An early revascularization strategy is associated with a survival benefit for diabetic patients in cardiogenic shock after acute myocardial infarction

BACKGROUND: The role of diabetes mellitus (DM) in cardiogenic shock (CS) complicating an acute myocardial infarction (AMI) is not well understood. Previous studies have reported an in-hospital mortality rate for patients with DM and CS of about 60%. OBJECTIVES: This study compares the 1-year mortality rates of patients with DM and those without (NDM) and evaluates early revascularization (ERV) compared with initial medical stabilization (IMS) in patients with DM and CS. Methods: Baseline characteristics, clinical and hemodynamic measures, and management were compared for 90 patients (31%) with DM and 198 with NDM (69%) who were randomized to ERV or IMS in the SHOCK Trial. RESULTS: When compared with NDM, patients with DM were of similar age but had higher rates of prior MI (44.4 vs. 27.8%, p = 0.007) and hypertension (56.2 vs. 42.5%, p = 0.04). The DM group had a lower rate of fibrinolytic therapy (44.4 vs. 60.1%, p = 0.02). In patients randomized to ERV, patients with DM had a higher rate of coronary artery bypass grafting (CABG) (50.0 vs. 30.9%, p = 0.03) despite similar rates of triple-vessel disease. The 1-year mortality rates in both groups were equivalent (58.9%). One-year mortality was not associated with diabetes (hazard ratio [HR] 1.02, 95% CI, 0.73-1.42, p = 0.91). The benefit of an ERV strategy was similar (HR [DM] 0.62; HR [NDM] 0.75, p = 0.58). Even after adjusting for the imbalance in CABG rates, 1-year mortality was not associated with DM. CONCLUSION: Diabetes mellitus is not a predictor of 1-year mortality in CS after AMI. The benefit from an ERV strategy is similar for DM and NDM. The management strategies and influence of DM on mortality in CS deserve further evaluation.     

Percutaneous coronary intervention versus coronary bypass graft surgery for patients with medically refractory myocardial ischemia and risk factors for adverse outcomes with bypass: The VA AWESOME multicenter registry: comparison with the randomized clinical trial.

OBJECTIVES: This study was designed to compare the three-year survival after percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG) in physician-directed and patient-choice registries with the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) randomized trial results. BACKGROUND: The AWESOME multicenter randomized trial and registry compared the long-term survival after PCI and CABG for the treatment of patients with medically refractory myocardial ischemia and at least one additional risk factor for adverse outcome with CABG. The randomized trial demonstrated comparable three-year survival. METHODS: Over a five-year period (1995 to 2000), 2,431 patients with medically refractory myocardial ischemia and at least one of five risk factors (prior heart surgery, myocardial infarction within seven days, left ventricular ejection fraction <0.35, age >70 years, intra-aortic balloon required to stabilize) were identified. By physician consensus, 1,650 patients formed a physician-directed registry assigned to CABG (692), PCI (651) or further medical therapy (307), and 781 were angiographically eligible for random allocation; 454 of these patients constitute the randomized trial, and the remaining 327 constitute a patient choice registry. Survival for CABG and PCI was compared using Kaplan-Meier curves and log-rank tests. RESULTS: The CABG and PCI 36-month survival rates for randomized patients were 79% and 80%, respectively. The CABG and PCI 36-month survival rates were both 76% for the physician-directed subgroup; comparable survival rates for the patient-choice subgroup were 80% and 89%, respectively. None of the global log-rank tests for survival demonstrated significant differences. CONCLUSIONS: Both registries support the randomized trial conclusion: PCI is an alternative to CABG for some medically refractory high-risk patients.     

Alterations in transmural blood flow and body surface ST segment abnormalities produced by ischemia in the circumflex and left anterior descending coronary arterial beds of the dog

Previous studies have documented a quantitative relation between alterations in transmural myocardial blood flow and body surface electrocardiographic distributions during rapid atrial pacing after chronic occlusion of the left circumflex coronary artery (LCx). Because other studies have described functional differences between the left anterior descending (LAD) and the LCx perfusion beds, we tested the hypothesis that these two territories exhibit quantitative differences in their responses to demand-dependent myocardial ischemia. To do so, 25 sedated dogs were studied 3 weeks after implantation of an ameroid constrictor around the proximal LCx (15 dogs, group I) or the LAD (group II). Oxygen demand was increased by rapid atrial pacing at rates of 90 to 210 beats/min, myocardial blood flow was measured by serial injections of radiolabeled microspheres, and the electrocardiographic consequences were evaluated by isopotential body surface mapping. Endocardial flows and the endocardial/epicardial flow ratio fell to significantly lower levels during atrial pacing in the ischemic LAD bed than in the LCx perfusion zone. Electrocardiographic patterns indicative of subendocardial ischemia also developed with lesser abnormalities in endocardial/epicardial ratios as determined by logistic regression models, in the LAD than in the LCx bed. Thus the LAD bed is more susceptible to ischemia than the LCx region because of differences in collateral blood flow patterns. In addition, the intensity of the surface electrocardiographic potentials during ischemia was significantly greater, as measured by linear regression, after LAD than after LCx obstruction. These data thus demonstrate significant differences between the two cardiac regions as electrocardiographic potential sources during ischemia.     

