Impact of Ultrasound Attenuation and Plaque Rupture as Detected by Intravascular Ultrasound on the Incidence of No-Reflow Phenomenon After Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction

Prediction of Slow-Flow Phenomenon After Stent Implantation Using Near-Infrared Spectroscopy in Patients With Acute and Chronic Coronary Syndrome

BACKGROUND

The slow-flow phenomenon is associated with worse clinical outcomes after percutaneous coronary intervention (PCI), so our goal for this study was to see how predictive how near-infrared spectroscopy (NIRS) could be.Methods and Results: We enrolled 179 lesions from 152 patients who had de novo coronary stent implantation guided by NIRS-intravascular ultrasound (IVUS) (male: 69.1%, mean age: 74.3±11.5 years, acute coronary syndrome: 65.1%, diabetes: 42.1%). NIRS automatically determined the maximum 4-mm lipid core burden index (maxLCBI4 mm) value at pre- and post-PCI procedures. The slow-flow phenomenon was defined as the deterioration of TIMI (Thrombolysis in Myocardial Infarction) flows on angiography during the PCI procedure in the absence of mechanical obstruction. The slow-flow phenomenon occurred in 13 (7.3%) lesions, and the slow-flow phenomenon group had a significantly higher maxLCBI4 mm(740±147 vs. 471±223, P<0.001). The best maxLCBI4 mmcutoff point in both acute and chronic coronary syndrome was 578 and 480, with sensitivity of 100%, for predicting the slow-flow phenomenon. In the receiver-operating characteristics analysis, the area under the curve for acute and chronic coronary syndrome was 0.849 and 0.851, respectively.

CONCLUSIONS

The results of this study support the utility of NIRS-IVUS-guided PCI for the prediction of the slow-flow phenomenon.

Calcified plaque harboring lipidic materials associates with no-reflow phenomenon after PCI in stable CAD

Calcified atheroma has been viewed conventionally as stable lesion which less likely increases no-reflow phenomenon. Given that lipidic materials triggers the formation of calcification, lipidic materials could exist within calcified lesion, which may cause no-reflow phenomenon after PCI. The REASSURE-NIRS registry (NCT04864171) employed near-infrared spectroscopy and intravascular ultrasound imaging to evaluate maximum 4-mm lipid-core burden index (maxLCBI4mm) at target lesions containing small (maximum calcification arc < 180°: n = 272) and large calcification (maximum calcification arc ≥ 180°: n = 189) in stable CAD patients. The associations of maxLCBI4mm with corrected TIMI frame count (CTFC) and no-reflow phenomenon after PCI were analyzed in patients with target lesions containing small and large calcification, respectively. No-reflow phenomenon occurred in 8.0% of study population. Receiver-operating characteristics curve analyses revealed that optimal cut-off values of maxLCBI4mm for predicting no-reflow phenomenon were 585 at small calcification (AUC = 0.72, p < 0.001) and 679 at large calcification (AUC = 0.76, p = 0.001). Target lesions containing small calcification with maxLCBI4mm ≥ 585 more likely exhibited a greater CTFC (p < 0.001). In those with large calcification, 55.6% of them had maxLCBI4mm ≥ 400 [vs. 56.2% (small calcification), p = 0.82]. Furthermore, a higher CTFC (p < 0.001) was observed in association with maxLCBI4mm ≥ 679 at large calcification. On multivariable analysis, maxLCBI4mm at large calcification still independently predicted no-reflow phenomenon (OR = 1.60, 95%CI = 1.32-1.94, p < 0.001). MaxLCBI4mm at target lesions exhibiting large calcification elevated a risk of no-reflow phenomenon after PCI. Calcified plaque containing lipidic materials is not necessarily stable lesion, but could be active and high-risk one causing no-reflow phenomenon.

Translational large animal model of coronary microvascular embolism: characterization by serial cardiac magnetic resonance and histopathology

This study aimed to construct a large animal model of coronary microvascular embolism, and investigate whether it could mimic the clinical imaging phenotypes of myocardial hypoperfusion in patients with ST-segment elevation myocardial infarction (STEMI). Nine minipigs underwent percutaneous coronary embolization with microspheres, followed by cardiac magnetic resonance (CMR) on week 1, 2 and 4 post operation. Microvascular obstruction (MVO) was defined as the isolated hypointense core within the enhanced area on late gadolinium enhancement images, which evolved during a 4-week follow-up. Fibrotic fraction of the segments was measured by Masson trichrome staining using a panoramic analysis software. Iron deposit and macrophage infiltration were quantified based on Perl's blue and anti-CD163 staining, respectively. Seven out of 9 (77.8%) minipigs survived and completed all of the imaging follow-ups. Four out of 7 (57.1%) minipigs were identified as transmural infarct with MVO. The systolic wall thickening (SWT) of MVO zone was similar to that of infarct zone (P = 0.762). Histopathology revealed transmural deposition of collagen, with microvessels obstructed by microspheres. The fibrotic fraction of infarct with MVO segments was similar to that of infarct without MVO segments (P = 0.954). The fraction of iron deposit in infarct with MVO segments was higher than that of infarct without MVO segments (P < 0.05), but the fraction of macrophage infiltration between these two segments did not show statistical difference (P = 0.723). Large animal model of coronary microvascular embolism could mimic most clinical imaging phenotypes of myocardial hypoperfusion in patients with STEMI, demonstrated by serial CMR and histopathology.

