NEW YORK (Reuters Health) – Using CT angiography to determine plaque characteristics before electively implanting a coronary artery stent may help gauge the risk of injury or myocardial infarction (MI), according to a report from Japan.
The clinicians there found that low-attenuation plaque was an independent predictor of post-procedural myocardial injury.
Low-attenuation plaque "may represent lipid-rich plaque," which may be more likely to embolize during stent placement, lead author Dr. Tadayuki Uetani of Chubu Rosai Hospital in Nagoya told Reuters Health by email.
In 189 consecutive patients scheduled for stent implantation in the next two weeks, Dr. Uetani and colleagues used 64-slice multi-detector CT angiography to characterize target lesions. Low-attenuation plaque was defined as having a CT density of < 50 Hounsfield units (HU); moderate-attenuation plaque as 50 to 150 HU; and high-attenuation plaque as greater than >500 HU. (The density of the dye-filled lumen was 151 to 500 HU).
After coronary intervention, troponin T levels rose (indicating myocardial injury) in 59 patients (31.2%), the researchers report in the January issue of JACC: Cardiovascular Imaging.
According to their paper, the group with post-procedural myocardial injury had a significantly larger mean volume of low-attenuation plaque (87.9 vs 47.4 mm3, p < 0.01) than the group without injury.
"The association was striking — in patients with troponin increase, the average volume of low-(attenuation) plaque was twice as high as in patients without troponin elevation,