The Odorant Receptor Recognizing Camphor in a Camphor Tree Specialist Orthaga achatina (Lepidoptera: Pyralidae).

Camphor has been used as an effective repellent and pesticide to stored products for a long history, but Orthaga achatina (Lepidoptera: Pyralidae) has evolved to specifically feed on the camphor tree Cinnamomum camphora. However, the behavioral response of O. achatina to camphor and the molecular basis of camphor perception are totally unknown. Here, we demonstrated that both male and female adults were behaviorally attracted to camphor, suggesting the adaptation of O. achatina to and utilization of camphor as a signal of C. camphora. Second, in 40 O. achatina OR genes obtained by analyzing antenna transcriptomes, only OachOR16/Orco significantly responded to camphor in the Xenopus oocyte system. Finally, by molecular docking analysis and site-directed mutagenesis, the Ser209 residue is confirmed to be essential for binding of the oachOR16 with camphor. This study not only reveals the camphor-based host plant choice and olfactory mechanisms of O. achatina but also provides a molecular target for screening more potential insect repellents.

Enhanced interfacial boiling of impacting droplets upon vibratory surfaces.

HYPOTHESIS: Despite the flourishing studies of droplet interfacial boiling, the boiling upon vibratory surfaces, which may cause vigorous liquid-vapor-solid interactions, has rarely been investigated. Enhanced boiling normally can be gained from rapid removal of vapor and disturbance of liquid-vapor interface. We hypothesize that the vibratory surfaces enhance both effects with new intriguing phenomena and thus, attain an enhanced boiling heat transfer. EXPERIMENTS: We experimentally investigated the impacting fluid dynamics and coupled heat transfer patterns of multiple droplets and a single droplet impinging on still and vibratory surfaces of various materials and different wettability. FINDINGS: The boiling under vibratory surfaces with increased vibration velocity amplitude and enhanced wettability can be enhanced by 80% in heat transfer coefficient and Nusselt number, which is attributed to several reasons: shortened bubble lifespan, thinner and smaller bubbles, and enhanced disturbances in liquid-vapor interfaces. The vibration also delays the Leidenfrost point when the droplet impacts a descending surface, which shows that the droplet impact moment (vibration phase angle) is particularly crucial. The descending surface releases the generated vapor actively and facilitates liquid-solid contact, thereby delaying the Leidenfrost. From fundamentals to application, this article strengthens our understanding of vibrated interfacial boiling in scenarios closer to multiple natural processes and practical industries.

An odorant receptor tuned to an attractive plant volatile vanillin in Spodoptera litura.

The insect olfaction plays crucial roles in many important behaviors, in which ORs are key determinants for signal transduction and the olfactory specificity. Spodoptera litura is a typical polyphagous pest, possessing a large repertoire of ORs tuning to broad range of plant odorants. However, the specific functions of those ORs remain mostly unknown. In this study, we functionally characterized one S. litura OR (OR51) that was highly expressed in the adult antennae. First, by using Xenopus oocyte expression and two-electrode voltage clamp recording system (XOE-TEVC), OR51 was found to be strongly and specifically responsive to vanillin (a volatile of S. litura host plants) among 77 tested odorants. Second, electroantennogram (EAG) and Y-tube behavioral experiment showed that vanillin elicited significant EAG response and attraction behavior especially of female adults. This female attraction was further confirmed by the oviposition experiment, in which the soybean plants treated with vanillin were significantly preferred by females for egg-laying. Third, 3D structural modelling and molecular docking were conducted to explore the interaction between OR51 and vanillin, which showed a high affinity (-4.46 kcal/mol) and three residues (Gln163, Phe164 and Ala305) forming hydrogen bonds with vanillin, supporting the specific binding of OR51 to vanillin. In addition, OR51 and its homologs from other seven noctuid species shared high amino acid identities (78-97%) and the same three hydrogen bond forming residues, suggesting a conserved function of the OR in these insects. Taken together, our study provides some new insights into the olfactory mechanisms of host plant finding and suggests potential applications of vanillin in S. litura control.