Role of transesophageal echocardiography in the clinical management of a patient with a giant coronary artery aneurysm

Transthoracic echocardiography (TTE) has substantial limitations for the study of abnormalities of the coronary tree. Transesophageal echocardiography (TEE) allows a more complete examination of the coronary arteries, particularly the proximal segments. This report describes the use of TEE after cardiac catheterization in the clinical management of a patient with unstable angina. While angiography first showed the giant aneurysm of the left circumflex coronary artery, TEE, by revealing an active thrombus of the lumen, prompted an immediate surgical resolution.     

A score predicts failure of reperfusion after fibrinolytic therapy for acute myocardial infarction

Background A rapid, accurate, noninvasive means of predicting the likelihood of failure to achieve Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow within 90 minutes after the start of fibrinolysis with streptokinase could help to identify patients who might benefit from additional therapies that aim to preserve myocytes. Methods We measured ST recovery, which was assessed as the sum of ST deviation on a 12-lead electrocardiogram, and blood levels of the myocardial proteins, troponin T, creatine kinase myocardial band (CK-MB), and myoglobin before and 60 minutes after commencing streptokinase infused for 30 to 60 minutes in 107 patients, who presented within 12 hours of symptom onset and underwent angiography at 90 minutes. Results At 90 minutes, 56% of patients (95% CI 46-66) had TIMI-3 flow. The baseline levels of troponin T, CK-MB, and myoglobin were more commonly below the discrimination values in patients with TIMI-3 flow than in patients without TIMI-3 flow (all P < .005). On multivariate analysis, the factors associated with failure to achieve TIMI-3 flow were ST recovery of <70% (P = .009), a 60-minute/baseline troponin T ratio of ≤5 (P = .0004), a baseline CK-MB level of >4 μg/L (P = .039), or a baseline myoglobin level of >85 μg/L (P = .048). Age and a history of myocardial infarction were added into the multivariate model, and a risk score was developed to predict the likelihood of failure to achieve TIMI-3 flow. A score of ≤2 excluded failure to achieve TIMI-3 flow with 96% accuracy, and a score of ≥7 predicted failure to achieve TIMI-3 flow with 90% accuracy. Conclusion Failure to achieve TIMI-3 flow in the infarct-related artery within 90 minutes after the start of fibrinolysis can be accurately predicted at approximately 60 minutes by a score incorporating clinical variables, ST recovery, and the 60-minute/baseline ratios of troponin T, CK-MB, and/or myoglobin levels. This score may facilitate triage of patients at 60 minutes after fibrinolysis to additional reperfusion therapies. (Am Heart J 2003;145:508-14.)     

Characterization of a novel,papain‐inducible murine model of eosinophilic rhinosinusitis

Background

Eosinophilic chronic rhinosinusitis (ECRS) is a disease characterized by eosinophilic inflammatory infiltrate and a local type 2 cytokine milieu. Current animal models fail to recapitulate many of the innate and adaptive immunologic hallmarks of the disease, thus hindering the development of effective therapeutics. In the present study, mice were exposed intranasally to the cysteine protease papain, which shares functional similarities with parasitic proteases and aeroallergens, to generate a rapidly inducible murine model of eosinophilic rhinosinusitis.

Methods

C57BL/6 mice were intranasally instilled with 20 μg papain or heat‐inactivated papain (HP) on days 0–2 and days 7–10, and then euthanized on day 11. Nasal lavage fluid (NALF) was analyzed to quantify eosinophils and inflammatory cytokine secretion. Sinonasal tissue was sectioned and stained for goblet cells or homogenized to analyze cytokine levels. Serum samples were assayed for immunoglobulin E (IgE) by enzyme‐linked immunoassay. Sinonasal mucosal tissue was dissociated and analyzed by flow cytometry.

