The correlation between lipid volume in the target lesion, measured by integrated backscatter intravascular ultrasound, and post-procedural myocardial infarction in patients with elective stent implantation

Evolocumab for prevention of microvascular dysfunction in patients undergoing percutaneous coronary intervention: the randomised, open-label EVOCATION trial

BACKGROUND

Statins have been shown to prevent microvascular dysfunction that may cause periprocedural myocardial infarction after percutaneous coronary intervention (PCI). Evolocumab has more potent lipid-lowering properties than statins.  Aims: The aims of this study were to investigate whether evolocumab pretreatment on top of statin therapy could prevent periprocedural microvascular dysfunction.  Methods: This study included 100 patients with stable coronary artery disease who were scheduled to undergo PCI and had high low-density lipoprotein cholesterol (LDL-C) under statin therapy. Patients were randomised to receive evolocumab 140 mg every 2 weeks for 2 to 6 weeks before PCI (evolocumab group: N=54) or not (control group: N=46). The primary endpoint was the index of microvascular resistance (IMR) after PCI. Troponin T was measured before and 24 hours after PCI.  Results: Geometric mean LDL-C was 94.1 (95% confidence interval [CI]: 86.8-102.1) mg/dl and 89.4 (95% CI: 83.5-95.7) mg/dl at baseline, and 25.6 (95% CI: 21.9-30.0) mg/dl and 79.8 (95% CI: 73.9-86.3) mg/dl before PCI, in the evolocumab group and in the control group, respectively. PCI was performed 22.1±8.5 days after allocation. Geometric mean IMR was 20.6 (95% CI: 17.2-24.6) in the evolocumab group and 20.6 (95% CI: 17.0-25.0) in the control group (p=0.98). There was no significant difference in the geometric mean of post-PCI troponin T (0.054, 95% CI: 0.041-0.071 ng/ml vs 0.054, 95% CI: 0.038-0.077 ng/ml; p=0.99) and in the incidence of major periprocedural myocardial infarction between the 2 groups (44.4% vs 44.2%; p=1.00).  Conclusions: Evolocumab pretreatment did not prevent periprocedural microvascular dysfunction in patients on modern medical management with statins.

Comparison of the Incidence of Periprocedural Myocardial Infarction in Bifurcation Lesions Between Medina (1,1,1) and (0,1,1) in Elective Percutaneous Coronary Intervention

Periprocedural myocardial infarction (PMI) following percutaneous coronary intervention (PCI) is more frequently observed in true bifurcation lesions such as Medina (1,1,1) and (0,1,1). The aim of this study is to compare the incidence of PMI in elective PCI between Medina (1,1,1) and (0,1,1) bifurcation lesions. This was a retrospective, single-center study. We included 162 true bifurcation lesions, which were divided into the (1,1,1) group (n = 85) and the (0,1,1) group (n = 77). We compared the incidence of PMI between the two groups and performed multivariate logistic regression analysis using PMI as a dependent variable. The incidence of PMI was similar in the (1,1,1) group and the (0,1,1) group (12.9% versus 15.6%, P = 0.658). The final TIMI flow grade of the side branches and that of the main branches were also similar in the two groups. In multivariate logistic regression analysis, Medina classification (1,1,1) was not associated with PMI (odds ratio (OR), 0.996; 95% confidence interval (CI), 0.379-2.621; P = 0.994), but the angle of the side branch < 45° (OR, 3.569; 95% CI, 1.320-9.654; P = 0.012), lesion length in a main vessel (per 10-mm increase) (OR, 1.508; 95% CI, 1.104-2.060; P = 0.010), and absence of side branch protection (OR, 3.034; 95% CI, 1.095-8.409; P = 0.033) were significantly associated with PMI. In conclusion, the Medina (1,1,1) bifurcation lesions did not increase the incidence of PMI as compared to Medina (0,1,1). However, the narrow side branch angle, diffuse long lesion, and absence of side branch protection were significantly associated with PMI. We should pay attention to these high-risk features in the treatment of true bifurcation lesions.

Development of 60 MHz integrated backscatter intravascular ultrasound and tissue characterization of attenuated signal coronary plaques that cause myocardial injury after percutaneous coronary intervention

The purpose of the present study was to develop a 60 MHz integrated backscatter intravascular ultrasound (IB-IVUS) and to evaluate its usefulness for the detection of lipid area with backward attenuation of ultrasound signal (AT) that for the prediction of post-procedural myocardial injury (PMI) after percutaneous coronary intervention (PCI). In a pathological study, images were acquired from 221 cross-sections of 18 coronary arteries from 13 cadavers obtained at autopsy. In the clinical training study, we compared non-targeted plaques in 38 patients by a previous IB-IVUS system (38 MHz) and a new IB-IVUS system (60 MHz). In the clinical testing study, we included 70 consecutive patients who underwent PCI. Serum troponin-I was measured just before and 24 h after PCI to evaluate PMI. As the % microcalcification + % cholesterol cleft area increased, the attenuation of IB values increased (r = 0.56, p < 0.001). The slopes of regression lines of the area of each tissue component between 38 and 60 MHz IB-IVUS were excellent. The lipid pool area with AT tended to be more useful than that of the conventional lipid pool area for the prediction of PMI (p = 0.11). We developed a 60 MHz IB-IVUS imaging system for tissue characterization of coronary plaques. Cutoff value of purple color was the most reliable value for the prediction of PMI.

Determinants of Periprocedural Myocardial Infarction in Current Elective Percutaneous Coronary Interventions

Periprocedural myocardial infarction (PMI) is closely associated with long-term cardiovascular events. The factors associated with PMI are not fully understood. The purpose of this study was to investigate the determinants of PMI in contemporary elective percutaneous coronary intervention (PCI). Overall, 731 elective PCI was divided into the PMI (n = 27) and non-PMI (n = 704) groups. Univariate and multivariate logistic regression analysis was used to find factors associated with PMI. In the univariate analysis, PMI was associated with complex lesion characteristics, such as the lesion length, lesion angle, calcification, and Medina classification. In the multivariate logistic regression analysis, the lesion length (per 10-mm increase: odds ratio (OR), 1.477; 95% confidence interval (CI), 1.161‒1.879; P = 0.002), lesion angle ≥ 45° (versus lesion angle < 45°: OR, 4.244; 95% CI, 1.187‒15.171; P = 0.026), and Medina classification (0,1,1) / (1,1,1) (versus other lesions: OR, 14.843; 95% CI, 6.235‒35.334; P < 0.001) were significantly associated with PMI. Of the 24 lesions with lesion angle ≥ 45° in the PMI group, 14 had final TIMI flow grade ≤ 2 in side branches and 9 had transient slow flow in main branches/transient ST elevation during PCI. Of the 87 lesions with Medina classification (1,1,1) / (0,1,1), 19 had final TIMI grade ≤ 2 in side branches. In conclusion, the lesion length, lesion angle ≥ 45°, and Medina classification (0,1,1) / (1,1,1) were significantly associated with PMI in contemporary elective PCI. Preventing flow limitation in both side branches and main vessels in elective PCI for the diffuse long, angulated, or true bifurcation lesions is important.

Three-dimensional assessment of coronary high-intensity plaques with T1-weighted cardiovascular magnetic resonance imaging to predict periprocedural myocardial injury after elective percutaneous coronary intervention

BACKGROUND

Periprocedural myocardial injury (pMI) is a common complication of elective percutaneous coronary intervention (PCI) that reduces some of the beneficial effects of coronary revascularization and impacts the risk of cardiovascular events. We developed a 3-dimensional volumetric cardiovascular magnetic resonance (CMR) method to evaluate coronary high intensity plaques and investigated their association with pMI after elective PCI.

METHODS

Between October 2012 and October 2016, 141 patients with stable coronary artery disease underwent T1-weighted CMR imaging before PCI. A conventional 2-dimensional CMR plaque-to-myocardial signal intensity ratio (2D-PMR) and the newly developed 3-dimensional integral of PMR (3Di-PMR) were measured. 3Di-PMR was determined as the sum of PMRs above a threshold of > 1.0 for voxels in a target plaque. pMI was defined as high-sensitivity cardiac troponin T > 0.07 ng/mL.

RESULTS

pMI following PCI was observed in 46 patients (33%). 3Di-PMR was significantly higher in patients with pMI than those without pMI. The optimal 3Di-PMR cutoff value for predicting pMI was 51 PMR*mm3 and the area under the receiver operating characteristic curve (0.753) was significantly greater than that for 2D-PMR (0.683, P = 0.015). 3Di-PMR was positively correlated with lipid volume (r = 0.449, P < 0.001) based on intravascular ultrasound. Stepwise multivariable analysis showed that 3Di-PMR ≥ 51 PMR*mm3 and the presence of a side branch at the PCI target lesion site were significant predictors of pMI (odds ratio [OR], 11.9; 95% confidence interval [CI], 4.6-30.4, P < 0.001; and OR, 4.14; 95% CI, 1.6-11.1, P = 0.005, respectively).

CONCLUSIONS

3Di-PMR coronary assessment facilitates risk stratification for pMI after elective PCI.

TRIAL REGISTRATION

retrospectively registered.

Diagnostic Performance of High-Resolution Intravascular Ultrasound for the Detection of Plaque Rupture in Patients With Acute Coronary Syndrome

BACKGROUND

The new 60-MHz high-resolution intravascular ultrasound (HR-IVUS) is the next-generation IVUS technology, providing higher image resolution than conventional IVUS. It gives clear images of plaque morphology and can discriminate the underlying mechanism of acute coronary syndrome (ACS). Our study aimed to evaluate the diagnostic performance of 60-MHz HR-IVUS in the detection of plaque rupture in patients with ACS.Methods and Results:Patients with ACS who underwent percutaneous coronary intervention for de novo native coronary artery lesions were enrolled. Both HR-IVUS and optical coherence tomography (OCT) were performed for the culprit lesions prior to interventions other than aspiration thrombectomy. Keeping plaque rupture detected by OCT as the gold standard, the diagnostic performance of HR-IVUS was evaluated. Overall, 70 patients underwent both HR-IVUS and OCT examinations. Of these, imaging assessments by HR-IVUS were available for all 70 patients (100%), and those by OCT were available for 54 patients (77.1%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of HR-IVUS for identifying a plaque rupture were 84.8%, 57.1%, 75.7%, 70.6%, and 74.1%, respectively.

CONCLUSIONS

HR-IVUS had high sensitivity, but modest specificity for identifying OCT-derived plaque rupture. Compared with results from previous conventional IVUS studies, HR-IVUS might have increased ability to detect OCT-derived plaque rupture, but there is still substantial scope for improvement, especially in the specificity.

Association between changes in platelet reactivity during elective percutaneous coronary intervention and periprocedural myocardial infarction: A pilot study

BACKGROUND

High platelet reactivity before percutaneous coronary intervention (PCI) reportedly increases the risk of PCI-related myocardial infarction (PMI) following elective PCI. We conducted a pilot study to evaluate changes in platelet reactivity during PCI and their association with the incidence of PMI.

METHODS

In total, 133 consecutive patients undergoing elective PCI after pretreatment with dual antiplatelet therapy for at least 7 days were prospectively enrolled. Platelet reactivity was measured by the VerifyNow^® assay (International Technidyne Corporation, Edison, NJ, USA) immediately before and after PCI.

RESULTS

Platelet reactivity significantly increased from 177.3 ± 53.4 P2Y12 reaction units (PRU) before PCI to 203.4 ± 52.8 PRU immediately after PCI (p < 0.001). Absolute changes in platelet reactivity were significantly greater in patients with than without PMI (32.4 ± 29.0 vs. 21.2 ± 24.8 PRU, respectively; p = 0.021). In the multivariable logistic regression analysis, the absolute change in PRU was an independent predictor of the incidence of PMI. Receiver operating characteristic curve analysis of the change in PRU during PCI for discriminating PMI showed a sensitivity, specificity, and the cut-off value of 46%, 76%, and 37 PRU, respectively (area under the curve = 0.607, p = 0.0235). When the patients were divided into two groups, namely a greater (change in PRU ≥ 37) and smaller (change in PRU < 37) increase group, the incidence rate of PMI was significantly higher in the greater than smaller increase group (59.1% vs. 34.8%, respectively; p = 0.008). Additional exploratory analyses by intracoronary imaging demonstrated that the proximal reference lumen area in the greater increase group was significantly smaller than that in the smaller increase group (6.5 ± 2.4 vs. 7.7 ± 3.1 mm², respectively; p = 0.032).

CONCLUSION

An increase in platelet reactivity after elective PCI is possibly associated with PMI. This finding should be validated by a larger-scale study.

The utility of total lipid core burden index/maximal lipid core burden index ratio within the culprit plaque to predict filter-no reflow: insight from near-infrared spectroscopy with intravascular ultrasound

Filter-no reflow (FNR) is a phenomenon wherein flow improves after the retrieve of distal protection. Near-infrared spectroscopy with intravascular ultrasound (NIRS-IVUS) enables lipid detection. We evaluated the predictors of FNR during PCI using NIRS-IVUS. Thirty-two patients who underwent PCI using the Filtrap® for acute coronary syndrome (ACS) were enrolled. The culprit plaque (CP) was observed using NIRS-IVUS. Total lipid-core burden index (T-LCBI) and maximal LCBI over any 4-mm segment (max-LCBI4mm) within CP were evaluated. T-LCBI/max-LCBI4mm ratio within CP was calculated as an index of the extent of longitudinal lipid expansion. The attenuation grade (AG) and remodeling index (RI) in CP were analyzed. AG was scored based on the extent of attenuation occupying the number of quadrants. The patients were divided into FNR group (N = 8) and no-FNR group (N = 24). AG was significantly higher in FNR group than in no-FNR group (1.6 ± 0.6 vs. 0.9 ± 0.42, p = 0.01). RI in FNR group tended to be greater than in no-FNR group. T-LCBI/max-LCBI4mm ratio within the culprit plaque was significantly higher in FNR group than in no-FNR group (0.50 ± 0.10 vs. 0.33 ± 0.13, p < 0.01). In multivariate logistic regression analysis, AG > 1.04 (odds ratio [OR] 18.4, 95% confidence interval [CI] 1.5-215.7, p = 0.02) and T-LCBI/max-LCBI4mm ratio > 0.42 (OR 14.4, 95% CI 1.2-176.8, p = 0.03) were independent predictors for the occurrence of FNR. The use of T-LCBI/max-LCBI4mm ratio within CP might be an effective marker to predict FNR during PCI in patients with ACS.

Predictive value of plaque morphology assessed by frequency-domain optical coherence tomography for impaired microvascular perfusion after elective stent implantation: the intracoronary electrocardiogram study

Aims

This study was undertaken to assess the association between plaque features at culprit lesions assessed by frequency-domain optical coherence tomography (FD-OCT) and impaired microvascular perfusion estimated by intracoronary electrocardiogram (IcECG) after elective percutaneous coronary intervention (PCI). Furthermore, we investigated whether IcECG could predict future cardiac events.

Methods and results

This study consisted of 84 patients who underwent both FD-OCT and IcECG during PCI. Patients were classified into two groups based on ST-segment elevation (ST-E) on IcECG after the procedure; ST-E (-) group (n = 53) and ST-E (+) group (n = 31). Minimum fibrous cap thickness was significantly thinner in the ST-E (+) group than in the ST-E (-) group (240 μm [IQR 180 to 310] vs. 100 μm [IQR 60 to 120], P < 0.001). Plaque rupture (7.5% vs. 35.5%, P = 0.001), lipid-rich plaque (75.5% vs. 100%, P < 0.001), the thin cap fibroatheroma (0% vs. 25.8%, P < 0.001) on pre-FD-OCT, protrusion (18.9% vs. 56.7%, P < 0.001), and intra-stent dissection (15.1% vs. 50.0%, P < 0.001) on post-FD-OCT were significantly more frequently found in the ST-E (+) group than in the ST-E (-) group. The incidence of MACE (cardiac death, myocardial infarction, revascularization, hospitalization for heart failure) during 1-year was significantly higher in the ST-E (+) group than in the ST-E (-) group (5.7% vs. 19.4%, P < 0.05).

Conclusion

Plaque features assessed by FD-OCT might be associated with impaired microvascular perfusion and ST-segment elevation on IcECG after the procedure could predict 1-year cardiac events after elective PCI.

Utility of intracoronary imaging in the cardiac catheterization laboratory: comprehensive evaluation with intravascular ultrasound and optical coherence tomography

BACKGROUND

Intracoronary imaging is an important tool for guiding decision making in the cardiac catheterization laboratory.

SOURCES OF DATA

We have reviewed the latest available evidence in the field to highlight the various potential benefits of intravascular imaging.

AREAS OF AGREEMENT

Coronary angiography has been considered the gold standard test to appropriately diagnose and manage patients with coronary artery disease, but it has the inherent limitation of being a 2-dimensional x-ray lumenogram of a complex 3-dimensional vascular structure.

AREAS OF CONTROVERSY

There is well-established inter- and intra-observer variability in reporting coronary angiograms leading to potential variability in various management strategies. Intracoronary imaging improves the diagnostic accuracy while optimizing the results of an intervention. Utilization of intracoronary imaging modalities in routine practice however remains low worldwide. Increased costs, resources, time and expertise have been cited as explanations for low incorporation of these techniques.

GROWING POINTS

Intracoronary imaging supplements and enhances an operator's decision-making ability based on detailed and objective lesion assessment rather than a subjective visual estimation. The benefits of intravascular imaging are becoming more profound as the complexity of cases suitable for revascularization increases.

AREAS TIMELY FOR DEVELOPING RESEARCH

While the clinical benefits of intravascular ultrasound have been well validated, optical coherence tomography in comparison is a newer technology, with robust clinical trials assessing its clinical benefit are underway.

Prediction of cardiovascular outcomes by imaging coronary atherosclerosis

Over the last two decades, several invasive and non-invasive coronary atherosclerosis imaging modalities have emerged as predictors of cardiovascular outcomes in at-risk population. These modalities have demonstrated independent or incremental prognostic information over existing/standard risk stratification schemes, such as the Framingham risk score (FRS), by identifying characteristics of coronary artery diseases (CADs). In this review, we begin with discussing the importance of pre-test probability and quality of outcome measure, followed by specific findings of each modality in relation to prognosis. We focused on both short and long term prognostic aspects of coronary computed tomography (CT) (including coronary calcium score and coronary angiography) and magnetic resonance imaging as non-invasive tools, as well as invasive modalities including intravascular ultrasound (IVUS), optical coherence tomography (OCT), near infrared spectroscopy and Angioscopy.

Relationship of non-cardiac biomarkers with periprocedural myocardial injury in patients undergoing percutaneous coronary intervention

percutaneous coronary intervention (PCI) is one of the dominant methods for revascularization in patient with coronary artery disease (CAD), which accompanied with high incidence of periprocedural myocardial injury (PMI) evaluated by postprocedural cardiac biomarker elevation. For the convenience of risk stratification of PMI following PCI, the aim of present review provides a unique opportunity to summarize the relationship of non-cardiac biomarkers with PMI by extensively searching in the MEDLINE to identify all the relevant studies. In conclusion, we found that PCI related PMI might be correlated positively to those non-cardiac biomarkers such as low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol, total cholesterol, triglyceride, the ratios of LDL-C to high-density lipoprotein cholesterol (HDL-C), the ratios of HDL-C to apolipoprotein A-I, the ratio of eicosapentaenoic acid to arachidonic acid, lectin-like oxidized low-density lipoprotein receptor-1, C-reactive protein, high on-treatment platelet reactivity, platelet-monocyte aggregates, N-term pro-B-type natriuretic peptide, hemoglobin and albuminuria. Inversely, no relationships of PMI with those non-cardiac biomarkers such as mean platelet volume, platelet distribution width, platelet-larger cell ratio, uric acid, eosinophils count and the genetic variant of methylenetetrahydrofolate reductase (MTHFR) 677 C>T polymorphism. Moreover, there were controversial associations between PMI and those non-cardiac biomarkers such as high-density lipoprotein cholesterol, glycosylated hemoglobin, homocysteine and the polymorphism Leu33Pro of platelet glycoprotein IIbIIIa. However, almost all studies failed to provide definite mechanism of its findings, and further reaches are needed to focus on the potential mechanisms of association between non-cardiac biomarkers and PMI related to PCI.

Contribution of various lipid profile parameters in determining creatine kinase-MB levels in unstable angina patients

Context:

In India, the correlation of severity of minor myocardial damage with dyslipidemia has rarely been studied in patients of unstable angina (UA). Dyslipidemia is proven to be a major risk factor for developing acute coronary syndrome (ACS) but still there is doubt about the type of lipoproteins involved in causing minor myocardial damage occurring in UA patients of ACS.

Aims:

The aim of our study was to find out the contribution of various types of lipoproteins to predict the severity of minor myocardial damage occurring in the patients of UA.

Settings and Design:

Correlation design was used for the study. A single group of individuals was selected. Data were collected on dependent variable creatine kinase-MB (CK-MB) and independent variables (lipid profile parameters).

Subjects and Methods:

The study comprised fifty patients admitted in cardiac care unit with typical history of UA with electrocardiogram showing no ST-segment elevation. The severity of myocardial damage was assessed from on admission CK-MB levels. The lipid profile was estimated from fasting blood samples of all the patients.

Statistical Analysis Used:

For the purpose of the study, Pearson correlation and multiple linear regression analysis methods were applied.

Results:

The triacylglycerol (TAG), very-low-density lipoprotein (VLDL), total cholesterol/high-density lipoprotein (TC/HDL) showed significant positive correlation whereas HDL was negatively correlating with CK-MB levels.

Conclusions:

The TAG, VLDL, and TC/HDL were found to be significantly affecting the severity of myocardial damage in the patients of UA.

Coronary artery dominance and the risk of adverse clinical events following percutaneous coronary intervention: insights from the prospective, randomised TWENTE trial

AIMS

To investigate the prognostic value of coronary dominance for various adverse clinical events following the implantation of drug-eluting stents.

METHODS AND RESULTS

We assessed two-year follow-up data of 1,387 patients from the randomised TWENTE trial. Based on the origin of the posterior descending coronary artery, coronary circulation was categorised into left and non-left dominance (i.e., right and balanced). Target vessel-related myocardial infarction (MI) was defined according to the updated Academic Research Consortium (ARC) definition (2x upper reference limit of creatine kinase [CK], confirmed by CK-MB elevation), and periprocedural MI (PMI) as MI ≤48 hours following PCI. One hundred and thirty-six patients (9.8%) had left and 1,251 (90.2%) non-left dominance. Target lesions were more frequently located in dominant arteries (p<0.005). Left dominance was associated with more severe calcifications (p=0.006) and more bifurcation lesions (p=0.031). Non-left dominance tended to be less frequent in men (p=0.09). Left coronary dominance was associated with more target vessel-related MI (14 [10.3%] vs. 62 [5.0%], p=0.009). Left dominance independently predicted PMI (adjusted HR 2.19, 95% CI: 1.15-4.15, p=0.017), while no difference in other clinical endpoints was observed between dominance groups.

CONCLUSIONS

In the population of the TWENTE trial, we observed a higher incidence of periprocedural myocardial infarction in patients who had left coronary dominance.

Coronary plaque morphology on multi-modality imagining and periprocedural myocardial infarction after percutaneous coronary intervention

Percutaneous coronary intervention (PCI) may be complicated by periprocedural myocardial infarction (PMI) as manifested by elevated cardiac biomarkers such as creatine kinase (CK)-MB or troponin T. The occurrence of PMI has been shown to be associated with worse short- and long-term clinical outcome. However, recent studies suggest that PMI defined by biomarker levels alone is a marker of atherosclerosis burden and procedural complexity but in most cases does not have independent prognostic significance. Diagnostic multi-modality imaging such as intravascular ultrasound, optical coherence tomography, coronary angioscopy, near-infrared spectroscopy, multidetector computed tomography, and magnetic resonance imaging can be used to closely investigate the atherosclerotic lesion in order to detect morphological markers of unstable and vulnerable plaques in the patients undergoing PCI. With the improvement of technical aspects of multimodality coronary imaging, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes. There were numerous published data regarding the relationship between pre-PCI lesion subsets on multi-modality imaging and post-PCI biomarker levels. In this review, we discuss the relationship between coronary plaque morphology estimated by invasive or noninvasive coronary imaging and the occurrence of PMI. Furthermore, this review underlies that the value of the multimodality coronary imaging approach will become the gold standard for invasive or noninvasive prediction of PMI in clinical practice.

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Periprocedural myocardial infarction (PMI) has been shown to be associated with worse short- and long-term clinical outcome.

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Clinical practice and research are increasingly shifting toward the plaque morphology and patients outcomes.

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This review discusses the relationship between plaque morphology estimated by coronary imaging and the occurrence of PMI.

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This review underlies the value of the multimodality coronary imaging approach for prediction of PMI in clinical practice.

Association of Estimated Glomerular Filtration Rate and Proteinuria With Lipid-Rich Plaque in Coronary Artery Disease

BACKGROUND

Estimated glomerular filtration rate (eGFR) and proteinuria are both important determinants of the risk of cardiovascular disease and mortality. The aim of the present study was to investigate the independent and combined effects of eGFR and proteinuria on tissue characterization of the coronary plaques of culprit lesions.

METHODS AND RESULTS

Conventional intravascular ultrasound and 3-D integrated backscatter intravascular ultrasound (IB-IVUS) were performed in 555 patients undergoing elective percutaneous coronary intervention. They were divided into 2 groups according to the absence or presence of proteinuria (dipstick result ≥1+). Patients with proteinuria had coronary plaque with significantly greater percentage lipid volume compared with those without (43.6±14.8% vs. 48.6±16.1%, P=0.005). Combined analysis was done using eGFR and absence or presence of proteinuria. Subjects with eGFR 45-59 ml/min/1.73 m2 and proteinuria were significantly more likely to have higher percent lipid volume compared with those with eGFR >60 ml/min/1.73 m2 without proteinuria. After multivariate adjustment for confounders, the presence of proteinuria proved to be an independent predictor for lipid-rich plaque (OR, 1.85; 95% CI: 1.12-3.06, P=0.016).

CONCLUSIONS

The addition of proteinuria to eGFR level may be of value in the risk stratification of patients with coronary artery disease.

Coronary high-intensity plaque on T1-weighted magnetic resonance imaging and its association with myocardial injury after percutaneous coronary intervention

AIMS

Non-contrast T1-weighted imaging (T1WI) has emerged as a novel non-invasive imaging for vulnerable coronary plaque showing a high-intensity plaque (HIP). However, the association between HIP and percutaneous coronary intervention (PCI) has not been evaluated. We investigated the association between the presence of HIP and the incidence of myocardial injury after PCI.

METHODS AND RESULTS

A total of 77 patients with stable angina were imaged with non-contrast T1WI by using a 1.5 T magnetic resonance system (HIP and non-HIP group, N = 31 and 46 patients, respectively). We defined HIP as a coronary plaque to myocardium signal intensity ratio (PMR) of ≥1.4. High-sensitive cardiac troponin-T (hs-cTnT) was measured at baseline and 24 h after PCI. Percutaneous coronary intervention-related myocardial injury (PMI) was defined as an elevation of hs-cTnT >5× 99th percentile upper reference limit. High-intensity plaque was associated with the characteristics of ultrasound attenuation and positive remodelling on intravascular ultrasound. Although baseline hs-cTnT was similar between the groups, increase in hs-cTnT was significantly greater in the HIP vs. non-HIP group (0.065 [0.023-0.304] vs. 0.017 [0.005-0.026], P < 0.001). Percutaneous coronary intervention-related myocardial injury occurred more frequently in the HIP than non-HIP group (58.1 vs. 10.9%, P < 0.001), and the cut-off value of PMR found to be 1.44 for predicting PMI (sensitivity 78.3% and specificity 81.5%). In multivariate analysis, a PMR of ≥1.4 was a significant predictor of PMI (odds ratio 5.63, 95% confidence interval 1.28-24.7, P = 0.022).

CONCLUSION

High-intensity plaque on non-contrast T1WI was characterized as vulnerable coronary plaque on IVUS and was associated with higher incidence of PMI.

A combination of plaque components analyzed by integrated backscatter intravascular ultrasound and serum pregnancy-associated plasma protein a levels predict the no-reflow phenomenon during percutaneous coronary intervention

AIMS

Previous studies reported that integrated backscatter intravascular ultrasound (IB-IVUS) provides high diagnostic accuracy for tissue characterization of coronary plaques and that pregnancy-associated plasma protein A (PAPP-A) could be a marker of adverse cardiac outcome in patients with cardiovascular disease. We examined whether IB-IVUS and PAPP-A levels could predict the incidence of no-reflow during percutaneous coronary intervention (PCI) METHODS AND RESULTS: About 176 consecutive patients (138 men, mean age 68 ± 11 years) who underwent PCI with IB-IVUS were prospectively enrolled. Combined no-reflow, including transient filter no-reflow by using distal protection devices, was observed in 31 patients. The percentages of coronary lipid volume (%LV) analyzed by IB-IVUS and serum PAPP-A were significantly higher in patients with combined no-reflow than normal-reflow. To predict no-reflow, a receiver operating characteristic (ROC) analysis determined cut-off values of %LV as 62% and serum PAPP-A as 7.71 ng/mL. The multivariate logistic regression analysis showed that %LV (hazard ratio 4.5, 95% confidence interval 1.6-13.4, P < 0.01) and PAPP-A (hazard ratio 4.32, 95% confidence interval 1.5-12.7, P < 0.01) were independent predictors of combined no-reflow

CONCLUSIONS

%LV analyzed by IB-IVUS and serum PAPP-A levels were closely associated with the coronary no-reflow phenomenon. © 2014 Wiley Periodicals, Inc.

Impact of metabolic syndrome on myocardial injury and clinical outcome after percutaneous coronary intervention

AIMS

This study tested the associations between metabolic syndrome, postprocedural myocardial injury, and clinical outcome after percutaneous coronary intervention.

PATIENTS AND METHODS

We evaluated 204 patients who fulfilled the study criteria and were scheduled for elective percutaneous coronary intervention. The patients were divided into a metabolic syndrome group and a control group according to the definition of metabolic syndrome. Creatine kinase-MB and troponin I levels were measured at baseline, at 8 h, and 24 h after the procedure, while clinical outcomes were followed up for 1 year.

RESULTS

The incidence of postprocedural myocardial injury was significantly higher in the metabolic syndrome group than in the control group as indicated by either blood creatine kinase-MB elevation (32.9 % vs. 17.2 %, p = 0.010) or troponin I elevation (34.2 % vs. 17.2 %, p = 0.006). Postprocedural peak values of creatine kinase-MB (5.724 ± 7.678 ng/ml vs. 3.097 ± 5.317 ng/ml, p < 0.001) and troponin I (0.066 ± 0.093 ng/ml vs. 0.038 ± 0.079 ng/ml, p < 0.001) were also significantly higher in the metabolic syndrome group than in the control group. On multiple regression analysis, metabolic syndrome was independently associated with troponin I elevation (odds ratio 2.24, 95 % confidence interval, CI, 1.04-4.80, p = 0.039). During the 1-year follow-up, cardiac events occurred in 28.9 % of patients with metabolic syndrome and 17.9 % of controls, and there was a trend toward increased adverse outcomes in the metabolic syndrome group (hazard ratio 1.67, 95 % CI 0.93-3.00, p = 0.071, log rank test).

CONCLUSION

The results of this study demonstrate that metabolic syndrome is associated with postprocedural myocardial injury and with increased cardiac events.

Association of preprocedural low-density lipoprotein cholesterol levels with myocardial injury after elective percutaneous coronary intervention

BACKGROUND

Lower levels of low-density lipoprotein cholesterol (LDL-C) are associated with less cardiovascular risk in patients with coronary artery disease.

OBJECTIVES

To assess whether lower preprocedural LDL-C levels are associated with less risk of periprocedural myocardial injury in patients undergoing elective percutaneous coronary intervention (PCI).

METHODS

We enrolled 2529 consecutive patients with normal preprocedural cardiac troponin I (cTnI) who successfully underwent elective PCI. The association between preprocedural LDL-C levels and peak cTnI levels within 24 hours after PCI was evaluated.

RESULTS

Preprocedural LDL-C levels were correlated to postprocedural cTnI levels (r = 0.059, P = .003). In the multivariable model, preprocedural LDL-C levels between 70 and 99 mg/dL were associated with less risk of postprocedural cTnI elevation above 1 × upper limit of normal (ULN) (odds ratio [OR]: 0.804; 95% confidence interval [CI]: 0.663-0.975; P = .027) up to 15 × ULN (OR: 0.709; 95% CI: 0.530-0.949; P = .021) compared with preprocedural LDL-C levels ≥100 mg/dL. Moreover, preprocedural LDL-C levels <70 mg/dL were more strongly associated with less risk of postprocedural cTnI elevation above 1 × ULN (OR: 0.736; 95% CI: 0.584-0.927; P = .009) up to 15 × ULN (OR: 0.655; 95% CI: 0.452-0.950; P = .026).

CONCLUSIONS

Lower preprocedural LDL-C levels were associated with less risk of periprocedural myocardial injury in patients undergoing elective PCI.

Clinical utility of intravascular imaging and physiology in coronary artery disease

Intravascular imaging and physiology techniques and technologies are moving beyond the framework of research to inform clinical decision making. Currently available technologies and techniques include fractional flow reserve; grayscale intravascular ultrasound (IVUS); IVUS radiofrequency tissue characterization; optical coherence tomography, the light analogue of IVUS; and near-infrared spectroscopy that detects lipid within the vessel wall and that has recently been combined with grayscale IVUS in a single catheter as the first combined imaging device. These tools can be used to answer questions that occur during daily practice, including: Is this stenosis significant? Where is the culprit lesion? Is this a vulnerable plaque? What is the likelihood of distal embolization or periprocedural myocardial infarction during stent implantation? How do I optimize acute stent results? Why did thrombosis or restenosis occur in this stent? One of the legacies of coronary angiography is to presume that one technique will answer all of these questions; however, that often has been proved inaccurate in contemporary practice.

The Effect of Exogenous Creatine Phosphate on Myocardial Injury After Percutaneous Coronary Intervention

Objective:

To evaluate the effect of exogenous creatine phosphate (CP) on myocardial injury after percutaneous coronary intervention (PCI).

Method:

Four hundred patients were divided to receive conventional therapy (control group) or 3-day intravenous infusion of CP after PCI (CP group). Levels of creatine kinase MB (CK-MB) and troponin I (TnI) were measured before and on postprocedural day 3.

Results:

Postprocedural CK-MB and TnI in the CP group were significantly increased compared to the control group. In the CP group, 8.0% and 5.0% of patients had an increase in CK-MB 1 to 3 times and >3 times, respectively, which were significantly lower than that of the control group (19.0% and 9.0%, respectively); 12.0% and 10.0% of patients had an increase in TnI 1 to 3 times and >3 times, respectively, which were significantly lower than that of the control group (21.0% and 18.0%, respectively).

Conclusion:

Exogenous CP was helpful to reduce myocardial injury after PCI.

Positive association of coronary calcium detected by computed tomography coronary angiography with periprocedural myocardial infarction

BACKGROUND

Periprocedural myocardial infarction (PMI) may occur in approximately 5% to 30% of patients undergoing percutaneous coronary intervention. Whether the morphology of coronary plaque calcium affects the occurrence of PMI is unknown.

MATERIALS AND METHODS

A total of 616 subjects with stable angina and normal baseline cardiac troponin I levels who had undergone computed tomography angiography (CTA) were referred to elective percutaneous coronary intervention. The morphology of coronary calcium was determined by CTA analysis. PMI was defined as an elevation in 24-h post-procedural cardiac troponin I levels of > 5 times the upper limit of normal with either symptoms of myocardial ischemia, new ischemic electrocardiographic changes, or documented complications during the procedure. Logistic regression was performed to identify the effect of the morphology of coronary calcium on the occurrence of PMI.

RESULTS

According to the presence or morphology of coronary calcium as shown by CTA, 210 subjects were grouped in the heavy calcification group, 258 in the mild calcification group, 40 in the spotty calcification group and 108 in the control group. The dissection rate was significantly higher in the heavy calcification group than in the control group (7.1 % vs. 1.9%, p = 0.03). The occurrence of PMI in the heavy calcification group was significantly higher than that in the control group (OR 4.38, 95% CI 1.80-10.65, p = 0.001). After multivariate adjustment, the risk of PMI still remained significantly higher in the heavy calcification group than in the control group (OR 4.04, 95% CI 1.50-10.89, p = 0.003).

CONCLUSIONS

The morphology of coronary calcium determined by CTA may help to predict the subsequent occurrence of PMI. A large amount of coronary calcium may be predictive of PMI.

Impact of insulin resistance on post-procedural myocardial injury and clinical outcomes in patients who underwent elective coronary interventions with drug-eluting stents

OBJECTIVES

This study sought to evaluate the associations between homeostatic indexes of insulin resistance (HOMA-IR) and post-procedural myocardial injury and clinical outcome after a percutaneous coronary intervention (PCI) with a drug-eluting stent.

BACKGROUND

Insulin resistance increases the risk of cardiovascular events. However, the association between insulin resistance and clinical outcome after coronary intervention is unclear.

METHODS

We evaluated 516 consecutive patients who underwent elective PCI with drug-eluting stents. Blood samples were collected from venous blood after overnight fasting, and fasting plasma glucose and insulin levels were measured. HOMA-IR was calculated according to the homeostasis model assessment. Post-procedural myocardial injury was evaluated by analysis of troponin T and creatine kinase-myocardial band isozyme levels hours after PCI. Cardiac event was defined as the composite endpoint of cardiovascular death, myocardial infarction, and any revascularization.

RESULTS

With increasing tertiles of HOMA-IR, post-procedural troponin T and creatine kinase-myocardial band levels increased. In the multiple regression analysis, HOMA-IR was independently associated with troponin T elevation. During a median follow-up of 623 days, patients with the highest tertiles of HOMA-IR had the highest risk of cardiovascular events. The Cox proportional hazard models identified HOMA-IR as independently associated with worse clinical outcome after adjustment for clinical and procedural factors.

