Developmental or Procedural Vena Cava Interruption and Venous Thromboembolism: A Review.

The inferior vena cava (IVC) and superior vena cava are the main conduits of the systemic venous circulation into the right atrium. Developmental or procedural interruptions of vena cava might predispose to stasis and deep vein thrombosis (DVT) distal to the anomaly and may impact the subsequent rate of pulmonary embolism (PE). This study aimed to review the various etiologies of developmental or procedural vena cava interruption and their impact on venous thromboembolism. A systematic search was performed in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines per each clinical question. For management questions with no high-quality evidence and no mutual agreements between authors, Delphi methods were used. IVC agenesis is the most common form of congenital vena cava interruption, is associated with an increased risk of DVT, and should be suspected in young patients with unexpected extensive bilateral DVT. Surgical techniques for vena cava interruption (ligation, clipping, and plication) to prevent PE have been largely abandoned due to short-term procedural risks and long-term complications, although survivors of prior procedures are occasionally encountered. Vena cava filters are now the most commonly used method of procedural interruption, frequently placed in the infrarenal IVC. The most agreed-upon indication for vena cava filters is for patients with acute venous thromboembolism and coexisting contraindications to anticoagulation. Familiarity with different forms of vena cava interruption and their local and systemic adverse effects is important to minimize complications and thrombotic events.

Electronic alerts for ambulatory patients with atrial fibrillation not prescribed anticoagulation: A randomized, controlled trial (AF-ALERT2).

BACKGROUND: Despite widely available risk stratification tools, safe and effective anticoagulants, and guideline recommendations, anticoagulation for stroke prevention in atrial fibrillation (AF) is under-prescribed in ambulatory patients. To assess the impact of alert-based computerized decision support (CDS) on anticoagulation prescription in ambulatory patients with AF and high-risk for stroke, we conducted this randomized controlled trial. METHODS: Patients with AF and CHA2DS2-VASc score ≥ 2 who were not prescribed anticoagulation and had a clinic visit at Brigham and Women's Hospital were enrolled. Patients were randomly allocated, according to Attending Physician of record, to intervention (alert-based CDS) versus control (no notification). The primary efficacy outcome was the frequency of anticoagulant prescription. RESULTS: The CDS tool assigned 395 and 403 patients to the alert and control groups, respectively. Alert patients were more likely to be prescribed anticoagulation within 48 h of the clinic visit (15.4 % vs. 7.7 %, p < 0.001) and at 90 days (17.2 % vs. 9.9 %, p < 0.01). Direct oral anticoagulants were the predominantly prescribed form of anticoagulation. No significant differences were observed in stroke, TIA, or systemic embolic events (0 % vs. 0.8 %, p = 0.09), symptomatic VTE (0.5 % vs. 1 %, p = 0.43), all-cause mortality (2 % vs. 0.7 %, p = 0.12), or major adverse cardiovascular events (2.8 % vs. 2.5 %, p = 0.79) at 90 days. CONCLUSIONS: An alert-based CDS strategy increased a primary efficacy outcome of anticoagulation in clinic patients with AF and high-risk for stroke who were not receiving anticoagulation at the time of the office visit. The study was likely underpowered to assess an impact on clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier- NCT02958943.

Anticoagulation-Associated Adverse Drug Events in Hospitalized Patients Across Two Time Periods.

PURPOSE: Anticoagulants often cause adverse drug events (ADEs), comprised of medication errors and adverse drug reactions, in patients. Our study objective was to determine the clinical characteristics, types, severity, cause, and outcomes of anticoagulation-associated ADEs from 2015-2020 (a contemporary period following implementation of an electronic health record, infusion device technology, and anticoagulant dosing nomograms) and to compare them with those of a historical period (2004-2009). METHODS: We reviewed all anticoagulant-associated ADEs reported as part of our hospital-wide safety system. Reviewers classified type, severity, root cause, and outcomes for each ADE according to standard definitions. Reviewers also assessed events for patient harm. Patients were followed up to 30 days after the event. RESULTS: Despite implementation of enhanced patient safety technology and procedure, ADEs increased in the contemporary period. In the contemporary period, we found 925 patients who had 984 anticoagulation-associated ADEs, including 811 isolated medication errors (82.4%); 13 isolated adverse drug reactions (1.4%); and 160 combined medication errors, adverse drug reactions, or both (16.2%). Unfractionated heparin was the most frequent ADE-related anticoagulant (77.7%, contemporary period vs 58.3%, historical period). The most frequent anticoagulation-associated medication error in the contemporary period was wrong rate or frequency of administration (26.1%, n = 253), with the most frequent root cause being prescribing errors (21.3%, n = 207). The type, root cause, and harm from ADEs were similar between periods. CONCLUSIONS: We found that anticoagulation-associated ADEs occurred despite advances in patient safety technologies and practices. Events were common, suggesting marginal improvements in anticoagulant safety over time and ample opportunities for improvement.

Assessment of QTc and Risk of Torsades de Pointes in Ventricular Conduction Delay and Pacing: A Review of the Literature and Call to Action.