Results

Compared with HP treatment, papain induced significant eosinophilia in NALF, goblet cell hyperplasia, innate and adaptive immune cell infiltration, type 2 cytokine production, and IgE responses. Flow cytometric analysis of sinonasal tissues revealed significant inflammatory cell infiltration and interleukin‐13–producing cell populations.

Conclusion

In this study, we demonstrated that the cysteine protease papain induces allergic sinonasal eosinophilic rhinosinusitis and resembles T‐helper 2 cell inflammation and innate immune characteristics of ECRS. This model permits further study into the molecular mechanisms underlying ECRS pathology and provides a model system for the evaluation of potential pharmacologic interventions.

     

An enzyme thermistor-based assay for total and free cholesterol.

A method to evaluate the free (FC) and total cholesterol (TC) in human serum, bile and gallstone extract using an enzyme thermistor (ET)-based flow injection analysis (FIA) is presented. The cholesterol in high-density (HDL-C) and low density lipoprotein (LDL-C) have also been evaluated. A heparin functionalized Sepharose column was employed for the isolation of HDL and LDL fractions from serum. The estimation of cholesterol and its esters was based on their reaction with cholesterol oxidase (CO), cholesterol esterase (CE) and catalase (CAT). Three different enzyme columns, i.e. co-immobilized CO/CAT (column A), only CE (column B) and co-immobilized CO/CE/CAT (column C) were prepared by cross-linking the enzymes on glass beads using glutaraldehyde. Column A was used for estimating FC and column C was used for estimating total cholesterol (cholesterol plus esterified cholesterol). Column B was used as a pre-column which could be switched 'in' or 'out' in conjunction with column A for the estimation of TC or FC, respectively. A calibration between 1.0 and 8.0 mmol/l for FC and 0. 25 and 4.0 mmol/l for TC was obtained. For more than 2000 assays with the ET device a C.V. of less than 4% was obtained. The assay time was approximately 4 min per assay. The cholesterol estimations on the ET correlated well with similar estimations using a commercially available cholesterol diagnostic kit.     

Mechanical Properties of Aramid/Carbon Hybrid Fiber-Reinforced Concrete

In this study, aramid fiber (Kevlar^® 29 fiber) and carbon fiber were added into concrete in a hybrid manner to enhance the static and impact mechanical properties. The coupling agent presence on the surface of carbon fibers was spotted in Scanning Electron Microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) graphs. The carbon fiber with a coupling agent affected the mechanical strength of the reinforced concrete. At 1% fiber/cement weight percentage, the hybrid fiber-reinforced concrete (HFRC) prepared using Kevlar fiber and carbon fiber of 12 and 24 mm in length under different mix proportions was investigated to determine the maximum mechanical strengths. From the test results, the mechanical strength of the HFRC attained better performance than that of the concrete with only Kevlar or carbon fibers. Foremost, the mix proportion of Kevlar/carbon fiber (50–50%) significantly improved the compressive, flexural, and splitting tensile strengths. Under different impact energies, the impact resistance of the HFRC specimen was much higher than that of the benchmark specimen, and the damage of the HFRC specimens was examined with an optical microscope to identify slippage or rupture failure of the fiber in concrete.     

Observationally constrained estimates of carbonaceous aerosol radiative forcing

Carbonaceous aerosols (CA) emitted by fossil and biomass fuels consist of black carbon (BC), a strong absorber of solar radiation, and organic matter (OM). OM scatters as well as absorbs solar radiation. The absorbing component of OM, which is ignored in most climate models, is referred to as brown carbon (BrC). Model estimates of the global CA radiative forcing range from 0 to 0.7 Wm^-2, to be compared with the Intergovernmental Panel on Climate Change’s estimate for the pre-Industrial to the present net radiative forcing of about 1.6 Wm^-2. This study provides a model-independent, observationally based estimate of the CA direct radiative forcing. Ground-based aerosol network data is integrated with field data and satellite-based aerosol observations to provide a decadal (2001 through 2009) global view of the CA optical properties and direct radiative forcing. The estimated global CA direct radiative effect is about 0.75 Wm^-2 (0.5 to 1.0). This study identifies the global importance of BrC, which is shown to contribute about 20% to 550-nm CA solar absorption globally. Because of the inclusion of BrC, the net effect of OM is close to zero and the CA forcing is nearly equal to that of BC. The CA direct radiative forcing is estimated to be about 0.65 (0.5 to about 0.8) Wm^-2, thus comparable to or exceeding that by methane. Caused in part by BrC absorption, CAs have a net warming effect even over open biomass-burning regions in Africa and the Amazon.