Clinical outcomes and coronary artery lesion characteristics of young patients with ST elevation myocardial infarction and no standard modifiable risk factors

BACKGROUND

Among ST-elevation myocardial infarction (STEMI) patients, those with no standard modifiable risk factors (SMuRFs: hypertension, diabetes mellitus, hypercholesterolemia, and smoking) have higher 30-day mortality than those with SMuRFs. Differences in coronary lesion characteristics remain unclear.

METHODS

Data from STEMI patients aged ≤60 years from the Asia Pacific Evaluation of Cardiovascular Therapies Network (Australia, Hong Kong, Malaysia, Singapore, and Vietnam) was retrospectively analysed. Exclusion criteria included incomplete SMuRF data, prior myocardial infarction, or prior coronary revascularisation. Lesion type was defined using the American College of Cardiology criteria. Major adverse cardiovascular events (MACE) were defined as peri-procedural myocardial infarction, emergency coronary artery bypass surgery, cerebrovascular event, or mortality. Multiple logistic regressions were used.

RESULTS

Of 4404 patients, 767 (17.4%) were SMuRFless. SMuRFless patients were more frequently younger (median age 51 vs. 53 years; p < 0.001), female (22.6% vs. 15.5%; p < 0.001), thrombolysed (20.1% vs. 12.5%; p < 0.001), and in cardiogenic shock (11.2% vs. 8.6%; p = 0.020). SMuRFless patients had significantly higher in-hospital MACE (7.2% vs. 4.3%; adjusted odds ratio [aOR] 2.25; 95% confidence interval [CI] 1.24-4.08; p = 0.008) but 1-year mortality was not significantly different (3.6% vs. 5.7%, aOR 0.58; 95% CI 0.06-6.12; p = 0.549). Compared with patients with SMuRFs (4918 lesions), the SMuRFless (940 lesions) had fewer type B2/C lesions (60.8% vs. 65.6%; p = 0.020) and fewer lesions ≥20 mm (51.1% vs. 57.1%; p = 0.002) but more procedural complications (5.1% vs. 2.7%; p < 0.001).

CONCLUSIONS

Among young STEMI patients, the SMuRFless have shorter and less complex lesions, but worse procedural and short-term MACE outcomes.

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.

Multi-modality intravascular imaging for guiding coronary intervention and assessing coronary atheroma: the Novasight Hybrid IVUS-OCT system

Intravascular imaging has evolved alongside interventional cardiology as an adjunctive tool for assessing plaque pathology and for guiding and optimising percutaneous coronary intervention (PCI) in challenging lesions. The two modalities which have dominated the field are intravascular ultrasound (IVUS), which relies on sound waves and optical coherence tomography (OCT), relying on light waves. These approaches however have limited efficacy in assessing plaque morphology and vulnerability that are essential for guiding PCI in complex lesions and identifying patient at risk that will benefit from emerging therapies targeting plaque evolution. These limitations are complementary and, in this context, it has been recognised and demonstrated in multi-modality studies that the concurrent use of IVUS and OCT can help overcome these deficits enabling a more complete and accurate plaque assessment. The Conavi Novasight Hybrid IVUS-OCT catheter is the first commercially available device that is capable of invasive clinical coronary assessment with simultaneously acquired and co-registered IVUS and OCT imaging. It represents a significant evolution in the field and is expected to have broad application in clinical practice and research. In this review article we present the limitations of standalone intravascular imaging techniques, summarise the data supporting the value of multimodality imaging in clinical practice and research, describe the Novasight Hybrid IVUS-OCT system and highlight the potential utility of this technology in coronary intervention and in the study of atherosclerosis.

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.

Optimisation of percutaneous coronary intervention: indispensables for bioresorbable scaffolds

INTRODUCTION

With new developments in percutaneous coronary intervention (PCI), such as the introduction of bioresorbable scaffolds (BRS), percutaneous treatment of coronary artery diseases has entered a new era. Without metallic remnants, BRSs appear able to overcome several limitations of the existing metallic stents and provide a physiologic treatment of coronary artery pathology.

AREAS COVERED

BRS have different mechanical properties compared to the traditional metallic stents that should be taken into account during their implantation. Lesion selection, device sizing and satisfied pre-dilatation should be implemented prudently. Although intravascular imaging is not mandatory for the implantation of BRSs it may have a value in optimizing device deployment assess final results and reduce the risk of device related adverse events such as re-stenosis, or scaffold thrombosis. This review aims to reveal the crucial points about the methods of optimization in each steps of BRS implantation. Expert commentary: The target lesions for BRS should be selected meticulously. Pre-dilatation, post-dilatation and intra-vascular imaging techniques should be implemented appropriately to avoid undesirable events after scaffold implantation.

