Impact of Climate on the Incidence of Acute Coronary Syndrome - Differences Between Japan and Thailand

Background: Although there are many reports of temperature being associated with the onset of acute coronary syndrome (ACS), few studies have examined differences in ACS due to climatic differences between Japan and Thailand. The aim of this joint Japan-Thailand study was to compare patients with myocardial infarction in Japanese and Thai hospitals in different climates. Methods and Results: We estimated the climate data in 2021 for the Wakayama Prefecture and Chonburi Province, two medium-sized cities in Japan and Thailand, respectively, and ACS patients who were treated at the Wakayama Medical University (WMU) and Burapha University Hospital (BUH), the two main hospitals in these provinces (ACS patient numbers: WMU, n=177; BUH, n=93), respectively. In the Chonburi Province, although the average temperature was above 25℃, the number of ACS cases in BUH varied up to threefold between months (minimum: July, 4 cases; maximum: October, 14 cases). In Japan and Thailand, there was a mild to moderate negative correlation between temperature-atmospheric pressure at the onset of ACS, but different patterns for temperature-humidity (temperature-atmospheric pressure, temperature-humidity, and atmospheric pressure-humidity: correlation index; r=-0.561, 0.196, and -0.296 in WMU vs. r=-0.356, -0.606, and -0.502 in BUH). Conclusions: The present study suggests that other climatic conditions and factors, not just temperature, might be involved in the mechanism of ACS.

Intracoronary Near-Infrared Spectroscopy to Predict No-Reflow Phenomenon During Percutaneous Coronary Intervention in Acute Coronary Syndrome

Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) can identify the lipid-rich lesions, described as high lipid-core burden index (LCBI). The aim of this study was to investigate the relation between lipid-core plaque (LCP) in the infarct-related lesion detected using NIRS-IVUS and no-reflow phenomenon during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). We investigated 371 patients with ACS who underwent NIRS-IVUS in the infarct-related lesions before PCI. The extent of LCP in the infarct-related lesion was calculated as the maximum LCBI for each of the 4-mm longitudinal segments (maxLCBI4mm) measured by NIRS-IVUS. The patients were divided into 2 groups using a maxLCBI4mm cut-off value of 400. The overall incidence of no-reflow phenomenon was 53 of 371 (14.3%). No-reflow phenomenon more frequently occurred in patients with maxLCBI4mm ≥400 compared with those with maxLCBI4mm<400 (17.5% vs 2.5%, p <0.001). After propensity score matching, multivariable logistic regression analysis demonstrated that maxLCBI4mm (odds ratio: 1.008; 95% confidence interval: 1.005 to 1.012, p <0.001) was independently associated with the no-reflow phenomenon. The maxLCBI4mm of 719 in the infarct-related lesion had the highest combined sensitivity (69.8%) and specificity (72.1%) for the identification of no-reflow phenomenon. In conclusion, in patients with ACS, maxLCBI4mm in the infarct-related lesion assessed by NIRS-IVUS was independently associated with the no-reflow phenomenon during PCI.

Relationship between intrathrombotic appearance of HSP27 and HSP70 and thrombus ages in a murine model of deep vein thrombosis

Heat shock proteins (HSPs) are molecular chaperones whose primary function is cytoprotection, supporting cell survival under (sub) lethal conditions. They have been implicated in various diseases such as inflammatory diseases and cancer due to their cytoprotective and immunomodulatory effects, and their biological mechanisms have been studied. Central family members include, HSP27, which is induced by various stimuli such as heat shock, hypoxia, hyperoxia, ultraviolet exposure, and nutritional deficiency, and HSP70, which is homeostatically expressed in many organs such as the gastrointestinal tract and has anti-cell death and anti-inflammatory effects. In this study, HSP27 and HSP70 were investigated during thrombus formation and dissolution in a deep vein thrombosis model by immunohistochemistry to determine their involvement in this process and whether their expression could be used as a forensic marker. In the process of thrombus formation and lysis, HSP27 and HSP70 were found to be expressed by immunohistochemical analysis. The role of inhibitors of HSP27 and HSP70 in the pathogenesis of thrombosis in mice was also investigated. When HSP27 or HSP70 inhibitors were administered, thrombi were significantly smaller than in the control group on day 5 after inferior vena cava ligation, indicating pro-thrombotic effects HSP27 and HSP70. If HSP27- or HSP70-positive cells were clearly visible and easily identifiable in the thrombus sections, the thrombus was presumed to be more than 10 days old. Thus, the detection of intrathrombotic HSP27 and HSP70 could forensically provide useful information for the estimation of thrombus ages. Collectively, our study implied that both HSP27 and HSP70 might be molecular targets for thrombus therapy and that the detection of HSP-related molecules such as HSP27 and HSP70 could be useful for the determination of thrombus ages.

Diagnostic significance of paradoxical left ventricular hypertrophy in detecting cardiac amyloidosis

Background

Cardiac amyloidosis (CA) progresses rapidly with a poor prognosis. Therefore, methods for early diagnosis that are easily accessible in any hospital, are required. We hypothesized that based on the pathology of CA, morphological left ventricular hypertrophy (LVH) without electrical augmentation, namely paradoxical LVH, could be used to diagnose CA. This study aimed to investigate whether paradoxical LVH has diagnostic significance in identifying CA in patients with LVH.

Methods

Patients who presented with left ventricular (LV) wall thickness ≥ 12 mm on cardiac magnetic resonance (CMR) were enrolled from a multicentre CMR registry. Paradoxical LVH was defined as a LV wall thickness ≥ 12 mm on CMR, SV1 + RV5 < 3.5 mV, and a lack of secondary ST-T abnormalities. The diagnostic significance of paradoxical LVH in identifying CA was assessed.

Results

Of the 110 patients enrolled, 30 (27 %) were diagnosed with CA and 80 (73 %) with a non-CA aetiology. The CA group demonstrated paradoxical LVH more frequently than the non-CA group (80 % vs. 16 %, P < 0.001). It was an independent predictor for detecting CA in patients with LVH (odds ratio: 33.44, 95 % confidence interval: 8.325-134.3, P < 0.001). The sensitivity, specificity, positive predict value, negative predict value and accuracy of paradoxical LVH for CA detection were 80 %, 84 %, 65 %, 92 % and 83 %, respectively.

Conclusions

Paradoxical LVH can be used for identifying CA in patients with LVH. Our findings could contribute to the early diagnosis of CA, even in non-specialized hospitals.

Characteristics of Discharged Elderly Patients with Acute Heart Failure Followed by Board-Certified-Cardiologists in a Rural Area of Japan

The worldwide incidence rates of heart failure (HF) are approaching pandemic status due to aging societies. Board-certified cardiologists (BCCs) of the Japanese Circulation Society (JCS) are cardiologists who have completed the respective fellowship program and passed the examination. However, in rural areas, patients have limited access to medical care for social or geographical reasons. The clinical features of the specialist's follow-up for HF patients in rural areas are unclear.This study consists of 205 consecutive discharged elderly patients who were admitted to our hospital due to acute HF (AHF). All patients were recommended for follow-up with BCCs-JCS by the multidisciplinary HF team at the discharge-care planning meeting. The aim of this study was to investigate the clinical features and impact of BCC follow-up for discharged elderly patients with AHF in rural areas.A total of 156 patients chose follow-up with BCCs-JCS (BCC group), and 49 patients chose follow-up with non-BCCs-JCS (non-BCC group). Patients in the BCC group were younger (83 [76-86] versus 89 [75-93] years old, P < 0.001) and had more frequent use of β-blockers (67% versus 39%, P < 0.001). The degree of frailty assessed by the clinical frailty scale was more severe in the non-BCC group than in the BCC group (4 [3-5] versus 6 [4-7], P < 0.001). The non-BCC group lived in nursing homes more frequently than the BCC group (16% versus 5%, P = 0.011).The HF patients followed by BCCS-JCS in rural areas were younger and had less frailty.

Low Energy Intake Diagnosed Using the Harris-Benedict Equation Is Associated with Poor Prognosis in Elderly Heart Failure Patients

INTRODUCTION

Insufficient nutrient intake is a strong independent predictor of mortality in elderly patients with heart failure. However, it is unclear to what extent energy intake affects their prognosis. This study investigated the association between patient outcomes and actual measured energy intake in elderly patients (≥65 years) with heart failure.

METHODS

This study enrolled 139 elderly patients who were hospitalized with worsening heart failure at Shingu Municipal Medical Center, Shingu, Japan, between May 2017 and April 2018. Energy intake was evaluated for three days (from three days prior to the day of discharge until the day of discharge). Based on basal energy expenditure calculated using the Harris-Benedict equation, the patients were classified into a low-energy group (n = 38) and a high-energy group (n = 101). We assessed the prognosis in terms of both all-cause mortality and readmission due to worsening heart failure as a primary outcome.

RESULTS

Compared to the patients in the high-energy group, the patients in the low-energy group were predominantly female, less frequently had smoking habits and ischemic heart diseases, and had a higher left ventricular ejection fraction. The low-energy group had higher mortality than the high-energy group (p = 0.028), although the two groups showed equivalent event rates of the primary outcome (p = 0.569).

CONCLUSION

Calculations based on the Harris-Benedict equation revealed no significant difference in the primary outcome between the two groups, with a secondary outcome that showed worse mortality in the low-energy group. Given this result, energy requirement-based assessments using the Harris-Benedict equation might help in the management of elderly heart failure patients in terms of improved life outcomes.

Prognostic value of Toll-like receptor 4 on human monocyte subsets combined with computed tomography-adapted Leaman score assessing coronary artery disease

BACKGROUND

Upregulation of Toll-like receptor 4 (TLR-4) is associated with coronary plaque vulnerability assessed by coronary computed tomography angiography (CCTA). Computed tomography-adapted Leaman score (CT-LeSc) is an independent long-term predictor of cardiac events. The relationship between the TLR-4 expression of CD14 ++ CD16 + monocytes and future cardiac events is unknown. We investigated this relationship using CT-LeSc in patients with coronary artery disease (CAD).

METHODS

We analyzed 61 patients with CAD who underwent CCTA. Three monocyte subsets (CD14 ++ CD16 - , CD14 ++ CD16 + , and CD14 + CD16 + ) and the expression of TLR-4 were measured by flow cytometry. We divided the patients into two groups according to the best cutoff value of the TLR-4 expression on CD14 + CD16 + which could predict future cardiac events.

RESULTS

CT-LeSc was significantly greater in the high TLR-4 group than the low TLR-4 group [9.61 (6.70-13.67) vs. 6.34 (4.27-9.09), P  < 0.01]. The expression of TLR-4 on CD14 ++ CD16 + monocytes was significantly correlated with CT-LeSc ( R2  = 0.13, P  < 0.01). The expression of TLR-4 on CD14 ++ CD16 + monocytes was significantly higher in patients who had future cardiac events than in those who did not [6.8 (4.5-9.1) % vs. 4.2 (2.4-7.6) %, P  = 0.04]. High TLR-4 expression on CD14 ++ CD16 + monocytes was an independent predictor for future cardiac events ( P  = 0.01).

CONCLUSION

An increase in the TLR-4 expression on CD14 ++ CD16 + monocytes is related to the development of future cardiac events.

Long-term risk stratification for hospitalized patients with acute heart failure at a single rural cardiovascular centre

AIMS

Early risk stratification of patients with acute heart failure (AHF) is critical for appropriate triage and outcome improvement. The serum sodium, blood urea nitrogen, age, serum albumin, systolic blood pressure, and natriuretic peptide level (SOB-ASAP) score can predict in-hospital mortality of AHF. However, the relationship between the SOB-ASAP score and long-term prognosis is unknown. This study investigated the determinants of the long-term prognosis of AHF by evaluating the SOB-ASAP score.

METHODS

This retrospective cohort study included all patients with acute decompensated heart failure who were admitted to our hospital between April 2017 and March 2018. And those who discharged were analysed retrospectively. The follow-up period was 3 years. Primary end point was all-cause death.

RESULTS

Total of 140 patients were analysed. The median SOB-ASAP score of entire cohort on admission was 3 points (interquartile range; 1-5). The Kaplan-Meier curve demonstrated that patients in the higher SOB-ASAP group (score ≥3) had a higher incidence of all-cause death (log-rank test; P < 0.001) than those in the lower SOB-ASAP (group score <3).

CONCLUSIONS

At admission, the SOB-ASAP score may be useful for predicting the long-term prognosis of hospitalized patients with AHF.

Hyperglycemia and intramyocardial hemorrhage in patients with ST-segment elevation myocardial infarction

BACKGROUND

Hyperglycemia at admission and intramyocardial hemorrhage (IMH) are associated with poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI). Little is known about the relationship between glucose levels at admission and IMH. The association between matrix metalloproteinase-9 (MMP-9), which plays an important role in the development of IMH, and hyperglycemia is also unknown. This study aimed to investigate the relationship between hyperglycemia at admission and IMH in patients with STEMI.

METHODS

We enrolled 174 patients with first STEMI who underwent primary percutaneous coronary intervention (PCI) and cardiovascular magnetic resonance (CMR) imaging. T2-weighted imaging and late gadolinium enhancement (LGE)-CMR were performed to detect IMH and microvascular obstruction (MVO), respectively. Two patient groups were created: IMH group and non-IMH group. MMP-9 levels were measured in the culprit coronary arteries of 13 patients.

RESULTS

Glucose level at admission and the value of glycosylated hemoglobin were higher in the IMH group than in the non-IMH group [IMH group vs. non-IMH group; 208.5 (157.8-300.5) mg/dL vs. 157.0 (128.8-204.3) mg/dL, p < 0.001, and 6.2 (5.7-7.5) % vs. 5.8 (5.4-6.6) %, p = 0.030, respectively]. A multivariable logistic regression analysis revealed that only admission glucose level was an independent predictor of IMH (OR: 1.012; 95 % CI: 1.005-1.020, p = 0.001). The MMP-9 levels in patients with IMH were higher than those in patients without IMH [256.0 (161.0-396.0) ng/mL vs. 73.5 (49.5-131.0) ng/mL, p = 0.040]. There was a moderate positive correlation between glucose levels at admission and MMP-9 levels (r = 0.600, p = 0.030).

CONCLUSIONS

Hyperglycemia at admission is associated with the occurrence of IMH in patients with STEMI.

Vascular Response After Everolimus-Eluting Stent in Acute Myocardial Infarction Caused by Calcified Nodule

BACKGROUND

Patients with acute myocardial infarction (AMI) caused by calcified nodules (CN) have worse clinical outcomes following primary percutaneous coronary intervention (PCI). This study investigated the late vascular response after everolimus-eluting stent (EES) implantation assessed by optical coherence tomography (OCT) in patients with AMI caused by CN, by comparing with plaque rupture (PR) and plaque erosion (PE).Methods and Results: Based on the OCT findings in AMI culprit lesions before PCI, a total of 141 patients were categorized into 3 groups (PR, PE, or CN), and the OCT findings immediately and 10 months after PCI were compared. The frequency of PR, PE, and CN was 85 (60%), 45 (32%), and 11 patients (8%), respectively. In the 10-month follow-up OCT, the frequency of lesions with uncovered struts and lesions with malapposed struts were highest in the CN group, followed by the PR and PE groups (82% vs. 52% vs. 40%, P=0.042 and 73% vs. 26% vs. 16%, P<0.001, respectively). The incidence of intra-stent thrombus, re-appearance of CN within the stent, and target lesion revascularization were higher in the CN group compared with the PR and PE groups (36% vs. 9% vs. 7%, P=0.028; 27% vs. 0% vs. 0%, P<0.001; and 18% vs. 2% vs. 2%, P=0.024, respectively).

CONCLUSIONS

Late arterial healing response at 10 months after EES implantation in the CN was worse compared with PR and PE in patients with AMI.

Forensic significance of intracardiac heme oxygenase-1 expression in acute myocardial ischemia

Heme oxygenase-1 (HO-1), an inducible stress-response protein, exerts anti-oxidant and anti-apoptotic effects. However, its significance in forensic diagnosis of acute ischemic heart diseases (AIHD) such as myocardial infarction (MI) is still unknown. We examined the immunohistochemical expression of HO-1 in the heart samples to discuss their forensic significance to determine acute cardiac ischemia. The heart samples were obtained from 23 AIHD cases and 33 non-AIHD cases as controls. HO-1 positive signals in cardiomyocyte nuclear were detected in 78.2% of AIHD cases, however, that were detected in only 24.2% control cases with statistical difference between AIHD and non-AIHD groups. In contrast to HO-1 protein expression, there was no significant difference in the appearance of myoglobin pallor regions and leukocyte infiltration in the hearts between AIHD and non-AIHD groups. From the viewpoints of forensic pathology, intracardiac HO-1 expression would be considered a valuable marker to diagnose AIHD as the cause of death.

Lesion characteristics and prognosis of acute coronary syndrome without angiographically significant coronary artery stenosis

AIMS

While patients with acute coronary syndrome (ACS) presenting with non-obstructive coronary artery disease (CAD) are at high risk for cardiovascular mortality and morbidity, detailed lesion characteristics are unclear. The aim of this study was to investigate the lesion characteristics and prognosis of ACS with non-obstructive CAD.

METHODS AND RESULTS

This study consisted of 82 consecutive ACS patients without obstructive CAD who underwent optical coherence tomography (OCT). Based on the presence of high-risk lesions (HL) in the culprit artery, we classified the patients into two groups: HL group and non-high-risk lesions (NHL) group. A systematic clinical follow-up was performed at our outpatient clinic for up to 24 months. Our endpoint was recurrence of ACS with obstructive CAD. OCT revealed that 42 (51.2%) of 82 patients had hidden HL in the culprit artery, including ruptured plaque (15.9%), calcified nodule (11.0%), spontaneous coronary artery dissection (8.5%), lone thrombus (8.5%), thin-cap fibroatheroma (6.1%), and plaque erosion (1.2%). During angiography, 5 (11.9%) HL patients complained of chest pain without ST elevation. Patients in the HL group had poorer prognoses than those in the other groups (P = 0.040).

CONCLUSION

Hidden high-risk lesions accompany ACS patients without obstructive CAD, resulting in poorer outcomes. Vascular injury itself might provoke acute chest pain.

Real-time venography-guided extrathoracic puncture technique for cardiovascular implantable electronic device implantation

Central venous access is an essential technique for cardiovascular implantable electronic device (CIED) implantation, and the use of axillary vein approach has recently been increasing. This study sought to examine whether real-time venography-guided extrathoracic puncture facilitates the procedure. We retrospectively analyzed 179 consecutive patients who underwent CIED implantation using the axillary vein puncture method. Patients were divided into two groups: the conventional method group (CG, n = 107) and the real-time venography-guided group (RG, n = 82). The application of real-time venography was at the discretion of individual operators. Operators with experience of less than 50 CIED implantations were defined as inexperienced operators in this study. Puncture duration and number of attempts were significantly less in the RG group than in the CG group (283 ± 198 vs. 421 ± 361 s, p < 0.01, and 3.19 ± 2.00 vs. 4.18 ± 2.85, p < 0.01). These benefits of real-time venography were observed in inexperienced operators, but not in experienced operators. In addition, the success rate without extra attempts at puncture was higher in the RG group (54% vs. 32%, p < 0.01). Although the total amount of contrast medium was higher in the RG group (16.3 ± 4.1 mL vs. 11.9 ± 6.6 mL, p < 0.01), serum levels of creatinine pre- and post-operation were not different in the two groups (p = NS). We concluded that real-time venography is a safe and effective method for axillary vein puncture, especially in inexperienced operators.

Cancer-related vulnerable lesions in patients with stable coronary artery disease

BACKGROUND

Coronary artery disease (CAD) has become a major cause of morbidity and mortality in cancer survivors. It is still unclear whether cancer history influences lesion characteristics. The purpose of this study was to investigate cancer-related lesion morphology in patients with CAD.

METHODS

This study enrolled 400 patients with stable CAD. The patients were classified into a cancer survivor group (n = 69) and a noncancer group (n = 331). We investigated coronary lesion morphology by optical coherence tomography, and we assessed the prognosis in terms of both all-cause mortality and major adverse cardiovascular events (MACE).

RESULTS

Adenocarcinoma was the most common histopathological diagnosis. Serum C-reactive protein levels were significantly higher in the cancer survivor group than in the noncancer group (cancer survivors 0.12 [0.05-0.42] mg/dL vs. noncancer 0.08 [0.04-0.17] mg/dL, p = 0.019). The cancer survivor group was more likely than the noncancer group to have thrombi (cancer survivors 30.4% vs. noncancer 15.4%, p = 0.004), and layered fibrotic plaques (LFPs; cancer survivors 18.8% vs. noncancer 3.6%, p < 0.0001). Cancer survivors had poorer outcomes than noncancer controls in terms of both all-cause mortality (p = 0.020) and MACE (p = 0.036).

CONCLUSIONS

Because of underlying inflammation, CAD patients with cancer had more high-risk lesions than those without cancer, which could result in poorer prognosis for the former. This result might inform the management of CAD in cancer patients in terms of secondary prevention.

Impact of left ventricular ejection fraction and preoperative hemoglobin level on perioperative adverse cardiovascular events in noncardiac surgery

The prediction of a perioperative adverse cardiovascular event (PACE) is an important clinical issue in the medical management of patients undergoing noncardiac surgery. Although several predictors have been reported, simpler and more practical predictors of PACE have been needed. The aim of this study was to investigate the predictors of PACE in noncardiac surgery. We retrospectively analyzed 723 patients who were scheduled for elective noncardiac surgery and underwent preoperative examinations including 12-lead electrocardiography, transthoracic echocardiography, and blood test. PACE was defined as cardiac death, non-fatal myocardial infarction, unstable angina, congestive heart failure, arrhythmia attack that needs emergency treatment (rapid atrial fibrillation, ventricular tachycardia, and bradycardia), acute pulmonary embolism, asystole, pulseless electrical activity, or stroke during 30 days after surgery. PACE occurred in 54 (7.5%) of 723 patients. High-risk operation (11% vs. 3%, p = 0.003) was more often seen, left ventricular ejection fraction (LVEF) (55 ± 8% vs. 60 ± 7%, p = 0.001) and preoperative hemoglobin level (11.8 ± 2.2 g/dl vs. 12.7 ± 2.0 g/dl, p = 0.001) were lower in patients with PACE compared to those without PACE. By multivariate logistic regression analysis, high-risk operation (odds ratio (OR): 7.05, 95% confidence interval (CI) 2.16-23.00, p = 0.001), LVEF (OR 1.06, every 1% decrement, 95% CI 1.03-1.09, p = 0.001), and preoperative hemoglobin level (OR 1.22, every 1 g/dl decrement, 95% CI 1.07-1.39, p = 0.003) were identified as independent predictors of PACE. Receiver operating characteristic analysis demonstrated that LVEF of 58% (sensitivity = 80%, specificity = 61%, area under the curve (AUC) = 0.723) and preoperative hemoglobin level of 12.2 g/dl (sensitivity = 63%, specificity = 64%, AUC = 0.644) were optimal cut-off values for predicting PACE. High-risk operation, reduced LVEF, and reduced preoperative hemoglobin level were independently associated with PACE in patients undergoing noncardiac surgery.

Coronary artery lumen complexity as a new marker for refractory symptoms in patients with vasospastic angina

Refractory angina is an independent predictor of adverse events in patients with vasospastic angina (VSA). The aim of this study was to investigate the relationship between coronary lumen complexity and refractory symptoms in patients with VSA. Seventeen patients with VSA underwent optical coherence tomography. The patients were divided into the refractory VSA group (n = 9) and the stable VSA group (n = 8). A shoreline development index was used to assess the coronary artery lumen complexity. Shear stress was estimated using a computational fluid dynamics model. No difference was observed in the baseline characteristics between the two groups. The refractory VSA group showed the higher shoreline development index (refractory VSA 1.042 [1.017–1.188] vs stable VSA 1.003 [1.006–1.025], p = 0.036), and higher maximum medial thickness (refractory VSA 184 ± 17 μm vs stable VSA 148 ± 31 μm, p = 0.017), and higher maximum shear stress (refractory VSA 14.5 [12.1–18.8] Pa vs stable VSA 5.6 [3.0–10.5] Pa, p = 0.003). The shoreline development index positively correlates with shear stress (R² = 0.46, P = 0.004). Increased medial thickness of the coronary arteries provokes lumen complexity and high shear stress, which might cause refractory symptoms in patients with VSA. The shoreline index could serve as a marker for irritability of the medial layer of coronary arteries and symptoms.

Intrathrombotic appearances of AQP-1 and AQP-3 in relation to thrombus age in murine deep vein thrombosis model

Aquaporins (AQPs) are membrane-bound proteins for water transportation and are useful for diagnosing drowning and wound vitality in forensic pathology. Here, we examined intrathrombotic expression of AQP-1 and AQP-3 using deep vein thrombosis models in mice. To perform immunohistochemical analyses, we used anti-AQP-1 and anti-AQP-3 antibodies. In thrombus samples with the post-ligation intervals of 1 to 5 days, AQP-1⁺ areas were over 70%. At 7 days after the IVC ligation, AQP-1⁺ areas became less than 50%, eventually decreasing to 11% at 21 days. At 3 days after the IVC ligation, AQP-3⁺ cells started to appear from the peripheral area. Thereafter, the positive cell number progressively increased and reached to a peak at 10 days after the IVC ligation. When the intrathrombotic AQP-1⁺ area was as large as the intrathrombotic collagen area or smaller, it would indicate a thrombus age of ≥ 10 days. AQP-3⁺ cell number of > 30 would indicate a thrombus age of 10–14 days. Collectively, our study implied that the detection of AQP-1 and AQP-3 would be useful for the determination of thrombus age.

Prevalence, Features, and Prognosis of Artery-to-Artery Embolic ST-Segment-Elevation Myocardial Infarction: An Optical Coherence Tomography Study

Background The major underlying mechanisms contributing to acute coronary syndrome are plaque rupture, plaque erosion, and calcified nodule. Artery-to-artery embolic myocardial infarction (AAEMI) was defined as ST-segment-elevation myocardial infarction caused by migrating thrombus formed at the proximal ruptured plaque. The aim of this study was to investigate the prevalence and clinical features of AAEMI by using optical coherence tomography. Methods and Results This study retrospectively enrolled 297 patients with ST-segment-elevation myocardial infarction who underwent optical coherence tomography before percutaneous coronary intervention. Patients were divided into 4 groups consisting of plaque rupture, plaque erosion, calcified nodule, and AAEMI according to optical coherence tomography findings. The prevalence of AAEMI was 3.4%. The culprit vessel in 60% of patients with AAEMI was right coronary artery. Minimum lumen area at the culprit site was larger in AAEMI compared with plaque rupture, plaque erosion, and calcified nodule (4.0 mm² [interquartile range (IQR), 2.2-4.9] versus 1.0 mm² [IQR, 0.8-1.3] versus 1.0 mm² [IQR, 0.8-1.2] versus 1.1 mm² [IQR, 0.7-1.6], P<0.001). Lumen area at the rupture site was larger in patients with AAEMI compared with patients with plaque rupture (4.4 mm² [IQR, 2.5-6.7] versus 1.5 mm² [IQR, 1.0-2.4], P<0.001). In patients with AAEMI, the median minimum lumen area at the occlusion site was 1.2 mm² (IQR, 1.0-2.1), 40% of them had nonstent strategy, and the 3-year major adverse cardiac event rate was 0%. Conclusions AAEMI is a rare cause for ST-segment-elevation myocardial infarction and has unique morphological features of plaque including larger lumen area at rupture site and smaller lumen area at the occlusion site.

Increased plaque rupture forms peak incidence of acute myocardial infarction in winter

BACKGROUND

It has been widely documented that circannual variation has an impact on the incidence and prognosis of cardiovascular diseases. It is unclear why cold ambient temperature increase the incidence of acute myocardial infarction (AMI). We investigated the relationship between the ambient temperature at the onset of AMI, the morphology of the culprit lesion in patients with AMI.

METHODS

We investigated 202 consecutive patients with AMI who underwent optical coherence tomography (OCT). The participants were divided into lower (n = 100) and higher (n = 102) temperature groups based on the ambient temperature. The culprit lesion morphology was compared between the two groups.

RESULTS

The median temperature at the onset of AMI was 16.6 °C. The prevalence of plaque ruptures was higher at lower temperatures (lower 66% vs. higher 45%, p = .003), whereas OCT-erosion was more frequent in the higher temperature group (lower 13% vs. higher 26%, p = .021). The lower temperature group showed more cholesterol crystals (lower 71% vs. higher 54%, p = .014).

CONCLUSION

The peak incidence of AMI in the winter is formed by increased plaque rupture, suggesting environmental temperature has an influence on the pathogenesis of AMI.

Prevention of CaCl2-induced aortic inflammation and subsequent aneurysm formation by the CCL3-CCR5 axis

Inflammatory mediators such as cytokines and chemokines are crucially involved in the development of abdominal aortic aneurysm (AAA). Here we report that CaCl₂ application into abdominal aorta induces AAA with intra-aortic infiltration of macrophages as well as enhanced expression of chemokine (C-C motif) ligand 3 (CCL3) and MMP-9. Moreover, infiltrating macrophages express C-C chemokine receptor 5 (CCR5, a specific receptor for CCL3) and MMP-9. Both Ccl3^−/− mice and Ccr5^−/− but not Ccr1^−/− mice exhibit exaggerated CaCl₂-inducced AAA with augmented macrophage infiltration and MMP-9 expression. Similar observations are also obtained on an angiotensin II-induced AAA model. Immunoneutralization of CCL3 mimics the phenotypes observed in CaCl₂-treated Ccl3^−/− mice. On the contrary, CCL3 treatment attenuates CaCl₂-induced AAA in both wild-type and Ccl3^−/− mice. Consistently, we find that the CCL3–CCR5 axis suppresses PMA-induced enhancement of MMP-9 expression in macrophages. Thus, CCL3 can be effective to prevent the development of CaCl₂-induced AAA by suppressing MMP-9 expression.

Inflammatory cytokines and chemokines are involved in the development of abdominal aortic aneurysm (AAA). Here the authors show that CCL3 prevents the development of CaCl₂-induced AAA by suppressing MMP-9 expression.

A biodegradable microneedle sheet for intracorporeal topical hemostasis

Management of bleeding is critical for improving patient outcomes. While various hemostatic products are used in daily practice, technical improvement is still needed. To addresses this problem, we newly developed a microneedle hemostatic sheet based on microneedle technology. We demonstrated the unique features of this microneedle hemostatic sheet, including reduced hemostatic time, biodegradable polymer composition that allows intracorporeal use without increasing infectious risk incorporation of microneedles to fix the sheet to the wound even on the left ventricular wall of a swine while beating, and a mesh structure with flexibility comparable to that of bonding surgical tape and sufficient rigidity to penetrate human aorta tissue and swine left ventricular wall. One potential application of the microneedle hemostatic sheet is intracorporeal topical hemostasis for parenchymatous organs, large vessels, and heart wall during trauma or surgery, in addition to new, widespread applications.

Crucial Involvement of IL-6 in Thrombus Resolution in Mice via Macrophage Recruitment and the Induction of Proteolytic Enzymes

After the ligation of the inferior vena cava (IVC) of wild-type (WT) mice, venous thrombi formed and grew progressively until 5 days and resolved thereafter. Concomitantly, intrathrombotic gene expression of Il6 was enhanced later than 5 days after IVC ligation. IL-6 protein expression was detected mainly in F4/80-positive macrophages in thrombus. When Il6-deficient (Il6^−/−) mice were treated in the same manner, thrombus mass was significantly larger than in WT mice. Moreover, the recovery of thrombosed IVC blood flow was markedly delayed in Il6^−/− compared with WT mice. F4/80-positive macrophages in thrombus expressed proteolytic enzymes such as matrix metalloproteinase (Mmp) 2, Mmp9, and urokinase-type plasminogen activator (Plau); and their mRNA expression was significantly reduced in Il6^−/− mice. Consistently, the administration of anti-IL-6 antibody delayed the thrombus resolution in WT mice, whereas IL-6 administration accelerated thrombus resolution in WT and Il6^−/− mice. Moreover, IL-6 in vitro enhanced Mmp2, Mmp9, and Plau mRNA expression in WT-derived peritoneal macrophages in a dose-dependent manner; and the enhancement was abrogated by a specific Stat3 inhibitor, Stattic. Thus, IL-6/Stat3 signaling pathway can promote thrombus resolution by enhancing Mmp2, Mmp9, and Plau expression in macrophages.

Combination of Lesion Stenosis and Myocardial Supply Area Assessed by Coronary Computed Tomography Angiography for Prediction of Myocardial Ischemia

Recent clinical studies revealed that anatomical information assessed by coronary computed tomography angiography (CTA) may be used effectively to diagnose coronary artery disease (CAD). However, a physiological assessment, demonstrating myocardial ischemia, is required to justify a therapeutic strategy for CAD. This study aimed to investigate whether using CTA to assess myocardial supply area can improve the prediction of myocardial ischemia.We analyzed 201 vessels with moderate (luminal narrowing ≥ 50%, < 70%) and severe (luminal narrowing ≥ 70%, < 99%) stenosis on CTA from 174 patients, who were suspected of having stable angina and underwent measurement of fractional flow reserve (FFR). The myocardial area supplied by the coronary artery, distal to the stenosis, was evaluated with CTA, as reported previously (modified Alberta Provincial Project for Outcome Assessment in Coronary Heart score) and was classified into 3 groups (large, medium, and small).Both percentage area stenosis and myocardial supply area were significantly correlated with FFR (r = -0.46, P < 0.01, and r = -0.45, P < 0.01). Among patients who had coronary plaques, with moderate stenosis and a small myocardial supply area, only 3 of 42 lesions (7%) were identified as ischemic; deviation from the ischemic threshold (FFR = 0.80) was P < 0.01. The combined assessment of lesion stenosis and myocardial supply area, using CTA, improved the prediction of myocardial ischemia significantly compared to lesion stenosis alone (77% versus 59%, P < 0.01).Adding the assessment of myocardial supply area to standard CTA might help predict myocardial ischemia in patients with stable angina pectoris.

