| 강수진¹, 이종영¹, 안정민¹, 김원장¹, 박덕우¹, 윤성철², 이승환¹, 김영학¹, 이철환¹, 박성욱¹, 박승정¹ |
Background We assessed optimal intravascular ultrasound (IVUS) criteria for predicting functional significance of intermediate coronary lesions.
Methods Overall, 201 patients with 236 coronary lesions underwent IVUS and invasive physiologic assessment pre-intervention. Fractional flow reserve (FFR) was measured at maximal hyperemia induced by intravenous adenosine infusion.
Results FFR<0.8 at maximum hyperemia was seen in 49 (21%) of the overall 236 lesions. The independent determinants of FFR were minimal lumen area (MLA, β=0.269, 95% CI=0.010-0.035, p<0.001), plaque burden (PB, β=-0.204, 95% CI= -0.003--0.001, p=0.001) and lesion length with a lumen area <3.0mm2 (β=-0.237, 95% CI= -0.006--0001, p=0.001). The best cut-off value (with a maximal accuracy) of the MLA to predict FFR<0.8 was <2.4mm2 with a diagnostic accuracy of 68% (90% sensitivity, 60% specificity, and AUC=0.800, 95% CI=0.742-0.848, p<0.001). The cut-off value of PB to predict FFR<0.8 was ≥79% (sensitivity 69%, specificity 72%, AUC=0.756, 95% CI=0.696-0.810, p<0.001). The cut-off value of lesion length with a lumen area <3.0mm2 was 3.1mm (sensitivity 84%, specificity 63%, AUC=0.765, 95% CI=0.706-0.818, p<0.001). Among 117 lesions with an MLA ≥2.4 mm2, 112 (96%) had an FFR≥0.8; and all but one showed FFR ≥0.75. Conversely, 44 (37%) lesions with an MLA <2.4mm2 had an FFR <0.8.
Conclusion IVUS-derived MLA ≥2.4mm2 may be useful to exclude FFR<0.8, but poor specificity limits its value for physiologic assessment of lesions with MLA <2.4mm2. Thus, FFR or stress tests may be necessary to accurately identify ischemia–inducible intermediate stenoses.
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