A positive correlation between post-procedural myocardial injury (PMI) and volume and fraction of low-attenuation plaque (LAP) within target lesions measured by multidetector CT angiography after elective PCI was discovered by Tadayuki Uetani, MD, from the department of cardiology at Chubu Rosai Hospital in Nagoya, Japan, and colleagues.
In a study published in the January edition of the Journal of the American College of Cardiology: Cardiovascular Imaging, the authors wrote that previous studies have indicated that plaque characterization of the target lesion could provide information regarding coronary stenting and the potential risk it may carry.
A cohort of 189 patients was recruited for the study, each of whom underwent elective stent implantation after volumetric plaque analysis with a 64-slice multidetector CT. Plaque components and lumen, which were filled with dye, were classified to be low-attenuation plaque (500 HU). Post-procedural levels of the isoforms creatine kinase-MB and troponin-T (TnT) after a period of 18 hours after stent implantation were also evaluated.
The volumes of LAP (87.9 mm3 vs. 47.4 mm3) and moderate-attenuation plaque (MAP) (111.6 mm3 vs. 89.8 mm3) were larger in patients with post-procedural myocardial injury (defined as positive TnT) than in those with negative TnT, according to Uetani and colleagues.
The researchers found that low-attenuation plaque and MAP levels were the highest in patients with PMI, or those who tested positively for the biomarker TnT, than those who did not have TnT. Moreover, low-attenuation plaque and MAP and fraction of low-attenuation plaque in total plaque was found to be associated with the biomarkers, while the MAP fraction was determined to not be correlated with the biomarkers.
In addition, the authors said that LAP detected by multidetector CT can be associated with acute coronary syndrome, which “suggests that plaque with a larger low-attenuation plaque volume may be a high-risk finding,” said Uetani and colleagues.
Further studies will be necessary in determining whether another modality aside from multidetector CT can be utilized for this patient-population, said the researchers, noting the small sample size, single-center analysis and arbitrary definition of PMI as limitations of their study.
“Plaque analysis by multidetector CT would be a useful method for predicting post-procedural myocardial injury after PCI,” concluded the authors.