Association between tissue characteristics of coronary plaque and distal embolization after coronary intervention in acute coronary syndrome patients: insights from a meta-analysis of virtual histology-intravascular ultrasound studies

Background and Objectives

The predictive value of plaque characteristics assessed by virtual histology-intravascular ultrasound (VH-IVUS) including fibrous tissue (FT), fibrofatty (FF), necrotic core (NC) and dense calcium (DC) in identifying distal embolization after percutaneous coronary intervention (PCI) is still controversial. We performed a systematic review and meta-analysis to summarize the association of pre-PCI plaque composition and post-PCI distal embolization in acute coronary syndrome patients.

Methods

Studies were identified in PubMed, OVID, EMBASE, the Cochrane Library, the Current Controlled Trials Register, reviews, and reference lists of relevant articles. A meta-analysis using both fixed and random effects models with assessment of study heterogeneity and publication bias was performed.

Results

Of the 388 articles screened, 10 studies with a total of 872 subjects (199 with distal embolization and 673 with normal flow) met the eligibility of our study. Compared with normal flow groups, significant higher absolute volume of NC [weighted mean differences (WMD): 5.79 mm³, 95% CI: 3.02 to 8.55 mm³; p<0.001] and DC (WMD: 2.55 mm³, 95% CI: 0.22 to 4.88 mm³; p = 0.03) were found in acute coronary syndrome patients with distal embolization. Further subgroup analysis demonstrated that the predictive value of tissue characteristics in determining distal embolization was correlated to clinical scenario of the patients, definition of distal embolization, and whether the percutaneous aspiration thrombectomy was applied.

Conclusion

Our study that pooled current evidence showed that plaque components were closely related to the distal embolization after PCI, especially the absolute volume of NC and DC, supporting further studies with larger sample size and high-methodological quality.

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.

Fibro-Fatty Component is Important for the Long-Term Clinical Events in Patients Who Have Undergone Primary Percutaneous Coronary Intervention

Background and Objectives

We evaluated which plaque components are associated with long-term clinical events in patients who underwent primary percutaneous coronary intervention (PCI).

Subjects and Methods

The study subjects consisted of 57 consecutive patients (mean age, 58.5±14.5 years; 45 males) who underwent primary PCI and a virtual histology-intravascular ultrasound examination. Major adverse cardiac events (MACEs) including death, acute myocardial infarction, stroke, and revascularization were evaluated during the mean 28 month follow-up period.

Results

Patients with high fibro-fatty volume (FFV >13.4 mm³, n=29; mean age, 61.3 years) had a lower ejection fraction (52.7% vs. 59.4%, p=0.022), a higher incidence of multi-vessel disease (69.0% vs. 28.6%, p=0.002), larger plaque area (25.7 mm² vs. 15.9 mm², p<0.001), and larger plaque volume (315 mm³ vs. 142 mm³, p<0.001) than those with a low FFV (≤13.4 mm³, n=28; mean age, 55.6 years). Patients with high FFV had a significantly higher incidence (32.1% vs. 8.3%, p=0.036) of MACE than those with low FFV. When we divided the study population according to the necrotic core volume (NCV), fibrous volume, or dense calcified volume, no significant findings in terms of demographics and MACE rates were observed. A Cox regression analysis revealed that the independent factor for MACE was FFV (hazard ratio, 6.748; 95% confidence interval, 1.168-38.971, p=0.033) in this study population.

Conclusion

The coronary plaque component, particularly FFV, but not NCV, was important in long-term clinical outcomes in patients who underwent primary PCI.

New modality for evaluating plaque characteristics of the culprit lesion in a patient with acute coronary syndrome and no reflow phenomenon

No reflow phenomenon during percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) has an unfavorable outcome. Previously, some investigators have tried to determine the predictors of this phenomenon, but there are still controversies as to whether it is possible to make predictions beforehand. Here we report the first clinical case by intravascular ultrasound (IVUS) with a newly designed pattern recognition algorithm to evaluate the tissue characteristics of the culprit lesion in a 64-year-old patient with ACS who suffered from no reflow phenomenon during PCI. We also reveal the plaque composition of the culprit lesion of another ACS patient without no reflow as well as a stable angina pectoris patient. The percentage of necrotic tissue was higher in the culprit lesion in a patient with no reflow than in the others. In conclusion, a new spectral similarity concept of IVUS is promising in differentiating ambiguous tissue characterization results.

Relation between plaque components and plaque prolapse after drug-eluting stent implantation--virtual histology-intravascular ultrasound

BACKGROUND

It is not well known which plaque components are associated with the development of plaque prolapse (PP) and what are the major components in prolapsed plaque. The relationship between pre-stenting plaque components and post-stenting PP was assessed and the plaque components of prolapsed plaque were evaluated in patients who underwent drug-eluting stent (DES) implantation using virtual histology-intravascular ultrasound (VH-IVUS).