Prognostic Value of Human Peripheral Monocyte Subsets for Future Coronary Events in Patients Without Significant Coronary Artery Stenosis

BACKGROUND

Monocytes in human peripheral blood are heterogeneous and can be divided into 2 groups, inflammatory and pro-inflammatory, according to the differential expression of CD14 and CD16. Pro-inflammatory monocytes (CD14⁺CD16⁺) seem to contribute to the development of coronary artery disease. This study aimed to investigate the involvement of specific human peripheral monocyte subsets in the development of future coronary events.Methods and Results:We enrolled 271 patients who were suspected to have either stable angina pectoris or silent myocardial ischemia and underwent coronary angiography (CAG). Two monocyte subsets (CD14⁺CD16^-and CD14⁺CD16⁺) were measured by flow cytometry. Patients who did not undergo coronary artery revascularization at initial CAG were followed as the medical therapy group, which included 136 patients among whom 15 had future coronary events. The frequency of CD14⁺CD16⁺monocytes was significantly higher in patients who had future coronary events than in those who did not (P<0.01). Furthermore, the frequencies of CD14⁺CD16⁺monocyte were not significantly different between patients who had future coronary events and those who underwent coronary revascularization at initial CAG (P<0.33). Multivariate analysis revealed that the frequency of CD14⁺CD16⁺monocytes was an independent predictor for future coronary events (P<0.01).

CONCLUSIONS

An increase in the abundance of human peripheral pro-inflammatory monocytes is related to the development of future coronary events.

Feasibility and Clinical Significance of In Vivo Cholesterol Crystal Detection Using Optical Coherence Tomography

OBJECTIVE

Cholesterol crystals (CCs) are frequently found at the site of acute myocardial infarctions (AMIs), but the role of CCs in the onset of AMI remains unclear due to the lack of validated in vivo imaging tools. The aim of this study was to validate the ability of optical coherence tomography (OCT) to detect CCs and to compare the prevalence and distribution of CCs in patients with AMIs and stable angina pectoris. Approach and Results: CC assessment using OCT were compared with histopathology results in 45 coronary samples. We investigated 152 consecutive patients with AMIs and 41 patients with single vessel-diseased stable angina pectoris. Based on the presence of plaque ruptures (PR), AMI patients were divided into 2 groups: those with PR (n=112) and those without PR (n=40). CCs invading fibrous caps were defined as superficial-type CCs. A multivariable logistic regression analysis was performed to determine PR predictors. The sensitivity and specificity of OCT for detecting CCs were 68% and 92%, respectively. The prevalence of plaques with CCs was higher in the AMI with PR group (AMI with PR 81%, AMI without PR 48%, stable angina pectoris 39%, P<0.01). A multivariable logistic model showed that superficial-type CCs and thin-cap fibroatheromas were positive predictors for PR.

CONCLUSIONS

OCT has a high specificity and modest sensitivity for the detection of CCs. The combination of CCs invading fibrous cap and thin-cap fibroatheromas detected by OCT may better identify rupture-prone plaques.

P3576Histopathological validation of optical coherence tomography assessment for cholesterol crystals

Background

Cholesterol crystals (CCs) are well recognized as one of important components of advanced atherosclerotic plaques. Whilethe consensus document for intravascular optical coherence tomography (OCT) has proposed that CCs are appeared as thin, linear regions of high-signal intensity within a plaque, no study has validated CCs assessment by OCT in comparison with histopathology.

Purpose

Thepurpose of this study was to validate OCT assessments of CCs with histopathology.

Methods

A total of 27 diseased coronary artery samples (10–20 mm length) were resected from 7 randomly selected cadavers. OCT imaging was performed for the samples. Then, arterial samples were fixed in 10% formalin for ≥48 hours, decalcified and processed for standard paraffin embedding. Sections 5μm thick were sliced at the ink-marked imaging sites and stained with hematoxylin and eosin, and Masson's Trichrome. An independent pathologist blinded to the OCT results diagnosed all of the plaques. Subsequently, the OCT images were interpreted by an observer blinded to the histological results. In the OCT assessment, CCs were defined as thin, linear regions of high-signal intensity within a plaque.

Results

We obtained 27 pairs of OCT/ histopathology. CCs were diagnosed by histology in 10 (37%) of the 27 pairs. The sensitivity and specificity of OCT for detecting CCs were 60% and 94%, respectively.

Conclusion

OCT has a high specificity but modest sensitivity for detection of CCs in comparison with histopathology. CCs diagnosed with OCT would help the identification of advanced atherosclerotic plaques.

Acknowledgement/Funding

JSPS KAKENHI 17K09557

Contribution of the TNF-α (Tumor Necrosis Factor-α)-TNF-Rp55 (Tumor Necrosis Factor Receptor p55) Axis in the Resolution of Venous Thrombus

Objective- Deep vein thrombosis results from a combination of risk factors including genetic conditions, obesity, drugs, pregnancy, aging, and malignancy. We examined pathophysiological roles of the TNF-α (tumor necrosis factor-α)-TNF-Rp55 (tumor necrosis factor receptor p55) axis in thrombus resolution using Tnfrp55^-/- (TNF-Rp55-deficient) mice. Approach and Results- On ligating the inferior vena cava of wild-type (WT) mice, venous thrombi formed and grew progressively until 5 days but shrunk to <50% of the thrombus weight at day 14. Concomitantly, inferior vena cava ligation enhanced intrathrombotic gene expression of Tnfa and Tnfrp55, and intrathrombotic macrophages expressed both TNF-α and TNF-Rp55 proteins. In Tnfrp55^-/- mice treated with the same manner, thrombus formed at a similar rate for 5 days, but shrinking was delayed compared with WT mice. Moreover, the blood flow recovery in thrombosed inferior vena cava was suspended in Tnfrp55^-/- mice compared with WT mice. Intrathrombotic Plau (urokinase-type plasminogen activator), Mmp2 (matrix metalloproteinase 2), and Mmp9 (matrix metalloproteinase 9) mRNA expression was significantly reduced in Tnfrp55^-/- mice, compared with WT ones. Supportingly, the administration of anti-TNF-α antibody or TNF-α inhibitor (etanercept) delayed the thrombus resolution in WT mice. Furthermore, TNF-α treatment enhanced gene expression of Plau, Mmp2, and Mmp9 in WT macrophages but not Tnfrp55^-/- macrophages. These effects were significantly suppressed by ERK (extracellular signal regulated kinase) and NF-κB (nuclear factor-kappa B) inhibitors. Therefore, the lack of TNF-Rp55 has detrimental roles in the thrombus resolution by suppressing PLAU, MMP-2, and MMP-9 expression. In contrast, TNF-α administration accelerated thrombus resolution in WT but not Tnfrp55^-/- mice. Conclusions- The TNF-α-TNF-Rp55 axis may have essential roles in the resolution of venous thrombus in mice.

