BACKGROUND: Assessing the clinical importance of angiographically intermediate coronary artery stenoses at the time of cardiac catheterization remains a challenge. Spectral analysis of radiofrequency ultrasound backscatter signals, or virtual histology (VH), allows in vivo assessment of plaque composition. This study characterizes the VH composition of fractional flow reserve (FFR)-negative intermediate stenoses and adjacent vessel segments. METHODS: Intermediate coronary artery stenoses (> 40% and < 70% diameter stenosis) were assessed by pressure wire. If the FFR was > or = 0.75, percutaneous coronary intervention was deferred and VH was performed on the lesion and adjacent segments using a commercially available system. The primary clinical endpoint was any adverse cardiac event. RESULTS: Thirty-seven intermediate stenoses in 30 patients were studied. The reference vessel size was 3.02 +/- 0.71 mm, the QCA diameter stenosis was 52 +/- 6% and the FFR was 0.89 +/- 0.07. The target stenoses were characterized by VH as: thin-cap fibroatheroma (VH-TCFA; n = 22); fibrous cap atheroma (n = 5), fibrocalcific lesion (n = 7) and pathological intimal thickening (n = 3). The relative contribution of each stenosis plaque component was conserved across adjacent segments ("signature" plaque). Three patients, all with VH-TCFAs at index, had events in the clinical follow-up period of 12 +/- 2 months, but only 1 of these patients had an event related to the index stenosis. CONCLUSIONS: FFR-negative intermediate stenoses have heterogeneous plaque by VH, but are enriched in VH-TCFAs. Relative plaque composition is conserved along adjacent vessel segments. Although the specificity of VH-TCFA for index stenosis-related events appears low, larger trials are needed to assess the prognostic value of VH in this lesion subset.
BACKGROUND: Assessing the clinical importance of angiographically intermediate coronary artery stenoses at the time of cardiac catheterization remains a challenge. Spectral analysis of radiofrequency ultrasound backscatter signals, or virtual histology (VH), allows in vivo assessment of plaque composition. This study characterizes the VH composition of fractional flow reserve (FFR)-negative intermediate stenoses and adjacent vessel segments. METHODS: Intermediate coronary artery stenoses (> 40% and < 70% diameter stenosis) were assessed by pressure wire. If the FFR was > or = 0.75, percutaneous coronary intervention was deferred and VH was performed on the lesion and adjacent segments using a commercially available system. The primary clinical endpoint was any adverse cardiac event. RESULTS: Thirty-seven intermediate stenoses in 30 patients were studied. The reference vessel size was 3.02 +/- 0.71 mm, the QCA diameter stenosis was 52 +/- 6% and the FFR was 0.89 +/- 0.07. The target stenoses were characterized by VH as: thin-cap fibroatheroma (VH-TCFA; n = 22); fibrous cap atheroma (n = 5), fibrocalcific lesion (n = 7) and pathological intimal thickening (n = 3). The relative contribution of each stenosis plaque component was conserved across adjacent segments ("signature" plaque). Three patients, all with VH-TCFAs at index, had events in the clinical follow-up period of 12 +/- 2 months, but only 1 of these patients had an event related to the index stenosis. CONCLUSIONS: FFR-negative intermediate stenoses have heterogeneous plaque by VH, but are enriched in VH-TCFAs. Relative plaque composition is conserved along adjacent vessel segments. Although the specificity of VH-TCFA for index stenosis-related events appears low, larger trials are needed to assess the prognostic value of VH in this lesion subset.
Authors: Salvatore Brugaletta; Hector M Garcia-Garcia; Zhu Jun Shen; Josep Gomez-Lara; Roberto Diletti; Giovanna Sarno; Nieves Gonzalo; William Wijns; Bernard de Bruyne; Fernando Alfonso; Patrick W Serruys Journal: Int J Cardiovasc Imaging Date: 2011-02-19 Impact factor: 2.357