Intravascular ultrasound-guided versus angiography-guided percutaneous coronary intervention in acute coronary syndromes (IVUS-ACS): a two-stage, multicentre, randomised trial.

BACKGROUND: Intravascular ultrasound-guided percutaneous coronary intervention has been shown to result in superior clinical outcomes compared with angiography-guided percutaneous coronary intervention. However, insufficient data are available concerning the advantages of intravascular ultrasound guidance for patients with an acute coronary syndrome. This trial aimed to investigate whether the use of intravascular ultrasound guidance, as compared with angiography guidance, improves the outcomes of percutaneous coronary intervention with contemporary drug-eluting stents in patients presenting with an acute coronary syndrome. METHODS: In this two-stage, multicentre, randomised trial, patients aged 18 years or older and presenting with an acute coronary syndrome at 58 centres in China, Italy, Pakistan, and the UK were randomly assigned to intravascular ultrasound-guided percutaneous coronary intervention or angiography-guided percutaneous coronary intervention. Patients, follow-up health-care providers, and assessors were masked to random assignment; however, staff in the catheterisation laboratory were not. The primary endpoint was target vessel failure, a composite of cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularisation at 1 year after randomisation. This trial is registered at ClinicalTrials.gov, NCT03971500, and is completed. FINDINGS: Between Aug 20, 2019 and Oct 27, 2022, 3505 patients with an acute coronary syndrome were randomly assigned to intravascular ultrasound-guided percutaneous coronary intervention (n=1753) or angiography-guided percutaneous coronary intervention (n=1752). 1-year follow-up was completed in 3504 (>99·9%) patients. The primary endpoint occurred in 70 patients in the intravascular ultrasound group and 128 patients in the angiography group (Kaplan-Meier rate 4·0% vs 7·3%; hazard ratio 0·55 [95% CI 0·41-0·74]; p=0·0001), driven by reductions in target vessel myocardial infarction or target vessel revascularisation. There were no significant differences in all-cause death or stent thrombosis between groups. Safety endpoints were also similar in the two groups. INTERPRETATION: In patients with an acute coronary syndrome, intravascular ultrasound-guided implantation of contemporary drug-eluting stents resulted in a lower 1-year rate of the composite outcome of cardiac death, target vessel myocardial infarction, or clinically driven revascularisation compared with angiography guidance alone. FUNDING: The Chinese Society of Cardiology, the National Natural Scientific Foundation of China, and Jiangsu Provincial & Nanjing Municipal Clinical Trial Project. TRANSLATION: For the Mandarin translation of the abstract see Supplementary Materials section.

Preventive percutaneous coronary intervention versus optimal medical therapy alone for the treatment of vulnerable atherosclerotic coronary plaques (PREVENT): a multicentre, open-label, randomised controlled trial.

BACKGROUND: Acute coronary syndrome and sudden cardiac death are often caused by rupture and thrombosis of lipid-rich atherosclerotic coronary plaques (known as vulnerable plaques), many of which are non-flow-limiting. The safety and effectiveness of focal preventive therapy with percutaneous coronary intervention of vulnerable plaques in reducing adverse cardiac events are unknown. We aimed to assess whether preventive percutaneous coronary intervention of non-flow-limiting vulnerable plaques improves clinical outcomes compared with optimal medical therapy alone. METHODS: PREVENT was a multicentre, open-label, randomised controlled trial done at 15 research hospitals in four countries (South Korea, Japan, Taiwan, and New Zealand). Patients aged 18 years or older with non-flow-limiting (fractional flow reserve >0·80) vulnerable coronary plaques identified by intracoronary imaging were randomly assigned (1:1) to either percutaneous coronary intervention plus optimal medical therapy or optimal medical therapy alone, in block sizes of 4 or 6, stratified by diabetes status and the performance of percutaneous coronary intervention in a non-study target vessel. Follow-up continued annually in all enrolled patients until the last enrolled patient reached 2 years after randomisation. The primary outcome was a composite of death from cardiac causes, target-vessel myocardial infarction, ischaemia-driven target-vessel revascularisation, or hospitalisation for unstable or progressive angina, assessed in the intention-to-treat population at 2 years. Time-to-first-event estimates were calculated with the Kaplan-Meier method and were compared with the log-rank test. This report is the principal analysis from the trial and includes all long-term analysed data. The trial is registered at ClinicalTrials.gov, NCT02316886, and is complete. FINDINGS: Between Sept 23, 2015, and Sept 29, 2021, 5627 patients were screened for eligibility, 1606 of whom were enrolled and randomly assigned to percutaneous coronary intervention (n=803) or optimal medical therapy alone (n=803). 1177 (73%) patients were men and 429 (27%) were women. 2-year follow-up for the primary outcome assessment was completed in 1556 (97%) patients (percutaneous coronary intervention group n=780; optimal medical therapy group n=776). At 2 years, the primary outcome occurred in three (0·4%) patients in the percutaneous coronary intervention group and in 27 (3·4%) patients in the medical therapy group (absolute difference -3·0 percentage points [95% CI -4·4 to -1·8]; p=0·0003). The effect of preventive percutaneous coronary intervention was directionally consistent for each component of the primary composite outcome. Serious clinical or adverse events did not differ between the percutaneous coronary intervention group and the medical therapy group: at 2 years, four (0·5%) versus ten (1·3%) patients died (absolute difference -0·8 percentage points [95% CI -1·7 to 0·2]) and nine (1·1%) versus 13 (1·7%) patients had myocardial infarction (absolute difference -0·5 percentage points [-1·7 to 0·6]). INTERPRETATION: In patients with non-flow-limiting vulnerable coronary plaques, preventive percutaneous coronary intervention reduced major adverse cardiac events arising from high-risk vulnerable plaques, compared with optimal medical therapy alone. Given that PREVENT is the first large trial to show the potential effect of the focal treatment for vulnerable plaques, these findings support consideration to expand indications for percutaneous coronary intervention to include non-flow-limiting, high-risk vulnerable plaques. FUNDING: The CardioVascular Research Foundation, Abbott, Yuhan Corp, CAH-Cordis, Philips, and Infraredx, a Nipro company.

Plaque Ruptures Are Related to High Plaque Stress and Strain Conditions: Direct Verification by Using In Vivo OCT Rupture Data and FSI Models.

BACKGROUND: While it has been hypothesized that high plaque stress and strain may be related to plaque rupture, its direct verification using in vivo coronary plaque rupture data and full 3-dimensional fluid-structure interaction models is lacking in the current literature due to difficulty in obtaining in vivo plaque rupture imaging data from patients with acute coronary syndrome. This case-control study aims to use high-resolution optical coherence tomography-verified in vivo plaque rupture data and 3-dimensional fluid-structure interaction models to seek direct evidence for the high plaque stress/strain hypothesis. METHODS: In vivo coronary plaque optical coherence tomography data (5 ruptured plaques, 5 no-rupture plaques) were acquired from patients using a protocol approved by the local institutional review board with informed consent obtained. The ruptured caps were reconstructed to their prerupture morphology using neighboring plaque cap and vessel geometries. Optical coherence tomography-based 3-dimensional fluid-structure interaction models were constructed to obtain plaque stress, strain, and flow shear stress data for comparative analysis. The rank-sum test in the nonparametric test was used for statistical analysis. RESULTS: Our results showed that the average maximum cap stress and strain values of ruptured plaques were 142% (457.70 versus 189.22 kPa; P=0.0278) and 48% (0.2267 versus 0.1527 kPa; P=0.0476) higher than that for no-rupture plaques, respectively. The mean values of maximum flow shear stresses for ruptured and no-rupture plaques were 145.02 dyn/cm2 and 81.92 dyn/cm2 (P=0.1111), respectively. However, the flow shear stress difference was not statistically significant. CONCLUSIONS: This preliminary case-control study showed that the ruptured plaque group had higher mean maximum stress and strain values. Due to our small study size, larger scale studies are needed to further validate our findings.

Coronary Artery Lesion Lipid Content and Plaque Burden in Diabetic and Nondiabetic Patients: PROSPECT II.

