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 greater than or equal to 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.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Invasive Cardiology|
|State||Published - Oct 2006|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine