The Relationship Between Coronary Plaque Characteristics and Small Embolic Particles During Coronary Stent Implantation

Intracoronary Near-Infrared Spectroscopy to Predict No-Reflow Phenomenon During Percutaneous Coronary Intervention in Acute Coronary Syndrome

Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) can identify the lipid-rich lesions, described as high lipid-core burden index (LCBI). The aim of this study was to investigate the relation between lipid-core plaque (LCP) in the infarct-related lesion detected using NIRS-IVUS and no-reflow phenomenon during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). We investigated 371 patients with ACS who underwent NIRS-IVUS in the infarct-related lesions before PCI. The extent of LCP in the infarct-related lesion was calculated as the maximum LCBI for each of the 4-mm longitudinal segments (maxLCBI4mm) measured by NIRS-IVUS. The patients were divided into 2 groups using a maxLCBI4mm cut-off value of 400. The overall incidence of no-reflow phenomenon was 53 of 371 (14.3%). No-reflow phenomenon more frequently occurred in patients with maxLCBI4mm ≥400 compared with those with maxLCBI4mm<400 (17.5% vs 2.5%, p <0.001). After propensity score matching, multivariable logistic regression analysis demonstrated that maxLCBI4mm (odds ratio: 1.008; 95% confidence interval: 1.005 to 1.012, p <0.001) was independently associated with the no-reflow phenomenon. The maxLCBI4mm of 719 in the infarct-related lesion had the highest combined sensitivity (69.8%) and specificity (72.1%) for the identification of no-reflow phenomenon. In conclusion, in patients with ACS, maxLCBI4mm in the infarct-related lesion assessed by NIRS-IVUS was independently associated with the no-reflow phenomenon during PCI.

Optical Coherence Tomography Assessment of Coronary Lesions Associated With Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction

BACKGROUND

Microvascular reperfusion following percutaneous coronary intervention (PCI) is associated with the prognosis of patients with ST-segment elevation myocardial infarction (STEMI). We investigated how plaque characteristics detected by optical coherence tomography (OCT) in STEMI patients affect the status of the microcirculation during PCI.Methods and Results: This retrospective, single-center study was a post hoc analysis basedon the multicenter SALVAGE randomized control trial (NCT03581513) that enrolled 629 STEMI patients, and finally we enrolled 235 patients who underwent PCI and pre-intervention OCT. Microvascular perfusion was evaluated using the Thrombolysis in Myocardial Infarction (TIMI) myocardial perfusion frame count (TMPFC). Patients were divided into 3 groups based on the change in TMPFC from before to after PCI: improving TMPFC (n=11; 4.7%), stable TMPFC (n=182; 77.4%), and worsening TMPFC group (n=42; 17.9%). The proportion of patients with a microcirculation dysfunction before reperfusion was 11.9%, which increased significantly by (P=0.079) 8.5% to 20.4% after reperfusion. Compared with plaque characteristics in the stable and worsening TMPFC groups, the improving TMPFC group had fewer thrombi (90.7% and 90.5% vs. 89.4%, respectively; P=0.018), a lower proportion of plaque rupture (66.5% and 66.3% vs. 54.5%, respectively; P=0.029), and a lower proportion of lipid-rich plaques (89.6% and 88.1% vs. 63.6%, respectively; P=0.036).

CONCLUSIONS

PCI may not always achieve complete myocardial reperfusion. Thrombi, plaque rupture, and lipid-rich plaques detected by OCT can indicate microcirculation dysfunction during the reperfusion period.

No-reflow phenomenon and in vivo cholesterol crystals combined with lipid core in acute myocardial infarction

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The number of in vivo cholesterol crystals at the culprit plaque is increased in patients with the no-reflow phenomenon.

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The number of cholesterol crystals, lipid arch, and ostium lesion are independent predictors for the no-reflow phenomenon after PCI.

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The combination of the number of cholesterol crystals and lipid arc can improve the prediction ability for the no-reflow phenomenon.

Background

The release of lipid-laden plaque material subsequent to ST-segment elevation myocardial infarction (STEMI) may contribute to the no-reflow phenomenon. The aim of this study was to investigate the association between in vivo cholesterol crystals (CCs) detected by optical coherence tomography (OCT) and the no-reflow phenomenon after successful percutaneous coronary intervention (PCI) in patients with acute STEMI.

Methods

We investigated 182 patients with STEMI. Based on the thrombolysis in myocardial infarction (TIMI) flow grade after PCI, patients were divided into a no-reflow group (n = 31) and a reflow group (n = 151). On OCT, CCs were defined as thin, high-signal intensity regions within a plaque. A multivariable logistic regression analysis was performed to determine predictors for the no-reflow phenomenon.

Results

The prevalence of CCs was higher in the no-reflow group than the reflow group (no-reflow group, 77% vs. reflow group, 53%; p = 0.012). The multivariable logistic model showed that the CC number, lipid arc and ostial lesions were positive independent predictors of no-reflow. The combination of a lipid arc ≥ 139°and CC number ≥ 12 showed good predictive performance for the no-reflow phenomenon (sensitivity, 48%; specificity, 93%; and accuracy, 86%).

Conclusion

In vivo CCs at the culprit plaque are associated with the no-reflow phenomenon after PCI in patients with STEMI. The combination of the number of CCs and lipid arc can predict the no-reflow phenomenon after PCI with a high accuracy of 86%.

Impact of plaque burden and composition on coronary slow flow in ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention: intravascular ultrasound and virtual histology analysis

AIM

Coronary slow flow (SF) is an important complication of percutaneous coronary intervention (PCI) associated with poor prognosis. The aim was to assess grey-scale intravascular ultrasound (IVUS) and virtual histology (VH-IVUS) characteristics of culprit lesion in ST-elevation myocardial infarction (STEMI).

METHODS

A total of 295 consecutive patients with STEMI underwent coronary angiogram and IVUS. Following PCI, patients divided into two groups; SF (thrombolysis in myocardial infarction [TIMI] flow  ≤ 2, n = 74) and normal flow (NF) (TIMI flow >2, n = 221). Coronary plaque burden and its composition in relation to SF were evaluated.

RESULTS

On grey-scale IVUS, the plaque area (12.3 mm² vs. 11.5 mm², p = .01), plaque volume (110.7 mm³ vs. 99.8 mm³, p < .001), lesion external elastic membrane (EEM) cross-sectional area (14.9 mm² vs. 14.0 mm², p = .011) and remodelling index (1.3 vs. 1.2, p = .043) were significantly higher in SF group. On VH-IVUS, absolute fibrous volume (48.1 mm³ vs. 41.5 mm³, p ≤ .001), fibrofatty volume (23.8 mm³ vs. 18.6 mm³, p = .015), necrotic core volume (8.3 mm³ vs. 5.5 mm³, p < .001), dense calcium volume (1.2 mm³ vs. 0.6 mm³, p = .003) and thin cap fibroatheroma either single (30.1% vs. 16.1%, p < .001) or multiple (9.6% vs. 1.8%, p < .001) were higher in SF arm. In multivariable analysis, absolute necrotic core volume (odds ratio  =  1.159; 95% CI 1.030-1.305, p = .015) was the only independent predictor of SF.

CONCLUSIONS

Higher necrotic core volume as detected by VH-IVUS may be a potential risk factor for the development of coronary SF phenomenon in patients with STEMI after PCI.

Small lipid core burden index in patients with stable angina pectoris is also associated with microvascular dysfunction: Insights from intracoronary electrocardiogram

Near-infrared spectroscopy with intravascular ultrasound (NIRS)-IVUS enables precise detection of lipid core burden. Intracoronary electrocardiography (ECG) can detect slight ischemia during percutaneous coronary intervention (PCI), indicating microvascular dysfunction (MD) by distal embolization, etc. Thus, this study aimed to investigate whether plaques with a low max-lipid core burden index (LCBI) at 4 mm (LCBI4mm) influence MD, using intracoronary ECG. We enrolled 40 consecutive patients who underwent PCI for stable angina pectoris (SAP) due to stenosis of the proximal segment of the left anterior descending artery in this study. Max-LCBI4mm was measured for each culprit lesion. Gray-scale IVUS data including plaque burden were measured. Intracoronary ECG was performed to measure the time from the initiation of ST-segment elevation from the isoelectric baseline after stent balloon inflation to the return of the ST-segment to the isoelectric baseline after the deflation of the stent balloon, which was defined as the severity of the MD. The patients were divided into two groups according to median max-LCBI4mm of 120 as follows: low- [n = 20] and high- [n = 20] LCBI groups. The overall mean Max-LCBI4mm was 120 ± 86. No differences in baseline characteristics, including prevalence of dyslipidemia, were found between both groups, as well as in the gray-scale IVUS parameters. The severity of the MD was greater in the high-LCBI group than in the low-LCBI group (16.6 ± 9.1 vs 4.7 ± 4.8 s, P < 0.01). The no-reflow and slow-flow phenomena were not observed. Even max-LCBI4mm value <400 on NIRS-IVUS was associated with MD during PCI in patients with SAP.

Protective Effects of Salvianolate on Myocardial Injury or Myocardial Infarction after Elective Percutaneous Coronary Intervention in NSTE-ACS Patients: A Randomized Placebo-Controlled Trial

OBJECTIVE

To evaluate the protective effects of salvianolate on percutaneous coronary intervention (PCI) related myocardial injury or myocardial infarction after elective PCI in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients.

METHODS

A total of 149 patients with NSTE-ACS who underwent elective PCI were enrolled. The patients were randomly allocated in a 1:1 ratio to the salvianolate group (74 cases) or the control group (75 cases). After exclusion criteria of coronary angiography, 60 patients with PCI therapy remained in the salvianolate group and 68 in the control group. The incidence and the severity of PCI related myocardial injury or myocardial infarction, in addition to major adverse cardiac events (MACEs) during 1 year follow-up after PCI were studied between the two groups. Multivariate logistic regression analysis was used to determine the independent factors for PCI related myocardial injury or myocardial infarction after elective PCI.

RESULTS

Compared with the control group, salvianolate treatment reduced the incidence of PCI related severe myocardial injury or myocardial infarction (11.7% vs. 26.5%, P=0.035). The rate of MACEs or all-cause death within 1 month or 1 year after the procedure was not significantly different between the two groups.

CONCLUSIONS

Periprocedural treatment with salvianolate reduces the incidence of PCI related severe myocardial injury or myocardial infarction, although it does not influence clinical prognosis. [Chinese clinical trial registry: ChiCTR1800016992].

Periprocedural Myocardial Injury: Pathophysiology, Prognosis, and Prevention

The definition and clinical implications of myocardial infarction occurring in the setting of percutaneous coronary intervention have been the subject of unresolved controversy. The definitions of periprocedural myocardial infarction (PMI) are many and have evolved over recent years. Additionally, the recent advancement of different imaging modalities has provided useful information on a patients' pre-procedural risk of myocardial infarction. Nonetheless, questions on the benefit of different approaches to prevent PMI and their practical implementation remain open. This review aims to address these questions and to provide a current and contemporary perspective.

