Coronary artery spatial distribution of acute myocardial infarction occlusions

Patient-Specific Numerical Simulations of Coronary Artery Hemodynamics and Biomechanics: A Pathway to Clinical Use

PURPOSE

Numerical models that simulate the behaviors of the coronary arteries have been greatly improved by the addition of fluid-structure interaction (FSI) methods. Although computationally demanding, FSI models account for the movement of the arterial wall and more adequately describe the biomechanical conditions at and within the arterial wall. This offers greater physiological relevance over Computational Fluid Dynamics (CFD) models, which assume the walls do not move or deform. Numerical simulations of patient-specific cases have been greatly bolstered by the use of imaging modalities such as Computed Tomography Angiography (CTA), Magnetic Resonance Imaging (MRI), Optical Coherence Tomography (OCT), and Intravascular Ultrasound (IVUS) to reconstruct accurate 2D and 3D representations of artery geometries. The goal of this study was to conduct a comprehensive review on CFD and FSI models on coronary arteries, and evaluate their translational potential.

METHODS

This paper reviewed recent work on patient-specific numerical simulations of coronary arteries that describe the biomechanical conditions associated with atherosclerosis using CFD and FSI models. Imaging modality for geometry collection and clinical applications were also discussed.

RESULTS

Numerical models using CFD and FSI approaches are commonly used to study biomechanics within the vasculature. At high temporal and spatial resolution (compared to most cardiac imaging modalities), these numerical models can generate large amount of biomechanics data.

CONCLUSIONS

Physiologically relevant FSI models can more accurately describe atherosclerosis pathogenesis, and help to translate biomechanical assessment to clinical evaluation.

Variations and Associated Factors in Symptom-to-Balloon (STB) Time and Door-to-Balloon (DTB) Time Before and After the COVID-19 Lockdown: A Hospital-Based Cross-Sectional Study

INTRODUCTION

During the COVID-19 lockdown, India saw a major restriction in the movement of people. Patients with acute myocardial infarction (MI) required early interventions and follow-up of independent predictors like symptom-to-balloon (STB) time and door-to-balloon (DTB) time. This study aimed to determine changes in STB and DTB time before and after the COVID-19 lockdown and its associated risk factors.

METHODS

A hospital-based cross-sectional study of 105 patients admitted to the cardiac care units (CCU) of two tertiary care centers in a district of Southern India for six months was conducted to compare the changes in STB and DTB time before and after the COVID-19 lockdown (three months before March 2020 and three months after March 2020), and data was collected from medical records. The data collected was then entered into Microsoft Excel (Microsoft Corporation, Washington, USA), numerically coded, and analyzed using SPSS Statistics version 21 (IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp.). The Chi-square and Mann-Whitney U tests assessed the association between the dependent and independent variables. The STB/DTB time (before and after the COVID-19 lockdown) was the dependent variable, while the age, gender, co-morbidities, smoking status, and date of admission of patients (before and after the COVID-19 lockdown) were taken as the independent variables. A p-value of <0.05 was considered statistically significant. The predictor variables were identified using the regression method, where all variables with a significance of <0.2 were taken.

RESULTS

The overall mean (±SD) STB time was 408.7 (±307.1) minutes, and the mean (±SD) DTB time was 161.7 (±261.6) minutes. The pre-lockdown mean STB time was 404.6 minutes, and the mean DTB time was 153 minutes, whereas the post-lockdown mean STB and DTB time were higher at 413.3 minutes and 171.6 minutes, respectively. Out of the total 105 patients, 95 (90.5%) had an STB time of ≥120 minutes, and 77 (73.3%) had an ideal DTB time of <90 minutes. There was no statistically significant variation in the STB and DTB time before and after the lockdown. Only the age group >60 years (38 (97.4%)) was found to be statistically significant with an STB time of ≥120 minutes after the lockdown (p-value=0.040), and patients referred from primary and secondary care centers (AOR (95% CI)=4.669 (1.129-19.298)) were found to be an independent factor in reducing DTB time before and after the COVID-19 lockdown.

CONCLUSION

The efficiency of the health system, irrespective of the COVID-19 lockdown, was observed; nevertheless, a delay in the overall recognition of symptoms of MI was perceived. The importance of time factors in identifying the symptoms of non-communicable diseases (NCDs), especially MI and stroke, has to be ascertained among the general population.

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).

Prognostic value of coronary CTA-based classifications for predicting major events without obstructive coronary artery disease

We aim to explore the classifications based on coronary computed tomography angiography (CTA) for predicting the risk of major adverse cardiovascular events (MACE) in patients with suspected non-obstructive coronary artery disease (CAD) and compare with traditional non-obstructive CAD (NOCAD) classification, Duke prognostic NOCAD index, Non-obstructive coronary artery disease reporting and data system (NOCAD-RADS). 4378 consecutive non-obstructive CAD patients were assessed by coronary CTA for traditional NOCAD classification, Duke prognostic NOCAD index, NOCAD-RADS and a new classification (stenosis proximal involvement, SPI) from two medical centrals. We defined proximal involvement as any plaque was present in the main or proximal segments of coronary artery (left main, left anterior descending artery, left circumflex artery, or right coronary artery). The main outcome was MACE. During a median follow-up of 3.7 years, a total of 310 patients experienced MACE event. Kaplan-Meier survival curves showed the cumulative events increased significantly associated with traditional NOCAD, Duke NOCAD index, NOCAD-RADS and SPI classifications (all P < 0.001). In multivariate Cox regressions, the risk for the events increased from HR 1.20 (95% CI 0.78-1.83, P = 0.408) for SPI 1 to 1.35 (95% CI 1.05-1.73, P = 0.019) for SPI 2, using SPI 0 as the reference group. Coronary CTA based SPI classification provided important prognostic information for all cause-mortality risk and MACE prediction in patients with non-obstructive CAD, which was non-inferior than traditional NOCAD, Duke NOCAD Index and NOCAD-RADS classifications. The plaque location information by coronary CTA may provide additional risk prediction in patients with non-obstructive CAD.

New ECG Algorithm for the Prediction of Culprit Vessel in Acute Myocardial Infarction Involving Lateral Part of the Ventricle: Ilkay Classification

Background

Isolated lateral myocardial infarction sometimes does not meet ST-segment elevation myocardial infarction (STEMI) criteria according to contiguous leads. This condition could cause late diagnosis and the need for revascularization therapy.

Aim

To accurately predict the occlusion of lateral surface of the left ventricle, we defined a new electrocardiogram (ECG) algorithm by using angiographic and electrocardiographic correlations.

Methods

This was a retrospective, multicenter observational study. The study population consisted of 200 patients with STEMI affecting lateral surface of myocardium, between 2021 and 2022. According to the coronary angiography results, we identified 74 eligible patients for study protocol. The study patients were divided into two groups: isolated DB (14 patients) or circumflex obtuse marginal group (60 patients).

Results

ST depression in lead V2 had high positive predictive values for the prediction of obtuse marginal occlusion (positive predictive values (PPV), 100%; negative predictive value (NPV), 90%). ST elevation in V2 in ECG, in conjunction with ST depression in lead III had high positive predictive values for prediction of diagonal branch of LAD. Moreover, the presence of hyperacute T wave (≥10 mm) in lead V2 and ≥2 mm ST depression in lead III had large diagonal branch of LAD (PPV, 98%; NPV, 100%). However, <10 mm T wave in lead V2 and <2 mm ST depression in lead III had small diagonal branch of LAD.

Conclusion

We comprehensively classified the lateral STEMI definition through new electrocardiographic scheme as Ilkay classification, whereby we could accurately predict infarct-related artery and its occlusion level in lateral myocardial infarction.

Characteristics of conventional high-risk coronary plaques and a novel CT defined thin-cap fibroatheroma in patients undergoing CCTA with stable chest pain

BACKGROUND

Coronary computed tomography angiography (CCTA) can identify high-risk coronary plaque types. However, the inter-observer variability for high-risk plaque features, including low attenuation plaque (LAP), positive remodelling (PR), and the Napkin-Ring sign (NRS), may reduce their utility, especially amongst less experienced readers.

METHODOLOGY

In a prospective study, we compared the prevalence, location and inter-observer variability of both conventional CT-defined high-risk plaques with a novel index based on quantifying the ratio of necrotic core to fibrous plaque using individualised X-ray attenuation cut-offs (the CT-defined thin-cap fibroatheroma - CT-TCFA) in 100 patients followed-up for 7 years.

RESULTS

In total, 346 plaques were identified in all patients. Seventy-two (21%) of all plaques were classified by conventional CT parameters as high-risk (either NRS or PR and LAP combined), and 43 (12%) of plaques were considered high-risk using the novel CT-TCFA definition of (Necrotic Core/fibrous plaque ratio of >0.9). The majority (80%) of the high-risk plaques (LAP&PR, NRS and CT-TCFA) were located in the proximal and mid-LAD and RCA. The kappa co-efficient of inter-observer variability (k) for NRS was 0.4 and for PR and LAP combined 0.4. While the kappa co-efficient of inter-observer variability (k) for the new CT-TCFA definition was 0.7. During follow-up, patients with either conventional high-risk plaques or CT-TCFAs were significantly more likely to have MACE (Major adverse cardiovascular events) compared to patients without coronary plaques (p value 0.03 & 0.03, respectively).

CONCLUSION

The novel CT-TCFA is associated with MACE and has improved inter-observer variability compared with current CT-defined high-risk plaques.

Hepatic fat as a novel marker for high-risk coronary atherosclerotic plaque features in familial hypercholesterolaemia

BACKGROUND & AIMS

Hepatic steatosis has been associated with increased risk of coronary artery disease. Individuals with familial hypercholesterolaemia have accelerated but variable progression of coronary artery disease. We investigated whether hepatic steatosis is associated with novel coronary atherosclerosis biomarkers in adults with heterozygous familial hypercholesterolaemia, using comprehensive coronary computed tomographic angiography.

METHODS

We conducted a cross-sectional study of 213 asymptomatic patients with familial hypercholesterolaemia (median age 54.0 years, 59 % female) who underwent coronary computed tomographic angiography for cardiovascular risk assessment in an outpatient clinic. High-risk plaque features, plaque volume and pericoronary adipose tissue attenuation were assessed. From concurrently captured upper abdominal images, severity of hepatic steatosis was computed, as liver minus spleen computed tomography attenuation and stratified into quartiles.

RESULTS

Of 213 familial hypercholesterolaemia patients, 59 % had coronary artery calcium, 36 % obstructive coronary artery disease (≥50 % stenosis) and 77 % high-risk plaque features. Increasing hepatic steatosis was associated with higher calcium scores, more high-risk plaque features and presence of obstructive coronary artery disease. Hepatic steatosis was associated with the presence of high-risk plaque features (OR: 1.48; 95 % CI: 1.09-2.00; p = 0.01), particularly in the proximal coronary segments (OR: 1.52; 95 % CI: 1.18-1.96; p = 0.001). Associations persisted on multivariable logistic regression analysis adjusting for cardiometabolic factors, obstructive coronary artery disease and calcium score. Hepatic steatosis was associated with higher plaque volumes (Q4: 499 mm³ vs Q1: 414 mm³, p = 0.02), involving mainly low attenuation and noncalcified plaques (both p = 0.03). No differences in pericoronary adipose tissue attenuation were observed.

CONCLUSIONS

Hepatic steatosis is associated with multiple indices of advanced coronary atherosclerosis in familial hypercholesterolaemia patients, particularly high-risk plaque features, independent of conventional cardiovascular risk factors and markers. This may involve specific mechanisms related to hepatic steatosis.

CLINICAL TRIAL NUMBER

N/A.

Impact of diabetes mellitus on long-term clinical and graft outcomes after off-pump coronary artery bypass grafting with pure bilateral skeletonized internal thoracic artery grafts

BACKGROUND

The effect of diabetes mellitus (DM) on the long-term outcomes of coronary artery bypass graft (CABG) remained debatable and various strategies exist for CABG; hence, clarifying the effects of DM on CABG outcomes is difficult. The current study aimed to evaluate the effect of DM on clinical and graft-related outcomes after CABG with bilateral internal thoracic artery (BITA) grafts.

METHODS

From January 2001 to December 2017, 3395 patients who underwent off-pump CABG (OPCAB) with BITA grafts were enrolled. The study population was stratified according to preoperative DM. The primary endpoint was cardiac death and the secondary endpoints were myocardial infarction (MI), revascularization, graft failure, stroke, postoperative wound infection, and a composite endpoint of cardiac death, MI, and revascularization. Multiple sensitivity analyses, including Cox proportional hazard regression and propensity-score matching analyses, were performed to adjust baseline differences.

RESULTS

After CABG, the DM group showed similar rates of cardiac death, MI, or revascularization and lower rates of graft failure at 10 years (DM vs. non-DM, 19.0% vs. 24.3%, hazard ratio [HR] 0.711, 95% confidence interval [CI] 0.549-0.925; P = 0.009) compared to the non-DM group. These findings were consistent after multiple sensitivity analyses. In the subgroup analysis, the well-controlled DM group, which is defined as preoperative hemoglobin A1c (HbA1c) of < 7%, showed lower postoperative wound infection rates (well-controlled DM vs. poorly controlled DM, 3.7% vs. 7.3%, HR 0.411, 95% CI 0.225-0.751; P = 0.004) compared to the poorly controlled DM group, which was consistent after propensity-score matched analysis.

CONCLUSIONS

OPCAB with BITA grafts showed excellent and comparable long-term clinical outcomes in patients with and without DM. DM might have a protective effect on competition and graft failure of ITA. Strict preoperative hyperglycemia control with target HbA1c of < 7% might reduce postoperative wound infection and facilitate the use of BITA in CABG.

Assessment of Papillary Muscle Infarction with Dark-Blood Delayed Enhancement Cardiac MRI in Canines and Humans

Background The relationship between papillary muscle infarction (papMI) and the culprit coronary lesion has not been fully investigated. Delayed enhancement cardiac MRI may detect papMI, yet its accuracy is unknown. Flow-independent dark-blood delayed enhancement (FIDDLE) cardiac MRI has been shown to improve the detection of myocardial infarction adjacent to blood pool. Purpose To assess the diagnostic performance of delayed enhancement and FIDDLE cardiac MRI for the detection of papMI, and to investigate the prevalence of papMI and its relationship to the location of the culprit coronary lesion. Materials and Methods A prospective canine study was used to determine the accuracy of conventional delayed enhancement imaging and FIDDLE imaging for detection of papMI, with pathology-based findings as the reference standard. Participants with first-time myocardial infarction with a clear culprit lesion at coronary angiography were prospectively enrolled at a single hospital from 2015 to 2018 and compared against control participants with low Framingham risk scores. In canines, diagnostic accuracy was calculated for delayed enhancement and FIDDLE imaging. Results In canines (n = 27), FIDDLE imaging was more sensitive (100% [23 of 23] vs 57% [13 of 23], P < .001) and accurate (100% [54 of 54] vs 80% [43 of 54], P = .01) than delayed enhancement imaging for detection of papMI. In 43 participants with myocardial infarction (mean age, 56 years ± 16 [SD]; 28 men), the infarct-related artery was the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX), and right coronary artery in 47% (20 of 43), 26% (11 of 43), and 28% (12 of 43), respectively. The prevalence of anterior papMI was lower than posterior papMI (37% [16 of 43 participants] vs 44% [19 of 43 participants]) despite more LAD culprit lesions. Culprits leading to papMI were restricted to a smaller "at-risk" portion of the coronary tree for anterior papMI (subtended first diagonal branch of the LAD or first marginal branch of the LCX) compared with posterior (subtended posterior descending artery or third obtuse marginal branch of the LCX). Culprits within these at-risk portions were predictive of papMI at a similar rate (anterior, 83% [15 of 18 participants] vs posterior, 86% [18 of 21 participants]). Conclusion Flow-independent dark-blood delayed enhancement cardiac MRI, unlike conventional delayed enhancement cardiac MRI, was highly accurate in the detection of papillary muscle infarction (papMI). Anterior papMI was less prevalent than posterior papMI, most likely due to culprit lesions being restricted to a smaller portion of the coronary tree rather than because of redundant, dual vascular supply. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Kawel-Boehm and Bremerich in this issue.

Topography of immune cell infiltration in different stages of coronary atherosclerosis revealed by multiplex immunohistochemistry

Background

Aim of this study was to investigate immune cells and subsets in different stages of human coronary artery disease with a novel multiplex immunohistochemistry (mIHC) technique.

Methods

Human left anterior descending coronary artery specimens were analyzed: eccentric intimal thickening (N = 11), pathological intimal thickening (N = 10), fibroatheroma (N = 9), and fibrous plaque (N = 9). Eccentric intimal thickening was considered normal, and pathological intimal thickening, fibroatheroma, and fibrous plaque were considered diseased coronary arteries. Two mIHC panels, consisting of six and five primary antibodies, autofluoresence, and DAPI, were used to detect adaptive and innate immune cells. Via semi-automated analysis, (sub)types of immune cells in whole plaques and specific plaque regions were quantified.

Results

Increased numbers of CD3⁺ T cells (P < 0.001), CD20⁺ B cells (P = 0.013), CD68⁺ macrophages (P = 0.003), CD15⁺ neutrophils (P = 0.017), and CD31⁺ endothelial cells (P = 0.024) were identified in intimas of diseased coronary arteries compared to normal. Subset analyses of T cells and macrophages showed that diseased coronary arteries contained an abundance of CD3⁺CD8^- non-cytotoxic T cells and CD68⁺CD206^- non-M2-like macrophages. Proportions of CD3⁺CD45RO⁺ memory T cells were similar to normal coronary arteries. Among pathological intimal thickening, fibroatheroma, and fibrous plaque, all immune cell numbers and subsets were similar.

Conclusions

The type of immune response does not differ substantially between different stages of plaque development and may provide context for mechanistic research into immune cell function in atherosclerosis. We provide the first comprehensive map of immune cell subtypes across plaque types in coronary arteries demonstrating the potential of mIHC for vascular research.

The Effects of Percutaneous Coronary Intervention on the Flow in Acute Coronary Syndrome Patients-Geometry in Focus

Evaluation of the effect of three dimensional (3D) coronary plaque characteristics derived from two dimensional (2D) invasive angiography images (ICA) on coronary flow determined by TIMI frame count (TFC) in acute coronary syndrome (ACS) has not been thoroughly investigated. A total of 71 patients with STEMI, and 73 with NSTEMI were enrolled after primary angioplasty. Pre- and post-PCI TFCs were obtained. From 2D images, 3D reconstruction was performed of the culprit vessel, and multiple plaque parameters were measured. In STEMI, the average post-PCI frame count decreased significantly, resulting in better flow. With regards to 2/3D parameters, no differences were found between the STEMI and NSTEMI groups. The 3D parameters in the subgroup with an increase with at least three frames resulting in worsening post-PCI flow were compared to parameters of the patients with improved or significantly not change flow (delta frame count < 3), and greater minimal luminal diameter and area was found in the worsening (increased) frame group. In STEMI 2/3D, parameters showed no correlation with worsening flow, whereas in NSTEMI, greater minimal luminal diameter and area correlated with decreased flow. We can conclude that certain 2/3D parameters can predict slower flow in ACS, resulting in the use of GP IIb/IIIa receptor blocker.