Intravascular Ultrasound in Vulnerable Plaque and Acute Coronary Syndrome

Vulnerable plaque plays a pivotal role in the pathogenesis of acute coronary syndrome (ACS), being responsible for most ACS. The concept of vulnerable plaque has evolved with advancements in basic and clinical investigations along with developments and rapid expansion of coronary imaging modalities. Intravascular ultrasound (IVUS) is the first widely applied clinical technology with sufficient tissue penetration and enables us to identify vulnerable plaque and comprehensively understand the pathophysiology of ACS. In this review, we summarize current clinical evidence established by IVUS and the recent advancements in our understanding of vulnerable plaque and its role in ACS management.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: Practical Application

Why is intravascular ultrasounography (IVUS) highly encouraged for the practical guidance of percutaneous coronary intervention (PCI)? First reason is to understand the mechanism of revascularization. Even if stenoses look similar in angiography, the pathophysiology could be different in each lesion. Second reason is to anticipate possible complications in advance. With prediction and appropriate preparation, most complications can be avoided or managed calmly when they occur. Third reason is to optimize PCI results with interactive IVUS use during the procedure. All these are essential to maximize the results of revascularization while minimizing acute complications, ultimately leading to improved long-term clinical outcomes.

Multimodality imaging to identify lipid-rich coronary plaques and predict periprocedural myocardial injury: Association between near-infrared spectroscopy and coronary computed tomography angiography

Background

This study compares the efficacy of coronary computed tomography angiography (CCTA) and near-infrared spectroscopy intravascular ultrasound (NIRS–IVUS) in patients with significant coronary stenosis for predicting periprocedural myocardial injury during percutaneous coronary intervention (PCI).

Methods

We prospectively enrolled 107 patients who underwent CCTA before PCI and performed NIRS–IVUS during PCI. Based on the maximal lipid core burden index for any 4-mm longitudinal segments (maxLCBI4mm) in the culprit lesion, we divided the patients into two groups: lipid-rich plaque (LRP) group (maxLCBI4mm ≥ 400; n = 48) and no-LRP group (maxLCBI4mm &lt; 400; n = 59). Periprocedural myocardial injury was a postprocedural cardiac troponin T (cTnT) elevation of ≥5 times the upper limit of normal.

Results

The LRP group had a significantly higher cTnT (p = 0.026), lower CT density (p &lt; 0.001), larger percentage atheroma volume (PAV) by NIRS–IVUS (p = 0.036), and larger remodeling index measured by both CCTA (p = 0.020) and NIRS–IVUS (p &lt; 0.001). A significant negative linear correlation was found between maxLCBI4mm and CT density (rho = −0.552, p &lt; 0.001). Multivariable logistic regression analysis identified maxLCBI4mm [odds ratio (OR): 1.006, p = 0.003] and PAV (OR: 1.125, p = 0.014) as independent predictors of periprocedural myocardial injury, while CT density was not an independent predictor (OR: 0.991, p = 0.22).

Conclusion

CCTA and NIRS–IVUS correlated well to identify LRP in culprit lesions. However, NIRS–IVUS was more competent in predicting the risk of periprocedural myocardial injury.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions (update)

There are 3 main reasons to promote the practical application of IVUS during PCI. First reason is to understand the mechanism of vessel dilatation. Even if angiographic stenoses are similar, their pathophysiologies are different. It is important to understand what can happen by dilating coronary artery with balloon/stent, and to develop a strategy to achieve the maximum effect. Second reason is to anticipate possible complications and to reduce them in advance. In that case, we can deal with it as calmly as possible. Third reason is to validate the PCI performed. This should lead to further improvements of the procedures, which in turn will lead to improved short- and long-term prognosis. Then, high-quality PCI could be possible. This review summarizes the standard usage of IVUS in routine clinical practice and the use of IVUS in specific situations, especially complex lesions.

Culprit Lesion Morphology of Rapidly Progressive and Extensive Anterior-Wall ST-Segment Elevation Myocardial Infarction

BACKGROUND

Rapidly progressive, extensive myocardial injury/infarction (RPEMI) beyond the concept of wave-front phenomenon can be observed even when achieving timely reperfusion; however, the pathogenesis of RPEMI remains unknown. This retrospective study investigated clinical and lesion characteristics of RPEMI, focusing on culprit-lesion morphology (CLM).

METHODS

Among patients with extensive anterior-wall ST-segment elevation myocardial infarction due to proximal left anterior descending artery lesions who had reperfusion within 3 hours of symptom onset, 60 patients undergoing both intravascular ultrasound and cardiac magnetic resonance imaging were enrolled. Myocardial injury/infarction before reperfusion therapy was assessed by QRS scores at hospitalization electrocardiogram, and the extent of myocardial injury/infarction was evaluated by cardiac magnetic resonance imaging, which measured area at risk, infarct size, myocardial salvage index, microvascular obstruction, and left ventricular ejection fraction. RPEMI was defined as lower left ventricular ejection fraction (less median value) with microvascular obstruction.