METHODS AND RESULTS

The study group consisted of 132 patients who underwent DES implantation and pre- and post-stenting VH-IVUS. Of these patients, 68 patients had 76 PP lesions and 64 patients had 76 non-PP lesions. Intra-stent PP volume was 3.6+/-1.5 mm(3). Plaque volume was significantly greater and absolute fibrotic (FT) and necrotic core (NC) volumes were significantly greater in PP lesions compared with non-PP lesions. On multivariate analysis, absolute NC (odds ratios [OR]=1.14, P<0.001) and FT volume (OR =1.09, P<0.001) were independently associated with the development of PP. In intra-stent prolapsed plaque the FT component was greatest, but the NC component was also large, and %NC volume correlated positively with Deltacreatine kinase-MB (r=0.489, P<0.001) and Deltatroponin-I (r=0.679, P<0.001), and %FT volume correlated negatively with DeltaCK-MB (r=-0.539, P<0.001) and Deltatroponin-I.

CONCLUSIONS

NC and FT components were associated with development of PP; and NC and FT components in prolapsed plaque were associated with cardiac enzyme elevation after DES implantation.

Assessment of coronary artery flow velocity pattern as a long-term predictor of left ventricular function and cardiac events after percutaneous coronary intervention in anterior acute myocardial infarction

BACKGROUND

Coronary flow velocity (CFV) can be used to assess short-term left ventricular function recovery and the clinical prognosis of patients with acute myocardial infarction (AMI). We evaluated CFV as a predictor of long-term left ventricular function recovery and cardiac events in patients with anterior wall AMI.

METHODS AND RESULTS

CFV pattern of the distal left anterior descending (LAD), wall motion score index (WMSI) and left ventricular ejection fraction (LVEF) were recorded at the points of time within 24 hours, 3 days, 6 months, and 3 years after percutaneous coronary intervention (PCI) in 50 consecutive patients with anterior wall AMI. The clinical data were collected. Patients were divided into two groups based on diastolic deceleration time (DDT) 3 days after PCI. Compared with 3 days, LVEF and WMSI in group A (DDT>600 ms, n=20) improved in 6 months and 3 years (p<0.01), but they were unchanged in group B (DDT< or =600 ms, n=30). The incidence of cardiac events was higher in group B than in group A during 6 months (p<0.01).With a 3-year follow up, the incidence of chronic heart failure was higher in group B than in group A (p=0.009).

CONCLUSION

CFV could be used as a predictor of long-term left ventricular function recovery and cardiac events in patients with anterior wall AMI.

Impact of plaque components on no-reflow phenomenon after stent deployment in patients with acute coronary syndrome: a virtual histology-intravascular ultrasound analysis

Aims

We used virtual histology-intravascular ultrasound (VH-IVUS) to evaluate the relation between coronary plaque characteristics and no-reflow in acute coronary syndrome (ACS) patients.

Methods and results

A total of 190 consecutive ACS patients were imaged using VH-IVUS and analysed retrospectively. Angiographic no-reflow was defined as TIMI flow grade 0, 1, and 2 after stenting. Virtual histology-intravascular ultrasound classified the colour-coded tissue into four major components: fibrotic, fibro-fatty, dense calcium, and necrotic core (NC). Thin-cap fibroatheroma (TCFA) was defined as focal, NC-rich (≥10% of the cross-sectional area) plaques being in contact with the lumen in a plaque burden ≥40%. Of the 190 patients studied at pre-stenting, no-reflow was observed in 24 patients (12.6%) at post-stenting. The absolute and %NC areas at the minimum lumen sites (1.6 ± 1.2 vs. 0.9 ± 0.8 mm², P < 0.001, and 24.5 ± 14.3 vs. 16.1 ± 10.6%, P = 0.001, respectively) and the absolute and %NC volumes (30 ± 24 vs. 16 ± 17 mm³, P = 0.001, and 22 ± 11 vs. 14 ± 8%, P < 0.001, respectively) were significantly greater, and the presence of at least one TCFA and multiple TCFAs within culprit lesions (71 vs. 36%, P = 0.001, and 38 vs. 15%, P = 0.005, respectively) was significantly more common in the no-reflow group compared with the normal-reflow group. In the multivariable analysis, %NC volume was the only independent predictor of no-reflow (odds ratio = 1.126; 95% CI 1.045–1.214, P = 0.002).

Conclusion

In ACS patients, post-stenting no-reflow is associated with plaque components defined by VH-IVUS analysis with larger NC and more TCFAs.