PMC9083256_01
Discrepancies between non-invasive and invasive hemodynamic assessment modalities in stented and calcified coronary arteries. (A) FFRCT of left anterior descending (LAD) could not to be interpreted because of prior stents. (B) CCTA showed calcium blooming artifact in right coronary artery (RCA) lesion and FFRCT was significant at 0.53. (C) Coronary angiogram demonstrated an anatomically obstructive > 70% stenosis in the mid LAD (white circle) with instantaneous wave-free ratio (iFR) of 0.88 and, (D) Non-obstructive coronary artery disease (CAD) in the RCA. (E) Vessel fractional flow reserve (vFFR) was hemodynamically significant in distal LAD (black arrow). (F) vFFR of the RCA was hemodynamically insignificant.
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F1
The FFRCT in the LAD was not interpretable due to prior stents (Figure 1A), whereas the FFRCT of the LCX was 0.90. The RCA stenosis was hemodynamically significant with FFRCT at 0.53 (Figure 1B). Accordingly, we proceeded with invasive coronary angiography, which showed obstructive CAD (>70% stenosis) in the mid LAD, distal to the prior stents (Figure 1C), which was hemodynamically significant by iFR (0.88). The mid RCA showed mild diffuse disease with <50% stenosis and no focal lesions (Figure 1D). Vessel fractional flow reserve (vFFR) of the LAD was significant at 0.73 which correlated well with the invasive iFR values (Figure 1E), whereas vFFR of the RCA was 0.91 (Figure 1F). This case demonstrates the following three points: (i) Excellent correlation between invasive wire-based (iFR) and non-wire-based (vFFR) studies, (ii) Superior performance of invasive functional studies in coronary arteries with stents where FFRCT is uninterpretable, and (iii) Overestimation of the hemodynamic significance of calcified plaques with FFRCT (Figure 1B).
PMC9083256_02
Discrepancy between non-invasive and invasive hemodynamic assessment modalities in severely calcified coronary arteries. (A) CCTA showing severely calcified plaque in the mid LAD. (B) FFRCT of the LAD was hemodynamically significant. (C) FFRCT could not be interpreted in the RCA because of motion artifact. (D) Coronary angiogram demonstrated <50% stenosis in the mid LAD (white circle) and iFR of 1.0. (E) Coronary angiography showed <50% stenosis in the mid RCA (white circle). Both, vFFR of the LAD (F) and vFFR of the RCA (G) were not hemodynamically significant.
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F2
CCTA showed a severely calcified plaque in the mid LAD which could not be accurately quantified because of the calcium blooming artifact (Figure 2A). FFRCT analysis of the LAD was 0.66, reflecting a hemodynamically significant stenosis (Figure 2B). FFRCT of the LCX was 0.88 and FFRCT was uninterpretable in the RCA because of motion artifact (Figure 2C). The patient underwent invasive coronary angiography which showed anatomically non-obstructive <50% stenosis of the mid LAD with iFR at 1.0 and vFFR at 0.85 (Figures 2D,F), and non-obstructive <50% stenosis in mid RCA with vFFR 0.95 (Figures 2E,G).
PMC9083256_03
Agreement between non-invasive and invasive hemodynamic assessment modalities. (A,B) Significant LAD and RCA stenoses by FFRCT. (C) Coronary angiogram demonstrated 70% stenoses in the proximal and mid LAD (white circles) and iFR values of 0.95 in proximal LAD and 0.83 in the distal LAD (black arrows). (D) LAD stenosis was significant by vFFR (white arrow).
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F3
FFRCT of the LAD and RCA were hemodynamically significant at 0.50 and 0.59, respectively (Figures 3A,B). Invasive coronary angiography showed 70% stenoses of the proximal and mid LAD (Figure 3C), patent LPDA stent with no evidence of obstructive disease in the LCX and a small, non-dominant RCA with proximal 70% stenosis. iFR of the LAD was 0.83 distally and during the iFR pullback jumped to 0.95 in the proximal LAD (Figure 3C). iFR pullback showed excellent correlation with FFRCT values. vFFR of the LAD was 0.67, which correlated with the iFR and FFRCT values (Figure 3D).