BACKGROUND: Patients with diabetes have increased rates of major adverse cardiac events (MACEs). We hypothesized that this is explained by diabetes-associated differences in coronary plaque morphology and lipid content. METHODS: In PROSPECT II (Providing Regional Observations to Study Predictors of Events in the Coronary Tree), 898 patients with acute myocardial infarction with or without ST-segment elevation underwent 3-vessel quantitative coronary angiography and coregistered near-infrared spectroscopy and intravascular ultrasound imaging after successful percutaneous coronary intervention. Subsequent MACEs were adjudicated to either treated culprit lesions or untreated nonculprit lesions. This substudy stratified patients by diabetes status and assessed baseline culprit and nonculprit prevalence of high-risk plaque characteristics defined as maximum plaque burden ≥70% and maximum lipid core burden index ≥324.7. Separate covariate-adjusted multivariable models were performed to identify whether diabetes was associated with nonculprit lesion-related MACEs and high-risk plaque characteristics. RESULTS: Diabetes was present in 109 of 898 patients (12.1%). During a median 3.7-year follow-up, MACEs occurred more frequently in patients with versus without diabetes (20.1% versus 13.5% [odds ratio (OR), 1.94 (95% CI, 1.14-3.30)]), primarily attributable to increased risk of myocardial infarction related to culprit lesion restenosis (4.3% versus 1.1% [OR, 3.78 (95% CI, 1.12-12.77)]) and nonculprit lesion-related spontaneous myocardial infarction (9.3% versus 3.8% [OR, 2.74 (95% CI, 1.25-6.04)]). However, baseline prevalence of high-risk plaque characteristics was similar for patients with versus without diabetes concerning culprit (maximum plaque burden ≥70%: 90% versus 93%, P=0.34; maximum lipid core burden index ≥324.7: 66% versus 70%, P=0.49) and nonculprit lesions (maximum plaque burden ≥70%: 23% versus 22%, P=0.37; maximum lipid core burden index ≥324.7: 26% versus 24%, P=0.47). In multivariable models, diabetes was associated with MACEs in nonculprit lesions (adjusted OR, 2.47 [95% CI, 1.21-5.04]) but not with prevalence of high-risk plaque characteristics (adjusted OR, 1.21 [95% CI, 0.86-1.69]). CONCLUSIONS: Among patients with recent myocardial infarction, both treated and untreated lesions contributed to the diabetes-associated ≈2-fold increased MACE rate during the 3.7-year follow-up. Diabetes-related plaque characteristics that might underlie this increased risk were not identified by multimodality imaging. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02171065.

Strategy to optimize PeriproCeduraL AnticOagulation in structural transseptal interventions: Design and rationale of the STOP CLOT trial.

BACKGROUND: Both transcatheter edge-to-edge repair (TEER) of mitral regurgitation or left atrial appendage closure (LAAC) require periprocedural anticoagulation with unfractionated heparin (UFH) that is administered either before or immediately after transseptal puncture (TSP). The optimal timing of UFH administration (before or after TSP) is unknown. The Strategy To Optimize PeriproCeduraL AnticOagulation in Structural Transseptal Interventions trial (STOP CLOT Trial) was designed to determine if early anticoagulation is effective in reducing ischemic complications without increasing the risk of periprocedural bleeding. METHODS: The STOP CLOT trial is a multicenter, prospective, double-blind, placebo-controlled, randomized trial. A total of 410 patients scheduled for TEER or LAAC will be randomized 1:1 either early UFH administration (iv. bolus of 100 units/kg UFH or placebo, given after obtaining femoral vein access and at least 5 minutes prior to the start of the TSP) or late UFH administration (iv. bolus of 100 units/kg UFH or placebo given immediately after TSP). Prespecified preliminary statistical analysis will be performed after complete follow-up of the first 196 randomized subjects. To ensure blinding, a study nurse responsible for randomization and UFH/placebo preparation is not involved in the care of the patients enrolled into the study. The primary study endpoint is a composite of (1) major adverse cardiac and cerebrovascular events (death, stroke, TIA, myocardial infarction, or peripheral embolization) within 30 days post-procedure, (2) intraprocedural fresh thrombus formation in the right or left atrium as assessed with periprocedural transesophageal echocardiography, or (3) occurrence of new ischemic lesions (diameter ≥4 mm) on brain magnetic resonance imaging performed 2 to 5 days after the procedure. The safety endpoint is the occurrence of moderate or severe bleeding complications during the index hospitalization. CONCLUSIONS: Protocols of periprocedural anticoagulation administration during structural interventions have never been tested in a randomized clinical trial. The Stop Clot trial may help reach consensus on the optimal timing of initiation of periprocedural anticoagulation. CLINICAL TRIALS REGISTRATION NUMBER: The study protocol is registered at ClinicalTrials.gov, identifier NCT05305612.

Prevalence and anatomical factors associated with stent under-expansion in non-severely calcified lesions.

BACKGROUND: Stent underexpansion, typically related to lesion calcification, is the strongest predictor of adverse events after percutaneous coronary intervention (PCI). Although uncommon, underexpansion may also occur in non-severely calcified lesions. AIM: We sought to identify the prevalence and anatomical characteristics of underexpansion in non-severely calcified lesions. METHODS: We included 993 patients who underwent optical coherence tomography-guided PCI of 1051 de novo lesions with maximum calcium arc <180°. Negative remodeling (NR) was the smallest lesion site external elastic lamina diameter that was also smaller than the distal reference. Stent expansion was evaluated using a linear regression model accounting for vessel tapering; underexpansion required both stent expansion <70% and stent area <4.5mm2. RESULTS: Underexpansion was observed in 3.6% of non-heavily calcified lesions (38/1051). Pre-stent maximum calcium arc and thickness were greater in lesions with versus without underexpansion (median 119° vs. 85°, p = 0.002; median 0.95 mm vs. 0.78 mm, p = 0.008). NR was also more common in lesions with underexpansion (44.7% vs. 24.5%, p = 0.007). In the multivariable logistic regression model, larger and thicker eccentric calcium, mid left anterior descending artery (LAD) location, and NR were associated with underexpansion in non-severely calcified lesions. The rate of underexpansion was especially high (30.7%) in lesions exhibiting all three morphologies. Two-year TLF tended to be higher in underexpanded versus non-underexpanded stents (9.7% vs. 3.7%, unadjusted hazard ratio [95% confidence interval] = 3.02 [0.92, 9.58], p = 0.06). CONCLUSION: Although underexpansion in the absence of severe calcium (<180°) is uncommon, mid-LAD lesions with NR and large and thick eccentric calcium were associated with underexpansion.

Distinct Challenges of Eruptive and Non-Eruptive Calcified Nodules in Percutaneous Coronary Intervention.

PURPOSE OF REVIEW: To provide a summary of prevalence, pathogenesis, and treatment of coronary calcified nodules (CNs). RECENT FINDINGS: CNs are most frequently detected at the sites of hinge motion of severely calcified lesions such as in the middle segment of right coronary artery and left main coronary bifurcation. On histopathology, CNs exhibit two distinctive morphologies: eruptive and non-eruptive. Eruptive CNs, which have a disrupted fibrous cap with adherent thrombi, are biologically active. Non-eruptive CNs, which have an intact fibrous cap without thrombi, are biologically inactive, representing either healed eruptive CNs or protrusion of calcium due to plaque progression. Recent studies using optical coherence tomography (OCT) have shown a difference in the mechanism of stent failure in the two subtypes, demonstrating early reappearance of eruptive CNs in the stent (at ~ 6 months) as a unique mechanism of stent failure that does not seem to be preventable by simply achieving adequate stent expansion. The cause of CN reappearance in stent is not known and could be due to acute or subacute intrusion or continued growth of the CN. Whether modification of CN is needed, the most effective calcium modification modality and effectiveness of stent implantation in eruptive CNs has not been elucidated. In this review, we discuss pathogenesis of CNs and how intravascular imaging can help diagnose and manage patients with CNs. We also discuss medical and transcatheter therapies beyond conventional stent implantation for effective treatment of eruptive CNs that warrant testing in prospective studies.

Peripheral atherosclerosis in acute coronary syndrome patients with plaque rupture vs plaque erosion: A prospective coronary optical coherence tomography and peripheral ultrasound study.

BACKGROUND: Plaque rupture (PR) and plaque erosion (PE) are 2 distinct, different, and most common culprit lesion morphologies responsible for acute coronary syndrome (ACS). However, the prevalence, distribution, and characteristics of peripheral atherosclerosis in ACS patients with PR vs PE has never been studied. The aim of this study was to assess peripheral atherosclerosis burden and vulnerability evaluated by vascular ultrasound in ACS patients with coronary PR vs PE identified by optical coherence tomography (OCT). METHODS: Between October 2018 and December 2019, 297 ACS patients who underwent preintervention OCT examination of the culprit coronary artery were enrolled. Peripheral ultrasound examinations of carotid, femoral, and popliteal arteries were performed before discharge. RESULTS: Overall, 265 of 297 (89.2%) patients had at least one atherosclerotic plaque in a peripheral arterial bed. Compared with coronary PE, patients with coronary PR had a higher prevalence of peripheral atherosclerotic plaques (93.4% vs 79.1%, P < .001), regardless of location: carotid, femoral, or popliteal arteries. The number of peripheral plaques per patient was significantly larger in the coronary PR group than coronary PE (4 [2-7] vs 2 [1-5], P < .001). Additionally, there was a greater prevalence of peripheral vulnerable characteristics including plaque surface irregularity, heterogeneous plaque, and calcification in patients with coronary PR vs PE. CONCLUSIONS: Peripheral atherosclerosis exists commonly in patients presenting with ACS. Patients with coronary PR had greater peripheral atherosclerosis burden and more peripheral vulnerability compared to those with coronary PE, suggesting that comprehensive evaluation of peripheral atherosclerosis and multidisciplinary cooperative management maybe necessary, especially in patients with PR. TRIAL REGISTRATION: clinicaltrials.gov (NCT03971864).

