Target Lesion Lipid Content Detected by Near-Infrared Spectroscopy After Stenting and the Risk of Subsequent Target Lesion Failure

Near-Infrared Spectroscopy-Guided Percutaneous Coronary Intervention: Practical Applications and Available Evidence

Intracoronary near-infrared spectroscopy (NIRS) has been extensively validated against the gold standard of histopathology to identify lipid-rich plaque. NIRS is currently in clinical use as a combined multimodality imaging catheter with intravascular ultrasonography. When used before PCI, NIRS has clinical utility in determining the mechanism underlying acute coronary syndromes and can be used to guide stent length selection and identify the risk of periprocedural myocardial infarction. When used after PCI, NIRS can identify vulnerable patients at increased risk of future patient-level cardiovascular events and can detect vulnerable plaques at increased risk of future site-specific coronary events.

Current Toolset in Predicting Acute Coronary Thrombotic Events: The “Vulnerable Plaque” in a “Vulnerable Patient” Concept

Despite major advances in pharmacotherapy and interventional procedures, coronary artery disease (CAD) remains a principal cause of morbidity and mortality worldwide. Invasive coronary imaging along with the computation of hemodynamic forces, primarily endothelial shear stress and plaque structural stress, have enabled a comprehensive identification of atherosclerotic plaque components, providing a unique insight into the understanding of plaque vulnerability and progression, which may help guide patient treatment. However, the invasive-only approach to CAD has failed to show high predictive value. Meanwhile, it is becoming increasingly evident that along with the “vulnerable plaque”, the presence of a “vulnerable patient” state is also necessary to precipitate an acute coronary thrombotic event. Non-invasive imaging techniques have also evolved, providing new opportunities for the identification of high-risk plaques, the study of atherosclerosis in asymptomatic individuals, and general population screening. Additionally, risk stratification scores, circulating biomarkers, immunology, and genetics also complete the armamentarium of a broader “vulnerable plaque and patient” concept approach. In the current review article, the invasive and non-invasive modalities used for the detection of high-risk plaques in patients with CAD are summarized and critically appraised. The challenges of the vulnerable plaque concept are also discussed, highlighting the need to shift towards a more interdisciplinary approach that can identify the “vulnerable plaque” in a “vulnerable patient”.

The Residual Lipid-Rich Coronary Atheroma Behind the Implanted Newer-Generation Drug-Eluting Stent and Future Stent-Related Event Risks

BACKGROUND

Lipid-rich plaque is an important substrate that causes future coronary events. However, the clinical implications of underlying plaque characteristics in coronary lesions after newer-generation drug-eluting stent (DES) implantation remain unknown.

METHODS

The current study analyzed 445 target lesions after newer-generation DES implantation in 416 patients with coronary artery disease (CAD) (chronic coronary syndrome/acute coronary syndrome = 264/181) from the REASSURE-NIRS multicentre registry. Near-infrared spectroscopy (NIRS) imaging was used to evaluate maximum lipid core burden index after stent implantation in target lesions (residual maxLCBI4mm). The primary and secondary outcomes were 3-year lesion-oriented clinical outcomes (LOCO): cardiac death, nonfatal target-lesion-related myocardial infarction (MI), or ischemia-driven target-lesion revascularization (ID-TLR) and patient-oriented clinical outcomes (POCO): all-cause death, nonfatal MI, or ID unplanned revascularization. Outcomes were compared by residual maxLCBI4mm tertile.

RESULTS

Median residual maxLCBI4mm was 183; 16% of lesions had residual maxLCBI4mm > 400. Higher residual maxLCBI4mm was not associated with a greater likelihood of LOCO or POCO during the observational period (LOCO, log-rank P = 0.76; POCO, log-rank P = 0.84). Mixed-effects logistic regression demonstrated that residual maxLCBI4mm does not predict LOCO (odds ratio [OR], 1.000; 95% confidence interval [CI], 0.997-1.003; P = 0.95). There was no significant relationship between residual maxLCBI4mm and POCO (OR, 1.001; 95% CI, 0.999-1.002; P = 0.30).

CONCLUSIONS

Residual maxLCBI4mm is not associated with LOCO or POCO in patients with CAD after newer-generation DES implantation. Our findings suggest that NIRS-derived underlying lipid-rich plaque is not associated with the risk of stent-related events and patient-based outcomes in patients with CAD who have received newer-generation DESs.