RESULTS

Despite comparable onset-to-door and onset-to-reperfusion times and area at risk, patients with RPEMI showed higher QRS scores at hospitalization (5 [4.3-6] versus 3 [2-4], P<0.001) and infarct size (26.5±9.1 versus 20.4±10.5%, P=0.04), and a tendency toward lower myocardial salvage index (0.27±0.14 versus 0.36±0.20, P=0.10) compared with those without. Patients with versus without RPEMI more frequently observed specific CLM on intravascular ultrasound, characterized by the combination of vulnerable plaques, plaque ruptures, and/or large thrombi. When stratified by CLM-score composed of these 3 criteria, higher CLM-scores were or tended to be associated with higher QRS scores and incidence of RPEMI. In multivariate analyses including no-reflow phenomenon and final coronary-flow deterioration, increased CLM-score (≥2) was independently associated with high QRS scores and RPEMI (odd ratio 11.25 [95% CI, 2.43-52.00]; P=0.002).

CONCLUSIONS

Vulnerable CLM was a consistent determinant of advanced myocardial injury/infarction both before and after reperfusion therapy and may play a pivotal role in the development of RPEMI.

Association between High Lipid Burden of Target Lesion and Slow TIMI Flow in Coronary Interventions

Decreased thrombolysis in myocardial infarction (TIMI) flow is associated with poor clinical outcomes. However, its predictors are not fully known. A combination of near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) could be used to detect lesions at high risk of slow TIMI flow. This study evaluated 636 consecutive patients undergoing target-lesion NIRS-IVUS imaging prior to percutaneous coronary intervention (PCI). The maximal lipid core burden index over 4-mm segments (maxLCBI4mm) per target vessel was calculated. The primary endpoint was the association between maxLCBI4mm and post-interventional TIMI flow. A high lipid core burden index (LCBI) cut-off point was determined using receiver-operating characteristic analysis. Decreased TIMI flow (TIMI less than 3) occurred in 90 patients and normal TIMI flow in 546 patients. The decreased TIMI flow group showed significantly higher incidence of cardiovascular events (5.6% vs. 1.5%, log-rank p = 0.010) in three months of composite events including cardiac death, myocardial infarction, stent thrombosis, and target lesion revascularization. In multivariable analysis, a high LCBI (≥354) was independently associated with slow TIMI flow (OR, 2.59 (95% CI, 1.33–5.04), p = 0.005). High LCBI measured using NIRS-IVUS imaging was an independent predictor of decreased post-PCI TIMI flow. Performing PCI for high-LCBI lesions may necessitate adjunctive measures to prevent suboptimal post-PCI reperfusion.

Tissue characterisation and primary percutaneous coronary intervention guidance using intravascular ultrasound: rationale and design of the SPECTRUM study

Introduction

Intravascular ultrasound (IVUS) improves clinical outcome in patients undergoing percutaneous coronary intervention (PCI) but dedicated prospective studies assessing the safety and efficacy of IVUS guidance during primary PCI are lacking.

Methods and analysis

The SPECTRUM study is a prospective investigator-initiated single-centre single-arm observational cohort study aiming to enrol 200 patients presenting with ST-segment elevation myocardial infarct undergoing IVUS-guided primary PCI. IVUS will be performed at baseline, postintervention and postoptimisation (if applicable), using a 40–60 MHz high-definition (HD) system. Baseline tissue characterisation includes the morphological description of culprit lesion plaque characteristics and thrombus as assessed with HD-IVUS. The primary endpoint is target vessel failure at 12 months (defined as a composite of cardiac death, target vessel myocardial infarction and clinically driven target vessel revascularisation). The secondary outcome of interest is IVUS-guided optimisation, defined as IVUS-guided additional balloon dilatation or stent placement. Other endpoints include clinical and procedural outcomes along with post-PCI IVUS findings.

Ethics and dissemination

The protocol of this study was approved by the Ethics Committee of the Erasmus University Medical Center, Rotterdam, the Netherlands. Written informed consent is obtained from all patients. Study findings will be submitted to international peer-reviewed journals in the field of cardiovascular imaging and interventions and will be presented at international scientific meetings.

Trial registration number

NCT05007535.

Intravascular ultrasound-guided versus coronary angiography-guided percutaneous coronary intervention in patients with acute myocardial infarction: A systematic review and meta-analysis

BACKGROUND

Intravascular ultrasound (IVUS) can overcome the intrinsic limitations of coronary angiography for lesion assessment and stenting. IVUS improves outcomes of patients presenting with stable or complex coronary artery disease, but dedicated data on the impact of IVUS-guided percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) remains scarce.

METHODS

We systematically searched Embase, MEDLINE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials and Google Scholar for studies that compared clinical outcomes for IVUS- versus angio-guided PCI in patients with AMI. The primary endpoint was all-cause mortality and the secondary endpoint major adverse cardiovascular events (MACE). Mantel-Haenszel random-effects model was used to calculate pooled risk ratios (RR) with 95% confidence intervals (CI).

RESULTS

Nine studies (8 observational, 1 RCT) with a total of 838.902 patients (796.953 angio-guided PCI, 41.949 IVUS-guided PCI) were included. In patients with AMI, IVUS-guided PCI was associated with a significantly lower risk of all-cause mortality (pooled RR: 0.70; 95% CI, 0.59-0.82; p < 0.01), MACE (pooled RR: 0.86; 95% CI, 0.74-0.99; p = 0.04) and target vessel revascularization (TVR) (pooled RR: 0.83; 95% CI, 0.73-0.95; p < 0.01). In the subset of patients presenting with ST-segment elevation, IVUS-guided PCI remained associated with a reduced risk for both all-cause mortality (pooled RR: 0.79; 95% CI, 0.66-0.95, p = 0.01) and MACE (pooled RR: 0.86; 95% CI, 0.74-0.99, p = 0.04).