Fractional flow reserve versus intravascular imaging to guide decision-making for percutaneous coronary intervention in intermediate lesions: A meta-analysis.

BACKGROUND: Both fractional flow reserve (FFR) and intravascular imaging (IVI) have been used to guide the decision-making for percutaneous coronary intervention (PCI) in intermediate coronary stenosis. Nevertheless, studies that directly compared the prognostic significance of these two strategies are scarce. AIMS: The aim of this meta-analyses was to evaluate the impact of FFR versus IVI to guide the decision-making in PCI for intermediate stenosis on clinical outcomes. METHODS: We systematically searched PubMed, Embase, Cochrane, and relevant database from inception date to September 2022 for observational studies and randomized clinical trials (RCTs) which compared FFR and IVI-based decision-making in PCI for intermediate stenosis. The primary outcome was a composite of major adverse cardiac event (MACE). Pooled risk ratios (RR) were calculated using random effects models and heterogeneity were evaluated with the I2 statistic. RESULTS: We identified 5 studies (3 RCTs and 2 observational studies) with 3208 patients. The follow-up duration ranged from 12 to 24 months. Among five studies, four compared FFR with intravascular ultrasound while one compared FFR with optical coherence tomography. There was no statistically difference between FFR and IVI in the incidence of MACE (RR: 1.19; 95% confidence interval: 0.85-1.68; p = 0.31) and its individual components. These results were consistent regardless of various cut-off value of PCI across the studies. Compared with IVI, FFR was associated with a lower PCI rate (37.0% vs. 60.3%; p < 0.001). CONCLUSIONS: The decision to perform PCI for intermediate stenosis guided by FFR or IVI showed a similar clinical outcome. The use of FFR significantly reduced the need for PCI.

Intracoronary imaging guided percutaneous coronary intervention outcomes among individuals with cardiogenic shock.

BACKGROUND: Limited data exist around the utility of intracoronary imaging (ICI) during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS) and cardiogenic shock (CS), who are inherently at a high risk of stent thrombosis (ST). METHODS: All PCI procedures for ACS patients with CS in England and Wales between 2014 and 2020 were retrospectively analysed, stratified into two groups: ICI and angiography-guided groups. Multivariable logistic regression analyses were performed to examine odds ratios (OR) of in-hospital outcomes, including major adverse cardiovascular and cerebrovascular events (MACCE; composite of all-cause mortality, acute stroke/transient ischaemic attack (TIA), and reinfarction) and major bleeding, in the ICI-guided group compared with angiography-guided PCI. RESULTS: Of 15,738 PCI procedures, 1240(7.9%) were ICI-guided. The rate of ICI use amongst those with CS more than doubled from 2014 (5.7%) to 2020 (13.3%). The ICI-guided group were predominantly younger, males, with a higher proportion of non-ST-elevation ACS and ST. MACCE was significantly lower in the ICI-guided group compared with the angiography-guided group (crude: 29.8% vs. 38.2%, adjusted odds ratio (OR) 0.65 95% confidence interval [CI] 0.56-0.76), driven by lower all-cause mortality (28.6% vs. 37.0%, OR 0.65 95% CI 0.55-0.75). There were no differences in other secondary outcomes between groups. CONCLUSION: ICI use among CS patients has more than doubled over 6 years but remains significantly under-utilized, with less than 1-in-6 patients in receipt of ICI-guided PCI by 2020. ICI-guided PCI is associated with prognostic benefits in CS patients and should be more frequently utilized to increase their long-term survival.

Utility of optical coherence tomography in acute coronary syndromes.

Studies utilizing intravascular imaging have replicated the findings of histopathological studies, identifying the most common substrates for acute coronary syndromes (ACS) as plaque rupture, erosion, and calcified nodule, with spontaneous coronary artery dissection, coronary artery spasm, and coronary embolism constituting the less common etiologies. The purpose of this review is to summarize the data from clinical studies that have used high-resolution intravascular optical coherence tomography (OCT) to assess culprit plaque morphology in ACS. In addition, we discuss the utility of intravascular OCT for effective treatment of patients presenting with ACS, including the possibility of culprit lesion-based treatment by percutaneous coronary intervention.

Neo-Commissural Alignment by Withdrawing and Readvancing the Delivery System during Transcatheter Aortic Valve Replacement with Self-Expanding Prosthesis.