Conserved Odorant Receptors Involved in Nonanal-Induced Female Attractive Behavior in Two Spodoptera Species.

Moths rely on plant volatiles to locate appropriate plants for feeding and laying eggs. While extensive research has been conducted on the global agricultural pests, Spodoptera frugiperda and Spodoptera litura, their molecular mechanisms for detecting plant volatiles remain mostly unknown. Here, we have demonstrated that nonanal, a common plant volatile, is attractive for both virgin and gravid females of the two species. Second, we have identified a conserved odorant receptor clade (SfruOR47 clade) that is primarily tuned to nonanal. Finally, by three-dimensional (3D) structure prediction, molecular docking, and site-directed mutagenesis, we have revealed that the His57 and Glu61 residues, also shared by other six orthologous ORs, are essential for nonanal binding in SfruOR47 and SlituOR9, indicating the conserved structure and function of ORs in the SfruOR47 clade. These findings offer novel insights into the molecular mechanisms and evolutionary aspects of moth behavior in response to plant volatiles.

Design and Scalable Fabrication of Liquid Metal and Nano-Sheet Graphene Hybrid Phase Change Materials for Thermal Management.

Here, a paraffin/liquid metal (LM)/graphene hybrid thermal composite material with a high thermal-conductivity as well as  high latent heat is developed. The paraffin is encapsulated in calcium alginate, which produces leakage-free phase change material (PCM) capsules. LM is filled among the gaps of PCM capsules to enhance overall heat conduction. Graphene nano-sheets coating attains efficient heat dissipation because of its high spectral emissivity (>91%) in the spectrum of the mid-infrared region. The developed material is verified to have strong compatibility and durable stability. The composite is utilized as a thermal buffer (TB) for central processing unit thermal management to demonstrate the synergy of these superior thermal properties. In certain cases, active cooling normally used could be replaced by the developed TB without any energy consumption for thermal management, demonstrating a completely passive cooling strategy. Compared to traditional heat sink active cooling, general energy savings of 10.4-26.3% could thus be achieved by the developed composite in wider operating conditions, proving its potential for more efficient and sustainable data center cooling alongside thermal management of other ground-based electrical/electronic equipment.

In-situ Electrochemical Transformed Cu Oxide from Cu Sulfide for Efficient Upgrading of Biomass Derived 5-Hydroxymethylfurfural in Anion Exchange Membrane Electrolyzer.

The electrochemical transformation of biomass to high value-added products is attractive. Herein, Cu sulfide-mediated in-situ synthesis of Cu oxide was achieved for efficient electro-oxidation of biomass derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). The copper foam-supported Cu sulfide (Cu-S/CF) was in-situ converted to Cu oxide during the electro-oxidation process. The in-situ formed Cu oxide presented high HMF conversion, FDCA yield, and faradaic efficiency in 1 m KOH with HMF concentration up to 100 mm. The oxidation of HMF on Cu oxide started with the formation of high-valence Cu species with the assistance of OH- , which then oxidized HMF spontaneously. An anion exchange membrane (AEM) electrolyzer with Cu-S/CF as the anode was assembled to continuously produce FDCA with H2 generation at the cathode. The AEM electrolyzer ran stably for 60 h with FDCA content higher than 85 % at a cell voltage between 1.50 and 1.60 V.

Ventilation reconstruction in bathrooms for restraining hazardous plume: Mitigate COVID-19 and beyond.

Converging evidence reports that the probability of vertical transmission patterns via shared drainage systems, may be responsible for the huge contactless community outbreak in high-rise buildings. Publications indicate that a faulty bathroom exhaust fan system is ineffective in removing lifted hazardous virus-laden aerosols from the toilet bowl space. Common strategies (boosting ventilation capability and applying disinfection tablets) seem unsustainable and remain to date untested. Using combined simulation and experimental approaches, we compared three ventilation schemes in a family bathroom including the traditional ceiling fan, floor fan, and side-wall fan. We found that the traditional ceiling fan was barely functional whereby aerosol particles were not being adequately removed. Conversely, a side-wall fan could function efficiently and an enhanced ventilation capability can have increased performance whereby nearly 80.9% of the lifted aerosol particles were removed. There exists a common, and easily-overlooked mistake in the layout of the bathroom, exposing occupants to a contactless vertical pathogen aerosol transmission route. Corrections and dissemination are thus imperative for the reconstruction of these types of family bathrooms. Our findings provide evidence for the bathroom and smart ventilation system upgrade, promoting indoor public health and human hygiene.

Prognostic Value of Metabolic Syndrome in Patients With Non-ST Elevated Myocardial Infarction Undergoing Percutaneous Coronary Intervention.

Objective: We aim to investigate the prognostic effects of metabolic syndrome (MS) on patients with non-ST elevated myocardial infarction (NSTEMI) after percutaneous coronary intervention (PCI). Methods: Patients with NSTEMI undergoing PCI were consecutively collected. According to the presence or absence of MS, they were divided into two groups and followed up for 1 year. The endpoint was major adverse cardiovascular events (MACE), including all-cause death, unstable angina hospitalization, heart failure (HF) hospitalization, non-fatal recurrent myocardial infarction (MI), and target lesion revascularization. Also, six subgroups were made according to gender, age, left ventricular ejection fraction (LVEF), Global Registry of Acute Coronary Events (GRACE) score, hypersensitive troponin (hsTNT), and several diseased vessels. Cox proportional hazard model was adopted to analyze the effect of MS on MACE in all the patients and different subgroups. Results: A total of 1,295 patients were included in the current analysis and 660 (50.97%) of them had MS. About 88 patients were lost to follow-up, and the overall average follow-up was 315 days. MS was an independent risk factor for MACE (HR 1.714, CI 1.265-2.322, p = 0.001), all-cause death, heart failure (HF) hospitalization, and non-fatal recurrent MI. In the MS component, BMI ≥28 kg/m2 was positively associated with MACE. Subgroup analysis indicated the prognostic value of MS was more striking for patients with the following: age of >60, LVEF of ≤40%, GRACE of >140, multivessel disease, or hsTNT of >0.1 ng/ml. Conclusions: The MS was a robust adverse prognostic factor in patients diagnosed with NSTEMI, especially among those of older age and at higher ischemic risk. A BMI of ≥28 kg/m2 independently predicted the occurrence of MACE. Prognosis may be improved by controlling abdominal obesity.

Latent class cluster analysis of knowledge on acute myocardial infarction in community residents: a cross-sectional study in Tianjin, China.

OBJECTIVE: Public knowledge of early onset symptoms and risk factors (RF) of acute myocardial infarction (AMI) is very important for prevention, recurrence and guide medical seeking behaviours. This study aimed to identify clusters of knowledge on symptoms and RFs of AMI, compare characteristics and the awareness of the need for prompt treatment. DESIGN: Multistage stratified sampling was used in this cross-sectional study. Latent GOLD Statistical Package was used to identify and classify the respondent subtypes of the knowledge on AMI symptoms or modifiable RFs. Multivariable logistic regression was performed to identify factors that predicted high knowledge membership. PARTICIPANTS: A structured questionnaire was used to interview 4200 community residents aged over 35 in China. 4122 valid questionnaires were recovered. RESULTS: For AMI symptoms and RFs, the knowledge levels were classified into two or three distinct clusters, respectively. 62.7% (Symptom High Knowledge Cluster) and 39.5% (RF High Knowledge Cluster) of the respondents were able to identify most of the symptoms and modifiable RFs. Respondents who were highly educated, had higher monthly household income, were insured, had regular physical examinations, had a disease history of AMI RFs, had AMI history in immediate family member or acquaintance or had received public education on AMI were observed to have higher probability of knowledge on symptoms and RFs. There was significant difference in awareness of the prompt treatment in case of AMI occurs among different clusters. 'Calling an ambulance' was the most popular option in response of seeing others presenting symptoms of AMI. CONCLUSIONS: A moderate or relatively low knowledge on AMI symptoms and modifiable RFs was observed in our study. Identification of Knowledge Clusters could be a way to detect specific targeted groups with low knowledge of AMI, which may facilitate health education, further reduce the prehospital delay in China and improve patient outcomes.

The Relevance of Interventional Time and Clinical Outcomes in Patients with NSTEMI Based on the GRACE Score.

Objective: To investigate the relevance between interventional time and clinical outcomes in non-ST-elevation myocardial infarction (NSTEMI) patients of different risk stratifications, which were divided into different groups according to GRACE scores and the time from admission to percutaneous coronary intervention (PCI). Method: Patients were grouped according to the GRACE score and the time from admission to intervention therapy. The Cox multivariate risk regression model was used to analyze the correlation between the GRACE score and the time from admission to intervention therapy with major adverse cardiovascular events (MACEs). Cox interactive item regression was also used to investigate the correlation between the time of intervention therapy and GRACE risk stratification with clinical outcomes and to evaluate the efficacy of intervention therapy in different risk stratifications of patients with NSTEMI. Results: Interactive item Cox regression analysis and subgroup analysis show that high-risk NSTEMI patients with a GRACE score > 140 points and the time from admission to intervention < 24 h (p = 0.0004) and 24-72 h (p = 0.0143) have interactive effects on the impact of the MACE event with the reference of intervention time > 72 h and GRACE score < 108 points. The time from admission to intervention < 24 h is an independent protective factor for the occurrence of MACE events (HR = 0.166, 95% CI 0.052-0.532, p = 0.0025). Middle-risk patients with NSTEMI with a GRACE score of 109-140 points and the time from admission to intervention < 24 h (p = 0.0370) and 24-72 h (p = 0.0471) have an interactive effect on the impact of MACE. The time from admission to intervention > 72 h is an independent protective factor for the occurrence of MACE (HR = 0.201, 95% CI 0.045-0.897, p = 0.0355). Conclusion: The time from admission to intervention < 24 h could effectively reduce the risk of MACE events within 1 year in high-risk patients with NSTEMI (GRACE score > 140 points); the time from admission to intervention > 72 h can reduce the risk of MACE events within 1 year in low-risk patients with NSTEMI (GRACE score ≤ 108 points).

Reconsidering treatment guidelines for acute myocardial infarction during the COVID-19 pandemic.

BACKGROUND: COVID-19 affects healthcare resource allocation, which could lead to treatment delay and poor outcomes in patients with acute myocardial infarction (AMI). We assessed the impact of the COVID-19 pandemic on AMI outcomes. METHODS: We compared outcomes of patients admitted for acute ST-elevation MI (STEMI) and non-STEMI (NSTEMI) during a non-COVID-19 pandemic period (January-February 2019; Group 1, n = 254) and a COVID-19 pandemic period (January-February 2020; Group 2, n = 124). RESULTS: For STEMI patients, the median of first medical contact (FMC) time, door-to-balloon time, and total myocardial ischemia time were significantly longer in Group 2 patients (all p < 0.05). Primary percutaneous intervention was performed significantly more often in Group 1 patients than in Group 2 patients, whereas thrombolytic therapy was used significantly more often in Group 2 patients than in Group 1 patients (all p < 0.05). However, the rates of and all-cause 30-day mortality and major adverse cardiac event (MACE) were not significantly different in the two periods (all p > 0.05). For NSTEMI patients, Group 2 patients had a higher rate of conservative therapy, a lower rate of reperfusion therapy, and longer FMC times (all p < 0.05). All-cause 30-day mortality and MACE were only higher in NSTEMI patients during the COVID-19 pandemic period (p < 0.001). CONCLUSIONS: COVID-19 pandemic causes treatment delay in AMI patients and potentially leads to poor clinical outcome in NSTEMI patients. Thrombolytic therapy should be initiated without delay for STEMI when coronary intervention is not readily available; for NSTEMI patients, outcomes of invasive reperfusion were better than medical treatment.