Association of Plaque Location and Vessel Geometry Determined by Coronary Computed Tomographic Angiography With Future Acute Coronary Syndrome-Causing Culprit Lesions

IMPORTANCE

Distinct plaque locations and vessel geometric features predispose to altered coronary flow hemodynamics. The association between these lesion-level characteristics assessed by coronary computed tomographic angiography (CCTA) and risk of future acute coronary syndrome (ACS) is unknown.

OBJECTIVE

To examine whether CCTA-derived adverse geometric characteristics (AGCs) of coronary lesions describing location and vessel geometry add to plaque morphology and burden for identifying culprit lesion precursors associated with future ACS.

DESIGN, SETTING, AND PARTICIPANTS

This substudy of ICONIC (Incident Coronary Syndromes Identified by Computed Tomography), a multicenter nested case-control cohort study, included patients with ACS and a culprit lesion precursor identified on baseline CCTA (n = 116) and propensity score-matched non-ACS controls (n = 116). Data were collected from July 20, 2012, to April 30, 2017, and analyzed from October 1, 2020, to October 31, 2021.

EXPOSURES

Coronary lesions were evaluated for the following 3 AGCs: (1) distance from the coronary ostium to lesion; (2) location at vessel bifurcations; and (3) vessel tortuosity, defined as the presence of 1 bend of greater than 90° or 3 curves of 45° to 90° using a 3-point angle within the lesion.

MAIN OUTCOMES AND MEASURES

Association between lesion-level AGCs and risk of future ACS-causing culprit lesions.

RESULTS

Of 548 lesions, 116 culprit lesion precursors were identified in 116 patients (80 [69.0%] men; mean [SD], age 62.7 [11.5] years). Compared with nonculprit lesions, culprit lesion precursors had a shorter distance from the ostium (median, 35.1 [IQR, 23.6-48.4] mm vs 44.5 [IQR, 28.2-70.8] mm), more frequently localized to bifurcations (85 [73.3%] vs 168 [38.9%]), and had more tortuous vessel segments (5 [4.3%] vs 6 [1.4%]; all P < .05). In multivariable Cox regression analysis, an increasing number of AGCs was associated with a greater risk of future culprit lesions (hazard ratio [HR] for 1 AGC, 2.90 [95% CI, 1.38-6.08]; P = .005; HR for ≥2 AGCs, 6.84 [95% CI, 3.33-14.04]; P < .001). Adverse geometric characteristics provided incremental discriminatory value for culprit lesion precursors when added to a model containing stenosis severity, adverse morphological plaque characteristics, and quantitative plaque characteristics (area under the curve, 0.766 [95% CI, 0.718-0.814] vs 0.733 [95% CI, 0.685-0.782]). In per-patient comparison, patients with ACS had a higher frequency of lesions with adverse plaque characteristics, AGCs, or both compared with control patients (≥2 adverse plaque characteristics, 70 [60.3%] vs 50 [43.1%]; ≥2 AGCs, 92 [79.3%] vs 60 [51.7%]; ≥2 of both, 37 [31.9%] vs 20 [17.2%]; all P < .05).

CONCLUSIONS AND RELEVANCE

These findings support the concept that CCTA-derived AGCs capturing lesion location and vessel geometry are associated with risk of future ACS-causing culprit lesions. Adverse geometric characteristics may provide additive prognostic information beyond plaque assessment in CCTA.

Vulnerable Plaque in Patients with Acute Coronary Syndrome: Identification, Importance, and Management

MI is a leading cause of morbidity and mortality worldwide. Coronary artery thrombosis is the final pathologic feature of the most cases of acute MI primarily caused by atherosclerotic coronary artery disease. The concept of vulnerable plaque has evolved over the years but originated from early pioneering work unveiling the crucial role of plaque rupture and subsequent coronary thrombosis as the dominant cause of MI. Along with systemic cardiovascular risk factors, developments of intravascular and non-invasive imaging modalities have allowed us to identify coronary plaques thought to be at high risk for rupture. However, morphological features alone may only be one of many factors which promote plaque progression. The current vulnerable-plaque-oriented approaches to accomplish personalized risk assessment and treatment have significant room for improvement. In this review, the authors discuss recent advances in the understanding of vulnerable plaque and its management strategy from pathology and clinical perspectives.

Enxerto de Bypass de Artéria Coronária Guiado por Angiografia ou Fisiologia: Uma Metanálise

Fundamento:

Enquanto a angiografia coronária invasiva é considerada padrão outro para o diagnóstico da doença arterial coronariana (DAC), envolvendo os vasos coronários epicárdicos, a revascularização coronariana guiada por fisiologia representa uma prática padrão ouro contemporânea para a administração invasiva de pacientes com DAC intermediária. Porém, os resultados de longo prazo da avaliação da gravidade da estenose por meio da fisiologia, em comparação à angiografia como guia para a cirurgia de bypass – enxerto de bypass de artéria coronária (CABG), ainda são incertos. Esta metanálise visa avaliar os resultados clínicos de um CABG guiado por fisiologia em comparação a um CABG guiado pela angiografia.

Objetivos:

Buscamos determinar se os resultados entre um CABG guiado por fisiologia e os de um CABG guiado por angiografia são diferentes entre si.

Métodos:

Pesquisamos nas bases Medline, EMBASE e Cochrane Library. A última data de busca foi junho de 2020, e todos os estudos anteriores foram incluídos. Realizamos uma metanálise de razão de risco agrupado para quatro principais resultados: morte por todas as causas, infarto do miocárdio (IM), revascularização do vaso alvo (TVR) e eventos cardiovasculares adversos maiores (MACE). Valor de p <0,05 foi considerado estatisticamente significante. A heterogeneidade foi avaliada com o teste Q de Cochran, e quantificada pelo índice I2.

Resultados:

Identificamos cinco estudos incluindo um total de 1.114 pacientes. Uma metanálise agrupada não demonstrou diferenças significativas entre a estratégia da fisiologia e da angiografia para IM (razão de risco [RR] = 0,72; IC95%, 0,39–1,33; I2 = 0%; p = 0,65), TVR (RR = 1,25; IC95% = 0,73–2,13; I2 = 0%; p = 0,52), ou MACE (RR = 0,81; IC95% = 0,62–1,07; I2 = 0%; p = 1). A estratégia da fisiologia apresentou 0,63 vezes o risco de morte por todas as causas em comparação à estratégia da angiografia (RR = 0,63; IC95% = 0,42–0,96; I2 = 0%; p = 0,55).

Conclusão:

Esta metanálise demonstrou uma redução nas mortes por todas as causas quando usada a estratégia do CABG guiado por fisiologia. Porém, o curto período de acompanhamento, o tamanho da amostra pequeno dos estudos incluídos e a não-discriminação das causas de morte podem justificar essas conclusões. Estudos com períodos mais longos de acompanhamento são necessários para tirar conclusões mais robustas e definitivas.

Prognostic significance of plaque location in non-obstructive coronary artery disease: from the CONFIRM registry

AIM

Obstructive coronary artery disease (CAD) in proximal coronary segments is associated with a poor prognosis. However, the relative importance of plaque location regarding the risk for major adverse cardiovascular events (MACE) in patients with non-obstructive CAD has not been well defined.

METHODS AND RESULTS

From the Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter (CONFIRM) registry, 4644 patients without obstructive CAD were included in this study. The degree of stenosis was classified as 0 (no) and 1-49% (non-obstructive). Proximal involvement was defined as any plaque present in the left main or the proximal segment of the left anterior descending artery, left circumflex artery, and right coronary artery. Extensive CAD was defined as segment involvement score of >4. During a median follow-up of 5.2 years (interquartile range 4.1-6.0), 340 (7.3%) MACE occurred. Within the non-obstructive CAD group (n = 2065), proximal involvement was observed in 1767 (85.6%) cases. When compared to non-obstructive CAD patients without proximal involvement, those with proximal involvement had an increased MACE risk (log-rank P = 0.033). Multivariate Cox analysis showed when compared to patients with no CAD, proximal non-obstructive CAD was associated with increased MACE risk [hazard ratio (HR) 1.90, 95% confidence interval (CI) 1.47-2.45, P < 0.001] after adjusting for extensive CAD and conventional cardiovascular risk factors; however, non-proximal non-obstructive CAD did not increase MACE risk (HR 1.26, 95% CI 0.79-2.01, P = 0.339).

CONCLUSIONS

Independent of plaque extent, proximal coronary involvement was associated with increased MACE risk in patients with non-obstructive CAD. The plaque location information by coronary computed tomography angiography may provide additional risk prediction over CAD extent in patients with non-obstructive CAD.

