Impact of coronary plaque morphology assessed by optical coherence tomography on cardiac troponin elevation in patients with non-ST segment elevation acute coronary syndrome

Using Optical Coherence Tomography to Identify Lipid and Its Impact on Interventions and Clinical Events - A Scoping Review

BACKGROUND

Optical coherence tomographic (OCT) imaging has enabled identification of lipid, with increasing interest in how it may affect coronary interventions and clinical outcomes. This review summarizes the available evidence around OCT identification of lipid and its effect on interventions, clinical events, and the natural history of coronary disease.

METHODS AND RESULTS

We conducted a scoping review using the Medline, HealthStar, and Embase databases for articles published between 1996 and 2021. We screened 1,194 articles and identified 51 for inclusion in this study, summarizing the key findings. The literature supports a common OCT definition of lipid as low-signal regions with diffuse borders, validated against histology and other imaging modalities with acceptable intra- and inter-rater reliability. There is evidence that OCT-identified lipid at the site of stent implantation increases the risk of edge dissection, incomplete stent apposition, in-stent tissue protrusion, decreased coronary flow after stenting, side branch occlusion, and post-procedural cardiac biomarker increases. In mostly retrospective studies, lipid indices measured at non-stented sites are associated with plaque progression and the development of recurrent ischemic events.

CONCLUSIONS

There is extensive literature supporting the ability of OCT to identify lipid and demonstrating a substantial impact of lipid on percutaneous coronary intervention outcomes. Future work to prospectively evaluate the effect of the characteristics of lipid-rich plaques on long-term clinical outcomes is needed.

PDCD4 expression in coronary atherosclerosis rat models and its mechanism

This study investigated the expression of programmed cell death protein 4 (PDCD4) in rat models of coronary atherosclerosis (AS) and analyzed its role and mechanism. A total of 80 Wistar rats were selected and divided into the control group (n=40) and research group (n=40) according to the principle of similar body weight, of which coronary AS models were established in rats in the research group. PDCD4 expression in coronary artery tissues was detected using western blotting, and the expression of interleukin-6 (IL-6) and IL-8 in the coronary artery tissues were measured by means of reverse transcription-polymerase chain reaction (RT-PCR). The apoptotic rate of coronary artery smooth muscle cells was determined via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The relative expression of PDCD4 in coronary artery tissues in the research group was obviously higher than that in the control group, and the difference was statistically significant (t=6.121, P<0.01). In terms of the relative expression of messenger ribonucleic acid (mRNA) of IL-6 in the coronary artery tissues, the research group had a remarkably higher level than the control group, with a statistically significant difference (t=21.03, P<0.01). The difference in the relative expression of IL-8 mRNA between the research group and the control group was statistically significant, of which a much higher level was detected in the research group (t=19.96, P<0.01). The apoptotic rate of smooth muscle cells in the research group was increased notably compared with that in the control group, and the difference was statistically significant (t=5.985, P<0.01). PDCD4 may participate in the formation of coronary AS plaque, and its possible function in the process is to inhibit the proliferation of vascular smooth muscle cells and promote the upregulation of IL-6 and IL-8.

Peri-procedural myocardial infarction: Plaques and patients "at-risk"

Patients with acute coronary syndrome are at risk for peri-procedural myocardial infarction (PMI) Lipid-laden plaques with thinned disrupted fibrous caps are most prone to PMI PMI is associated with worse outcome over time, though whether such damaging events are causal or instead reflect patients prone to future instability from non-culprit vulnerable plaques requires further delineation.

Ultrahigh-resolution optical coherence microscopy accurately classifies precancerous and cancerous human cervix free of labeling

Cervical cancer remains the fourth most common cause of cancer worldwide and the third leading cause of cancer deaths for women in developing countries. Traditional screening tools, such as human papillomavirus and Pap tests, cannot provide results in real-time and cannot localize suspicious regions. Colposcopy-directed biopsies are invasive in nature and only a few sites of the cervix may be chosen for investigation. A non-invasive, label-free and real-time imaging method with a resolution approaching that of histopathology is desirable for early detection of the disease.

Methods: Ultrahigh-resolution optical coherence microscopy (OCM) is an emerging imaging technique used to obtain 3-dimensional (3-D) “optical biopsies” of biological samples with cellular resolution. In this study, 497 3-D OCM datasets from 159 specimens were collected from 92 patients.

Results: Distinctive patterns for normal cervix, squamocolumnar junction, ectropion, low-grade and high-grade squamous intraepithelial lesions (LSIL and HSIL) and invasive cervical lesions were clearly observed from OCM images, which matched well with corresponding histological slides. OCM images demonstrated a sensitivity of 80% (95% confidence interval, CI, 72%-86%) and a specificity of 89% (95% CI, 84%-93%) for detecting high-risk lesions (HSIL and invasive lesions) when blindly tested by three investigators. A substantial inter-observer agreement was observed (κ=0.627), which showed high diagnostic consistency among three investigators.

Conclusion: These results laid the foundation for future non-invasive optical evaluation of cervical tissue in vivo, which could lead to a less invasive and more effective screening and “see-and-treat” strategy for the management of cervical cancer.