On male urination and related environmental disease transmission in restrooms: From the perspectives of fluid dynamics.

Indoor transmission of COVID-19 is highly probable. Multiple sources have verified that the SARS-CoV-2 can be detected within toilets, and people can be infected in restrooms. There is a huge gap in the coronavirus transmission mechanism in restrooms. Understanding it can help to flatten the curve of the infected cases as well as prevent other viruses transmitted through the sewage or human body fluid. Previous studies have shown how simple actions in daily life (coughing, sneezing, or toilet flushing) contribute to virus transmission. This paper visually and quantitatively demonstrates that male urination, which is also a daily action, can agitate virus particles within the toilet and raise them, which may be the main promoter of cross-infection of COVID-19 in restrooms. Adopting numerical and experimental methods, we demonstrate that male urination can cause strong turbulent flow with an averaged urine impinging velocity of 2.3 m/s, which can act as an agitator to raise the virus particles. The climbing velocity of the airflow can be 0.75-1.05 m/s. The observed upwards flow will disturb and spread any lurking virus particles (not limited to SARS-CoV-2). Experiments demonstrated that the concentration of the airborne particle could be tripled during male urination. Corresponding precautions are offered as well to prepare the public to act properly when and after using facilities in restrooms for preventing emerging and re-emerging pandemics not limited to the current COVID-19, contributing to the sustainability of human society.

Nanostructured jumping-droplet thermal rectifier.

Analogous to an electrical rectifier, a thermal rectifier (TR) can ensure that heat flows in a preferential direction. In this paper, thermal transport nonlinearity is achieved through the development of a phase-change based TR comprising an enclosed vapor chamber having separated nanostructured copper oxide superhydrophobic and superhydrophilic functional surfaces. In the forward direction, heat transfer is facilitated through evaporation on the superhydrophilic surface and self-propelled jumping-droplet condensation on the superhydrophobic surface. In the reverse direction, heat transfer is minimized due to condensate film formation within the superhydrophilic condenser and inability to return the condensed liquid to the superhydrophobic evaporator. We examine the coupled effects of gap size, coolant mass, heat transfer rate, and applied electric field on the thermal performance of the TR. A maximum thermal diodicity, defined as the ratio of forward to reverse heat transfer, of 39 is achieved.

An air distribution optimization of hospital wards for minimizing cross-infection.

Currently, the "2019-CoV-2" has been raging across the world for months, causing massive death, huge panic, chaos, and immeasurable economic loss. Such emerging epidemic viruses come again and again over years, leading to similar destructive consequences. Air-borne transmission among humans is the main reason for the rapid spreading of the virus. Blocking the air-borne transmission should be a significant measure to suppress the spreading of the pandemic. Considering the hospital is the most probable place to occur massive cross-infection among patients as emerging virus usually comes in a disguised way, an air distribution optimization of a general three-bed hospital ward in China is carried out in this paper. Using the Eulerian-Lagrangian method, sneeze process from patients who are assumed to be the virus carrier, which is responsible for a common event to trigger cross-infection, is simulated. The trajectory of the released toxic particle and the probability of approaching others in the same ward are calculated. Two evaluation parameter, total maximum time (TMT) and overall particle concentration (OPC) to reflect the particle mobility and probability to cause cross-infection respectively, are developed to evaluate the proposed ten air distributions in this paper. A relatively optimized air distribution proposal with the lowest TMT and OPC is distinguished through a three-stage analysis. Results show that a bottom-in and top-out air distribution proposal is recommended to minimize cross-infections.