CCL2-Mediated Reversal of Impaired Skin Wound Healing in Diabetic Mice by Normalization of Neovascularization and Collagen Accumulation

Patients with diabetes frequently present with complications such as impaired skin wound healing. Skin wound sites display a markedly enhanced expression of CCL2, a potent macrophage chemoattractant, together with macrophage infiltration during the early inflammatory phase in skin wound healing of healthy individuals, but the association of CCL2 with delayed skin wound healing in patients with diabetes remains elusive. In this study, we showed that, compared with control mice, mice with streptozotocin-induced diabetes displayed impaired healing after excisional skin injury, with decreased neovascularization, CCL2 expression, and macrophage infiltration. Compromised skin wound healing in mice with diabetes was reversed by the administration of topical CCL2 immediately after the injury, as evidenced by normalization of wound closure rates, neovascularization, collagen accumulation, and infiltration of macrophages expressing vascular endothelial growth factor, a potent angiogenic factor, and transforming growth factor-β. CCL2 treatment further increased the accumulation of endothelial progenitor cells at the wound sites of mice with diabetes and eventually accelerated neovascularization. Thus, the topical application of CCL2 can be an effective therapeutic option for the treatment of patients with diabetes with defective wound repair, promoting neovascularization and collagen accumulation at skin wound sites.

Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology

Optical coherence tomography (OCT) is a coronary artery imaging technique with high resolution. Second-generation frequency-domain OCT (FD-OCT) technology allows safer and faster clinical application compared with first-generation time-domain OCT (TD-OCT). Only limited validation studies compare FD-OCT with other modes of analysis: histology, which is the current gold standard, and intravascular ultrasound (IVUS). This study therefore aims to demonstrate the accuracy of FD-OCT images compared with IVUS and histology. FD-OCT and IVUS images were acquired from 203 segments from 31 coronary arteries obtained at autopsy from 20 cadavers. Of these, 30 randomly-selected pairs were used to create three classifications of plaque type based on morphological features in FD-OCT and IVUS compared with corresponding histopathology. The remaining 173 pairs were used to demonstrate the diagnostic accuracy for classification of coronary plaques by FD-OCT. Plaque type distributions were 27% fibroatheroma, 22% fibrocalcific plaque and 51% fibrous plaque. The diagnostic accuracies of FD-OCT for fibroatheroma, fibrocalcific plaque and fibrous plaque were 90, 95 and 93%, respectively. Those of IVUS were 81, 89 and 84%, respectively. FD-OCT achieved high diagnostic accuracy for the classification of coronary plaques comparable to TD-OCT. Physicians should consider the differences in the ability to classify plaque morphology of OCT of imaging devices when applying their use.

Automated lipid-rich plaque detection with short wavelength infra-red OCT system

Aims

Vulnerable coronary plaque is characterized by a large lipid core. Although commercially-available optical coherence tomography (OCT) systems use near-infrared light at 1300 nm wavelength, lipid shows characteristic absorption at 1700 nm. Therefore, we developed a novel, short wavelength infra-red, spectroscopic, spectral-domain OCT. The aim of the present study is to evaluate the accuracy of short wavelength (1700 nm) infra-red optical coherence tomography (SWIR-OCT) for identification of lipid tissue within coronary plaques.

Methods and results

Twenty-three coronary arteries from 10 cadavers were imaged at physiological pressure with 2.7 Fr SWIR-OCT catheter. When a blood-free image was observed, the SWIR-OCT imaging core was withdrawn at a rate of 20 mm/s using an automatic pullback device. SWIR-OCT images were acquired at 94 frames/s and digitally archived. SWIR-OCT generated grey-scale cross sectional images and colour tissue maps of all of the plaque by using a lipid analysis algorithm. After SWIR-OCT imaging, the arteries were pressure-fixed, sliced by cryostat and stained with Oil Red O, and then corresponding histology was collected in matched images. Regions of interest, selected from histology, were 117 lipidic and 34 fibrotic/calcified regions. SWIR-OCT showed high sensitivity (89%) and specificity (92%) for identifying lipid tissue within coronary plaques. The positive predictive value and negative predictive value were 97% and 74%, respectively.

Conclusion

SWIR-OCT accurately identified lipid tissue in coronary autopsy specimens. This new technique may hold promise for identifying histopathological features of coronary plaque at risk for rupture.

Usefulness of rescue ultrasound guidance for transradial cardiac catheterization

INTRODUCTION AND OBJECTIVES

Transradial cardiac catheterization reduces access site complications and is more comfortable for patients than the transfemoral approach. However, failure of the transradial approach is more common than the transfemoral approach. This study aimed to investigate whether ultrasound-guided rescue could facilitate transradial cardiac catheterization.

METHODS

We retrospectively analyzed 592 consecutive patients who underwent coronary angiography and/or percutaneous coronary intervention. Patients were divided into 2 groups: the palpation technique (PT) (n = 280) and the ultrasound guidance (UG) available group (n = 312). The application and the timing of introduction of ultrasound guidance in the UG group were at the discretion of the individual operators.

RESULTS

Real-time ultrasound guidance was used in 98 patients (31.4%) in the UG group. No statistically significant intergroup differences were observed in the incidence of hematoma (6.8% vs. 5.8%, p = 0.62). Although the procedural time in the UG group was longer than that in the PT group (303 s vs. 357 s, p < 0.01), the success rate of sheath insertion was significantly higher in the UG group (97% vs. 92%, p < 0.01). Multivariate analysis revealed that the availability of UG was the only independent predictor of success of sheath insertion (odds ratio 2.79, 95% confidence interval 1.24-6.31, p = 0.01).

CONCLUSIONS

Although UG maneuvers require additional procedural time for setting up systems, UG rescue was effective for successful transradial cardiac catheterization.

High-density lipoprotein cholesterol as a therapeutic target for residual risk in patients with acute coronary syndrome

Objective

The current guideline recommends lowering low-density lipoprotein cholesterol (LDL-C) for the primary management of dyslipidemia in patients at high-risk of cardiovascular events. Patients who have achieved LDL-C levels below the recommended targets may still experience cardiovascular events, suggesting additional therapeutic targets beyond LDL-C. The aim of this study was to investigate whether high-density lipoprotein cholesterol (HDL-C) levels had an impact on plaque stabilization in patients with acute coronary syndrome (ACS).

Methods

This study consisted of 90 ACS patients with untreated dyslipidemia. In optical coherence tomography (OCT) analysis, a plaque with fibrous cap thickness ≦160 μm was defined as a high-risk plaque. We registered one high-risk plaque per one patient by baseline OCT imaging, and then administrated high-intensity statin. Based on the follow-up OCT results, patients whose registered plaque was no longer high-risk plaque were classified into a responder group and the remains into a non-responder group.

Results

No differences were observed in the baseline LDL-C and HDL-C levels between the two groups. Reduction of LDL-C levels (δ LDL-C: −53 ± 21 mg/dL vs. −42 ± 29 mg/dL, p = 0.036) and increase of HDL-C levels (δ HDL-C: 2.5 ± 5.9 mg/dL vs. −0.3 ± 6.7 mg/dL, p = 0.039) were greater in the responder group. On multivariate logistic regression analysis, δ LDL-C levels (OR: 0.956, 95% CI: 0.921–0.993; p = 0.020) and δ HDL-C levels (OR: 1.143; 95% CI: 1.005–1.300, p = 0.041) were independent contributors for plaque stabilization.