CONCLUSIONS

This is the first systematic review and meta-analysis comparing IVUS- versus angio-guided PCI in patients with AMI, showing a beneficial effect of IVUS-guided PCI on all-cause mortality, MACE and TVR. Results of ongoing dedicated prospective studies are needed to confirm these findings.

Salvage from hemodialysis via percutaneous transluminal renal artery stenting for a jeopardized solitary functioning kidney: A case report

Atherosclerotic renal artery stenosis (ARAS) causes resistant hypertension, progressively declining renal function, and cardiac destabilization syndromes, including heart failure. We report a patient who underwent successful percutaneous transluminal renal angioplasty (PTRA) for anuretic acute kidney injury (AKI) due to ARAS. This patient, admitted to our hospital with congestive heart failure, developed anuretic AKI and started hemodialysis 3 days after admission. Computed tomography and magnetic resonance angiograms showed total occlusion of the proximal right renal artery, with atrophy of the right kidney and severe stenosis of the proximal left renal artery. These findings suggested that only the left kidney was functioning. We performed PTRA of the left renal artery in which the culprit lesion causing the AKI appeared to be located. Using intravascular ultrasound, severe calcification in the ostium of the left renal artery and a necrotic core with plaque rupture in the culprit lesion were observed. Kidney function recovered immediately after revascularization, which permitted successful withdrawal of hemodialysis. There is no clear consensus regarding the indication for PTRA in patients with ARAS; however, our experience suggests that PTRA may be beneficial for patients with a jeopardized solitary functioning kidney. <Learning objective: There is no clear consensus regarding the indication for percutaneous transluminal renal angioplasty (PTRA) in patients with atherosclerotic renal artery stenosis. However, patients with a jeopardized solitary functioning kidney may benefit from PTRA, which should be considered as soon as possible before irreversible ischemic changes occur. It is important to recognize that PTRA may be indicated in select similar cases.>.

Utility of near-infrared spectroscopy to detect the extent of lipid core plaque leading to periprocedural myocardial infarction

OBJECTIVES

The aim of this study was to investigate whether lipid core plaque (LCP) in the entire stented segment detected by near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) could predict procedural myocardial infarction (PMI) in patients undergoing percutaneous coronary artery intervention (PCI).

BACKGROUND

NIRS-IVUS can identify LCP, described as high lipid core burden index (LCBI). Previously, the highest LCBI contained only in the 4-mm segment (maxLCBI_4mm ) was reported to predict PMI.

METHODS

Patients who underwent NIRS-IVUS examination during PCI for coronary artery disease at Chiba University Hospital were included. The extent of LCP in the stented segment derived from NIRS-IVUS analysis was presented as LCBI, maxLCBI_4mm , and LCP area index (LAI), reflecting the total amount of LCP in the entire stented segment calculated as LCBI×lesion length. PMI was defined as an elevation of creatine kinase MB > 3 times upper reference level (URL), and periprocedural myocardial injury (PMInj) was defined as an elevation of troponin I>5 times URL within 12 to 24 h after PCI.

RESULTS

Out of 141 enrolled patients, PMI occurred in 20 (14.2%) and PMInj occurred in 62 (44.0%) patients. Receiver-operating characteristic curve analysis revealed LAI was the strongest predictor for both PMI and PMInj (area under curve 0.771, p < 0.001, and 0.717, p < 0.001, respectively). Multiple logistic regression analysis determined high LAI value as the independent predictor of both PMI and PMInj.

CONCLUSIONS

Greater extent of LCP in the entire stented segment detected by NIRS-IVUS was significantly associated with PMI as well as PMInj in patients undergoing PCI.

The Predictive Value of Baseline Target Lesion SYNTAX Score for No-Reflow during Urgent Percutaneous Coronary Intervention in Acute Myocardial Infarction

Objectives

To evaluate the predictive value of target lesion SYNTAX score (TL-SS) for no-reflow in the patients with acute myocardial infarction undergoing urgent percutaneous coronary intervention (PCI).

Background

Risk assessment, prevention, and prompt management of no-reflow in urgent PCI are crucial but remain challenging. SYNTAX score emerged as a tool for prediction, but may contain redundant information.

Methods

After screening of consecutive patients who underwent urgent PCI in Fuwai Hospital from January 2013 to December 2013, 487 patients with 528 lesions were involved. The endpoint was no-reflow during the PCI procedure.

Results

No-reflow occurred in 52 patients (10.7%) and 53 lesions (10.0%). High TL-SS levels were strongly associated with increased risks of no-reflow in the urgent PCI procedure (all adjusted P < 0.05). TL-SS displayed good discrimination ability for no-reflow (C-statistics = 0.76, 95% CI 0.72–0.80), which was better than that of SYNTAX score (P=0.016). Following categorizing the lesions into two groups according to the Youden Index, the high-risk group (TL-SS ≥8) showed significantly higher no-reflow rate compared with the low-risk group (TL-SS <8) (20.6% vs. 3.6%, odds ratio 6.86, 95% confidence interval 3.50–13.41, P < 0.001). In the target lesions that underwent balloon predilation, maximum predilation pressure >10 atm was associated with higher rate of no-reflow in the high-risk group (odds ratio 3.81, 95% confidence interval 1.10–13.17).

Conclusions

TL-SS is a potential predictor for risk stratification of no-reflow in urgent PCI. In the high TL-SS lesions that underwent balloon predilation, maximum predilation pressure >10 atm was associated with higher risk of no-reflow.