Plaque Character and Progression According to the Location of Coronary Atherosclerotic Plaque

Although acute coronary syndrome culprit lesions occur more frequently in the proximal coronary artery, whether the proximal clustering of high-risk plaque is reflected in earlier-stage atherosclerosis remains unclarified. We evaluated the longitudinal distribution of stable atherosclerotic lesions on coronary computed tomography angiography (CCTA) in 1,478 patients (mean age, 61 years; men, 58%) enrolled from a prospective multinational registry of consecutive patients undergoing serial CCTA. Of 3,202 coronary artery lesions identified, 2,140 left lesions were classified (based on the minimal lumen diameter location) into left main (LM, n = 128), proximal (n = 739), and other (n = 1,273), and 1,062 right lesions were classified into proximal (n = 355) and other (n = 707). Plaque volume (PV) was the highest in proximal lesions (median, 26.1 mm³), followed by LM (20.6 mm³) and other lesions (15.0 mm³, p <0.001), for left lesions, and was lager in proximal (25.8 mm³) than in other lesions (15.2 mm³, p <0.001) for right lesions. On both sides, proximally located lesions tended to have greater necrotic core and fibrofatty components than other lesions (left: LM, 10.6%; proximal, 5.8%; other, 3.4% of the total PV, p <0.001; right: proximal, 8.4%; other 3.1%, p <0.001), with less calcified plaque component (left: LM, 18.3%; proximal, 30.3%; other, 37.7%, p <0.001; right: proximal, 23.3%, other, 36.6%, p <0.001), and tended to progress rapidly (adjusted odds ratios: left: LM, reference; proximal, 0.95, p = 0.803; other, 0.64, p = 0.017; right: proximal, reference; other, 0.52, p <0.001). Proximally located plaques were larger, with more risky composition, and progressed more rapidly.

Age and Phenotype of Patients With Plaque Erosion

Background

A recent study reported that the outcome of patients with plaque erosion treated with stenting is poor when the underlying plaque is lipid rich. However, the detailed phenotype of patients with plaque erosion, particularly as related to different age groups, has not been systematically studied.

Methods and Results

Patients with acute coronary syndromes caused by plaque erosion were selected from 2 data sets. Demographic, clinical, angiographic, and optical coherence tomography findings of the culprit lesion were compared between 5 age groups. Among 579 erosion patients, male sex and current smoking were less frequent, and hypertension, diabetes, and chronic kidney disease were more frequent in older patients. ST‐segment–elevation myocardial infarction was more frequent in younger patients. Percentage of diameter stenosis on angiogram was greater in older patients. The prevalence of lipid‐rich plaque (27.3% in age <45 years and 49.4% in age ≥75 years, P<0.001), cholesterol crystal (3.9% in age <45 years and 21.8% in age ≥75 years, P=0.027), and calcification (5.5% in age <45 years and 54.0% in age ≥75 years, P<0.001) increased with age. After adjusting risk factors, younger patients were associated with the presence of thrombus, and older patients were associated with greater percentage of diameter stenosis and the presence of lipid‐rich plaque and calcification.

Conclusions

The demographic, clinical, angiographic, and plaque phenotypes of patients with plaque erosion distinctly vary depending on age. This may affect the clinical outcome in these patients.

Registration

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT03479723, NCT02041650.

Focal Geometry and Characteristics of Erosion-Prone Coronary Plaques in vivo Angiography and Optical Coherence Tomography Study

Objective: This study compared focal geometry and characteristics of culprit plaque erosion (PE) vs. non-culprit plaques in ST-segment elevated myocardial infarction (STEMI) patients in whom optical coherence tomography (OCT) identified PE as the cause of the acute event.

Background: Culprit PE is a distinct clinical entity with specific coronary risk factors and its own tailored management strategy. However, not all plaques develop erosion resulting in occlusive thrombus formation.

Methods: Between January 2017 and July 2019, there were 484 STEMI patients in whom OCT at the time of primary percutaneous intervention identified culprit lesion PE to be the cause of the event; 484 culprit PE were compared to 1,132 non-culprit plaques within 1,196 imaged vessels.

Results: Culprit PE were highly populated at “hot spots” within the proximal 40 mm in the left anterior descending artery (LAD) and tended to cluster proximal to a nearby bifurcation mainly in the LAD. Minimal lumen area (MLA) <2.51 mm² and AS (area stenosis) >64.02% discriminated culprit PE from non-culprit plaques. In the multivariable analysis, focal geometry (LAD location, distance from coronary ostium <40 mm, and location proximal to a nearby bifurcation), luminal narrowing (MLA <2.51 mm², AS > 64.02%), and TCFA phenotype were independent predictors of culprit PE overall. Cholesterol crystals were predictive of culprit PE with underlying LRP morphology while the absence of calcification and microchannels were risk factors for culprit PE with an underlying non-LRP. Similarities and differences in predictors of culprit PE were found between males and females; distance from coronary ostium <40 mm, MLA <2.51 mm², TCFA, and less spotty calcium were risk factors of culprit PE in males, but not in females while smaller RVD was associated with culprit PE only in females.

Conclusions: Irrespective of underlying lesion substrates and patient risk factors, there are lesion-specific and OCT-identifiable predictors of developing culprit PE in erosion-prone vulnerable patients.

Using Restricted Cubic Splines to Study the Trajectory of Systolic Blood Pressure in the Prognosis of Acute Myocardial Infarction

Background: Acute myocardial infarction (AMI) is still the most serious manifestation of coronary artery disease. Systolic blood pressure (SBP) is the best predictor of blood pressure in AMI. Thus, its influence on AMI is necessary to be explored. Methods: A total of 4,277 patients with AMI were extracted from the Medical Information Mart for Intensive Care database. Chi-square test or Student's t-test was used to judge differences between groups, and Cox regression was used to identify factors that affect AMI prognosis. SBP was classified as low (<90 mmHg), normal (90-140 mmHg), or high (>140 mmHg), and a non-linear test was performed. Meaningful variables were incorporated into models for sensitivity analysis. Patient age was classified as low and high for subgroup analysis, and the cutoff value of the trajectory was identified. P < 0.05 indicates statistical significance. Results: The effect of SBP on the prognosis of patients with AMI is non-linear. The risks in models 1-3 with low SBP are 6.717, 4.910, and 3.080 times those of the models with normal SBP, respectively. The risks in models 1-3 with high SBP are 1.483, 1.637, and 2.937 times those of the models with normal SBP, respectively. The cutoff point (95% confidence interval) of the trajectory is 114.489 mmHg (111.275-117.702 mmHg, all P < 0.001). Conclusions: SBP has a non-linear effect on AMI prognosis. Low and high SBP show risks, and the risk of low SBP is obviously greater than that of high SBP.

Systemic Vulnerability, as Expressed by I-CAM and MMP-9 at Presentation, Predicts One Year Outcomes in Patients with Acute Myocardial Infarction-Insights from the VIP Clinical Study

(1) Background: The prediction of recurrent events after acute myocardial infarction (AMI) does not sufficiently integrate systemic inflammation, coronary morphology or ventricular function in prediction algorithms. We aimed to evaluate the accuracy of inflammatory biomarkers, in association with angiographical and echocardiographic parameters, in predicting 1-year MACE after revascularized AMI. (2) Methods: This is an extension of a biomarker sub-study of the VIP trial (NCT03606330), in which 225 AMI patients underwent analysis of systemic vulnerability and were followed for 1 year. Hs-CRP, MMP-9, IL-6, I-CAM, V-CAM and E-selectin were determined at 1 h after revascularization. The primary end-point was the 1-year MACE rate. (3) Results: The MACE rate was 24.8% (n = 56). There were no significant differences between groups in regard to IL-6, V-CAM and E-selectin. The following inflammatory markers were significantly higher in MACE patients: hs-CRP (11.1 ± 13.8 vs. 5.1 ± 4.4 mg/L, p = 0.03), I-CAM (452 ± 283 vs. 220.5 ± 104.6, p = 0.0003) and MMP-9 (2255 ± 1226 vs. 1099 ± 706.1 ng/mL p = 0.0001). The most powerful predictor for MACE was MMP-9 of >1155 ng/mL (AUC-0.786, p < 0.001) even after adjustments for diabetes, LVEF, acute phase complications and other inflammatory biomarkers. For STEMI, the most powerful predictors for MACE included I-CAM > 239.7 ng/mL, V-CAM > 877.9 ng/mL and MMP-9 > 1393 ng/mL. (4) Conclusions: High levels of I-CAM and MMP-9 were the most powerful predictors for recurrent events after AMI for the overall study population. For STEMI subjects, the most important predictors included increased levels of I-CAM, V-CAM and MMP-9, while none of the analyzed parameters had proven to be predictive. Inflammatory biomarkers assayed during the acute phase of AMI presented a more powerful predictive capacity for MACE than the LVEF.

Effect of nicorandil on the spatial arrangement of primary motor cortical neurons in the sub-acute phase of stroke in a rat model

INTRODUCTION

Ischemic stroke remains a major cause of disability and death worldwide. The density and the spatial distribution of the primary motor (M1) cortical neurons are important in signal transmission and control the movement-related functions. Recently, the neuroprotective effect of nicorandil in cerebral ischemia was described through its anti-apoptosis, antioxidant and anti-inflammatory properties. This study aimed to determine the effects of nicorandil on the neurobehavioral outcome, infarct size, and density, and spatial distribution of M1 cortical neurons after cerebral ischemia.