Prediction of Major Adverse Cardiovascular Events and Slow/No-Reflow by Virtual Histology Imaging After Percutaneous Interventions on Saphenous Vein Grafts

Saphenous vein grafts disease (SVGD) is a common complication after coronary artery bypass graft (CABG) and usually treated by percutaneous coronary intervention (PCI). In this prospective cohort study, we performed virtual histology-intravascular ultrasound to investigate whether plaque composition and morphological characteristics were associated with post-PCI major adverse cardiac events (MACEs) and slow/no-reflow in patients with SVGD. Patients (n = 90) were studied (76.7% men, mean age 64.9 ± 8.2 years and mean duration of SVG 8.0 ± 3.6 years). There were 77.8% lesions with a plaque burden of at least 70%; 18 MACE incidences accumulated in 14 patients over 12 months post-PCI and slow/no-reflow was observed in 12 patients. On adjusted multivariate analysis, lesion length (hazard ratio [HR] = 1.05; 95% confidence interval [CI]: 1.01-1.08]); age of CABG (HR = 1.51 [95% CI: 1.11-2.05], and absolute necrotic core (NC) area (HR = 8.04 [95% CI: 1.86-34.73]) were independently associated with MACEs. Factors independently associated with slow/no-reflow post-PCI were preprocedure systolic blood pressure (odds ratio [OR] = 0.98; 95% CI: 0.96-0.99) and absolute NC area (OR = 2.47 (95% CI: 1.14-5.36). A cutoff value of absolute NC area at ≥1.1 mm² may serve as a significant risk predictor for no-reflow after SVG-PCI. Factors associated with MACEs and the slow/no-reflow phenomenon following PCI of the SVG can be used in risk assessment of SVG.

Application of virtual histological intravascular ultrasound in plaque composition assessment of saphenous vein graft diseases

OBJECTIVE

Saphenous vein grafts disease (SVGD) is a common complication after coronary artery bypass graft (CABG) and normally treated by percutaneous coronary intervention (PCI). The most common complication after SVG-PCI is slow or no-reflow. It is known that the no-reflow phenomenon occurs in up to 15% of the SVG-PCI and is associated with high risk of major adverse cardiac events (MACEs) and mortality, therefore, it is important to investigate the factors that could predict the clinical outcome of PCI for risk stratification and guiding interventions. In recent years, the spectral analysis of intravascular ultrasound (IVUS) radiofrequency data (virtual histology-IVUS [VH-IVUS]) has been used to provide quantitative assessment on both plaque compositions and morphologic characteristics.

DATA SOURCES

The PubMed, Embase, and Central databases were searched for possible relevant studies published from 1997 to 2018 using the following index keywords: "Coronary artery bypass grafting," "Saphenous venous graft disease," "Virtual histology-intravascular ultrasound," "Virtual histology-intravascular ultrasound," and "Percutaneous coronary intervention."

STUDY SELECTION

The primary references were Chinese and English articles including original studies and literature reviews, were identified and reviewed to summarize the advances in the application of VH-IVUS techniques in situ vascular and venous graft vascular lesions.

RESULTS

With different plaque components exhibiting a defined spectrum, VH-IVUS can classify atherosclerotic plaque into four types: fibrous tissue (FT), fibro fatty (FF), necrotic core (NC), and dense calcium (DC). The radiofrequency signal is mathematically transformed into a color-coded representation, including lipid, fibrous tissue, calcification, and necrotic core. Several studies have demonstrated the independent relationship between VH-IVUS-defined plaque classification or plaque composition and MACEs, but a significant association between plaque components and no-reflow after PCI in acute coronary syndrome. In recent years, VH-IVUS are applied to assess the plaque composition of SVGD, based on the similarity of pathophysiological mechanisms between coronary artery disease (CAD) and SVGD, further studies with the larger sample size, the long-term follow-up, multicenter clinical trials may be warranted to investigate the relationship between plaque composition of saphenous vein graft (SVG) by VH-IVUS and clinical outcomes in patients with SVGD undergoing PCI.

CONCLUSIONS

In degenerative SVG lesions, VH-IVUS found that plaque composition was associated with clinical features, future studies need to explore the relationship between VH-IVUS defined atherosclerotic plaque components and clinical outcomes in SVGD patients undergoing PCI, an innovative prediction tool of clinical outcomes can be created.

Periprocedural Myocardial Infarction in Contemporary Practice

"Periprocedural myocardial infarction (MI) occurs infrequently in the current era of percutaneous coronary interventions (PCI) and is associated with an increased risk of mortality and morbidity. Periprocedural MI can occur due to acute side branch occlusion, distal embolization, slow flow or no reflow phenomenon, abrupt vessel closure, and nonidentifiable mechanical processes. Therapeutic strategies to reduce the risk of periprocedural MI include dual antiplatelet therapy, intravenous cangrelor in the periprocedural setting, intravenous glycoprotein IIb/IIIa inhibitor in high-risk patients, anticoagulation with unfractionated heparin, low-molecular-weight heparin or bivalirudin, and embolic protection devices during saphenous vein graft interventions."

Novel predictor of target vessel revascularization after coronary stent implantation: Intraluminal intensity of blood speckle on intravascular ultrasound

BACKGROUND

The difference in intraluminal intensity of blood speckle (IBS) on integrated backscatter-intravascular ultrasound (IB-IVUS) across the coronary artery stenosis (i.e., ΔIBS) has been reported to negatively correlate with fractional flow reserve. Fractional flow reserve after coronary stenting is known as a predictor of target vessel revascularization (TVR). However, the relation between ΔIBS and TVR is unclear.

METHODS

Seven hundred and three vessels which underwent percutaneous coronary intervention with stents were screened. Vessels without IVUS-guidance and follow-up information were excluded. Intraluminal IBS values were measured using IB-IVUS in cross-sections at the ostium of the target vessel and at the distal reference of implanted stent. ΔIBS was calculated as (distal IBS) - (ostium IBS).

RESULTS

A total of 393 vessels were included. Mean ΔIBS at postprocedure was 6.22 ± 5.65. During the follow-up period (11.2 ± 3.1 months), 24 cases (6.1%) had TVR. ΔIBS was significantly greater in the vessels with TVR than in those without (11.10 ± 5.93 vs. 5.90 ± 5.49, P <0.001). In receiver operating characteristic curve analysis, ΔIBS significantly predicted TVR (AUC 0.74, best cut-off value 8.24, P < 0.001). Multiple logistic regression analysis showed use of drug eluting stent and ΔIBS ≥ 8.24 as independent predictors of TVR.

CONCLUSIONS

ΔIBS at postprocedure was significantly associated with TVR. IVUS may be able to predict TVR by physiological assessment with measurement of ΔIBS.

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.

Intraluminal Intensity of Blood Speckle on Intravascular Ultrasound, a Novel Predictor of Periprocedural Myocardial Injury After Coronary Stenting

The difference in the intraluminal intensity of blood speckle (IBS) on integrated backscatter-intravascular ultrasound (IB-IVUS) across a coronary artery stenosis (i.e., ΔIBS) has previously shown a negative correlation with fractional flow reserve, reflecting an impaired coronary blood flow. Periprocedural myocardial injury (PMI) after coronary stenting has also been associated with coronary circulatory dysfunction. The aim of this study was to investigate the relation between ΔIBS after coronary stenting and PMI. A total of 180 patients who underwent elective coronary stenting under IVUS guidance for a single lesion were included. Intraluminal IBS was measured using IB-IVUS in cross sections at the ostium of the target vessel and at the distal reference of the stent. ΔIBS was calculated as (distal IBS value) - (ostium IBS value). PMI was defined as an elevation of troponin I >5 times the 99th percentile upper reference limit (>0.45 ng/ml) within 24 hours after the procedure. The mean ΔIBS after coronary stenting was 6.52 ± 5.71. There was a significantly greater use of the rotational atherectomy, the number of stents, the total stent length, and ΔIBS in patients with PMI than those without. In the receiver operating characteristic curve analysis, ΔIBS significantly predicted PMI (area under the curve 0.64, best cut-off value 7.88, p = 0.001). Multiple logistic regression analysis determined that the total stent length, the use of rotational atherectomy, and ΔIBS were independent predictors of PMI. In conclusion, greater ΔIBS assessed by IB-IVUS was significantly associated with PMI after coronary stenting in patients with a stable coronary artery disease.

Impact of multi-vessel therapy to the risk of periprocedural myocardial injury after elective coronary intervention: exploratory study

Backgrounds

Periprocedural myocardial injury (PMI) after elective percutaneous coronary intervention (PCI) significantly influences the prognosis of coronary artery disease (CAD). However, it was unclear whether the occurrence of PMI was associated with a series of controllable factors, such as PCI strategy or severity of CAD.

Methods

A total of 544 consecutive stable CAD patients underwent elective PCI were enrolled. The main outcome is PMI, defined as troponin T after PCI was at least one value above the 99th percentile upper reference limit. Major adverse cardiac events (MACE), including all-cause death, repeat myocardial infarction and target vessel revascularization were record in the period of follow-up. Univariate and multivariate analysis was applied to assess predictors for the occurrence of PMI.

Results

The incidence of PMI was 38.8% in the study. Compared with non-PMI patients (n = 333), PMI patients (n = 211) had more diseased vessels, higher Gensini and Syntax score. Meanwhile, there were higher incidence of MACE in PMI groups (9.5% vs. 3.2%, P < 0.01). We found that PMI patients underwent higher proportion of multi-vessel PCI simultaneously (32.2% vs. 10.5%, P < 0.01) and had more stents implanted (1.8 ± 0.8 vs. 1.4 ± 0.6, P < 0.01). Importantly, after simultaneously adjusted by other factors (such as age, diabetes, total cholesterol, number of diseased vessels, Gensini score and stent length), the risk of PMI was still increased 84% by multi-vessel PCI independently (OR = 1.654, 95% CI = 1.004–2.720, P < 0.05).

Conclusions

The phenomenon of PMI occurred more commonly in stable CAD patients underwent multi-vessel PCI. Multi-vessel international therapy could increase the risk of PMI in elective PCI.

Quantified coronary frequency domain optical coherence tomography signal analysis for the evaluation of erythrocyte-rich thrombus: ex-vivo validation study

Previous study has demonstrated that erythrocyte-rich thrombi contain more inflammatory cells and reflect high thrombus burden, leading to impaired myocardial reperfusion in myocardial infarction. The aim of this study is to investigate the utility of quantified frequency domain optical coherence tomography (FD-OCT) signal analysis in evaluating the erythrocyte-rich thrombus with ex-vivo materials. We evaluated 54 specimens of coronary artery thrombus obtained by thrombectomy catheter from 8 patients who underwent primary percutaneous coronary intervention. The thrombi were immersed in saline immediately after thrombectomy and FD-OCT image acquisition was performed ex-vivo. Quantitative analysis for all contiguous frames was performed by the dedicated automated software (OCT system software, Light Lab Inc.). For the maximum thrombus area, mean signal intensity (MSI) and normalized standard deviation of signal (NSD) was evaluated. All thrombi were stained using double staining of phosphotungstic acid-hematoxylin and eosin to enable automatic extraction of erythrocyte from fibrin. Computer-assisted analysis was performed using dedicated image processing software (WinROOF, Mitani Corp., Tokyo, Japan) for color identification of the erythrocyte area. Erythrocyte-rich thrombus, defined as % erythrocyte [(erythrocyte area/total thrombus area) × 100] ≥ 10%, showed significantly lower MSI [4.39 ± 0.24 vs. 4.74 ± 0.35, p = 0.002] than that of <10%. The cut-off point for prediction of erythrocyte-rich thrombus was defined as MSI ≤ 4.56, sensitivity: 87.5%, specificity: 82.9%, area under the curve: 0.836, respectively). The present ex-vivo study suggested the utility of quantified FD-OCT signal analysis on the detection of erythrocyte-rich thrombus.

Efficacy of Danlou Tablet in Patients with Non-ST Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: Results from a Multicentre, Placebo-Controlled, Randomized Trial

This study seeks to investigate potential cardioprotection of Danlou Tablets in patients undergoing PCI with non-ST elevation acute coronary syndrome (NSTE-ACS). 219 patients with NSTE-ACS were randomised to Danlou Tablet pretreatment (n = 109) or placebo (n = 110). No patients received statins prior to PCI and all patients were given atorvastatin (10 mg/day) after procedure. The main endpoint was the composite incidence of major adverse cardiac events (MACEs) within 30 days after PCI. The proportion of patients with elevated levels of cTn I>5 × 99% of upper reference limit was significantly lower in the Danlou Tablet group at 8 h (22.0% versus 34.5%, p = 0.04) and 24 h (23.9% versus 38.2%, p = 0.02) after PCI. The 30-day MACEs occurred in 22.0% of the Danlou Tablet group and 33.6% in the placebo group (p = 0.06). The incidence of MACE at 90-day follow-up was significantly decreased in the Danlou Tablet group compared to the placebo group (23.9% versus 37.3%, p = 0.03). The difference between the groups at 90 days was the incidence of nonfatal myocardial infarction (22% versus 34.5%, p = 0.04). These findings might support that treatment with Danlou Tablet could reduce the incidence of periprocedural myocardial infarction in patients with ACS undergoing PCI.

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.

Quantitative assessment of the stent/scaffold strut embedment analysis by optical coherence tomography

The degree of stent/scaffold embedment could be a surrogate parameter of the vessel wall-stent/scaffold interaction and could have biological implications in the vascular response. We have developed a new specific software for the quantitative evaluation of embedment of struts by optical coherence tomography (OCT). In the present study, we described the algorithm of the embedment analysis and its reproducibility. The degree of embedment was evaluated as the ratio of the embedded part versus the whole strut height and subdivided into quartiles. The agreement and the inter- and intra-observer reproducibility were evaluated using the kappa and the interclass correlation coefficient (ICC). A total of 4 pullbacks of OCT images in 4 randomly selected coronary lesions with 3.0 × 18 mm devices [2 lesions with Absorb BVS and 2 lesions with XIENCE (both from Abbott Vascular, Santa Clara, CA, USA)] from Absorb Japan trial were evaluated by two investigators with QCU-CMS software version 4.69 (Leiden University Medical Center, Leiden, The Netherlands). Finally, 1481 polymeric struts in 174 cross-sections and 1415 metallic struts in 161 cross-sections were analyzed. Inter- and intra-observer reproducibility of quantitative measurements of embedment ratio and categorical assessment of embedment in Absorb BVS and XIENCE had excellent agreement with ICC ranging from 0.958 to 0.999 and kappa ranging from 0.850 to 0.980. The newly developed embedment software showed excellent reproducibility. Computer-assisted embedment analysis could be a feasible tool to assess the strut penetration into the vessel wall that could be a surrogate of acute injury caused by implantation of devices.

Manual Thrombus Aspiration and the Improved Survival of Patients With Unstable Angina Pectoris Treated With Percutaneous Coronary Intervention (30 Months Follow-Up)

The clinical effect of intracoronary thrombus aspiration during percutaneous coronary intervention in patients with unstable angina pectoris is unknown. In this study, we aimed to assess how thrombus aspiration during percutaneous coronary intervention affects in-hospital and 30-month mortality and complications in patients with unstable angina pectoris.We undertook an observational cohort study of 645 consecutive unstable angina pectoris patients who had performed percutaneous coronary intervention from February 2011 to March 2013. Before intervention, 159 patients who had culprit lesion with thrombus were randomly assigned to group 1 (thrombus aspiration group) and group 2 (stand-alone percutaneous coronary intervention group). All patients were followed-up 30 months until August 2015.Thrombus aspiration was performed in 64 patients (46%) whose cardiac markers (ie, creatinine kinase [CK-MB] mass and troponin T) were significantly lower after percutaneous coronary intervention than in those of group 2 (CK-MB mass: 3.80 ± 1.11 vs 4.23 ± 0.89, P = 0.012; troponin T: 0.012 ± 0.014 vs 0.018 ± 0.008, P = 0.002). Left ventricular ejection fraction at 6, 12, and 24 months postintervention was significantly higher in the group 1. During a mean follow-up period of 28.87 ± 6.28 months, mortality rates were 6.3% in the group 1 versus 12.9% in the group 2. Thrombus aspiration was also associated with significantly less long-term mortality in unstable angina pectoris patients (adjusted HR: 4.61, 95% CI: 1.16-18.21, P = 0.029).Thrombus aspiration in the context of unstable angina pectoris is associated with a limited elevation in cardiac enzymes during intervention that minimises microembolization and significantly improves both of epicardial flow and myocardial perfusion, as shown by angiographic TIMI flow grade and frame count. Thrombus aspiration during percutaneous coronary intervention in unstable angina pectoris patients has better survival over a 30-month follow-up period.

Role of Intravascular Ultrasound in Patients with Acute Myocardial Infarction

Rupture of a vulnerable plaque and subsequent thrombus formation are important mechanisms leading to the development of an acute myocardial infarction (AMI). Typical intravascular ultrasound (IVUS) features of AMI include plaque rupture, thrombus, positive remodeling, attenuated plaque, spotty calcification, and thin-cap fibroatheroma. No-reflow phenomenon was attributable to the embolization of thrombus and plaque debris that results from mechanical fragmentation of the vulnerable plaque by percutaneous coronary intervention (PCI). Several grayscale IVUS features including plaque rupture, thrombus, positive remodeling, greater plaque burden, decreased post-PCI plaque volume, and tissue prolapse, and virtual histology-IVUS features such as large necrotic corecontaining lesion and thin-cap fibroatheroma were the independent predictors of no-reflow phenomenon in AMI patients. Non-culprit lesions associated with recurrent events were more likely than those not associated with recurrent events to be characterized by a plaque burden of ≥70%, a minimal luminal area of ≤4.0 mm(2), or to be classified as thin-cap fibroatheromas.

Long-term prognostic impact of the attenuated plaque in patients with acute coronary syndrome

Several intravascular ultrasound studies have reported that culprit lesion-attenuated plaque (AP) is related to slow flow/no reflow after percutaneous coronary intervention (PCI). Long-term prognostic impact of the AP is unknown. The aim of this study was to investigate acute and long-term clinical impact of the AP in patients with acute coronary syndrome (ACS). A total of 110 ACS patients who underwent successful PCI were enrolled. Acute and long-term clinical outcomes were compared between patients with AP (AP group: n = 73) and those without AP (non-AP group: n = 37). Long-term cardiac event was defined as a composite of death and ACS. Baseline characteristics in 2 groups were similar. AP was associated with higher TIMI frame count immediately after the first balloon inflation. After thrombectomy and intracoronary drug administration, final TIMI frame count became similar between AP and non-AP group. Although AP was associated with higher incidence of fatal arrhythmia during hospitalization, in-hospital mortality did not differ between the 2 groups. During follow-up (median 6.2 years), cardiac event-free survival did not differ between the 2 groups. Despite the initial unfavorable effect on coronary reflow, presence of AP did not affect acute as well as long-term clinical outcome in patients with ACS.

Association of target lesion characteristics evaluated by coronary computed tomography angiography and plaque debris distal embolization during percutaneous coronary intervention

BACKGROUND

The slow-flow or no re-flow phenomenon has been associated with distal embolization, especially of plaque debris, and with unfavorable clinical outcomes. Therefore, we examined the association between the coronary computed tomography angiography (CCTA) findings of the target lesion and distal embolization during percutaneous coronary intervention (PCI). METHODS AND RESULTS: Consecutive patients (n=55: 18 unstable angina, 19 stable effort angina, 18 silent ischemia) who underwent PCI with a filter-type distal protection device after evaluation of the target lesion by CCTA were analyzed. CCTA examined low-attenuation plaque (LAP), positive remodeling (PR), and ring-like enhancement of the target lesion. Distal embolization of thrombus and plaque debris was evaluated by pathological examination of material collected in the filter.Any distal embolization and distal embolization of plaque debris were respectively detected in 75% and 0% of patients with LAP or PR alone, in 95% and 17% of patients with both LAP and PR, and in 100% and 27% of patients with all of LAP, PR and ring-like enhancement. The sensitivity and specificity to predict plaque debris embolization by having both findings of LAP and PR was 100% and 46%, respectively.

CONCLUSIONS

The CCTA findings of the target lesion were associated with distal embolization and were very sensitive for predicting plaque debris embolization.

Assessment of plaque composition by intravascular ultrasound and near-infrared spectroscopy: from PROSPECT I to PROSPECT II

Atherosclerosis is the main cause of coronary artery disease (CAD), which is today the leading cause of death worldwide and will continue to be the first in the world in 2030. Vulnerable coronary plaques are usually characterized by a high content of necrotic core, a thin inflamed fibrous cap (intense accumulation of macrophages) and scarce presence of smooth muscle cells. None of these characteristics can be estimated by coronary angiography, which on the contrary underestimates the magnitude of atherosclerotic burden, particularly in earlier stage disease when positive vascular remodeling may allow "normal" lumen caliber despite substantial vascular wall plaque. The recognition of the ubiquity of substantial but non-flow limiting lesions that may be at high risk for subsequent plaque rupture has resulted in a paradigm shift in thinking about the pathophysiology of CAD, with the focus no longer solely on the degree of arterial luminal narrowing. This growing need for more information about coronary atherosclerosis in order to identify patients and lesions at risk for complications during PCI and for future adverse cardiac events has been the primary impetus for the development of novel intracoronary imaging methods able to detect plaque composition, in particular presence of a necrotic core/lipid pool, such as intravascular ultrasound virtual histology and near-infrared spectroscopy. These imaging technologies and their clinical and clinical/research applications are discussed in detail.