Optimization of GRACE Risk Stratification by N-Terminal Pro-B-type Natriuretic Peptide Combined With D-Dimer in Patients With Non-ST-Elevation Myocardial Infarction.

We aimed to explore the utility of multiple biomarkers with GRACE risk stratification for non-ST-elevation myocardial infarction (NSTEMI). A total of 1,357 patients diagnosed with NSTEMI were enrolled in this study at multiple medical centers in Tianjin, China. The outcomes were 1-year all-cause death and major adverse cardiac events (MACE: all-cause death, hospital admission for unstable angina, hospital admission for heart failure, nonfatal recurrent myocardial infarction, and stroke). C-index, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to verify that the biomarkers improve the predictive accuracy of the GRACE score. A total of 57 participants died, while 211 participants experienced 231 MACEs during follow-up (mean: 339 days). For all-cause death, the combination of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and D-dimer improved the predictive accuracy of GRACE the most, with C-index, IDI, and NRI values of 0.88, 0.085, and 1.223, respectively. For MACE, trigeminal combination of NT-proBNP, fibrinogen, and D-dimer resulted in C-index, IDI, and NRI values of 0.80, 0.079, and 0.647, respectively. As a result, NT-proBNP, D-dimer, fibrinogen, and GRACE comprise a new scoring system for assessing 1-year clinical events. Kaplan-Meier analysis revealed a significant increase in 1-year mortality (score ≥3.85 vs <3.85, p < 0.0001) and 1-year MACE (score ≥1.72 vs <1.72, p < 0.0001) between different score groups. In conclusion, the combination of NT-proBNP and D-dimer added prognostic value to GRACE for all-cause death. Combining NT-proBNP, fibrinogen, and D-dimer increased the prognostic value of GRACE for MACE. This newly developed scoring system is strongly correlated with all-cause mortality and MACE, and can be easily utilized in clinical practice.

Liquid-curtain-based strategy to restrain plume during flushing.

How to prevent the flushing-induced plume without changing people's daily habits? Enlightened by thoughts of redesigning the restroom, this article provides a redesigned toilet using liquid-curtain-based strategy and verifies its advantages from the computational fluid dynamics. Two favorable effects are spotted: (1) the liquid curtain can suppress the upward virus particles (only 1% viruses can be lifted out of the toilet) and (2) the flow distribution caused by the liquid curtain can deliver virus particles into the sewage efficiently.

Virus transmission from urinals.

A virus-laden particle movement from urinal flushing is simulated. Similar to the toilet-induced flushing, results indicate that the trajectory of the particles triggered by the urinal flushing manifests an external spread type. Even more alarmingly, the particle can reach 0.84 m (man's thigh) in 5.5 s when compared with the diffusion performance of the toilet-induced one (around 0.93 m in 35 s). A more violent climbing tendency is discovered in this Letter. Wearing masks should be made mandatory in public washrooms, and anti-diffusion improvements of facilities in public washrooms are urgently needed, especially in the current "SARS-CoV-2" crisis.

Can a toilet promote virus transmission? From a fluid dynamics perspective.

Currently, a novel coronavirus named "SARS-CoV-2" is spreading rapidly across the world, causing a public health crisis, economic losses, and panic. Fecal-oral transmission is a common transmission route for many viruses, including SARS-CoV-2. Blocking the path of fecal-oral transmission, which occurs commonly in toilet usage, is of fundamental importance in suppressing the spread of viruses. However, to date, efforts at improving sanitary safety in toilet use have been insufficient. It is clear from daily experience that flushing a toilet generates strong turbulence within the bowl. Will this flushing-induced turbulent flow expel aerosol particles containing viruses out of the bowl? This paper adopts computational fluid dynamics to explore and visualize the characteristics of fluid flow during toilet flushing and the influence of flushing on the spread of virus aerosol particles. The volume-of-fluid (VOF) model is used to simulate two common flushing processes (single-inlet flushing and annular flushing), and the VOF-discrete phase model (DPM) method is used to model the trajectories of aerosol particles during flushing. The simulation results are alarming in that massive upward transport of virus particles is observed, with 40%-60% of particles reaching above the toilet seat, leading to large-scale virus spread. Suggestions concerning safer toilet use and recommendations for a better toilet design are also provided.