Objective: To investigate the feasibility of obtaining neo-commissural alignment by withdrawing and readvancing the delivery system during transcatheter aortic valve replacement (TAVR) with self-expanding prosthesis. Methods: TAVR was performed in five patients with severe aortic valve stenosis by the femoral approach. The delivery catheter was withdrawn and readvanced with the opposite orientation when the Venus-A plus transcatheter heart valve (THV) centre marker was found to be overlapped with or close to the left marker at the aortic annulus level on the fluoroscopic image at the projection of the right and left coronary cusps superimposing. Neo-commissural alignment was evaluated by comparing the aortic computed tomography before TAVR with it after TAVR. Results: The THV centre marker was overlapped with or close to the right marker at the aortic annulus level on the fluoroscopic image at the projection of the right and left coronary cusps superimposed in all the present five patients after withdrawing and readvancing the delivery system. The commissural angle deviation before vs. post TAVR was 12.3° ± 7.0°. Three of five patients had neo-commissural alignment. Two of the five patients had mild neo-commissural misalignment. Conclusions: It is possible to obtain the neo-commissural alignment by controlling delivery catheter insertion orientation using the markers on the inflow of the Venus-A plus valve.

Identification of vulnerable plaques and patients by intracoronary near-infrared spectroscopy and ultrasound (PROSPECT II): a prospective natural history study.

BACKGROUND: Near-infrared spectroscopy (NIRS) and intravascular ultrasound are promising imaging modalities to identify non-obstructive plaques likely to cause coronary-related events. We aimed to assess whether combined NIRS and intravascular ultrasound can identify high-risk plaques and patients that are at risk for future major adverse cardiac events (MACEs). METHODS: PROSPECT II is an investigator-sponsored, multicentre, prospective natural history study done at 14 university hospitals and two community hospitals in Denmark, Norway, and Sweden. We recruited patients of any age with recent (within past 4 weeks) myocardial infarction. After treatment of all flow-limiting coronary lesions, three-vessel imaging was done with a combined NIRS and intravascular ultrasound catheter. Untreated lesions (also known as non-culprit lesions) were identified by intravascular ultrasound and their lipid content was assessed by NIRS. The primary outcome was the covariate-adjusted rate of MACEs (the composite of cardiac death, myocardial infarction, unstable angina, or progressive angina) arising from untreated non-culprit lesions during follow-up. The relations between plaques with high lipid content, large plaque burden, and small lumen areas and patient-level and lesion-level events were determined. This trial is registered with ClinicalTrials.gov, NCT02171065. FINDINGS: Between June 10, 2014, and Dec 20, 2017, 3629 non-culprit lesions were characterised in 898 patients (153 [17%] women, 745 [83%] men; median age 63 [IQR 55-70] years). Median follow-up was 3·7 (IQR 3·0-4·4) years. Adverse events within 4 years occurred in 112 (13·2%, 95% CI 11·0-15·6) of 898 patients, with 66 (8·0%, 95% CI 6·2-10·0) arising from 78 untreated non-culprit lesions (mean baseline angiographic diameter stenosis 46·9% [SD 15·9]). Highly lipidic lesions (851 [24%] of 3500 lesions, present in 520 [59%] of 884 patients) were an independent predictor of patient-level non-culprit lesion-related MACEs (adjusted odds ratio 2·27, 95% CI 1·25-4·13) and non-culprit lesion-specific MACEs (7·83, 4·12-14·89). Large plaque burden (787 [22%] of 3629 lesions, present in 530 [59%] of 898 patients) was also an independent predictor of non-culprit lesion-related MACEs. Lesions with both large plaque burden by intravascular ultrasound and large lipid-rich cores by NIRS had a 4-year non-culprit lesion-related MACE rate of 7·0% (95% CI 4·0-10·0). Patients in whom one or more such lesions were identified had a 4-year non-culprit lesion-related MACE rate of 13·2% (95% CI 9·4-17·6). INTERPRETATION: Combined NIRS and intravascular ultrasound detects angiographically non-obstructive lesions with a high lipid content and large plaque burden that are at increased risk for future adverse cardiac outcomes. FUNDING: Abbott Vascular, Infraredx, and The Medicines Company.

When coronary imaging and physiology are discordant, how best to manage coronary lesions? An appraisal of the clinical evidence.