Conclusions

Increase of HDL-C levels is associated with plaque stabilization in patients with ACS. HDL-C could be a therapeutic target for residual risk management.

Protective Roles of Interferon-γ in Cardiac Hypertrophy Induced by Sustained Pressure Overload

BACKGROUND

A clear understanding of the molecular mechanisms underlying hemodynamic stress-initiated cardiac hypertrophy is important for preventing heart failure. Interferon-γ (IFN-γ) has been suggested to play crucial roles in various diseases other than immunological disorders by modulating the expression of myriad genes. However, the involvement of IFN-γ in the pathogenesis of cardiac hypertrophy still remains unclear.

METHODS AND RESULTS

In order to elucidate the roles of IFN-γ in pressure overload-induced cardiac pathology, we subjected Balb/c wild-type (WT) or IFN-γ-deficient (Ifng-/-) mice to transverse aortic constriction (TAC). Three weeks after TAC, Ifng-/- mice developed more severe cardiac hypertrophy, fibrosis, and dysfunction than WT mice. Bone marrow-derived immune cells including macrophages were a source of IFN-γ in hearts after TAC. The activation of PI3K/Akt signaling, a key signaling pathway in compensatory hypertrophy, was detected 3 days after TAC in the left ventricles of WT mice and was markedly attenuated in Ifng-/- mice. The administration of a neutralizing anti-IFN-γ antibody abrogated PI3K/Akt signal activation in WT mice during compensatory hypertrophy, while that of IFN-γ activated PI3K/Akt signaling in Ifng-/- mice. TAC also induced the phosphorylation of Stat5, but not Stat1 in the left ventricles of WT mice 3 days after TAC. Furthermore, IFN-γ induced Stat5 and Akt phosphorylation in rat cardiomyocytes cultured under stretch conditions. A Stat5 inhibitor significantly suppressed PI3K/Akt signaling activation in the left ventricles of WT mice, and aggravated pressure overload-induced cardiac hypertrophy.

CONCLUSIONS

The IFN-γ/Stat5 axis may be protective against persistent pressure overload-induced cardiac hypertrophy by activating the PI3K/Akt pathway.

Fibroatheroma identification in Intravascular Optical Coherence Tomography images using deep features

Identifying vulnerable plaque is important in coronary heart disease diagnosis. Recent emerged imaging modality, Intravascular Optical Coherence Tomography (IVOCT), has been proved to be able to characterize the appearance of vulnerable plaques. Comparing with the manual method, automated fibroatheroma identification would be more efficient and objective. Deep convolutional neural networks have been adopted in many medical image analysis tasks. In this paper, we introduce deep features to resolve fibroatheroma identification problem. Deep features which extracted using four deep convolutional neural networks, AlexNet, GoogLeNet, VGG-16 and VGG-19, are studied. And a dataset of 360 IVOCT images from 18 pullbacks are constructed to evaluate these features. Within these 360 images, 180 images are normal IVOCT images and the rest 180 images are IVOCT images with fibroatheroma. Here, one pullback belongs to one patient; leave-one-patient-out cross-validation is employed for evaluation. Data augmentation is applied on training set for each classification scheme. Linear support vector machine is conducted to classify the normal IVOCT image and IVOCT image with fibroatheroma. The experimental results show that deep features could achieve relatively high accuracy in fibroatheroma identification.

Prognosis of spontaneous coronary artery dissection treated by percutaneous coronary intervention with optical coherence tomography

BACKGROUND

Although about half of patients with spontaneous coronary artery dissection (SCAD) face ongoing necrosis, conservative therapy is recommended due to a high complication rate in angiography-guided percutaneous coronary intervention (PCI). The aim of this study was to investigate clinical outcomes of SCAD treated by optical coherence tomography (OCT)-guided PCI.

METHODS

This study consisted of consecutive 306 patients with acute coronary syndrome (ACS) who underwent OCT-guided PCI. Based on the culprit lesion morphology by OCT, patients were assigned to four groups: a SCAD group, a plaque rupture (PR) group, a calcified nodule (CN) group, and an undetermined etiology (UE) group. Successful PCI was defined as thrombolysis in myocardial infarction flow grade 3 in final angiography without any complications. Primary endpoint was defined as occurrence rate of major adverse cardiac events (MACE) including cardiac death, myocardial infarction, and unstable angina pectoris.

RESULTS

OCT revealed 12 SCADs, 149 PRs, 16 CNs, and 129 UEs, respectively. No significant difference was observed in the success rate of PCI (SCAD 91.7%, PR 85.2%, CN 81.2%, UE 86.8%, p=0.88), while wire repositioning was needed in 2 SCAD cases (p<0.01). The mean follow-up periods were 17.1±13.3 months. No significant difference was observed in MACE among the groups (p=0.56).

CONCLUSIONS

The clinical outcomes of OCT-guided PCI for SCAD were favorable, as well as those for other ACS etiologies. OCT-guided PCI could become a therapeutic option for SCAD compromised with ongoing necrosis.

Association of Toll-Like Receptor 4 on Human Monocyte Subsets and Vulnerability Characteristics of Coronary Plaque as Assessed by 64-Slice Multidetector Computed Tomography

BACKGROUND

Although Toll-like receptor 4 (TLR-4) is involved in monocyte activation in patients with accelerated forms of atherosclerosis, the relationship between the expression of TLR-4 on circulating monocytes and coronary plaque vulnerability has not previously been evaluated. We investigated this relationship using 64-slice multidetector computed tomography (MDCT) in patients with stable angina pectoris (SAP).Methods and Results:We enrolled 65 patients with SAP who underwent MDCT. Three monocyte subsets (CD14⁺⁺CD16^-, CD14⁺⁺CD16⁺, and CD14⁺CD16⁺) and expression of TLR-4 were measured by flow cytometry. Intracoronary plaques were assessed by 64-slice MDCT. We defined vulnerability of intracoronary plaques according to the presence of positive remodeling (remodeling index >1.05) and/or low CT attenuation (<35 HU). The circulating CD14⁺⁺CD16⁺monocytes more frequently expressed TLR-4 than CD14⁺⁺CD16^-and CD14⁺CD16⁺monocytes (P<0.001). The relative proportion of the expression of TLR-4 on CD14⁺⁺CD16⁺monocytes was significantly greater in patients with vulnerable plaque compared with those without (10.4 [4.1-14.5] % vs. 4.5 [2.8-7.8] %, P=0.012). In addition, the relative proportion of TLR-4 expression on CD14⁺⁺CD16⁺monocytes positively correlated with the remodeling index (r=0.28, P=0.025) and negatively correlated with CT attenuation value (r=-0.31, P=0.013).

CONCLUSIONS

Upregulation of TLR-4 on CD14⁺⁺CD16⁺monocytes might be associated with coronary plaque vulnerability in patients with SAP.