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.

Inflammation during Percutaneous Coronary Intervention-Prognostic Value, Mechanisms and Therapeutic Targets

Periprocedural myocardial injury and myocardial infarction (MI) are not infrequent complications of percutaneous coronary intervention (PCI) and are associated with greater short- and long-term mortality. There is an abundance of preclinical and observational data demonstrating that high levels of pre-, intra- and post-procedural inflammation are associated with a higher incidence of periprocedural myonecrosis as well as future ischaemic events, heart failure hospitalisations and cardiac-related mortality. Beyond inflammation associated with the underlying coronary pathology, PCI itself elicits an acute inflammatory response. PCI-induced inflammation is driven by a combination of direct endothelial damage, liberation of intra-plaque proinflammatory debris and reperfusion injury. Therefore, anti-inflammatory medications, such as colchicine, may provide a novel means of improving PCI outcomes in both the short- and long-term. This review summarises periprocedural MI epidemiology and pathophysiology, evaluates the prognostic value of pre-, intra- and post-procedural inflammation, dissects the mechanisms involved in the acute inflammatory response to PCI and discusses the potential for periprocedural anti-inflammatory treatment.

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.

Long-Term Clinical Outcomes After Filter Protection During Percutaneous Coronary Intervention in Patients With Attenuated Plaque - 1-Year Follow up of the VAMPIRE 3 (Vacuum Aspiration Thrombus Reemoval 3) Trial

BACKGROUND

Selective use of distal filter protection during percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) decreased the incidence of no-reflow phenomena and in-hospital serious adverse cardiac events compared with conventional PCI in patients with attenuated plaque ≥5 mm; however, its long-term clinical outcome remains unknown.Methods and Results:Patients who had ACS with attenuated plaque ≥5 mm were assigned to receive distal protection (DP) (n=98) or conventional treatment (CT) (n=96). The rate of major adverse cardiovascular events (MACE), a composite of death from any cause, non-fatal myocardial infarction, or target vessel revascularization (TVR) at 1 year, was the pre-specified secondary endpoint of the trial. MACE at 1 year occurred in 12 patients (12.2%) in the DP group and 3 patients (3.1%) in the CT group (P=0.029), which was driven by a higher risk of TVR (11 [11.2%] vs. 2 [2.1%], P=0.018). In patients treated with bare-metal stents (n=42), MACE occurred in 25.0% of the patients in the DP group and in none of the patients in the CT group (P=0.029), whereas in patients treated with drug-eluting stents (n=151), rates of MACE were similar in the groups (8.1% vs. 3.9%, P=0.32).

CONCLUSIONS

In ACS patients with attenuated plaque ≥5 mm, the 1-year rates of MACE were higher in the DP group than in the CT group. This effect might be mitigated by the use of drug-eluting stents.

When to use intravascular ultrasound or optical coherence tomography during percutaneous coronary intervention?

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are intravascular imaging technologies widely used in the cardiac catheterization laboratory. The impact of these modalities for optimizing the acute and longer-term clinical impact following percutaneous coronary intervention (PCI) is supported by a wealth of clinical evidence. Intravascular imaging provides unique information for enhanced lesion preparation, optimal stent sizing, recognizing post PCI complications, and the etiology of stent failure. This review compares and contrasts the key aspects of these imaging modalities during PCI.

Platelet-Derived Thrombogenicity Measured by Total Thrombus-Formation Analysis System in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Prompt and potent antiplatelet effects are important aspects of management of ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). We evaluated the association between platelet-derived thrombogenicity during PPCI and enzymatic infarct size in STEMI patients.Methods and Results:Platelet-derived thrombogenicity was assessed in 127 STEMI patients undergoing PPCI by: (1) the area under the flow-pressure curve for the PL-chip (PL₁₈-AUC₁₀) using the total thrombus-formation analysis system (T-TAS); and (2) P2Y₁₂reaction units (PRU) using the VerifyNow system. Patients were divided into 2 groups (High and Low) based on median PL₁₈-AUC₁₀during PPCI. PRU levels during PPCI were suboptimal in both the High and Low PL₁₈-AUC₁₀groups (median [interquartile range] 266 [231-311] vs. 272 [217-317], respectively; P=0.95). The percentage of final Thrombolysis in Myocardial Infarction (TIMI) 3 flow was lower in the High PL₁₈-AUC₁₀group (75% vs. 90%; P=0.021), whereas corrected TIMI frame count (31.3±2.5 vs. 21.0±2.6; P=0.005) and the incidence of slow-flow/no-reflow phenomenon (31% vs. 11%, P=0.0055) were higher. The area under the curve for creatine kinase (AUC_CK) was greater in the High PL₁₈-AUC₁₀group (95,231±7,275 IU/L h vs. 62,239±7,333 IU/L h; P=0.0018). Multivariate regression analysis identified high PL₁₈-AUC₁₀during PPCI (β=0.29, P=0.0006) and poor initial TIMI flow (β=0.37, P<0.0001) as independent determinants of AUC_CK.

CONCLUSIONS

T-TAS-based high platelet-derived thrombogenicity during PPCI was associated with enzymatic infarct size in patients with STEMI.

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.

Inflammation-Related MicroRNAs Are Associated with Plaque Stability Calculated by IVUS in Coronary Heart Disease Patients

Objectives

This study aimed to investigate the association between inflammation-related microRNAs (miR-21, 146a, 155) and the plaque stability in coronary artery disease patients.

