Thin-cap fibroatheroma in acute coronary syndrome: Implication for intravascular imaging assessment.

Acute coronary syndrome (ACS), a significant cardiovascular disease threat, has garnered increased focus concerning its etiological mechanisms. Thin-cap fibroatheroma (TCFA) are central to ACS pathogenesis, characterized by lipid-rich plaques, profuse foam cells, cholesterol crystals, and fragile fibrous caps predisposed to rupture. While TCFAs may be latent and asymptomatic, their pivotal role in ACS risk is undeniable. High-resolution imaging techniques like Optical coherence tomography (OCT) and Intravascular ultrasound (IVUS) are instrumental for effective TCFA detection. Therapeutic strategies encompass pharmacological and interventional measures, including antiplatelet agents, statins, and Percutaneous Coronary Intervention (PCI), aiding in plaque stabilization, inflammation reduction, and rupture risk mitigation. Despite the strong correlation between TCFAs and adverse prognoses in ACS patients, early detection and rigorous treatment significantly enhance patient prognosis and diminish cardiovascular events. This review aims to encapsulate recent advancements in TCFA research within ACS, covering formation mechanisms, clinical manifestations, and prognostic implications.

Twenty-five-year trends in incidence, angiographic appearance, and management of spontaneous coronary artery dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) has been described as an infrequent cause of acute coronary syndrome (ACS). Knowledge about the disease is still limited and SCAD might still be underdiagnosed. OBJECTIVES: Trends in incidence, presentation, angiographic appearance, management, and outcomes of SCAD over 25 years were analyzed. METHODS: Patients with SCAD between 1997 and 2021 at the University Hospital Zurich, Switzerland, were included. Incidences were assessed as total numbers and proportions of ACS cases. Clinical data were collected from medical records and angiographic findings were reviewed. Major adverse cardiac events (MACE) were defined as the composite of all-cause death, cardiac arrest, SCAD recurrence or progression, other myocardial infarction, and stroke. RESULTS: One hundred fifty-six SCAD cases were included in this study. The incidence increased significantly in total (p < 0.001) and relative to ACS cases (p < 0.001). This was based on an increase of shorter lesions (p = 0.004), SCAD type 2 (p < 0.001), and lesions in side branches (p = 0.014), whereas lesions in the left main coronary artery and proximal segments were decreasing (p-values 0.029 and < 0.001, respectively). There was an increase in conservative therapy (p < 0.001). The rate of MACE (24%) was stable, however, there was a reduced proportion of patients with a need for intensive care treatment (p = 0.017). CONCLUSIONS: SCAD represents an important entity of ACS that still might be underappreciated. The increasing incidence of SCAD is likely based on better awareness and familiarity with the disease. A lower need for intensive care treatment suggests positive effects of the increasing implementation of conservative management.

Assessment of vasa vasorum on coronary plaques in patients with acute coronary syndromes using intravascular ultrasound and iMap analysis: A retrospective cohort study.

Studies have revealed that vasa vasorum (VV) neovascularization is vital for the progression and vulnerability of coronary atherosclerotic plaques. The correlation between VV, plaque constituents, and the no-reflow phenomenon (NRP) in percutaneous coronary intervention (PCI) remains elusive. We explored plaque constituents in iMap-intravascular ultrasound (iMap-IVUS) and NRP during PCI for VV lesions. We studied 166 coronary lesions in 166 patients with acute coronary syndromes (ACS) (118 lesions with VV) undergoing pre-intervention intravascular ultrasound (IVUS). We evaluated the diversity in plaque morphological status and post-PCI results based on the presence or absence of VV. The lesions with VV group had significantly higher high-sensitivity C-reactive protein (hs-CRP) levels than the lesions without VV group (8.41 ± 4.98 vs 4.19 ± 3.69 mg/L, P < .001). The frequency of after-stent deployment thrombolysis in myocardial infarction (TIMI) flow grades 0, 1, and 2 was remarkably greater in lesions with VV than in those without VV (22.9% vs 10.4%, P < .001). Plaques at the minimum lumen, necrotic core (1.26 ± 0.64 vs 0.92 ± 0.61 mm2, P < .001; 20.95 ± 7.19 vs 13.34% ± 6.54%, P < .001), and fibrous areas (4.23 ± 1.32 vs 3.92 ± 1.01 mm2, P = .006; 61.01 ± 9.41 vs 56.92% ± 11.42%, P = .001) were considerably larger in the lesions with VV than in those without VV. In addition, densely calcified plaques (0.41 ± 0.26 vs 0.81 ± 0.59 mm2, P < .001; 3.63 ± 2.19 vs 7.18% ± 2.01%, P < .001) were considerably smaller in the lesions with VV than in those without VV. Multivariate analyses revealed that VV and plaque volume were independent predictors of NRP after stent deployment (odds ratio [OR]: 5.13, 95% confidence interval [CI]: 1.19-15.32, P = .002; OR: 4.79, 95% CI: 1.08-9.01, P = .005). Lesions with VV exhibited considerable plaque vulnerability in patients with ACS, and they displayed more NRP during PCI. VV and plaque volume were independent predictors of NRP after stent deployment.

Early computed tomography coronary angiography in adults presenting with suspected acute coronary syndrome: the RAPID-CTCA RCT.

BACKGROUND: Acute coronary syndrome is a common medical emergency. The optimal strategy to investigate patients who are at intermediate risk of acute coronary syndrome has not been fully determined. OBJECTIVE: To investigate the role of early computed tomography coronary angiography in the investigation and treatment of adults presenting with suspected acute coronary syndrome. DESIGN: A prospective, multicentre, open, parallel-group randomised controlled trial with blinded end-point adjudication. SETTING: Thirty-seven hospitals in the UK. PARTICIPANTS: Adults (aged ≥ 18 years) presenting to the emergency department, acute medicine services or cardiology department with suspected or provisionally diagnosed acute coronary syndrome and at least one of the following: (1) a prior history of coronary artery disease, (2) a cardiac troponin level > 99th centile and (3) an abnormal 12-lead electrocardiogram. INTERVENTIONS: Early computed tomography coronary angiography in addition to standard care was compared with standard care alone. Participants were followed up for 1 year. MAIN OUTCOME MEASURE: One-year all-cause death or subsequent type 1 (spontaneous) or type 4b (stent thrombosis) myocardial infarction, measured as the time to such event adjudicated by two cardiologists blinded to the computerised tomography coronary angiography ( CTCA ) arm. Cost-effectiveness was estimated as the lifetime incremental cost per quality-adjusted life-year gained. RESULTS: Between 23 March 2015 and 27 June 2019, 1748 participants [mean age 62 years (standard deviation 13 years), 64% male, mean Global Registry Of Acute Coronary Events score 115 (standard deviation 35)] were randomised to receive early computed tomography coronary angiography (n = 877) or standard care alone (n = 871). The primary end point occurred in 51 (5.8%) participants randomised to receive computed tomography coronary angiography and 53 (6.1%) participants randomised to receive standard care (adjusted hazard ratio 0.91, 95% confidence interval 0.62 to 1.35; p = 0.65). Computed tomography coronary angiography was associated with a reduced use of invasive coronary angiography (adjusted hazard ratio 0.81, 95% confidence interval 0.72 to 0.92; p = 0.001) but no change in coronary revascularisation (adjusted hazard ratio 1.03, 95% confidence interval 0.87 to 1.21; p = 0.76), acute coronary syndrome therapies (adjusted odds ratio 1.06, 95% confidence interval 0.85 to 1.32; p = 0.63) or preventative therapies on discharge (adjusted odds ratio 1.07, 95% confidence interval 0.87 to 1.32; p = 0.52). Early computed tomography coronary angiography was associated with longer hospitalisations (median increase 0.21 days, 95% confidence interval 0.05 to 0.40 days) and higher mean total health-care costs over 1 year (£561 more per patient) than standard care. LIMITATIONS: The principal limitation of the trial was the slower than anticipated recruitment, leading to a revised sample size, and the requirement to compromise and accept a larger relative effect size estimate for the trial intervention. FUTURE WORK: The potential role of computed tomography coronary angiography in selected patients with a low probability of obstructive coronary artery disease (intermediate or mildly elevated level of troponin) or who have limited access to invasive cardiac catheterisation facilities needs further prospective evaluation. CONCLUSIONS: In patients with suspected or provisionally diagnosed acute coronary syndrome, computed tomography coronary angiography did not alter overall coronary therapeutic interventions or 1-year clinical outcomes, but it did increase the length of hospital stay and health-care costs. These findings do not support the routine use of early computed tomography coronary angiography in intermediate-risk patients with acute chest pain. TRIAL REGISTRATION: This trial is registered as ISRCTN19102565 and Clinical Trials NCT02284191. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 37. See the NIHR Journals Library website for further project information.

WHY DID WE DO THE RESEARCH?: Chest pain is a common medical emergency. It is important to decide if the cause is a heart attack. The two tests that are often used are a heart recording (electrocardiogram) and a blood test (troponin levels). If both are normal, the cause of chest pain is unlikely to be a heart attack and the patient is often discharged home. If either test is positive or if the patient has had previous heart problems, then the patient may require further investigation. We wanted to test whether or not adding a heart scan called a computerised tomography coronary angiogram improved patients' care. HOW DID WE DO THE RESEARCH?: We carried out a randomised trial in which half of the patients attending hospital with chest pain had a computerised tomography coronary angiography scan as part of their assessment and half of the patients did not. In total, 1749 patients were recruited and followed up for 1 year. BRINGING IT ALL TOGETHER: The use of an additional early computerised tomography coronary angiography scan for chest pain patients of medium risk produced only small improvements in patient care.

Assessment of Myocardial Work of the Left Ventricle before and after PCI in Patients with Non-ST-Segment Elevation Acute Coronary Syndrome by Pressure-Strain Loop Technology.

Objectives: Noninvasive left ventricular pressure-strain loop (PSL) is a new method for quantitative evaluation of myocardial work, which is developed on the basis of speckle tracking echocardiography. It is necessary to fit the noninvasive left ventricular pressure and the strain by speckle tracking echocardiography to construct a pressure-strain loop. Compared with traditional left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS), it has potential application value and is a useful supplement for clinical evaluation of left ventricular systolic function. We perform this study to evaluate the changes of myocardial function in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) before and after percutaneous coronary intervention (PCI) with noninvasive left ventricular pressure-strain loop (PSL). Methods: 33 NSTE-ACS patients admitted to the Department of Cardiovascular Medicine of the Affiliated Lianyungang Hospital of Xuzhou Medical University who successfully underwent early PCI were included as the PCI group. At the same time, 30 healthy patients matched in age and sex were selected as the control group. All patients received routine echocardiography. The parameters such as GWI, GCW, GWW, and GWE were obtained by EchoPAC 203 software. The differences in the general clinical data and echocardiographic parameters between the two groups, including controls and patients 1 day before surgery and 1 month after surgery, were compared. Results: Compared with the control group, GWI, GCW, and GWI in the PCI group were decreased 1 day before surgery and 1 month after surgery, while GWW was increased, with statistical significance (P < 0.05). In the PCI group, compared with 1 day before surgery, GWI and GCW were all increased 1 month after surgery (P < 0.05), and GWW and GWE were not significantly different between the two groups (P > 0.05). Conclusion: The noninvasive left ventricular PSL technology can early and accurately evaluate the myocardial function impairment in NSTE-ACS patients and the recovery of myocardial function after PCI, providing a new noninvasive method for clinical postoperative myocardial function evaluation.

Assessment of radial artery atherosclerosis in acute coronary syndrome patients: an in vivo study using optical coherence tomography.

BACKGROUND: Radial artery (RA) atherosclerosis in acute coronary syndrome (ACS) patients has not been systematically observed in vivo. The study aims to characterize plaque morphology and intimal hyperplasia of the RA in patients with ACS, using optical coherence tomography (OCT). METHODS: In this retrospective study involving 239 ACS patients underwent RA OCT without guidewire shadow, 3 groups were divided according to the following criteria: radial artery plaque (RAP) group included patients with fibrous, lipid or calcified plaque; patients without RAP were further classified into radial intimal hyperplasia (RIH) group (intima media thickness ratio [IMR] ≥ 1) or normal group (IMR < 1). The presence and characteristics of RAP and its related risk factors were identified. RESULTS: The RAP, RIH and normal groups included 76 (31.8%), 69 (28.9%) and 94 (39.3%) patients, respectively. Patients in RAP group were the oldest, compared with those in the RIH and normal groups (p < 0.001), and more frequently had triple vessel disease (p = 0.004). The percentage of plaque rupture (72.4% vs. 56.4%, p = 0.018) and calcification (42.1% vs. 27.6%, p = 0.026) at culprit lesion were significantly higher in patients with RAP than those without RAP. A total of 148 RAP were revealed by OCT, including fibrous (72, 48.6%), lipid (50, 33.8%) and calcified plaques (26, 17.6%). The microvessels were also frequently observed in the RAP group than that in RIH and normal groups (59.2% vs. 8.7% vs. 9.6%, p < 0.001). Multivariate logistic regression analysis showed that age, diabetes, and smoking history (all p < 0.05) were independent risk factors for RAP. CONCLUSIONS: In terms of insights gained from OCT, RA atherosclerosis is not uncommon in ACS patients by OCT, sharing several morphological characters with early coronary atherosclerosis. Aging, diabetes, and smoking are risk factors for RAP.

Alternative sites of echocardiographic epicardial fat assessment and coronary artery disease.

AIMS: Increasing evidence points towards the use of epicardial fat (EF) as a reliable biomarker of coronary artery disease extent and severity. We aim to assess the different locations of echocardiographic EF thickness measurement and their relation with the presence, extent, and severity of coronary artery disease (CAD) in patients admitted with acute coronary syndromes (ACS). METHODS: Prospective cohort study including patients admitted for ACS. EF was assessed by transthoracic echocardiography and compared with coronary angiography findings. Spearmen correlation analysis was used to search for EF correlations. Receiver-operating characteristic curve analysis was performed to assess the predictive value of the different sites of measurement of EF thickness for the presence of CAD. To evaluate other potential variables independently associated with CAD, we performed multivariate analysis employing logistic regression. RESULTS: 196 patients were included. Significant CAD was diagnosed in 83.7% of patients. In all views, EF thickness was greater in patients with CAD (p < 0.001). We found a moderate correlation between EF thickness and CAD extent and severity. EF thickness measured at RV basal level showed a good performance in predicting significant CAD in patients with ACS (AUC = 0.885, 95% CI 0.80-0.97, p < 0.001). For a value of mean RV basal region EF thickness ≥ 12.57 mm, sensitivity was 85% and specificity was 80.8%. CONCLUSION: In patients admitted with ACS, echocardiographic EF thickness predicted the presence of CAD, as well as its extent and severity. We found EF thickness measured at the RV basal region to be the best predictor of significant CAD.

Early invasive versus non-invasive assessment in patients with suspected non-ST-elevation acute coronary syndrome.

Non-ST-elevation acute coronary syndrome (NSTE-ACS) comprises a broad spectrum of disease ranging from unstable angina to myocardial infarction. International guidelines recommend a routine invasive strategy for managing patients with NSTE-ACS at high to very high-risk, supported by evidence of improved composite ischaemic outcomes as compared with a selective invasive strategy. However, accurate diagnosis of NSTE-ACS in the acute setting is challenging due to the spectrum of non-coronary disease that can manifest with similar symptoms. Heterogeneous clinical presentations and limited uptake of risk prediction tools can confound physician decision-making regarding the use and timing of invasive coronary angiography (ICA). Large proportions of patients with suspected NSTE-ACS do not require revascularisation but may unnecessarily undergo ICA with its attendant risks and associated costs. Advances in coronary CT angiography and cardiac MRI have prompted evaluation of whether non-invasive strategies may improve patient selection, or whether tailored approaches are better suited to specific subgroups. Future directions include (1) better understanding of risk stratification as a guide to investigation and therapy in suspected NSTE-ACS, (2) randomised clinical trials of non-invasive imaging versus standard of care approaches prior to ICA and (3) defining the optimal timing of very early ICA in high-risk NSTE-ACS.

Economic Impact And SafetY of Same-Day Discharge Following Percutaneous Coronary Intervention: A Tertiary-Care Centre Experience From Northern India (EASY-SDD).

BACKGROUND: The literature about the safety and feasibility of same-day discharge (SDD) following complex percutaneous coronary intervention (PCI) and in acute coronary syndrome (ACS) is scarce. The economic impact of SDD has not been evaluated in this geographical region. We in the present study evaluated the safety, feasibility, and economic impact of SDD following PCI at a tertiary care centre of north India. METHODS: It was a single-centre, non-randomized, prospective study, in which all consecutive PCI patients during the study period of 15 months were evaluated for SDD using a "patient-centred" approach. The patients who were discharged on the next calendar day were included in the next day discharge (NDD) group. The baseline demographic data including coronary risk factors, clinical presentation, and management details were noted for all patients. All patients were followed up for 6 weeks. The Indian health system is only partially insured, hence most of the expendable costs are borne by patients. In the present study, we computed the total societal expenditure of each PCI which includes both the health system costs and the expenditure borne by the patients. A standardized tool and bottoms up costing method were used for recording out-of-pocket expenditure (OOPE) by the patients and health care expenditure respectively. RESULTS: Out of a total of 675 PCI patients, 617 patients were enrolled in the study, and 132/617 (21.39%) patients were discharged the same day. Sixty-five % of patients (86/132) in the SDD cohort and 70% of patients (337/485) in the NDD cohort presented with ACS. Baseline characteristics in the two cohorts were identical. A higher syntax score, greater number of stents, and longer stented segment predicted the NDD. The mean length of stay after PCI in patients with SDD and NDD was 8.71 ± 2.48 and 21.76 ± 2.42 h, respectively. In the SDD group, there were no readmissions or adverse events after discharge till 6 weeks of follow-up. The total mean cost of PCI (health care system and OOPE) for SDD and NDD was Indian Rupees (INR) 129,322.14 [United States dollar (US$) 1810.51] and INR 165500.71 [US$ 2317.01] respectively. An amount of INR 36178.57 (health system cost: INR 10242.76 and OOPE: INR 25935.71 was saved for each SDD. Besides 100 cardiac unit bed days including 85 intensive cardiac care bed days were saved with 21% SDD in the present cohort. CONCLUSION: Post PCI SDD is safe and feasible in selected ACS/chronic stable angina patients using the "patient-centred" approach. Besides, decreasing OOPE for the patients, SDD also helps in the efficient use of scarce health system resources.

Coronary CT angiography for improved assessment of patients with acute chest pain and low-range positive high-sensitivity troponins: study protocol for a prospective, observational, multicentre study (COURSE trial).

INTRODUCTION: Current evaluation of patients suspected of a non-ST-elevation acute coronary syndrome (NSTE-ACS) involves the use of algorithms that incorporate clinical information, electrocardiogram (ECG) and high-sensitivity cardiac troponins (hs-troponins). While primarily designed to rule out NSTE-ACS safely, these algorithms can also be used for rule in of NSTE-ACS in some patients. Still, in a substantial number of patients, these algorithms do not provide a conclusive work-up. These patients often present with an atypical clinical profile and low-range positive hs-troponin values without a characteristic rise or fall pattern. They represent a heterogeneous group of patients with various underlying conditions; only a fraction (30%-40%) will eventually be diagnosed with a myocardial infarction. Uncertainty exists about the optimal diagnostic strategy and their management depends on the clinical perspective of the treating physician ranging from direct discharge to admission for invasive coronary angiography. Coronary CT angiography (CCTA) is a non-invasive test that has been shown to be safe, fast and reliable in the evaluation of coronary artery disease. In this study, we will determine the usefulness of CCTA in patients with acute chest pain and low-range positive hs-troponin values. METHODS AND ANALYSIS: A prospective, double-blind, observational, multicentre study conducted in the Netherlands. Patients aged 30-80 years presenting to the emergency department with acute chest pain and a suspicion of NSTE-ACS, a normal or non-diagnostic ECG and low-range positive hs-troponins will be scheduled to undergo CCTA. The primary outcome is the diagnostic accuracy of CCTA for the diagnosis of NSTE-ACS at discharge, in terms of sensitivity and negative predictive value. ETHICS AND DISSEMINATION: This study was approved by the Medical Research Ethics Committee of Erasmus Medical Center in Rotterdam, the Netherlands (registration number MEC-2017-506). Written informed consent to participate will be obtained from all participants. This study's findings will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT03129659).

Prognostic Impact of Pancoronary Quantitative Flow Ratio Assessment in Patients Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndromes.

BACKGROUND: Quantitative flow ratio (QFR) has been introduced as a novel angiography-based modality for fast hemodynamic assessment of coronary artery lesions and validated against fractional flow reserve. This study sought to define the prognostic role of pancoronary QFR assessment in patients with acute coronary syndrome (ACS) including postinterventional culprit and nonculprit vessels. METHODS: In a total of 792 patients with ACS (48.6% ST-segment-elevation ACS and 51.4% non-ST-segment-elevation ACS), QFR analyses of postinterventional culprit (n=792 vessels) and nonculprit vessels (n=1231 vessels) were post hoc performed by investigators blinded to clinical outcomes. The follow-up comprised of major adverse cardiovascular events, including all-cause mortality, nonfatal myocardial infarction, and ischemia-driven coronary revascularization within 2 years after the index ACS event. RESULTS: Major adverse cardiovascular events as composite end point occurred in 99 patients (12.5%). QFR with an optimal cutoff value of 0.89 for postinterventional culprit vessels and 0.85 for nonculprit vessels emerged as independent predictor of major adverse cardiovascular events after ACS (nonculprit arteries: adjusted odds ratio, 3.78 [95% CI, 2.21-6.45], P<0.001 and postpercutaneous coronary intervention culprit arteries: adjusted odds ratio, 3.60 [95% CI, 2.09-6.20], P<0.001). CONCLUSIONS: The present study for the first time demonstrates the prognostic implications of a pancoronary angiography-based functional lesion assessment in patients with ACS. Hence, QFR offers a novel tool to advance risk stratification and guide therapeutic management after ACS.

Importance of Risk Assessment in Timing of Invasive Coronary Evaluation and Treatment of Patients With Non-ST-Segment-Elevation Acute Coronary Syndrome: Insights From the VERDICT Trial.

Background The optimal timing of invasive examination and treatment of high-risk patients with non-ST-segment-elevation acute coronary syndrome has not been established. We investigated the efficacy of early invasive coronary angiography compared with standard-care invasive coronary angiography on the risk of all-cause mortality according to the GRACE (Global Registry of Acute Coronary Events) risk score in a predefined subgroup analysis of the VERDICT (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography) trial. Methods and Results Patients with clinical suspicion of non-ST-segment-elevation acute coronary syndrome with ECG changes indicating new ischemia and/or elevated troponin, in whom invasive coronary angiography was clinically indicated and deemed logistically feasible within 12 hours, were eligible for inclusion. Patients were randomized 1:1 to an early (≤12 hours) or standard (48-72 hours) invasive strategy. The primary outcome of the present study was all-cause mortality. Of 2147 patients randomized in the VERDICT trial, 2092 patients had an available GRACE risk score. Of these, 1021 (48.8%) patients had a GRACE score >140. During a median follow-up of 4.1 years, 192 (18.8%) and 54 (5.0%) patients died in the high and low GRACE score groups, respectively. The risk of death with the early invasive strategy was increased in patients with a GRACE score ≤140 (hazard ratio [HR], 2.04 [95% CI, 1.16-3.59]), whereas there was a trend toward a decreased risk of death with the early invasive strategy in patients with a GRACE score >140 (HR, 0.83 [95% CI, 0.63-1.10]) (Pinteraction=0.006). Conclusions In patients with non-ST-segment-elevation acute coronary syndrome, we found a significant interaction between timing of invasive coronary angiography and GRACE score on the risk of death. Randomized clinical trials are warranted to establish the efficacy and safety among high-risk and low-risk patients with non-ST-segment-elevation acute coronary syndrome. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02061891.

NITRATE-CIN Study: Protocol of a Randomized (1:1) Single-Center, UK, Double-Blind Placebo-Controlled Trial Testing the Effect of Inorganic Nitrate on Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography for Acute Coronary Syndromes.

BACKGROUND: Contrast-induced nephropathy (CIN), an acute kidney injury resulting from the administration of intravascular iodinated contrast media, is a significant cause of morbidity/mortality following coronary angiographic procedures in high-risk patients. Despite preventative measures intended to mitigate the risk of CIN, there remains a need for novel effective treatments. Evidence suggests that delivery of nitric oxide (NO) through chemical reduction of inorganic nitrate to NO may offer a novel therapeutic strategy to reduce CIN and thus preserve long term renal function. DESIGN: The NITRATE-CIN trial is a single-center, randomized, double-blind placebo-controlled trial, which plans to recruit 640 patients presenting with acute coronary syndromes (ACS) who are at risk of CIN. Patients will be randomized to either inorganic nitrate therapy (capsules containing 12 mmol KNO3) or placebo capsules containing potassium chloride (KCl) daily for 5 days. The primary endpoint is development of CIN using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. A key secondary endpoint is renal function over a 3-month follow-up period. Additional secondary endpoints include serum renal biomarkers (e.g. neutrophil gelatinase-associated lipocalin) at 6 h, 48 h and 3 months following administration of contrast. Cost-effectiveness of inorganic nitrate therapy will also be evaluated. SUMMARY: This study is designed to investigate the hypothesis that inorganic nitrate treatment decreases the rate of CIN as part of semi-emergent coronary angiography for ACS. Inorganic nitrate is a simple and easy to administer intervention that may prove useful in prevention of CIN in at-risk patients undergoing coronary angiographic procedures.

Feasibility and diagnostic reliability of quantitative flow ratio in the assessment of non-culprit lesions in acute coronary syndrome.

Several studies have demonstrated the feasibility and safety of hemodynamic assessment of non-culprit coronary arteries in setting of acute coronary syndromes (ACS) using fractional flow reserve (FFR) measurements. Quantitative flow ratio (QFR), recently introduced as angiography-based fast FFR computation, has been validated with good agreement and diagnostic performance with FFR in chronic coronary syndromes. The aim of this study was to assess the feasibility and diagnostic reliability of QFR assessment during primary PCI. A total of 321 patients with ACS and multivessel disease, who underwent primary PCI and were planned for staged PCI of at least one non-culprit lesion were enrolled in the analysis. Within this patient cohort, serial post-hoc QFR analyses of 513 non-culprit vessels were performed. The median time interval between primary and staged PCI was 49 [42-58] days. QFR in non-culprit coronary arteries did not change between acute and staged measurements (0.86 vs 0.87, p = 0.114), with strong correlation (r = 0.94, p ≤ 0.001) and good agreement (mean difference -0.008, 95%CI -0.013-0.003) between measurements. Importantly, QFR as assessed at index procedure had sensitivity of 95.02%, specificity of 93.59% and diagnostic accuracy of 94.15% in prediction of QFR ≤ 0.80 at the time of staged PCI. The present study for the first time confirmed the feasibility and diagnostic accuracy of non-culprit coronary artery QFR during index procedure for ACS. These results support QFR as valuable tool in patients with ACS to detect further hemodynamic relevant lesions with excellent diagnostic performance and therefore to guide further revascularisation therapy.

Serial assessment of de novo coronary lesions after drug-coated balloon treatment analyzed by intravascular ultrasound: A comparison between acute coronary syndrome and stable angina pectoris.

BACKGROUND: This study aimed to assess the serial changes in de novo coronary lesions, including acute coronary syndrome (ACS), treated with a drug-coated balloon (DCB). METHODS: In this retrospective single-center study, the intravascular changes in patients with de novo lesions treated with DCB were evaluated with serial intravascular ultrasound (IVUS) pre-procedure, post-procedure, and at follow-up. A two-dimensional IVUS measurement was performed with slices at 1 mm intervals in the treated lesion. RESULTS: This study comprised 40 lesions, including 27 lesions with stable angina pectoris (SAP) and 13 ACS. IVUS showed that the median vessel and lumen area increased significantly from pre-procedure to post-procedure and from post-procedure to follow-up. The median plaque area decreased significantly from pre-procedure to post-procedure and follow-up. The IVUS between ACS and SAP demonstrated that the total vessel volume and the total lumen volume increased, and the total atheroma volume decreased significantly from pre- to follow-up in both groups. The percent change in the lumen area increased, and the plaque area decreased significantly in ACS compared to SAP from pre- to post-procedure and follow-up. CONCLUSION: The findings of this study suggest that DCB treatment for de novo coronary lesions in patients with ACS and SAP may maintain anatomical patency and increase lumen with positive vessel remodeling and regression of plaque.

Close Association of Matrix Metalloproteinase-9 Levels With the Presence of Thin-Cap Fibroatheroma in Acute Coronary Syndrome Patients: Assessment by Optical Coherence Tomography and Intravascular Ultrasonography.

BACKGROUND: Thin-cap fibroatheroma (TCFA) has been suggested as a precursor lesion of coronary plaque rupture. As elevated plasma matrix metalloproteinase-9 (MMP-9) levels have been documented in patients with acute coronary syndrome (ACS), we sought to determine whether the presence of TCFA is linked to MMP-9 levels in these patients. METHODS: We evaluated 51 ACS patients with de novo culprit lesions who were examined via optical coherence tomography and intravascular ultrasound. Blood samples were obtained from the peripheral vein (PV) and the ostium and culprit lesion of the infarct-related coronary artery (CA) in the acute phase of ACS and from the PV in the chronic phase (8 months after ACS). RESULTS: The plasma MMP-9 level in the acute phase was significantly higher than that in the chronic phase. Plasma MMP-9 levels at the culprit lesion of the infarct-related CA were significantly higher than, but positively correlated with those in the PV (10.9 (5.9-16.1) ng/mL and 8.9 (5.6-13.0) ng/mL, p < 0.0001, respectively; Spearman ρ = 0.84, p < 0.0001). Significantly higher PV plasma MMP-9 levels were observed in patients with TCFA than in patients without TCFA (12.1 (7.0-13.5) and 5.7 (4.0-8.2) ng/ml, p<0.0001, respectively). Further, plasma MMP-9 levels in the PV were positively correlated with the remodeling index (Spearman ρ = 0.29, p = 0.039) and negatively correlated with fibrous cap thickness (Spearman ρ = -0.42, p = 0.0021). Receiver operating characteristic curve analysis showed that the plasma MMP-9 levels in the PV could predict the presence of TCFA at a cut-off value of 9.9 ng/mL. CONCLUSIONS: Plasma MMP-9 levels were closely associated with MMP-9 levels in the CA and were further linked with TCFA in patients with ACS.

A novel risk assessment model of contrast-induced nephropathy after percutaneous coronary intervention in patients with diabetes.