Intravascular ultrasound as a clinical adjunct for carotid plaque characterization

OBJECTIVE

Virtual histology intravascular ultrasound (VH IVUS) is valuable for estimating minimal lumen diameter and plaque characterization. The clinical use of IVUS in carotid intervention is not well characterized. We aim to evaluate the role of IVUS in carotid plaque characterization and determine whether it could be predictive of procedure-related microemboli.

METHODS

From July 2010, patients with severe carotid stenosis who underwent elective carotid stenting procedures were prospectively enrolled. IVUS evaluation was performed before stent placement. Patient demographics, comorbidities, and preoperative images were recorded. Comparison of pre- and postoperative diffusion-weighted magnetic resonance images was used to identify the number of procedure-related microemboli. IVUS-derived minimal lumen diameter and vessel wall plaque characteristics were collected. Univariate and multivariate logistic regressions were used to search for associations between IVUS-derived VH data and incidence of microemboli.

RESULTS

A total of 38 high-risk patients receiving carotid stenting were enrolled. Among them, 25 patients had type I aortic arches and 17 of the patients were symptomatic (preoperative stroke or transient ischemic attack). VH IVUS data did not show strong associations with microemboli, however, a trend was found between the area of fibrous tissue and median or more incidence of microemboli (P = .099). IVUS-defined vessel diameter maximum was associated with median or more incidence of microemboli (P = .042). In addition, median or more incidence of microemboli showed trends with proximal common carotid artery calcification (P = .056) and with being over the age of 80 (P = .06). Contralateral carotid occlusion or high-grade stenosis was associated with postoperative contralateral microemboli (P = .036).

CONCLUSIONS

We demonstrate that periprocedural carotid IVUS is clinically feasible. VH IVUS may be helpful in better understanding plaque morphology and determining optimal stent placement. However, its use in predicting microembolization remains limited.

Correlation between plaque composition as assessed by virtual histology and C-reactive protein

Background

Previous studies have shown that coronary plaque composition plays a pivotal role in plaque instability, and imaging modalities and serum biomarkers have been investigated to identify vulnerable plaque. Virtual histology IVUS (VH-IVUS) characterizes plaque components as calcified, fibrotic, fibrofatty, or necrotic core. C-reactive protein (hsCRP) is an independent risk factor and a powerful predictor of future coronary events. However, a relationship between inflammatory response indicated by CRP and plaque characteristics in ACS patients remains not well established.

Objective

To determine, by using VH-IVUS, the relation between coronary plaque components and plasma high-sensitivity CRP levels in patients with acute coronary syndromes (ACS).

Methods

52 patients with ACS were enrolled in this prospective study. Electrocardiographically-gated VH-IVUS were performed in the culprit lesion before PCI. Blood sample was drawn from all patients before the procedure and after 24 hours, and hs-CRP levels were determined.

Results

Mean age was 55.3±4.9 years, 76.9% were men and 30.9% had diabetes. Mean MLA was 3.9±1.3 mm², and plaque burden was 69±11.3%, as assessed by IVUS. VH-IVUS analysis at the minimum luminal site identified plaque components: fibrotic (59.6±15.8%), fibrofatty (7.6±8.2%), dense calcium (12.1±9.2%) and necrotic core (20.7±12.7%). Plasma hs-CRP (mean 16.02±18.07 mg/L) did not correlate with necrotic core (r=-0.089, p = 0.53) and other plaque components.

Conclusions

In this prospective study with patients with ACS, the predominant components of the culprit plaque were fibrotic and necrotic core. Serum hs C-reactive protein levels did not correlate with plaque composition.

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.

Coronary plaque characteristics that indicate distal embolization during percutaneous coronary intervention in patients with stable angina-virtual histology intravascular ultrasound study

Distal embolization (DE) is a serious complication of percutaneous coronary intervention (PCI) in patients with stable angina. The purpose of this study was to evaluate the coronary plaque characteristics that indicate DE during PCI in patients with stable angina using virtual histology intravascular ultrasound (VH-IVUS). Three hundred and sixty-four consecutive stable angina patients who underwent PCI were enrolled in this study. The patients were divided into two groups as follows: patients exhibiting DE (DE group, n = 10) and patients without DE (non-DE group, n = 354). Coronary plaque compositions were assessed by VH-IVUS. The fibro-fatty (FF) ratio (28 ± 17 vs. 11 ± 9 %, p < 0.0001) was higher in the DE group compared with the non-DE group. The best cut-off value of FF ratio for prediction of DE was 20 %, with a sensitivity of 0.80 and a specificity of 0.81 (odds ratio; 17.1, 95 % confidence interval 3.56-82.5, p = 0.0004). Coronary plaques with a high FF ratio may be the predictor of indicating DE in patients with stable angina during PCI.

Culprit lesion remodelling and long-term prognosis in patients with acute coronary syndrome: an intravascular ultrasound study

AIMS

Positive arterial remodelling is recognized as one of the morphological characteristics of the vulnerable plaque. Limited data are available on a long-term outcome of acute coronary syndrome (ACS) patients with culprit lesion positive arterial remodelling (PR). The aim of this study was to investigate the long-term impact of culprit lesion PR in patients with ACS.