Methods

The expression of miR-21, 146a, and 155 was measured by real-time PCR in 310 consecutive patients. The level of hs-CRP, IL-6, and IL-8 was measured by ELISA. The plaque stability of coronary stenotic lesions was evaluated with intravascular ultrasound (IVUS).

Results

(1) The levels of hs-CRP, IL-6, and IL-8 were significantly increased in the UAP and AMI groups compared with the CPS group (P < 0.01). (2) The expression of miR-21 and miR-146a in peripheral blood mononuclear cells (PBMCs) and plasma was significantly higher in CAD patients compared with non-CAD patients, whereas the miR-155 expression in PBMCs and plasma was significantly lower in patients with CAD. (3) The miR-21 expression in PBMCs was higher in UAP and AMI groups compared with CPS group. The miR-146a expression in PBMCs was higher in SAP, UAP, and AMI groups than in CPS group. Although the level of miR-155 in PBMCs was lower in SAP, UAP, and AMI groups than in CPS group. The expression patterns of miR-21, miR-146a, and miR-155 in plasma were consistent with those of PBMCs. (4) The expressions of miR-21 and miR-146a in PBMCs and plasma were significantly higher in the vulnerable plaque group than those in stable plaque group. While miR-155 in PBMCs and plasma was significantly lower in vulnerable plaque group compared with stable plaque group. (5) The levels of miR-21 and miR-146a in PBMCs and plasma were significantly higher in soft plaque group than in fibrous plaque group and calcified plaque group. However, miR-155 in PBMCs and plasma was significantly lower in soft plaque group.

Conclusions

The expression of miR-21 and miR-146a are associated with the plaque stability in coronary stenotic lesions, whereas miR-155 expression is inversely associated with the plaque stability.

Usefulness of intracoronary administration of fasudil, a selective Rho-kinase inhibitor, for PCI-related refractory myocardial ischemia

BACKGROUND

Intra-procedural myocardial ischemia as an iatrogenic complication still remains a critical issue in contemporary interventional cardiology. The aim of this study was to examine the usefulness of fasudil, a selective Rho-kinase inhibitor, for percutaneous coronary intervention (PCI)-related myocardial ischemia.

METHODS

Among 448 PCI sessions performed between October 2015 and December 2017, we retrospectively examined 36 patients (69.0 ± 9.1 [SD] yrs., M/F 26/10) who underwent intracoronary administration of fasudil during a procedure to resolve myocardial ischemia that was resistant to intracoronary nitrate administration.

RESULTS

The refractory myocardial ischemia was caused by distal embolization (69%), enhanced vasoconstriction at distal site of chronic total occlusion (11%), coronary spasm (11%), and coronary dissection (8%), most of which occurred immediately after balloon or stent dilatation. Intracoronary fasudil significantly improved corrected TIMI frame count (from 37 [30-56] to 24 [12-36]) and TIMI flow grade (from 2 [1-2.5] to 3 [2-3]) (both P < 0.001). Finally, 86% of all subjects successfully obtained TIMI flow grade 3 at the end of the procedure. Intracoronary fasudil tended to be more effective in patients with an attenuated plaque detected by intravascular ultrasound. Importantly, among the 19 elective cases, fasudil successfully prevented 17 patients from developing post-procedure myocardial infarction. Although fasudil-induced transient hypotension requiring a vasopressor was noted in 22% of the subjects, no other adverse effects were noted.

CONCLUSIONS

These results indicate that fasudil is a useful and safe therapeutic option for PCI-related myocardial ischemia refractory intracoronary nitrate.

Treatment Windows and Clinical Outcomes in Late-Presenting Patients with ST-Segment Elevation Myocardial Infarction

BACKGROUND

Percutaneous coronary intervention (PCI) is the reperfusion strategy typically used in patients with ST-segment elevation myocardial infarction (STEMI) who present with prolonged ischemic symptoms (>12 hours after onset). However, there is no consensus on an optimal time window for PCI. We examined a real-world cohort, assessing time from symptom onset to balloon inflation in relation to long-term nonfatal recurrent myocardial infarction (MI) or all-cause mortality.

MATERIALS AND METHODS

A total of 825 consecutive patients presenting with ischemic symptoms of STEMI >12 hours after symptom onset and undergoing subsequent primary PCI were grouped by time-to-treatment status (≤7 days or >7 days post-MI). Primary endpoints were nonfatal recurrent MI and all-cause mortality.

RESULTS

Cumulative rates of recurrent nonfatal MI at 2 years were 4.1% and 3.3% in patients with symptom-onset-to-balloon inflation times of ≤7 days and >7 days, respectively (P = 0.049); and corresponding mortality rates were 3.4% and 4.7% (P = 0.238). In Cox multivariate analyses, syndrome-onset-to-balloon-inflation time was not independently predictive of recurrent MI (P = 0.052) or mortality (P = 0.651) at 2 years, once adjusted for certain clinical and angiographic variables known to influence patient outcomes. The 2-year rate of recurrent MI was highest in patients with multivessel coronary artery diseases undergoing primary PCI ≤7 days after symptom onset to balloon inflation (P = 0.005).