The purpose of our study was to develop a simple clinical pre-procedure risk model based on clinical characteristics for the prediction of contrast-induced nephropathy (CIN) and major adverse cardiac events (MACEs) after percutaneous coronary intervention (PCI) in patients with diabetes. A total of 1113 patients with diabetes who underwent PCI with contrast exposure were randomized into a development group (n = 742) and a validation group (n = 371) in a 2:1 ratio. CIN was defined as an increase of either 25% or 0.5 mg/dL (44.2 µmol/L) in serum creatinine within 72 hours after contrast infusion. A simple CIN risk score based on independent predictors was established. Four variables were identified for our risk score model: LVEF < 40%, acute coronary syndrome (ACS), eGFR < 60, and contrast volume > 300 mL. Based on this new CIN risk score, the incidence of CIN had a significant trend with increased predicting score values of 5.9%, 32.9% and 60.0%, corresponding to low-, moderate- and high-risk groups, respectively. The novel risk assessment exhibited moderate discrimination ability for predicting CIN, with an AUC of 0.759 [95% CI 0.668-0.852, P = .001] in the validation cohort. It also had similar prognostic values for one-year follow-up MACE (C-statistic: 0.705 and 0.606 for new risk score and Mehran score, respectively). This novel risk prediction model could be effective for preventing nephropathy in diabetic patients receiving contrast media during surgical procedures.

Reviewing imaging modalities for the assessment of plaque erosion.

Plaque rupture followed by intracoronary thrombus formation is recognized as the most common pathophysiological mechanism in acute coronary syndromes (ACS). The second most common underlying substrate for ACS is plaque erosion whose hallmark is thrombus formation without cap disruption. Invasive and non-invasive methods have emerged as a promising tool for evaluation of plaque features that either predict or detect plaque erosion. Optical coherence tomography (OCT), high-definition intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS), and near-infrared autofluorescence (NIRF) have been used to study plaque erosion. The detection of plaque erosion in the clinical setting, mainly facilitated by OCT, has shed light upon the complex pathophysiology underlying ACS not related to plaque rupture. Coronary computed tomography angiography (CCTA), which is to date the most commonly used non-invasive technique for coronary plaque evaluation, may also have a role in the evaluation of patients predisposed to erosion. Also, computational models enabling quantification of endothelial shear stress may pave the way to new research in coronary plaque pathophysiology. This review focuses on the recent imaging techniques for the evaluation of plaque erosion including invasive and non-invasive assessment.

Combined stress myocardial CT perfusion and coronary CT angiography as a feasible strategy among patients presenting with acute chest pain to the emergency department.

BACKGROUND: A combined approach of myocardial CT perfusion (CTP) with coronary CT angiography (CTA) was shown to have better diagnostic accuracy than coronary CTA alone. However, data on cost benefits and length of stay when compared to other perfusion imaging modalities has not been evaluated. Therefore, we aim to perform a feasibility study to assess direct costs and length of stay of a combined stress CTP/CTA and use SPECT myocardial perfusion imaging (SPECT-MPI) as a benchmark, among chest pain patients at intermediate-risk for acute coronary syndrome (ACS) presenting to the emergency department (ED). METHODS: This is a prospective two-arm clinical trial (NCT02538861) with 43 patients enrolled in stress CTP/CTA arm (General Electric Revolution CT) and 102 in SPECT-MPI arm. Mean age of the study population was 65 â€‹± â€‹12 years; 56% were men. We used multivariable linear regression analysis to compare length of stay and direct costs between the two modalities. RESULTS: Overall, 9 out of the 43 patients (21%) with CTP/CTA testing had an abnormal test. Of these 9 patients, 7 patients underwent invasive coronary angiography and 6 patients were found to have obstructive coronary artery disease. Normal CTP/CTA test was found in 34 patients (79%), who were discharged home and all patients were free of major adverse cardiac events at 30 days. The mean length of stay was significantly shorter by 28% (mean difference: 14.7 â€‹h; 95% CI: 0.7, 21) among stress CTP/CTA (20 â€‹h [IQR: 16, 37]) compared to SPECT-MPI (30 â€‹h [IQR: 19, 44.5]). Mean direct costs were significantly lower by 44% (mean difference: $1535; 95% CI: 987, 2082) among stress CTA/CTP ($1750 [IQR: 1474, 2114] compared to SPECT-MPI ($2837 [IQR: 2491, 3554]). CONCLUSION: Combined stress CTP/CTA is a feasible strategy for evaluation of chest pain patients presenting to ED at intermediate-risk for ACS and has the potential to lead to shorter length of stay and lower direct costs.