METHODS

Thirty Sprague-Dawley rats were randomly divided into three groups. Sham underwent surgery without middle cerebral artery occlusion (MCAO) and drug. The MCAO and treatment groups after MCAO received saline or nicorandil 2, 24, 48, and 72 h after the induction of brain ischemia. Neurobehavioral tests were performed, brains removed, sectioned, and stained by 2,3,5-triphenyltetrazolium chloride (TTC) to estimate the size of the infarction and Nissl staining to evaluate the numerical density, mean area, and the distribution pattern of M1 cortical neurons, using Voronoi spatial tessellation.

RESULTS

Although nicorandil treatment significantly decreased the neurological deficits and density of neuronal neighbors, it could not preserve the normal regular spatial distributions of M1 cortical neurons after MCAO. It also could not significantly improve motor function or reduce ischemic lesion size.

CONCLUSIONS

Treatment using the present dose of nicorandil during sub-acute ischemic stroke could not increase neuronal density or preserve the normal regular spatial distributions after MCAO. However, it had beneficial effects on neurobehavioral and motor function and somewhat reduced ischemic lesion size.

Screening and identification of potential protein biomarkers for the early diagnosis of acute myocardial infarction

Background

Acute myocardial infarction (AMI) is the most serious type of heart disease. Clinically, there is an urgent need to discover diagnostic biomarkers for the early diagnosis of AMI.

Methods

Serum proteomic profiles in AMI patients, healthy controls, and stable angina pectoris (SAP) patients were explored and compared by iTRAQ-2DLC-MS/MS. The clinical data of AMI patients were also analyzed. Differentially expressed proteins were validated by enzyme linked immunosorbent assay (ELISA), and diagnostic models were constructed.

Results

A total of 39 differentially expressed proteins were identified in AMI patients. The results showed that the serum levels of apolipoprotein E (APOE) in AMI patients were notably higher than those in the healthy controls (P=0.0172). The serum levels of aspartate aminotransferase (AATC) in AMI patients were markedly higher than those in the healthy controls and SAP patients (P<0.0001 and P<0.0001, respectively). The serum levels of fibronectin (FINC) in SAP patients were significantly higher than those in the healthy controls and AMI patients (P=0.0043 and P=0.0044, respectively). Clinical data analysis showed a considerable difference in blood glucose levels, troponin I (TNI), and creatine kinase (CK) in AMI patients compared with SAP patients and healthy controls. A diagnostic model consisting of AATC and clinical indicators [lactate dehydrogenase (LDH) and CK] was established to distinguish between AMI patients and healthy controls, with an area under the curve (AUC) value of 0.993 sensitivity and specificity of 96.2% and 96.3%, respectively. A diagnostic model consisting of AATC and CK was established to distinguish between AMI patients and SAP patients, with an AUC value of 0.975 and a sensitivity and specificity of 85.2% and 79.30%, respectively.

Conclusions

In this study, differentially expressed proteins in AMI patients were combined with clinical indexes, LDH and CK, and two diagnostic models were constructed. This study may provide meaningful data for the early diagnosis of AMI.

Effect of Presence of Ramus Intermedius Artery on Location of Culprit Lesions in Acute Left Circumflex Coronary Artery Occlusion

BACKGROUND AND AIM

Coronary artery anatomy frequently affects location of atherosclerotic plaques and subsequent culprit lesions. We sought to clarify whether presence or absence of Ramus Intermedius coronary artery (RI) would affect location of culprit lesions in acute left circumflex (LCX) coronary artery occlusion.

METHODS

The study included 180 patients, 100 with a diagnosis of non-ST elevation myocardial infarction (NSTEMI) and 80 with ST elevation myocardial infarction (STEMI). All culprit lesions were located in the LCX coronary artery. RI group included 45 patients and the No RI group included 135 patients.

RESULTS

Culprit LCX lesions were similarly located at a comparable distance from LCX ostium in both groups and the presence of RI was not associated with significantly more proximally located culprit LCX lesions (34.7 ± 15.2 mm compared to 30.8 ± 17.9 mm respectively, p > 0.05). The frequency distribution of culprit lesions' distance from LCX ostium showed no significant difference between both groups in any of the segments studied (10 mm each). There was no significant difference between both groups regarding markers of myocardial necrosis size as cardiac biomarkers (peak cardiac troponin-T 1077.4 ± 361.2 pg/dl vs 926 ± 462.2 pg/dl respectively, p = 0.13), (peak creatine kinase-MB 232.2 ± 81 ng/dl vs 194.7 ± 99.2 ng/dl respectively, p = 0.07) or left ventricular ejection fraction (EF 46.3 ± 6.3% vs 48.3 ± 8.3% respectively, p = 0.76).

CONCLUSION

Presence of RI coronary artery, as an additional flow divider, may not be associated with more proximal culprit lesions, compared to its absence, in cases of acute LCX coronary artery occlusion. Possible underlying pathophysiologic mechanisms remain to be clarified.

Epicardial Adipose Tissue Volume As a Marker of Subclinical Coronary Atherosclerosis in Rheumatoid Arthritis

OBJECTIVE

To assess epicardial adipose tissue volume (EATV) and its link to coronary atherosclerosis and plaque morphology in patients with rheumatoid arthritis (RA) and in age- and sex-matched controls.

METHODS

Computed tomography angiography was used to evaluate EATV and coronary plaque in 139 RA patients and 139 non-RA controls. All models assessing the effect of EATV on plaque were adjusted for age, sex, hypertension, diabetes, dyslipidemia, smoking status, family history of coronary artery disease, and obesity (body mass index of ≥30 kg/m² ). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Mean ± SD log-transformed EATV was similar in patients with RA (4.69 ± 0.36) and controls (4.70 ± 0.42). EATV was higher in RA patients with atherosclerosis compared to those without atherosclerosis (P = 0.046). In stratified analyses, EATV was associated with the number of segments with plaque in RA patients (rate ratio 1.20 [95% CI 1.01-1.41] per 1-SD increment of log-unit increase in EATV) but not in controls (P for interaction = 0.089). Likewise, EATV (per 1-SD log-unit increase) was related to the presence of multivessel or obstructive disease (OR 1.63 [95% CI 1.04-2.61]), noncalcified plaque (OR 1.78 [95% CI 1.17-2.70]), and vulnerable plaque (OR 1.77 [95% CI 1.03-3.04]) in RA patients but not in controls (P for interaction ≤ 0.048 for each). Among RA patients, EATV was associated with the number of segments with plaque in those with RA for <10 years who did not develop any cardiovascular risk factors and who were not obese (P for interaction ≤ 0.017).

CONCLUSION

Despite similar EATVs in RA patients and controls, EATVs were associated with greater plaque burden and presence of plaques with a noncalcified component and vulnerability features only in RA patients. EAT may be more pathogenic in RA and play a role in early-stage atherosclerosis. Its value as a biomarker of subclinical atherosclerosis and cardiovascular risk in RA warrants further studies.

The smoking-dyslipidaemia dyad: A potent synergistic risk for atherosclerotic coronary artery disease

BACKGROUND

Smoking and dyslipidaemia are known individual risk factors of coronary artery disease (CAD). The present study examined the combined risk of smoking and dyslipidaemia on coronary atherosclerosis.

METHODS

Coronary artery calcium (CAC), measured by cardiac CT, was used to assess the extent of CAD, which was related to smoking and dyslipidaemia using logistic regression, adjusted for age, sex, hypertension, BMI and family history of ischaemic heart disease.

RESULTS

Seventy-one patients (46 men, 25 women: median age of 53.7yrs; IQR = 47.0-59.5) were recruited. The mean log10 CAC score in never-smokers without dyslipidaemia (reference group) was 0.37 (SD = 0.73), while the value in those with a history of smoking was 0.44 ± 0.48 (mean difference: 0.07, 95%CI:-0.67 to 0.81, p = 0.844), dyslipidaemia was 1.07 ± 1.08 (mean difference: 0.71, 95%CI: 0.24 to 1.17, p = 0.003), and both risk factors was 1.82 ± 0.64 (mean difference: 1.45, 95%CI:0.88 to 2.02, p < 0.001). For individuals in the reference group, the proportions with none, one and multiple vessel disease were 80.6%, 16.1% and 3.2%; for those with a history of smoking or with dyslipidaemia were 50.0%, 25.0% and 25.0%; and for those with both risk factors were 8.3%, 25.0% and 66.7%. Patients with a history of both risk factors had greater adjusted risks of having one- vessel disease - OR = 14.3 (95%CI = 2.1-98.2) or multiple vessel disease: OR = 51.8 (95%CI = 4.2-609.6).

CONCLUSIONS

Smoking and dyslipidaemia together are associated with high coronary artery calcification and CAD, independent of other major risk factors.

Coronary 18F-sodium fluoride PET detects high-risk plaque features on optical coherence tomography and CT-angiography in patients with acute coronary syndrome

BACKGROUND AND AIMS

¹⁸F-Sodium Fluoride Positron Emission Tomography (¹⁸F-NaF PET) non-invasively detects micro-calcification activity, the earliest stage of atherosclerotic arterial calcification. We studied the association between coronary ¹⁸F-NaF uptake and high-risk plaque features on intra-coronary optical coherence tomography (OCT) and CT-angiography (CTCA) and the potential application to patient-level risk stratification.

METHODS

Sixty-two prospectively recruited patients with acute coronary syndrome (ACS) underwent multi-vessel OCT, ¹⁸F-NaF PET and CTCA. The maximum tissue to background ratio (TBRmax = standardised uptake value (SUV)max/SUVbloodpool) was measured in each coronary segment on ¹⁸F-NaF PET scans. High-risk plaque features on OCT and CTCA were compared in matched coronary segments. The number of patients testing positive (>2SD above the normal range) for micro-calcification activity was determined.

