Comprehensive multimodality characterization of hemodynamically significant and non-significant coronary lesions using invasive and noninvasive measures

Non-Invasive Modalities in the Assessment of Vulnerable Coronary Atherosclerotic Plaques

Coronary atherosclerosis is a complex, multistep process that may lead to critical complications upon progression, revolving around plaque disruption through either rupture or erosion. Several high-risk features are associated with plaque vulnerability and may add incremental prognostic information. Although invasive imaging modalities such as optical coherence tomography or intravascular ultrasound are considered to be the gold standard in the assessment of vulnerable coronary atherosclerotic plaques (VCAPs), contemporary evidence suggests a potential role for non-invasive methods in this context. Biomarkers associated with deleterious pathophysiologic pathways, including inflammation and extracellular matrix degradation, have been correlated with VCAP characteristics and adverse prognosis. However, coronary computed tomography (CT) angiography has been the most extensively investigated technique, significantly correlating with invasive method-derived VCAP features. The estimation of perivascular fat attenuation as well as radiomic-based approaches represent additional concepts that may add incremental information. Cardiac magnetic resonance imaging (MRI) has also been evaluated in clinical studies, with promising results through the various image sequences that have been tested. As far as nuclear cardiology is concerned, the implementation of positron emission tomography in the VCAP assessment currently faces several limitations with the myocardial uptake of the radiotracer in cases of fluorodeoxyglucose use, as well as with motion correction. Moreover, the search for the ideal radiotracer and the most adequate combination (CT or MRI) is still ongoing. With a look to the future, the possible combination of imaging and circulating inflammatory and extracellular matrix degradation biomarkers in diagnostic and prognostic algorithms may represent the essential next step for the assessment of high-risk individuals.

Additional Effect of Coronary High-Intensity Plaque on T1-Weighted Magnetic Resonance Imaging With Circulating Malondialdehyde-Modified Low-Density Lipoprotein on Cardiac Events

BACKGROUND

Although elevated levels of oxidized low-density lipoprotein (LDL) could play a critical role in vulnerable plaque, there are no studies that have compared coronary high-intensity plaque (HIP) and circulating malondialdehyde-modified (MDA)-LDL levels for the prediction of cardiac events.Methods and Results:A total of 139 patients with coronary artery stenosis (>70%) were examined with non-contrast T1-weighted magnetic resonance imaging (MRI) (HIP: n=64, non-HIP: n=75). Scheduled percutaneous coronary intervention (PCI) for culprit lesions was performed within 48 h after MRI. HIP was defined as a signal intensity of coronary plaque to cardiac muscle ratio (PMR) ≥1.4. We evaluated the subsequent major adverse cardiac events (MACE) during the follow-up period (5.6±1.3 years). MDA-LDL levels were independently associated with the presence of HIP (P<0.0001). The incidence of MACE was 15%, and it was significantly higher in patients with HIP (27%) than in those without HIP (5%; P=0.011). Cox proportional hazard analysis showed MDA-LDL levels (P=0.007) and PMR (P=0.016) were significantly associated with MACE. For MACE prediction, C-statistic values for MDA-LDL, PMR, and PMR+MDA-LDL were 0.724, 0.791, and 0.800, respectively. Compared with MDA-LDL alone, the addition of PMR to MDA-LDL increased net reclassification improvement by 0.78 (P=0.012).

CONCLUSIONS

MDA-LDL levels might be associated with the presence of HIP in patients with coronary artery disease. Furthermore, adding PMR to MDA-LDL levels markedly improved prediction of subsequent MACE after PCI.