Gut microbial taxa as potential predictive biomarkers for acute coronary syndrome and post-STEMI cardiovascular events.

Plasma trimethylamine N-oxide (TMAO) is associated with coronary atherosclerotic plaque and cardiovascular disease risk, but associations between gut microbes in acute coronary syndrome (ACS) and post-ST-segment elevation myocardial infarction (post-STEMI) events are unknown. We investigated associations between gut microbial taxa and systemic TMAO levels and the possible TMAO contribution to incident post-STEMI cardiovascular events. PATIENTS AND METHODS: A total of 60 patients, including 30 with unstable angina pectoris (UAP), 30 post-STEMI and 30 healthy controls, were enrolled from June to November 2017. Metagenomic sequencing was performed and TMAO and IL-6 were detected. RESULTS: Minimal discriminators of gut microbial taxa (top 40) distinguished ACS patients from controls. Serum TMAO levels were positively associated with increased abundance of Aerococcaceae, Ruminococcaceae_UCG.005, Ruminococcaceae_UCC.014 and X. Eubacterium_fissicatena, and decreased abundance of Lachnospiraceae_FCS020 (P < 0.05). Elevated serum TMAO levels correlated independently with ACS (P < 0.05). Risk stratification for incident major adverse cardiovascular events (MACE) improved at one year in patients with serum TMAO levels ≦2.19 µM. Serum interleukin-6 levels were not significantly increased in patients with ACS and post-STEMI MACE. CONCLUSIONS: ACS and incident post-STEMI MACE may be associated with the gut bacteria choline metabolite TMAO. The specific gut microbial taxa identified in association with serum TMAO levels may be potential predictive biomarkers for accurate diagnosis of ACS onset.

Prediction of Major Adverse Cardiovascular Events and Slow/No-Reflow by Virtual Histology Imaging After Percutaneous Interventions on Saphenous Vein Grafts.

Saphenous vein grafts disease (SVGD) is a common complication after coronary artery bypass graft (CABG) and usually treated by percutaneous coronary intervention (PCI). In this prospective cohort study, we performed virtual histology-intravascular ultrasound to investigate whether plaque composition and morphological characteristics were associated with post-PCI major adverse cardiac events (MACEs) and slow/no-reflow in patients with SVGD. Patients (n = 90) were studied (76.7% men, mean age 64.9 ± 8.2 years and mean duration of SVG 8.0 ± 3.6 years). There were 77.8% lesions with a plaque burden of at least 70%; 18 MACE incidences accumulated in 14 patients over 12 months post-PCI and slow/no-reflow was observed in 12 patients. On adjusted multivariate analysis, lesion length (hazard ratio [HR] = 1.05; 95% confidence interval [CI]: 1.01-1.08]); age of CABG (HR = 1.51 [95% CI: 1.11-2.05], and absolute necrotic core (NC) area (HR = 8.04 [95% CI: 1.86-34.73]) were independently associated with MACEs. Factors independently associated with slow/no-reflow post-PCI were preprocedure systolic blood pressure (odds ratio [OR] = 0.98; 95% CI: 0.96-0.99) and absolute NC area (OR = 2.47 (95% CI: 1.14-5.36). A cutoff value of absolute NC area at ≥1.1 mm2 may serve as a significant risk predictor for no-reflow after SVG-PCI. Factors associated with MACEs and the slow/no-reflow phenomenon following PCI of the SVG can be used in risk assessment of SVG.