METHODS AND RESULTS

In 134 patients with ACS, intravascular ultrasound (IVUS) was performed to assess target lesion remodelling before percutaneous coronary intervention. PR was defined as the ratio of the external elastic membrane cross-sectional area at the target lesion to that of at the proximal reference of >1.05, and intermediate or negative remodelling (IR/NR) was defined as that of ≤1.05. Major adverse cardiac event (MACE) was defined as a composite of death, ACS, and target lesion revascularization. During the follow-up (median 5.8 years), MACE-free survival was significantly lower in the PR group than that in the IR/NR group (log-rank, P = 0.005). Survival and ACS-free survival were also significantly lower in the PR group than that in the IR/NR group (log-rank, both P = 0.04). By multivariable Cox regression analysis, PR (hazard ratio = 2.4, P = 0.02) and diabetes (hazard ratio = 1.9, P = 0.03) were independent predictors of MACE.

CONCLUSION

Culprit lesion PR was associated with a poor long-term prognosis in patients with ACS. PR may be a marker of vulnerable patients.

Effect of the composition of atherosclerotic plaques and rate of platelet aggregation on elevation of serum levels of cardiac troponin T after percutaneous coronary interventions

PURPOSE

Elevation of the levels of myocardial biomarkers after percutaneous coronary intervention (PCI) has prognostic value in patients with coronary heart disease. We explored the relationship between elevation of the serum level of cardiac troponin T (cTnT) after PCI and platelet aggregation rate and coronary plaque composition.

METHODS

Eighty patients with unstable angina pectoris underwent PCI and were divided into two groups according to serum cTnT level 24 hours after PCI: group I (cTnT ≥2 times the normal level) and group II (cTnT <2 times the normal level). Coronary plaque composition was measured with virtual histology-intravascular ultrasound. Platelet aggregation rate was detected immediately before and 24 hours after PCI.

RESULTS

Compared with the patients in group II, patients in group I showed more unstable plaques, a larger necrotic core area (20.88 ± 8.04% vs. 15.31 ± 5.48%, P < 0.05), higher platelet aggregation rate (51.47 ± 12.72% vs. 44.78 ± 13.29%, P < 0.05), and longer stents. The serum cTnT level 24 hours after PCI was positively correlated with the necrotic core area.

CONCLUSIONS

In patients with unstable angina pectoris, a large necrotic core, high rate of platelet aggregation, and stent length are predictors of cTnT elevation after PCI.

Plaque characteristics and arterial remodeling in coronary and peripheral arterial systems

BACKGROUND

Few studies have examined plaque characteristics among multiple arterial beds in vivo. The purpose of this study was to compare the plaque morphology and arterial remodeling between coronary and peripheral arteries using gray-scale and radiofrequency intravascular ultrasound (IVUS) at clinical presentation.

METHODS AND RESULTS

IVUS imaging was performed in 68 patients with coronary and 93 with peripheral artery lesions (29 carotid, 50 renal, and 14 iliac arteries). Plaques were classified as fibroatheroma (VH-FA) (further subclassified as thin-capped [VH-TCFA] and thick-capped [VH-ThCFA]), fibrocalcific plaque (VH-FC) and pathological intimal thickening (VH-PIT). Plaque rupture (13% of coronary, 7% of carotid, 6% of renal, and 7% of iliac arteries; P = NS) and VH-TCFA (37% of coronary, 24% of carotid, 16% of renal, and 7% of iliac arteries; P = 0.02) were observed in all arteries. Compared with coronary arteries, VH-FA was less frequently observed in renal (P < 0.001) and iliac arteries (P < 0.006). Lesions with positive remodeling demonstrated more characteristics of VH-FA in coronary (84% vs. 25%, P < 0.001), carotid (72% vs. 20%, P = 0.001), and renal arteries (42% vs. 4%, P = 0.001) compared with those with intermediate/negative remodeling. There was positive relationship between remodeling index and percent necrotic area in all four arteries.

CONCLUSIONS

Atherosclerotic plaque phenotypes were heterogeneous among four different arteries; renal and iliac arteries had more stable phenotypes compared with coronary artery. In contrast, the associations of remodeling pattern with plaque phenotype and composition were similar among the various arterial beds.

Correlations between coronary plaque tissue composition assessed by virtual histology and blood levels of biomarkers for coronary artery disease

PURPOSE

We investigated correlations of coronary plaque composition determined by virtual histology (VH) intravascular ultrasound (IVUS) and blood levels of biomarkers that represent the vulnerability of coronary plaques.

MATERIALS AND METHODS

Pre- and postprocedural blood levels of high sensitivity C-reactive protein, soluble CD40 ligand (sCD40L), matrix metalloproteinase-9, and neopterin were measured in 70 patients with stable angina (SA) or unstable angina (UA) who were undergoing percutaneous coronary intervention (PCI) for single lesions. We evaluated the data for correlations between these biomarkers and necrotic core contents in PCI target lesions analyzed by VH.

RESULTS

Clinical characteristics, IVUS, VH, and biomarker blood levels were not different between the SA and the UA group except for more frequent previous statin use (52.3% vs. 23.1%, p=0.017) and lower remodeling index in the SA group (0.98±0.09 vs. 1.10±0.070, p<0.001). Among the biomarkers evaluated, only pre-PCI neopterin level showed a weakly significant correlation with the absolute volume of the necrotic core (r=0.320, p=0.008). Pre- and post-PCI blood levels of sCD40L (r=0.220, p=0.072; r=0.231, p=0.062) and post-PCI blood level of neopterin (r=0.238, p=0.051) showed trends toward weakly positive correlations with the absolute volume of necrotic core.

CONCLUSION

We found a weakly positive correlation between the pre-PCI neopterin level and necrotic core volume in the PCI-target lesion. The clinical implications of our findings need to be investigated in further studies.