BACKGROUND: Discordant physiology and anatomy may occur when nonsevere angiographic stenosis has positive physiology as well as the opposite situation. AIM: To underline the reasons behind the discrepancy in physiology and anatomy and to summarize the information that coronary imaging may add to physiology. METHODS: A review of the published literature on physiology and intravascular imaging assessment of intermediate lesions was carried out. RESULTS: The limitations of angiography, the possibility of an underlying diffuse disease, the presence of a "grey zone" in both techniques, the amount of myocardial mass that subtends the stenosis, and plaque vulnerability may play a role in such discrepancy. Intracoronary imaging has a poor diagnostic accuracy compared to physiology. However, it may add information about plaque vulnerability that might be useful in deciding whether to treat or not a certain lesion. CONCLUSIONS: Coronary revascularization is recommended for patients with ischemia based on physiology. Intracoronary imaging adds information on plaque vulnerability and can help on the decision whether to revascularize or not a lesion.

Reasons for lesion uncrossability as assessed by intravascular ultrasound.

OBJECTIVES: The purpose of the current study was to use intravascular ultrasound (IVUS) to clarify anatomical and morphological lesion characteristics of uncrossable lesions. BACKGROUND: Uncrossable lesions are not always severely calcified. The prevalence of uncrossable lesions that are nonseverely calcified as well as other mechanisms for uncrossability has not been well clarified. METHODS: A total of 252 de novo uncrossable lesions in native coronary arteries that underwent either rotational or orbital atherectomy due to inability of any balloon to cross the lesion and 38 lesions with severe calcium in which IVUS crossed preatherectomy were included. Severe calcium is defined as maximum arc of calcium ≥270°. RESULTS: Severe calcification was absent in 16% of uncrossable lesions, 83% of which had a significant vessel bend. Compared with crossable lesions with severe calcium, uncrossable lesions with severe calcium more often had a bend in the vessel (71% vs. 21%, p < 0.001) and a longer length of continuous severe calcium (median length of calcium ≥270° 3.8 mm vs. 1.9 mm, p = 0.001). Other than severe calcium (especially long continuous calcium) or a bend in the vessel, anatomical factors associated with uncrossabilty were aorto-ostial lesion location and small vessels. CONCLUSIONS: Uncrossable lesions are not always severely calcified. The interaction of lesion morphology (continuous long and large arcs of calcium) and vessel geometry (bend in the vessel or ostial lesion location) affect lesion crossability.

Correction: A prediction tool for plaque progression based on patient-specific multi-physical modeling.

[This corrects the article DOI: 10.1371/journal.pcbi.1008344.].

A prediction tool for plaque progression based on patient-specific multi-physical modeling.

Atherosclerotic plaque rupture is responsible for a majority of acute vascular syndromes and this study aims to develop a prediction tool for plaque progression and rupture. Based on the follow-up coronary intravascular ultrasound imaging data, we performed patient-specific multi-physical modeling study on four patients to obtain the evolutional processes of the microenvironment during plaque progression. Four main pathophysiological processes, i.e., lipid deposition, inflammatory response, migration and proliferation of smooth muscle cells (SMCs), and neovascularization were coupled based on the interactions demonstrated by experimental and clinical observations. A scoring table integrating the dynamic microenvironmental indicators with the classical risk index was proposed to differentiate their progression to stable and unstable plaques. The heterogeneity of plaque microenvironment for each patient was demonstrated by the growth curves of the main microenvironmental factors. The possible plaque developments were predicted by incorporating the systematic index with microenvironmental indicators. Five microenvironmental factors (LDL, ox-LDL, MCP-1, SMC, and foam cell) showed significant differences between stable and unstable group (p < 0.01). The inflammatory microenvironments (monocyte and macrophage) had negative correlations with the necrotic core (NC) expansion in the stable group, while very strong positive correlations in unstable group. The inflammatory microenvironment is strongly correlated to the NC expansion in unstable plaques, suggesting that the inflammatory factors may play an important role in the formation of a vulnerable plaque. This prediction tool will improve our understanding of the mechanism of plaque progression and provide a new strategy for early detection and prediction of high-risk plaques.

Determination of Optimal Fluoroscopic Angulations for Left Main Coronary Artery Ostial Interventions: 3-Dimensional Computed Tomography Validation.