CONCLUSIONS

These results indicated the impact of insulin resistance on post-procedural myocardial injury and clinical outcome after elective PCI with drug-eluting stent deployment. Evaluation of insulin resistance may provide useful information for predicting clinical outcomes after elective PCI.

Meta-analysis of plaque composition by intravascular ultrasound and its relation to distal embolization after percutaneous coronary intervention

Controversies exist regarding the association between plaque composition and distal embolization phenomenon after percutaneous coronary intervention (PCI). We evaluated the effect of plaque characteristics on embolization after PCI by grayscale and virtual histology-intravascular ultrasound (IVUS). We searched PubMed, Ovid MEDLINE, and Cochrane databases for IVUS studies evaluating the coronary plaque characteristics in no reflow, distal embolization, and periprocedural myocardial infarction after PCI. Sixteen studies were included, totaling 1,697 patients who underwent PCI (292 patients with embolization and 1,405 patients without embolization). At the minimum lumen sites, the external elastic membrane (weighted mean difference 2.38 mm(2), 95% confidence interval [CI] 1.02 to 3.74) and the plaque and media cross-sectional areas (weighted mean difference 2.44 mm(2), 95% CI 1.44 to 3.45) were significantly greater in the embolization group than in the no embolization group. Pooled analysis showed that the absolute necrotic core volume (standardized mean difference 0.49, 95% CI 0.13 to 0.85), absolute (standardized mean difference 0.73, 95% CI 0.14 to 1.31) and relative (standardized mean difference 1.02, 95% CI 0.72 to 1.31) necrotic core areas at the minimum lumen sites were significantly greater in the embolization group than in the no embolization group, but the other plaque components were similar in the 2 groups. In conclusion, the necrotic core component derived from virtual histology-IVUS and the morphologic characteristics of plaque derived from grayscale IVUS are closely related to the distal embolization phenomenon after PCI.

PERIPROCEDURAL MYOCARDIAL DAMAGE

Percutaneous coronary intervention (PCI), as a method of myocardial revascularisation, is widely and effectively used for the treatment of coronary heart disease (CHD), with immediate success rates of >90%. Depending on the diagnostic criteria, 5–30% of these patients could develop the signs of periprocedural myocardial damage (PMD) or periprocedural myocardial infarction (PMI). PMD predictors, mechanisms of PMD development, and its specific clinical features play an important role in the PMI prevention. At present, there is no universal agreement on the definition and diagnostics of periprocedural myocardial necrosis and PMI, or on their impact on the clinical outcomes. According to the results of the recent studies, which are presented in this review, the current criteria of PMI might need to be modified, due to the increasingly high sensitivity of the modern threshold levels of troponin. 

Prognostic value of creatine kinase-myocardial band isoenzyme elevation following percutaneous coronary intervention: a meta-analysis

OBJECTIVES

To assess whether different degrees of creatine kinase-myocardial band isoenzyme (CK-MB) elevation after percutaneous coronary intervention (PCI) affect the subsequent risk of death.

BACKGROUND

While there is consensus that extensive cardiac enzyme elevation increase mortality significantly, there is uncertainty about the exact clinical impact of smaller CK-MB elevations after PCI.

METHODS

The published literature was scanned by formal searches of electronic databases such as PubMed and MEDLINE from January 1999 to October 2011. Risk ratio (RR) was used as summary estimate.

RESULTS

Ten studies have been included totaling 48,022 patients who underwent PCI (12,246 patients with CK-MB elevation and 35,776 patients without CK-MB elevation). Mean followup duration for each study ranged from 6 to 48 months. CK-MB elevation >1× the upper limit of normal (ULN) conferred a significant increase in the risk of mortality with an overall RR of 1.74 (95% confidence interval [CI], 1.42 to 2.13, P < 0.001). Compared with patients without CK-MB elevation, there was a dose-response relationship with RR for death being 1.48 (95% CI, 1.25-1.77, P < 0.001) with CK-MB elevation 1 to <3× ULN, 1.71 (95% CI, 1.23-2.37, P = 0.001) with CK-MB elevation 3 to 5× ULN, and 2.83 (95% CI, 1.98-4.04, P < 0.001) with CK-MB elevation ≥ 5× ULN.

CONCLUSIONS

Even a small increase in CK-MB levels after PCI is associated with significantly higher risk of late mortality. Monitoring cardiac enzymes after PCI may help predict the long term clinical outcome.

Prediction of distal embolization during percutaneous coronary intervention for unstable plaques with grayscale and integrated backscatter intravascular ultrasound

OBJECTIVES

We performed microscopic examination of the debris collected by a distal protection device and investigated the usefulness of grayscale and integrated backscatter intravascular ultrasound (IB-IVUS) for the prediction of distal embolization during percutaneous coronary intervention (PCI) in cases of unstable angina.

BACKGROUND

The prediction of distal embolization during PCI has not been studied in depth because assessment of distal embolization is difficult.

METHODS

We prospectively studied 39 consecutive patients with unstable angina who underwent PCI with a filter distal protection device. The preprocedural plaque volume at target lesions was measured with grayscale IVUS and plaque characteristics were assessed with IB-IVUS. We performed microscopic examination of the particles collected by the distal protection device.

RESULTS

There was a significant correlation between the plaque volume and the number of the collected particles >100 μm in diameter (r = 0.48, P = 0.0034). Filter no-reflow (FNR) phenomenon was found in nine patients. The plaque volume was significantly greater (355 ± 133 mm(3) vs. 199 ± 90 mm(3) , P = 0.0004), and the lipid ratio was significantly higher (29.3 ± 4.3% vs. 26.1 ± 4.3 P = 0.045) in the FNR group compared with the non-FNR group. Multivariate logistic regression analysis showed that the plaque volume was an independent predictor of FNR phenomenon.

CONCLUSIONS

Although tissue characterization of IB-IVUS may provide additional information for distal embolization, plaque volume is the only significant predictor of distal embolization during PCI.