CONCLUSIONS

In patients presenting with ischemic signs or symptoms of STEMI >12 hours after initial symptom onset and treated by PCI, symptom-onset-to-balloon-inflation times ≤7 days showed no relation to nonfatal recurrent MI, unless in the presence of multivessel coronary artery diseases.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions

During the past three decades, since the invention of intravascular ultrasound (IVUS), it has become increasingly important as daily clinical applications. However, it evolved with no Japanese standards for the measurement of images, the index of percutaneous coronary intervention (PCI) procedures, and the reporting of results. Accordingly, the purpose of this review article is to provide an optimal and consistent approach to IVUS usage during PCI for clinicians and investigators.

IVUS-Guided Versus OCT-Guided Coronary Stent Implantation: A Critical Appraisal

Procedural guidance with intravascular ultrasound (IVUS) imaging improves the clinical outcomes of patients undergoing percutaneous coronary intervention (PCI) by: 1) informing the necessity for lesion preparation; 2) directing appropriate stent sizing to maximize the final stent area and minimize geographic miss; 3) selecting the optimal stent length to cover residual disease adjacent to the lesion, thus minimizing geographic miss; 4) guiding optimal stent expansion; 5) identifying acute complications (edge dissection, stent malapposition, tissue protrusion); and 6) clarifying the mechanism of late stent failure (stent thrombosis, neointimal hyperplasia, stent underexpansion or fracture, or neoatherosclerosis). Optical coherence tomography (OCT) provides similar information to IVUS (with some important differences), also potentially improving acute and long-term patient outcomes compared to angiography-guided PCI. The purpose of this review is to describe the similarities and differences between IVUS and OCT technologies, and to highlight the evidence supporting their utility to improve PCI outcomes.

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.

Determinants of slow flow following stent implantation in intravascular ultrasound-guided primary percutaneous coronary intervention

Slow flow is a serious complication in primary percutaneous coronary intervention (PCI) and is associated with poor clinical outcomes. Intravascular ultrasound (IVUS)-guided PCI may improve clinical outcomes after drug-eluting stent implantation. The purpose of this study was to seek the factors of slow flow following stent implantation, including factors related to IVUS-guided primary PCI. The study population consisted of 339 ST-elevation myocardial infarction patients, who underwent stent deployment with IVUS. During PCI, 56 patients (16.5%) had transient or permanent slow flow. Multivariate logistic regression analysis showed age (OR 1.04, 95% CI 1.01-1.07, P = 0.01), low attenuation plaque on IVUS (OR 3.38, 95% CI 1.70-6.72, P = 0.001), initial Thrombolysis In Myocardial Infarction (TIMI) flow grade 2 (vs. TIMI 0: OR 0.44, 95% CI 0.20-0.99, P = 0.046), and the ratio of stent diameter to vessel diameter (per 0.1 increase: OR 2.63, 95% CI 1.84-3.77, P < 0.001) were significantly associated with slow flow. A ratio of stent diameter to vessel diameter of 0.71 had an 80.4% sensitivity and 56.9% specificity to predict slow flow. There was no significant difference in ischemic-driven target vessel revascularization between the modest stent expansion (ratio of stent diameter to vessel diameter <0.71) and aggressive stent expansion (ratio of stent diameter to vessel diameter ≥0.71) strategies. Unlike other variables, the ratio of stent diameter to vessel diameter was the only modifiable factor. The modest stent expansion strategy should be considered to prevent slow flow following stent implantation in IVUS-guided primary PCI.

Impact of attenuated-signal plaque observed by intravascular ultrasound on vessel response after drug-eluting stent implantation

BACKGROUND AND AIMS

The aim of this study was to investigate the impact of attenuated-signal plaque (ASP) observed by intravascular ultrasound (IVUS) on vessel response after drug-eluting stent implantation.

METHODS

Data were derived from the IVUS cohort of the J-DESsERT trial comparing paclitaxel- and sirolimus-eluting stents. Serial IVUS analysis (pre- and post-intervention, and 8-month follow-up) was performed in 136 non-AMI lesions. ASP was defined as hypoechoic plaque with ultrasound attenuation without calcification. Calcified plaque (CP) was defined as brightly echoreflective plaque with acoustic shadowing. ASP and CP scores were calculated by grading their measured angle as 0 to 4 for 0°, <90°, 90-180°, 180-270° and >270°, respectively. The entire stented segment was analyzed at 1-mm intervals.

RESULTS

At pre-intervention, ASP was observed in 40.4% of lesions, and this group had greater % neointimal volume (%NIV) at follow-up than the no-ASP group (p = 0.011). ASP score at pre-intervention positively correlated with %NIV (p = 0.023). During the follow-up, ASP score significantly decreased (p < 0.001), and CP score significantly increased (p < 0.001), with a negative correlation between them (p < 0.001). A decrease in the ASP score was associated with less %NIV in PES (p = 0.031), but not in SES (p = 0.229).

CONCLUSIONS

The greater extent of plaque with IVUS-signal attenuation at pre-intervention and its persistence during follow-up were associated with neointimal proliferation, possibly representing sustained inflammatory status, depending on the type of DES used.

Intravascular ultrasound for morphological assessment of napkin-ring sign detected on multidetector computed tomography

BACKGROUND

Although napkin-ring sign (NRS) plaques assessed by multidetector computed tomography (MDCT) is identified as a high-risk feature, the detailed morphological features are still unknown. The purpose of this study was to elucidate the morphological features of the MDCT-assessed NRS using intravascular ultrasound (IVUS).