RESULTS

In 62 patients (age, mean ± standard deviation (SD) = 61 ± 9 years, 85% male) the coronary segments with elevated ¹⁸F-NaF uptake had higher lipid arc (LA) (median [25th-75th centile]: 74° [35°-117°] versus 48° [15°-83°], p=0.021), higher prevalence of macrophages [n(%): 37 (62%) versus 89 (39%), p=0.008] and lower plaque free wall (PFW) (50° [7°-110°] versus 94° [34°-180°], p=0.027) on OCT, and a higher total plaque burden (p=0.011) and higher dense calcified plaque burden (p= 0.001) on CTCA, when compared with ¹⁸F-NaF negative segments. Patients grouped by increasing number of coronary lesions positive for microcalcification activity (0,1, ≥2) showed decreasing plaque free wall, increasing calcification and increasing macrophages on OCT (respectively p=0.008, p < 0.001 and p=0.028).

CONCLUSIONS

¹⁸F-NaF uptake is associated with high-risk plaque features on OCT and CTCA in a per-segment and per-patient analysis in subjects hospitalized for ACS.

Mouse models of atherosclerosis and their suitability for the study of myocardial infarction

Atherosclerotic plaques impair vascular function and can lead to arterial obstruction and tissue ischaemia. Rupture of an atherosclerotic plaque within a coronary artery can result in an acute myocardial infarction, which is responsible for significant morbidity and mortality worldwide. Prompt reperfusion can salvage some of the ischaemic territory, but ischaemia and reperfusion (IR) still causes substantial injury and is, therefore, a therapeutic target for further infarct limitation. Numerous cardioprotective strategies have been identified that can limit IR injury in animal models, but none have yet been translated effectively to patients. This disconnect prompts an urgent re-examination of the experimental models used to study IR. Since coronary atherosclerosis is the most prevalent morbidity in this patient population, and impairs coronary vessel function, it is potentially a major confounder in cardioprotective studies. Surprisingly, most studies suggest that atherosclerosis does not have a major impact on cardioprotection in mouse models. However, a major limitation of atherosclerotic animal models is that the plaques usually manifest in the aorta and proximal great vessels, and rarely in the coronary vessels. In this review, we examine the commonly used mouse models of atherosclerosis and their effect on coronary artery function and infarct size. We conclude that none of the commonly used strains of mice are ideal for this purpose; however, more recently developed mouse models of atherosclerosis fulfil the requirement for coronary artery lesions, plaque rupture and lipoprotein patterns resembling the human profile, and may enable the identification of therapeutic interventions more applicable in the clinical setting.

Pancoronary Plaque Characteristics in STEMI Caused by Culprit Plaque Erosion Versus Rupture: 3-Vessel OCT Study

OBJECTIVES

This study sought to investigate nonculprit plaque characteristics in patients with ST-segment elevation myocardial infarction (STEMI) presenting with plaque erosion (PE) and plaque rupture (PR). Pancoronary vulnerability was considered at nonculprit sites: 1) the CLIMA (Relationship Between OCT Coronary Plaque Morphology and Clinical Outcome) study (NCT02883088) defined high-risk plaques with simultaneous presence of 4 optical coherence tomography (OCT) features (minimum lumen area <3.5 mm²; fibrous cap thickness [FCT] <75 μm; maximum lipid arc >180º; and macrophage accumulation); and 2) the presence of plaque ruptures or thin-cap fibroatheromas (TCFA).

BACKGROUND

PE is a unique clinical entity associated with better outcomes than PR. There is limited evidence regarding pancoronary plaque characteristics of patients with culprit PE versus culprit PR.

METHODS

Between October 2016 and September 2018, 523 patients treated by 3-vessel OCT at the time of primary percutaneous intervention were included with 152 patients excluded from final analysis.

RESULTS

Overall, 458 nonculprit plaques were identified in 202 STEMI patients with culprit PE; and 1,027 nonculprit plaques were identified in 321 STEMI patients with culprit PR. At least 1 CLIMA-defined OCT nonculprit high-risk plaque was seen in 11.4% of patients with culprit PE, but twice as many patients were seen with culprit PR (25.2%; p < 0.001). This proportion was also seen when individual high-risk features were analyzed separately. When patients with PE were divided by a heterogeneous substrate (fibrous or lipid-rich plaque) underlying the culprit site, the prevalence of nonculprits with FCT <75 μm, macrophages, and TCFA showed a significant gradient from PE_(Fibrous) to PE_{lipid-rich plaque (LRP)} to PR. Interestingly, nonculprit rupture was rarely found in patients with culprit PE_(Fibrous) (1.9%), although it was exhibited with comparable prevalence in patients with culprit PE_(LRP) (16.3%) versus PR (17.8%). Culprit PE predicted decreased pancoronary vulnerability independent of conventional risk factors.

CONCLUSIONS

STEMI patients with culprit PE have a limited pancoronary vulnerability that may explain better outcomes in these patients than in STEMI patients with culprit PR.

Effects of Altered Levels of Pro- and Anti-Inflammatory Mediators on Locations of In-Stent Reocclusions in Elderly Patients

Imbalances of proatherogenic inflammatory and antiatherogenic inflammatory mediators were involved in the pathogenesis of atherosclerosis. This study sought to investigate the effects of proatherogenic inflammatory and antiatherogenic inflammatory mediators on the proximal, middle, and distal coronary artery reocclusions in elderly patients after coronary stent implantations. We measured the expression levels of proatherogenic inflammatory/antiatherogenic inflammatory cytokines. This included interleukin-1 β (IL-1 β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), high-sensitivity C-reactive protein (hs-CRP), interleukin-10 (IL-10), interleukin-17 (IL-17), interleukin-13 (IL-13), and interleukin-37 (IL-37) in the elderly patients with the proximal, middle, and distal coronary artery reocclusions after coronary stent implantations. Levels of IL-1 β, IL-6, IL-8, TNF-α, and hs-CRP were remarkably increased (P < 0.001), and levels of IL-10, IL-17, IL-13, and IL-37 were remarkably lowered (P < 0.001) in the elderly patients with the proximal, middle, and distal coronary artery reocclusions. Imbalances of proatherogenic inflammatory and antiatherogenic inflammatory mediators may be involved in the formation and progression of proximal, middle, and distal coronary artery reocclusions in elderly patients after coronary stent implantations.

Urgent Pericardiocentesis Is More Frequently Needed After Left Circumflex Coronary Artery Perforation

Background: Coronary artery perforation (CAP) is a rare but potentially life-threatening complication of percutaneous coronary interventions (PCIs) due to the risk of cardiac tamponade. Strikingly, in contrast to numerous analyses of CAP predictors, only few studies were focused on the predictors of tamponade after PCI, once iatrogenic CAP has occurred. Our aim was to search for clinical and periprocedural characteristics, including the coronary artery involved, associated with the development of acute cardiac tamponade among patients experiencing CAP. Methods: From the medical records of nine centers of invasive cardiology in southern Poland, we retrospectively selected 81 patients (80% with acute myocardial infarction) who had iatrogenic CAP with a visible extravasation jet during angiography (corresponding to type III CAP by the Ellis classification, CAP_III) over a 15-year period (2005-2019). Clinical, angiographic and periprocedural characteristics were compared between the patients who developed acute cardiac tamponade requiring urgent pericardiocentesis in the cathlab (n = 21) and those with CAP_III and without tamponade (n = 60). Results: CAP_III were situated in the left anterior descending artery (LAD) or its diagonal branches (51%, n = 41), right coronary artery (RCA) (24%, n = 19), left circumflex coronary artery (LCx) (16%, n = 13), its obtuse marginal branches (7%, n = 6) and left main coronary artery (2%, n = 2). Acute cardiac tamponade occurred in 24% (10 of 41), 21% (4 of 19) and 37% (7 of 19) patients who experienced CAP_III in the territory of LAD, RCA and LCx, respectively. There were no significant differences in the need for urgent pericardiocentesis (37%) in patients with CAP_III in LCx territory (i.e., the LCx or its obtuse marginal branches) compared to CAP_III in the remaining coronary arteries (23%) (p = 0.24). However, when CAP_III in the LCx were separated from CAP_III in obtuse marginal branches, urgent pericardiocentesis was more frequently performed in patients with CAP_III in the LCx (54%, 7 of 13) compared to subjects with CAP_III in an artery other than the LCx (21%, 14 of 68) (p = 0.03). The direction of this tendency remained consistent regardless of CAP management: prolonged balloon inflation only (n = 26, 67% vs. 13%, p = 0.08) or balloon inflation with subsequent stent implantation (n = 55, 50% vs. 24%, p = 0.13). Besides LCx involvement, no significant differences in other characteristics were observed between patients according to the need of urgent pericardiocentesis. Conclusions: CAP_III in the LCx appears to lead to a higher risk of acute cardiac tamponade compared to perforations involving other coronary arteries. This association may possibly be linked to distinct features of LCx anatomy and/or well-recognized delays in diagnosis and management of LCx-related acute coronary syndromes.

Comparison of plaque distribution and wire-free functional assessment in patients with stable angina and non-ST elevation myocardial infarction: an optical coherence tomography and quantitative flow ratio study

BACKGROUND

Data comparing plaque characteristics and wire-free physiological assessment in the target vessel in patients with stable angina versus acute coronary syndrome are sparse. Therefore, we investigated the difference in plaque distribution between stable angina and non-ST-elevation myocardial infarction (NSTEMI) and explored the relationship between target vessel vulnerability by optical coherence tomography (OCT) and wire-free functional assessment with quantitative flow ratio (QFR).