Background: Current recommendations for the best views for the left main coronary artery (LMCA) ostium intervention are empirical. Objectives: To determine the optimal projection to visualize the LMCA ostium using only fluoroscopy. Methods: The optimal projection to visualize the LMCA ostium was determined using fluoroscopic images of superimposing the lowest points of the distal ends of two J tipped wires in the noncoronary cusp (NCC) and right coronary cusp (RCC). This was validated independently using 3-dimensional computed tomography (3D-CT) reconstruction. Results: Satisfactory images of the overlapping wires in NCC and RCC could be obtained in 90% (45/50). Between the fluoroscopic and the 3D-CT reconstruction approaches, the mean difference for NCC and RCC overlapping at horizontal axes is -1.8 with a 95% limit of agreement between -3.94 and 0.34 (p=0.10) and at vertical axes -1.6 with a 95% limit of agreement between -3.46 and 0.26 (p=0.09); and the mean difference for the optimal projection to visualize the LMCA ostium at horizontal axes is -3.22 with a 95% limit of agreement between -7.26 and 0.81 (p=0.11) and at vertical axes -2.31 with a 95% limit of agreement between -5.83 and 1.21 (p=0.09). The 3D angulation deviation for the optimal projection to visualize the LMCA ostium was 8.5° ± 4.7° when the LMCA ostium faced the NCC-RCC commissure (n = 32) and 22.3° ± 16.0° (p=0.009) when it did not (n = 13). Conclusions: The optimal projection for LMCA ostial intervention can be determined using fluoroscopic images of superimposing wires in the NCC and RCC when the LMCA ostium faces the NCC-RCC commissure, as was the case in 71% of the patients studied.

Impact of nodular calcification in patients with acute coronary syndrome (ACS) treated with primary percutaneous coronary intervention (PCI).

BACKGROUND: Calcified plaque is thought to adversely impact outcomes after percutaneous coronary intervention (PCI). This study sought to evaluate the impact of nodular calcification in patients with acute coronary syndrome treated with primary percutaneous coronary intervention. METHODS: Using optical coherence tomography (OCT), 500 culprit plaques with calcification were analyzed from 495 acute coronary syndrome (ACS) patients on whom PCI was performed. Based on morphology, we classified calcification into two subtypes: nodular calcification and non-nodular calcification. Nodular calcification was defined as protruding mass with an irregular surface, high backscattering, and signal attenuation while non-nodular calcification was defined as an area with low backscattering heterogeneous region with a well-delineated border without protrusion into the lumen on OCT. RESULTS: Calcified culprit plaques were divided into nodular calcification group (n = 238) and non-nodular calcification group (n = 262). Patients with nodular calcification were older (p < 0.001) and had lower left ventricular ejection fraction (p = 0.006) compared to patients with non-nodular calcification. Minimum stent area (5.0 (3.9, 6.3) mm2 vs. 5.4 (4.2, 6.7) mm2, p = 0.011) and stent expansion (70 (62.7, 81.8) % vs. 75 (65.2, 86.6) %, p = 0.004) were significantly smaller in the nodular calcification group than in the non-nodular calcification group. Stent under-expansion was most frequent (p = 0.003) in the nodular calcification group. CONCLUSION: This study demonstrate that the presence of nodular calcification is associated with a smaller minimum stent area and a higher incidence of stent under-expansion. Lesions with nodular calcification may be at risk of stent under-expansion.

Safety and efficacy of low-dose ticagrelor in Chinese patients with acute coronary syndrome undergoing percutaneous coronary intervention.

It remains unclear whether low-dose ticagrelor offers better safety and similar efficacy for Asian patients with acute coronary syndromes (ACS). We aimed to compare the safety and effectiveness of low-dose ticagrelor vs standard-dose ticagrelor in Chinese patients with ACS undergoing percutaneous coronary intervention (PCI). In this observational cohort study, a total of 2110 ACS patients who were event-free at 3 months after the index PCI were divided into standard-dose ticagrelor (90 mg twice daily) (n = 1830) or low-dose ticagrelor (45 mg twice daily) (n = 280) on a background of aspirin 100 mg once daily for at least another 9 months. The primary end point was type 2, 3, or 5 bleeding according to the Bleeding Academic Research Consortium (BARC) criteria over a 1-year follow-up period post-PCI. Predictors of the primary end point were identified. Both Cox regression and propensity score matching analyses were used. The cumulative incidence of BARC type 2, 3, or 5 bleeding was lower in the low-dose ticagrelor group vs the standard-dose group either before (adjusted HR 0.24; 95% CI 0.07-0.77; p = .016) or after matching (HR 0.25; 95% CI 0.08-0.85; p = .026). A composite of cardiac death, myocardial infarction, or stroke was not significantly different between the two groups (0.4% vs 0.9%, respectively). By multivariate analysis, only low-dose ticagrelor was a protected predictor of BARC type 2, 3, or 5 bleeding either before (HR 0.28, 95% CI 0.09-0.89) or after matching (HR 0.24, 95% CI 0.07-0.82). A low-dose regimen of ticagrelor might provide better safety than standard-dose ticagrelor in Chinese patients with ACS undergoing PCI.