Relation between estimated glomerular filtration rate and composition of coronary arterial atherosclerotic plaques

It is well known that chronic kidney disease is a risk factor for atherosclerosis. The present study was conducted to identify any relation between the estimated glomerular filtration rate (eGFR) and coronary plaque characteristics using integrated backscatter intravascular ultrasound (IB-IVUS), which can detect coronary plaque composition. We performed IB-IVUS for 201 consecutive patients undergoing percutaneous coronary intervention, and they were divided into 3 groups according to the eGFR values (group 1 [n = 20], ≥90 ml/min/1.73 m(2); group 2 [n = 123], 60 to 90 ml/min/1.73 m(2); and group 3 [n = 58], <60 ml/min/1.73 m(2)). Coronary plaques in nonculprit lesions on 3-dimensional analysis were evaluated using IB-IVUS. The baseline characteristics were similar, except for older age and a greater prevalence of men in group 3. IB-IVUS showed a percentage of lipid volume of 44.7 ± 5.0% in group 1, 53.6 ± 6.2% in group 2, and 63.5 ± 6.2% in group 3 (p <0.01), with a corresponding percentage of fibrous volume of 53.9 ± 4.9%, 45.1 ± 6.0%, and 35.3 ± 6.1%, respectively (p <0.01). The eGFR correlated significantly with both parameters (r = -0.68, p <0.001 and r = 0.68, p <0.001, respectively). In conclusion, lower eGFR levels were associated with greater lipid and lower fibrous contents, contributing to coronary plaque vulnerability.

Predictors of Periprocedural (Type IVa) Myocardial Infarction, as Assessed by Frequency-Domain Optical Coherence Tomography

Background—

Frequency-domain optical coherence tomography (FD-OCT) is easily able to define both pre- and post-stenting features of the atherosclerotic plaque that can potentially be related to periprocedural complications. We sought to examine which FD-OCT-defined characteristics, assessed both before and after stent deployment, predicted periprocedural (type IVa) myocardial infarction (MI).

Methods and Results—

FD-OCT was performed before and after coronary stenting in 50 patients undergoing percutaneous coronary intervention (PCI) for either non-ST segment elevation MI (NSTEMI) or stable angina. All patients underwent single-vessel stenting, and only drug-eluting stents were implanted. Troponin T was analyzed on admission, before PCI, and at 12 and 24 hours after PCI, and type IVa MI was defined in stable angina as a rise of at least 3× upper reference limit and in NSTEMI as a pre-PCI troponin T fall, followed by post-PCI troponin T rise >20%. Type IVa MI was diagnosed in 21 patients, while the remaining 29 represented the control group. FD-OCT analysis showed that thin-cap fibroatheroma (76.2% versus 41.4%; P =0.017) prior to PCI, intrastent thrombus (61.9% versus 20.7%; P =0.04), and intrastent dissection (61.9% versus 31%; P =0.03) after PCI were significantly more frequent in type IVa MI than in the control group. Multivariate logistic regression analysis confirmed thin-cap fibroatheroma (OR 29.7, 95% CI 1.4 to 32.1), intrastent thrombus (OR 5.5, CI 1.2 to 24.9) and intrastent dissection (OR 5.3, CI 1.2 to 24.3) as independent predictors of type IVa MI.

Conclusions—

In conclusion, presence of thin-cap fibroatheroma at pre-PCI FD-OCT and of intrastent thrombus and intrastent dissection at post-PCI FD-OCT predict type IVa MI in a contemporary sample of patients treated with second-generation drug-eluting stents. Interestingly, 2 of the 3 predictors of type IVa MI were not apparent at pre-PCI FD-OCT.

Impact of coronary plaque morphology assessed by optical coherence tomography on cardiac troponin elevation in patients with elective stent implantation

BACKGROUND

Mild elevations of cardiac troponin frequently occur after percutaneous coronary intervention (PCI), and patients with elevated post-PCI biomarkers have a worse prognosis. We used optical coherence tomography (OCT) to study the relationship between pre-PCI plaque morphology and post-PCI cardiac troponin I elevations.

METHODS AND RESULTS

One hundred thirty-one patients with normal pre-PCI cardiac troponin I levels underwent OCT before nonemergency stent implantation. Clinical and OCT findings were compared between patients with (n=31, 23.7%) and without (n=100, 76.3%) post-PCI cardiac troponin I of >3 × upper reference limit (post-PCI myocardial infarction [MI]). After PCI, long-term follow-up data were collected. Post-PCI MI was associated with angiographic lesion length, type B2/C lesions, presence of thin-cap fibroatheroma, and fibrous cap thickness. In multivariable analysis, presence of thin-cap fibroatheroma (odds ratio, 10.47; 95% confidence interval, 3.74 to 29.28; P<0.001) and type B2/C lesions (odds ratio, 3.74; 95% confidence interval, 1.41 to 9.92; P=0.008) were predictors of post-PCI MI. At a median follow-up of 12 months, cardiac event-free survival was significantly worse in patients with post-PCI MI (log-rank test χ(2)=8.9; P=0.003). Cox proportional hazards analysis showed that post-PCI MI (hazard ratio, 3.67; 95% confidence interval, 1.39 to 9.65; P=0.009) and ejection fraction (hazard ratio, 0.96; 95% confidence interval, 0.92 to 0.99; P=0.029) were independent predictors of adverse cardiovascular events during follow-up.

CONCLUSIONS

Type B2/C lesions and the presence of OCT-defined thin-cap fibroatheroma can predict post-PCI MI in patients treated with elective stent implantation, who may require adjunctive therapy after otherwise successful PCI.

Intense yellow culprit plaque coloration is closely associated with troponin-T elevation and flow complications following elective coronary stenting

AIM

The elevation of troponin-T (TnT) and occurrence of transient slow-flow phenomena have been recognized as procedure-related myocardial injuries. Little is known about the characteristics of high-risk plaque resulting in myocardial injury after coronary stenting.

METHODS

The culprit plaques in 42 consecutive patients with stable angina undergoing elective coronary stenting were observed by angioscopy. The plaque color upon angioscopic examination was classified as either intense yellow or not yellow. Slow flow was defined as < TIMI grade 3 flow during the procedure. The TnT levels were measured 8, 16, and 24 hours after stenting, and myocardial injury was defined as TnT ≥ 0.03 ng/mL at any time point.

RESULTS

Twenty-four patients (57%) had intense yellow plaques and myocardial injury occurred in 22 patients (52%). The frequency of intense yellow plaque was significantly higher in the patients with myocardial injury than in those without myocardial injury (91% vs. 20%, p < 0.001). Transient slow flow occurred frequently in patients with myocardial injury than in those without myocardial injury (23% vs. 0%, p = 0.049). All patients with transient slow flow had intense yellow plaques at the culprit lesions.

CONCLUSIONS

Intense yellow culprit plaque coloration was closely associated with TnT elevation and flow complications following elective coronary stenting. Angioscopically-observed intense yellow coloration may therefore predict high-risk plaque for peri-procedural myocardial injury.