METHODS

Patients with stable angina (n = 25) and NSTEMI (n = 24) were in the final prospective study cohort from the DECODE study (ClinicalTrials.gov, NCT02335086). All 5480 OCT frames in the region of interest were analyzed to study plaque morphology in the target vessel. QFR was analyzed from baseline coronary angiography before percutaneous coronary intervention. Vulnerable vessel score (VVS) was calculated from each plaque, and vessel QFR was then compared.

RESULTS

Out of all frames, thin-cap fibroatheroma was common with NSTEMI compared to stable angina (10.9 versus 6.3%, P < 0.01), while fibrous plaque was more commonly seen with stable angina compared to NSTEMI (19.7 versus 14.4%, P < 0.01). Calcified plaque was similar in both clinical settings (approximately 6%). Regression analysis showed that segments with normal vessel walls were located significantly farther from the other plaque types. Longitudinal distances for plaque-type in NSTEMI were numerically greater than those for stable angina; however, the mean difference was less than 10 mm. The VVS had a significant inverse linear correlation with QFR (r = -0.34, P = 0.009).

CONCLUSIONS

The plaque distribution by OCT between stable angina and NSTEMI was similar. Target vessel vulnerability was greater in patients with lower QFR value.

Spatial Distribution of Vulnerable Plaques: Comprehensive In Vivo Coronary Plaque Mapping

OBJECTIVES

The authors performed a comprehensive analysis on the distribution of coronary plaques with different phenotypes from our 3-vessel optical coherence tomography (OCT) database.

BACKGROUND

Previous pathology studies demonstrated that thin-cap fibroatheroma (TCFA) is localized in specific segments of the epicardial coronary arteries. A detailed description of in vivo coronary plaques of various phenotypes has not been reported.

METHODS

OCT images of all 3 coronary arteries in 131 patients were analyzed every 1 mm to assess plaque phenotype and features of vulnerability. In addition, plaques were divided into tertiles according to percent area stenosis (%AS).

RESULTS

Among 534 plaques identified in 393 coronary arteries, 27.0% were fibrous plaques, 13.3% were fibrocalcific plaques, 40.8% were thick-cap fibroatheromas, and 18.9% were TCFAs. TCFAs showed clustering in the proximal segment, particularly in the left anterior descending artery. On the other hand, fibrous plaques were relatively evenly distributed throughout the entire length of the coronary arteries. In patients with acute coronary syndromes (ACS), TCFAs showed stronger proximal clustering in the left anterior descending, 2 clustering peaks in the right coronary artery, and 1 clustering peak in the circumflex artery. The pattern of TCFA distribution was less obvious in patients without ACS. The prevalence of TCFA was higher in the highest %AS tertile, compared with the lowest %AS tertile (30% vs. 9%; p < 0.001).

CONCLUSIONS

The present 3-vessel OCT study showed that TCFAs cluster at specific locations in the epicardial coronary arteries, especially in patients with ACS. TCFA was more prevalent in segments with tight stenosis. (The Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538).

PCI and CABG for Treating Stable Coronary Artery Disease: JACC Review Topic of the Week

Percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are considered revascularization procedures, but only CABG can prolong life in stable coronary artery disease. Thus, PCI and CABG mechanisms may differ. Viability and/or ischemia detection to guide revascularization have been unable to accurately predict treatment effects of CABG or PCI, questioning a revascularization mechanism for improving survival. By contrast, preventing myocardial infarction may save lives. However, the majority of infarcts are generated by non-flow-limiting stenoses, but PCI is solely focused on treating flow-limiting lesions. Thus, PCI cannot be expected to significantly limit new infarcts, but CABG may do so through providing flow distal to vessel occlusions. All comparisons of CABG to PCI or medical therapy that demonstrate survival effects with CABG also demonstrate infarct reduction. Thus, CABG may differ from PCI by providing "surgical collateralization," prolonging life by preventing myocardial infarctions. The evidence is reviewed here.

In vivo predictors of plaque erosion in patients with ST-segment elevation myocardial infarction: a clinical, angiographical, and intravascular optical coherence tomography study

Aims

Plaque erosion is a significant substrate of acute coronary thrombosis. This study sought to determine in vivo predictors of plaque erosion in patients with ST-segment elevation myocardial infarction (STEMI).

Methods and results

A prospective series of 822 STEMI patients underwent pre-intervention optical coherence tomography. Using established diagnostic criteria, 209 had plaque erosion (25.4%) and 564 had plaque rupture (68.6%). Plaque erosion was more frequent in women <50 years when compared with those ≥50 years of age (P = 0.009). There was a similar, but less striking, trend in men (P = 0.011). Patients with plaque erosion were more frequently current smokers but had fewer other coronary risk factors (dyslipidaemia, hypertension, chronic kidney disease, and diabetes mellitus) than those with plaque rupture. There was a preponderance of plaque erosion in the left anterior descending artery (LAD; 61.2%), whereas plaque rupture was more equally distributed in both the LAD (47.0%) and right coronary artery (43.3%). Despite the similar spatial distribution of erosions and ruptures over the lengths of the coronary arteries, plaque erosion occurred more frequently near a bifurcation (P < 0.001). In the multivariable analysis, age <50 years, current smoking, absence of other coronary risk factors, lack of multi-vessel disease, reduced lesion severity, larger vessel size, and nearby bifurcation were significantly associated with plaque erosion. Nearby bifurcation and current smoking were especially notable in men, while age <50 years was most predictive in women.

Conclusions

Plaque erosion was a predictable clinical entity distinct from plaque rupture in STEMI patients, and gender-specific role of risk factors in plaque erosion should be considered.

The rationale and emergence of electroconductive biomaterial scaffolds in cardiac tissue engineering

The human heart possesses minimal regenerative potential, which can often lead to chronic heart failure following myocardial infarction. Despite the successes of assistive support devices and pharmacological therapies, only a whole heart transplantation can sufficiently address heart failure. Engineered scaffolds, implantable patches, and injectable hydrogels are among the most promising solutions to restore cardiac function and coax regeneration; however, current biomaterials have yet to achieve ideal tissue regeneration and adequate integration due a mismatch of material physicochemical properties. Conductive fillers such as graphene, carbon nanotubes, metallic nanoparticles, and MXenes and conjugated polymers such as polyaniline, polypyrrole, and poly(3,4-ethylendioxythiophene) can possibly achieve optimal electrical conductivities for cardiac applications with appropriate suitability for tissue engineering approaches. Many studies have focused on the use of these materials in multiple fields, with promising effects on the regeneration of electrically active biological tissues such as orthopedic, neural, and cardiac tissue. In this review, we critically discuss the role of heart electrophysiology and the rationale toward the use of electroconductive biomaterials for cardiac tissue engineering. We present the emerging applications of these smart materials to create supportive platforms and discuss the crucial role that electrical stimulation has been shown to exert in maturation of cardiac progenitor cells.

High arrhythmic risk in antero-septal acute myocardial ischemia is explained by increased transmural reentry occurrence

Acute myocardial ischemia is a precursor of sudden arrhythmic death. Variability in its manifestation hampers understanding of arrhythmia mechanisms and challenges risk stratification. Our aim is to unravel the mechanisms underlying how size, transmural extent and location of ischemia determine arrhythmia vulnerability and ECG alterations. High performance computing simulations using a human torso/biventricular biophysically-detailed model were conducted to quantify the impact of varying ischemic region properties, including location (LAD/LCX occlusion), transmural/subendocardial ischemia, size, and normal/slow myocardial propagation. ECG biomarkers and vulnerability window for reentry were computed in over 400 simulations for 18 cases evaluated. Two distinct mechanisms explained larger vulnerability to reentry in transmural versus subendocardial ischemia. Macro-reentry around the ischemic region was the primary mechanism increasing arrhythmic risk in transmural versus subendocardial ischemia, for both LAD and LCX occlusion. Transmural micro-reentry at the ischemic border zone explained arrhythmic vulnerability in subendocardial ischemia, especially in LAD occlusion, as reentries were favoured by the ischemic region intersecting the septo-apical region. ST elevation reflected ischemic extent in transmural ischemia for LCX and LAD occlusion but not in subendocardial ischemia (associated with mild ST depression). The technology and results presented can inform safety and efficacy evaluation of anti-arrhythmic therapy in acute myocardial ischemia.

The natural history of napkin-ring sign by coronary computed tomography angiography

Introduction

Despite their significance, the prevalence and the incidence of vulnerable plaques in coronary arteries, as well as their natural history, remain poorly known.

Aim

To evaluate the prevalence, incidence and evolution of napkin-ring sign (NRS), and to establish factors associated with its presence, progression, or regression, in patients with suspected coronary artery disease (CAD).

Material and methods

The study is based on a single-center prospective registry. Eighty-nine patients with suspected CAD underwent two computed tomography angiography (CTA) examinations within an interval of at least 24 months. High-risk plaque was defined by the presence of a low-attenuation area adjacent to the coronary lumen, surrounded by a ring of higher attenuation – NRS.

Results

At the baseline 53 NRS were observed in 22 (25%) patients, 7 (8%) patients had single NRS and 15 (17%) had multiple NRS. After the follow-up period, there were 68 NRS in 32 patients. In 18 patients progression was observed with 23 additional NRS. Presence of single NRS and diabetes were independent predictors of NRS progression.

