved when reference vessel–specific analyses were performed. An MLA <2.4 mm2 (AUC = 0.66) was best for reference vessel diameters <3.0 mm, an MLA <2.7 mm2 (AUC = 0.71) for reference vessel diameters of 3.0 to 3.5 mm, and an MLA <3.6 mm2 (AUC = 0.68) for reference vessel diameters >3.5 mm. FFR correlated with plaque burden (r = −0.220, p < 0.001) but not with other plaque morphology.
Conclusions Anatomic measurements by IVUS show a moderate correlation with the FFR values. The optimal cutoff for an MLA to FFR <0.8 is vessel dependent. Plaque morphology characteristics do not correlate with FFR. The utility of IVUS MLA as an alternative to FFR to guide intervention in intermediate lesions may be limited in accuracy and should be tested clinically. (Fractional Flow Reserve and Intravascular Ultrasound Relationship Study [FIRST]; NCT01153555)
This study was funded by Volcano Corporation. Dr. Haude receives grant support from Volcano Corporation. Dr. Legutko receives grant support from and is on the Speakers' Bureau of Volcano Corporation. Dr. Singh is a consultant to Volcano Corp. and St. Judes Corp.; is on the advisory board of Abbott Vascular and Boston Scientific; and the Speaker's Bureau of Medtronic Vascular and The Medicines Company. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Dr. John Tugaoen is deceased.
- Received September 18, 2012.
- Revision received November 18, 2012.
- Accepted December 10, 2012.
- American College of Cardiology Foundation
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