An Analysis of Mechanisms Underlying the Antifibrinolytic Properties of Radiographic Contrast Agents

Background: Radiographic contrast agents inhibit fibrinolysis, although by poorly defined pathways. The purpose of this study was to define specific mechanisms by which contrast agents inhibit clot lysis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47998/1/11239_2004_Article_397950.pd

Electrosurgery and Implantable Electronic Devices: Review and Implications for Office‐Based Procedures

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86867/1/j.1524-4725.2011.02006.x.pd

Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest

Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO2-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG) and electroencephalogram (EEG) signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients

Aspirin Dosing for Secondary Prevention of Atherosclerotic Cardiovascular Disease in Patients Treated With P2Y12 Inhibitors

Background The ADAPTABLE (Aspirin Dosing: A Patient‐Centric Trial Assessing Benefits and Long‐Term Effectiveness) was a large, pragmatic, randomized controlled trial that found no difference between high‐ versus low‐dose aspirin for secondary prevention of atherosclerotic cardiovascular disease. Whether concomitant P2Y12 inhibitor therapy modifies the effect of aspirin dose on clinical events remains unclear. Methods and Results Participants in ADAPTABLE were stratified according to baseline use of clopidogrel or prasugrel (P2Y12 group). The primary effectiveness end point was a composite of death, myocardial infarction, or stroke; and the primary safety end point was major bleeding requiring blood transfusions. We used multivariable Cox regression to compare the relative effectiveness and safety of aspirin dose within P2Y12 and non‐P2Y12 groups. Of 13 815 (91.6%) participants with available data, 3051 (22.1%) were receiving clopidogrel (2849 [93.4%]) or prasugrel (203 [6.7%]) at baseline. P2Y12 inhibitor use was associated with higher risk of the primary effectiveness end point (10.86% versus 6.31%; adjusted hazard ratio [HR], 1.40 [95% CI, 1.22–1.62]) but was not associated with bleeding (0.95% versus 0.53%; adjusted HR, 1.42 [95% CI, 0.91–2.22]). We found no interaction in the relative effectiveness and safety of high‐ versus low‐dose aspirin by P2Y12 inhibitor use. Overall, dose switching or discontinuation was more common in the high‐dose compared with low‐dose aspirin group, but the pattern was not modified by P2Y12 inhibitor use. Conclusions In this prespecified analysis of ADAPTABLE, we found that the relative effectiveness and safety of high‐ versus low‐dose aspirin was not modified by baseline P2Y12 inhibitor use. Registration https://www.clinical.trials.gov. Unique identifier: NCT02697916

Comparative Effectiveness of Aspirin Dosing in Cardiovascular Disease

BackgroundThe appropriate dose of aspirin to lower the risk of death, myocardial infarction, and stroke and to minimize major bleeding in patients with established atherosclerotic cardiovascular disease is a subject of controversy.MethodsUsing an open-label, pragmatic design, we randomly assigned patients with established atherosclerotic cardiovascular disease to a strategy of 81 mg or 325 mg of aspirin per day. The primary effectiveness outcome was a composite of death from any cause, hospitalization for myocardial infarction, or hospitalization for stroke, assessed in a time-to-event analysis. The primary safety outcome was hospitalization for major bleeding, also assessed in a time-to-event analysis.ResultsA total of 15,076 patients were followed for a median of 26.2 months (interquartile range [IQR], 19.0 to 34.9). Before randomization, 13,537 (96.0% of those with available information on previous aspirin use) were already taking aspirin, and 85.3% of these patients were previously taking 81 mg of daily aspirin. Death, hospitalization for myocardial infarction, or hospitalization for stroke occurred in 590 patients (estimated percentage, 7.28%) in the 81-mg group and 569 patients (estimated percentage, 7.51%) in the 325-mg group (hazard ratio, 1.02; 95% confidence interval [CI], 0.91 to 1.14). Hospitalization for major bleeding occurred in 53 patients (estimated percentage, 0.63%) in the 81-mg group and 44 patients (estimated percentage, 0.60%) in the 325-mg group (hazard ratio, 1.18; 95% CI, 0.79 to 1.77). Patients assigned to 325 mg had a higher incidence of dose switching than those assigned to 81 mg (41.6% vs. 7.1%) and fewer median days of exposure to the assigned dose (434 days [IQR, 139 to 737] vs. 650 days [IQR, 415 to 922]).ConclusionsIn this pragmatic trial involving patients with established cardiovascular disease, there was substantial dose switching to 81 mg of daily aspirin and no significant differences in cardiovascular events or major bleeding between patients assigned to 81 mg and those assigned to 325 mg of aspirin daily. (Funded by the Patient-Centered Outcomes Research Institute; ADAPTABLE ClinicalTrials.gov number, NCT02697916.)