Conclusions

The number of NRS plaque tends to increase over time in patients with suspected CAD. The progression may be predicted by the presence of diabetes or single NRS.

Predictors of mortality in patients with non-anterior ST-segment elevation myocardial infarction: Analysis from the HORIZONS-AMI trial

OBJECTIVES

We sought to identify clinical, electrocardiographic (ECG), and angiographic characteristics that are predictive of 3-year mortality after primary percutaneous coronary intervention (PCI) in patients with non-anterior ST-elevation myocardial infarction (NA-STEMI) from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial.

BACKGROUND

Which patients with NA-STEMI undergoing PCI have a poor prognosis is uncertain.

METHODS

NA-STEMI was defined as ST-segment elevation in lateral (V5, V6, I, aVL), inferior (II, III, aVF), or inferolateral (I, II, III, aVF, and V5-V6) ECG leads or posterior myocardial infarction with ST-segment depression of ≥1 mm in ≥2 contiguous anterior leads. Cox regression was used to identify independent predictors of 3-year mortality. Missing data were imputed using multiple imputation.

RESULTS

In HORIZONS-AMI, 2,578/3,602 patients had no prior coronary artery bypass grafting, underwent single-vessel PCI, and had baseline ECG data assessed in an independent core laboratory. Among them, 1,495 (58.0%) had NA-STEMI. Patients with NA-STEMI had lower 3-year mortality risk than those with anterior STEMI (4.5% versus 7.1%, P = 0.004). The independent predictors of increased 3-year mortality in NA-STEMI were older age (median > 59.0 years), diabetes, reduced LVEF (≤50%), Killip class ≥2, post-procedure TIMI flow 0-2 versus 3, renal insufficiency, and ST-resolution <30% at 60 min post-PCI. Patients with 0, 1, 2, 3, and ≥4 of these risk factors had 3-year mortality rates of 1.8%, 2.3%, 3.1%, 6.1%, and 36.3%, respectively (P < 0.0001).

CONCLUSIONS

Although NA-STEMI carries a better prognosis than anterior STEMI, high-risk patient cohorts with NA-STEMI may be identified who have substantial 3-year mortality.

Association between ADAMTS7 TagSNPs and the risk of myocardialinfarction

Purpose of the study

Genome-wide association studies have revealed an association of ADAMTS7 polymorphisms with the risk of cardiovascular diseases. Nonetheless, the role of ADAMTS7 polymorphisms on myocardial infarction (MI) risk remains poorly understood. Here, we aim to evaluate the effect of ADAMTS7 tag single nucleotide polymorphisms (SNPs) on individual susceptibility to MI.

Study design

Genotyping of the four tagSNPs (rs1994016, rs3825807, rs4380028 and rs7173743) was performed in 232 MI cases and 661 control subjects using PCR-ligase detection reaction (LDR) method. The association of these four tagSNPs with MI risk was performed with SPSS software.

Results

Multivariate logistic regression analysis showed that ADAMTS7 tagSNP rs3825807 exhibited a significant effect on MI risk. Compared with the TT homozygotes, the CT genotype (OR1.93, 95% CI1.30to 2.85, Pc=0.004) and the combined CC/CT genotypes (OR1.70, 95% CI1.16 to 2.50, Pc=0.028) were statistically significantly associated with the increased risk for MI. Further stratified analysis revealed a more significant association with MI risk among older subjects, hypertensives, non-diabetics and patients with hyperlipidaemia. Consistently, the haplotype rs1994016T–rs3825807C containing rs3825807 C allele exhibited increased MI risk (OR1.52, 95% CI1.10 to 2.10, p=0.010). However, we did not detect any association of the other three tagSNPs with MI risk.

Conclusions

Our finding suggest that ADAMTS7 tagSNP rs3825807 contributes to MI susceptibility in the Chinese Han population. Further studies are necessary to confirm the general validity of our findings and to clarify the underlying mechanism for this association.

[Coronary lesions in black African patients with acute coronary syndromes]

Introduction

les syndromes coronariens aigus (SCA) sont en progression en Afrique sub-saharienne. Les données angio-coronarographiques sont rares. L'objectif de cette étude était d'analyser les lésions coronaires observées dans les syndromes coronariens aigus (SCA) à Abidjan.

Méthodes

étude transversale, du 1^er janvier 2010 au 31 décembre 2014. Tous les patients admis pour SCA et ayant bénéficié d'une coronarographie à l'Institut de cardiologie d'Abidjan pendant la période d'étude ont été inclus. Deux cent cinquante-six patients ont été sélectionnés. Nous avons analysé et comparé les lésions coronaires chez les patients ayant présenté un SCA avec sus décalage persistant du segment ST (SCA ST+) et ceux ayant présenté SCA sans sus décalage du segment ST (SCA ST-).

Résultats

l'âge moyen des patients était de 53,2 ± 10,8 ans. Il existait une prédominance masculine avec un sex-ratio de 6,1. Le taux de coronarographies anormales était significativement plus élevé dans les SCA ST+ (95,4% et 64,2% respectivement, p < 0,001). Trois cent quatre lésions coronaires ont été observées dans les SCA ST+ contre 43 dans les SCA ST- . Les lésions sténosantes étaient majoritairement monotronculaires (45,3%) dans les SCA ST+ et bi ou tri tronculaires dans les SCA ST- (68,0%). Les lésions de type B1 étaient plus fréquentes dans les SCA ST- (62,8% versus 36,5%, p = 0,002). Les lésions les plus complexes de type C étaient plus fréquentes dans les SCA ST+ (17,8%), sans différence significative. La majorité des patients avait un score SYNTAX inférieur à 22 quel que soit le type de SCA (87,4% dans les SCA ST+ et 90,1% dans les SCA ST-).

Conclusion

les lésions coronaires dans les SCA sont majoritairement monotronculaires dans les SCA ST+ et plus diffuses dans les SCA ST- mais avec une proportion plus importante de coronaires angiographiquement normales. La prise en charge de ces lésions relève dans la majorité des cas de l'angioplastie coronaire.

Coronary Artery Vasospasm Induced by 5-fluorouracil: Proposed Mechanisms, Existing Management Options and Future Directions

Cardiovascular disease and cancer are leading contributors to the global disease burden. As a result of cancer therapy-related cardiotoxicities, cardiovascular disease results in significant morbidity and mortality in cancer survivors and patients with active cancer. There is an unmet need for management of cardio-oncology conditions, which is predicted to reach epidemic proportions, and better understanding of their pathophysiology and treatment is urgently required. The proposed mechanisms underlying cardiotoxicity induced by 5-fluorouracil (5-FU) are vascular endothelial damage followed by thrombus formation, ischaemia secondary to coronary artery vasospasm, direct toxicity on myocardium and thrombogenicity. In patients with angina and electrocardiographic evidence of myocardial ischaemia due to chemotherapy-related coronary artery vasospasm, termination of chemotherapy and administration of calcium channel blockers or nitrates can improve ischaemic symptoms. However, coronary artery vasospasm can reoccur with 5-FU re-administration with limited effectiveness of vasodilator prophylaxis observed. While pre-existing coronary artery disease may increase the ischaemic potential of 5-FU, cardiovascular risk factors do not appear to completely predict the development of cardiac complications. Pharmacogenomic studies and genetic profiling may help predict the occurrence and streamline the treatment of 5-FU-induced coronary artery vasospasm. Echocardiographic measures such as the Tei index may help detect subclinical 5-FU cardiotoxicity. Further research is required to explore the cardioprotective effect of agents such as coenzyme complex, GLP-1 analogues and degradation inhibitors on 5-FU-induced coronary artery vasospasm.

A smartphone-assisted pressure-measuring-based diagnosis system for acute myocardial infarction diagnosis

Background

Acute myocardial infarction (AMI), usually caused by atherosclerosis of coronary artery, is the most severe manifestation of coronary artery disease which results in a large amount of death annually. A new diagnosis approach with high accuracy, reliability and low measuring-time-consuming is essential for AMI quick diagnosis.

Purpose

The objective of this study was to develop a new point-of-care testing system with high accuracy and reliability for AMI quick diagnosis.

Patients and methods

50 plasma samples of acute myocardial infarction patients were analyzed by developed Smartphone-Assisted Pressure-Measuring-Based Diagnosis System (SPDS). The concentration of substrate was firstly optimized. The effect of antibody labeling and matrix solution on measuring result were then evaluated. And standard curves for cTnI, CK-MB and Myo were built for clinical sample analysis. The measuring results of 50 clinical samples were finally evaluated by comparing with the measuring result obtained by CLIA.

Results

The concentration of substrate H₂O₂ was firstly optimized as 30% to increase measuring signal. A commercial serum matrix was chosen as the matrix solution to dilute biomarkers for standard curve building to minimize matrix effect on the accuracy of clinical plasma sample measuring. The standard curves for cTnI, CK-MB and Myo were built, with measuring dynamic range of 0–25 ng/mL, 0–33 ng/mL and 0–250 ng/mL, and limit of detection of 0.014 ng/mL, 0.16 ng/mL and 0.85 ng/mL respectively. The measuring results obtained by the developed system of 50 clinical plasma samples for three biomarkers matched well with the results obtained by chemiluminescent immunoassay.

Conclusion

Due to its small device size, high sensitivity and accuracy, SPDS showed a bright potential for point-of-care testing (POCT) applications.