METHODS

We evaluated 204 plaques in 193 patients with non-ST-elevation acute coronary syndrome who were diagnosed using 128-slice MDCT and were assessed using IVUS prior to coronary intervention. Morphology was compared between plaques with and without MDCT-assessed NRS. Severe IVUS-assessed attenuation was defined as an attenuation angle >180°.

RESULTS

NRS was detected in 49 lesions. MDCT-assessed plaque attenuation was lower (p<0.0001), and cross-sectional plaque areas at lesion sites, remodeling index, and the prevalence of positive remodeling were greater, in lesions with NRS (p<0.005, p<0.0001, and p<0.0001, respectively). Furthermore, the IVUS-assessed remodeling index and prevalence of severe attenuation and speckled echo appearance were significantly greater in lesions with NRS (p<0.01, p<0.0001, and p<0.0001, respectively). Using multivariate analysis, IVUS-assessed speckled echo appearance was identified as an independent predictor of MDCT-assessed NRS (odds ratio, 3.59; 95% confidence interval, 1.49-8.66; p<0.005).

CONCLUSION

MDCT assessment of NRS may be associated with larger heterogeneous necrotic cores and greater positive remodeling.

Morphological predictors for no reflow phenomenon after primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction caused by plaque rupture

AIMS

Myocardial no reflow after percutaneous coronary intervention (PCI) is associated with poor outcome. Patients with ST-segment elevation myocardial infarction (STEMI) caused by plaque rupture are at high risk for no reflow. However, specific morphologic characteristics associated with no reflow are unknown in this population. The aim of this study is to identify the morphological characteristics of culprit plaques associated with no reflow in patients with STEMI caused by plaque rupture using both optical coherence tomography (OCT) and intravascular ultrasound (IVUS).

METHODS AND RESULTS

We enrolled 145 patients with STEMI who underwent both OCT and IVUS within 12 h of symptom onset. Among these patients, we excluded those with plaque erosion and calcified nodule and included 72 patients who had plaque rupture as an underlying mechanism for STEMI. Myocardial no reflow, defined as Thrombolysis in Myocardial Infarction flow grade 0-2 and/or myocardial blush grade 0-1 after PCI, was observed in 28 patients (38.9%). Onset to recanalization time was similar between the groups with and without no reflow. Receiver-operating curve analysis revealed OCT-derived lipid index > 3500 [area under curve (AUC) 0.77, P < 0.001] and IVUS-derived plaque burden > 81.5% (AUC 0.70, P = 0.002) were the best discriminators for myocardial no reflow.

CONCLUSION

No reflow occurred in nearly 40% of patients with STEMI caused by plaque rupture. Large lipid index and plaque burden were critical morphological discriminators between no reflow and normal flow.

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.

Main trunk crossover stenting in a patient with left internal thoracic artery--protected single coronary artery

A 74-year-old man with single coronary artery and history of previous coronary artery bypass graft (CABG) was admitted to our hospital with worsening angina. Because of high risk of redo-CABG, we performed transradial percutaneous coronary intervention against the just proximal left anterior descending coronary artery (LAD) stenosis coexisting with short main trunk, anomalous right coronary artery deriving from the mid LAD and patent left internal thoracic artery-distal LAD graft. Under the guidance of IVUS, we successfully implanted an everolimus-eluting stent from the main trunk ostium to the proximal LAD without complications.

A Combined Optical Coherence Tomography and Intravascular Ultrasound Study on Plaque Rupture, Plaque Erosion, and Calcified Nodule in Patients With ST-Segment Elevation Myocardial Infarction: Incidence, Morphologic Characteristics, and Outcomes After Percutaneous Coronary Intervention

OBJECTIVES

This study sought to evaluate the incidence of plaque rupture (PR), plaque erosion (PE), and calcified nodule (CN) using optical coherence tomography (OCT) in patients with ST-segment elevation myocardial infarction (STEMI); to compare detailed morphologic plaque characteristics of PR, PE, and CN with optical coherence tomography and intravascular ultrasound; and to compare the post-procedure outcomes among PR, PE, and CN.

BACKGROUND

The incidence and detailed morphologic characteristics of PR, PE, and CN in STEMI patients and their outcome after percutaneous coronary intervention (PCI) are unknown.

METHODS

A total of 112 STEMI patients who underwent PCI within 24 h [corrected] from symptom onset were included. Both optical coherence tomography and intravascular ultrasound were performed following aspiration thrombectomy.

RESULTS

The incidence of PR, PE, and CN was 64.3%, 26.8%, and 8.0%, respectively. PE and CN, compared with PR, had more fibrous plaque (p < 0.001 and p < 0.001) and less thin-cap fibroatheroma (p < 0.001 and p < 0.001) as well as smaller plaque burden (p = 0.003 and p = 0.001) and remodeling index (p = 0.003 and p < 0.001). PE had greater plaque eccentricity index than PR and CN (p < 0.001 and p < 0.001). CN had greater calcified arc and shallower calcium than PR (p < 0.001 and p < 0.001) or PE (p < 0.001 and p < 0.001). More than one-half of CN had negative remodeling. PE had a lower incidence of no-reflow phenomenon after PCI than PR (p = 0.011).

CONCLUSIONS

PE was the underlying mechanism in one-fourth of STEMI. PE was characterized by eccentric fibrous plaque. CN was characterized by superficial large calcium and negative remodeling. PE was associated with less microvascular damage after PCI.

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.

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.

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.

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.