BACKGROUND: Assessment of the heart rate-corrected QT-interval on the 12-lead electrocardiogram when prescribing medications known to increase the risk of Torsades de Pointes has become a common part of consultation-liaison psychiatry practice. OBJECTIVES: Highlighted by a patient who experienced psychiatric decompensation due to inaccurate interpretation of QTc prolongation in the setting of a wide QRS complex, we aimed to describe the approach to QTc interpretation in patients with ventricular conduction delay. METHODS: We reviewed the current literature on the approach to assessment of prolonged repolarization in patients with ventricular conduction delay due to bundle branch block (BBB) and ventricular pacing. RESULTS: Physicians of any specialty may perform initial electrocardiogram interpretation and should be proficient in the definition, recognition, and understanding of the basic pathophysiology of electrocardiographic abnormalities. We discuss current approaches to assessment of the QT-interval in patients with a wide QRS complex due to bundle branch block and ventricular pacing, including bivariate QTc modification, univariate QT-interval modifications, and use of the JT-interval. CONCLUSIONS: The QT-interval is prolonged ipso facto in patients with a wide QRS complex from ventricular conduction delay/ventricular pacing and must be adjusted for QRS duration. Multiple formulae have been proposed to account for wide QRS complex in this setting with no single universally accepted methodology. We suggest the use of either the Bogossian formula or JT-interval followed by Hodges or Framingham heart-rate correction to adjust for a wide QRS complex. It is critical that the C-L psychiatrist be able to identify a wide QRS complex on the electrocardiogram, understand implications for accurate assessment of prolonged depolarization, and apply an appropriate correction methodology.

North American lower-extremity revascularization and amputation during COVID-19: Observations from the Vascular Quality Initiative.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic's impact on vascular procedural volumes and outcomes has not been fully characterized. METHODS: Volume and outcome data before (1/2019 - 2/2020), during (3/2020 - 4/2020), and following (5/2020 - 6/2020) the initial pandemic surge were obtained from the Vascular Quality Initiative (VQI). Volume changes were determined using interrupted Poisson time series regression. Adjusted mortality was estimated using multivariable logistic regression. RESULTS: The final cohort comprised 57,181 patients from 147 US and Canadian sites. Overall procedure volumes fell 35.2% (95% CI 31.9%, 38.4%, p < 0.001) during and 19.8% (95% CI 16.8%, 22.9%, p < 0.001) following the surge, compared with presurge months. Procedure volumes fell 71.1% for claudication (95% CI 55.6%, 86.4%, p < 0.001) and 15.9% for chronic limb-threatening ischemia (CLTI) (95% CI 11.9%, 19.8%, p < 0.001) but remained unchanged for acute limb ischemia (ALI) when comparing surge to presurge months. Adjusted mortality was significantly higher among those with claudication (0.5% vs 0.1%; OR 4.38 [95% CI 1.42, 13.5], p = 0.01) and ALI (6.4% vs 4.4%; OR 2.63 [95% CI 1.39, 4.98], p = 0.003) when comparing postsurge with presurge periods. CONCLUSION: The first North American COVID-19 pandemic surge was associated with a significant and sustained decline in both elective and nonelective lower-extremity vascular procedural volumes. When compared with presurge patients, in-hospital mortality increased for those with claudication and ALI following the surge.

Manual, semiautomated, and fully automated measurement of the aortic annulus for planning of transcatheter aortic valve replacement (TAVR/TAVI): analysis of interchangeability.

BACKGROUND: Preprocedural 3-dimensional CT imaging of the aortic annular plane plays a critical role for transcatheter aortic valve replacement (TAVR) planning; however, manual reconstructions are complex. Automated analysis software may improve reproducibility and agreement between readers but is incompletely validated. METHODS: In 110 TAVR patients (mean age, 81 years; 37% female) undergoing preprocedural multidetector CT, automated reconstruction of the aortic annular plane and planimetry of the annulus was performed with a prototype of now commercially available software (syngo.CT Cardiac Function-Valve Pilot; Siemens Healthcare, Erlangen, Germany). Fully automated, semiautomated, and manual annulus measurements were compared. Intrareader and inter-reader agreement, intermodality agreement, and interchangeability were analyzed. Finally, the impact of these measurements on recommended valve size was evaluated. RESULTS: Semiautomated analysis required major correction in 5 patients (4.5%). In the remaining 95.5%, only minor correction was performed. Mean manual annulus area was significantly smaller than fully automated results (P < .001 for both readers) but similar to semiautomated measurements (5.0 vs 5.4 vs 4.9 cm(2), respectively). The frequency of concordant recommendations for valve size increased if manual analysis was replaced with the semiautomated method (60% agreement was improved to 82.4%; 95% confidence interval for the difference [69.1%-83.4%]). CONCLUSIONS: Semiautomated aortic annulus analysis, with minor correction by the user, provides reliable results in the context of TAVR annulus evaluation.

Stress positron emission tomography is safe and can guide coronary revascularization in high-risk patients being considered for transcatheter aortic valve replacement.

BACKGROUND: The safety and accuracy of regadenoson stress positron emission tomography (PET) in patients with significant aortic stenosis (AS) is unknown. In patients undergoing surgical aortic valve replacement, coronary artery bypass grafting for coronary artery disease is standard, but the appropriate revascularization strategy in patients undergoing TAVR is uncertain. Stress PET may identify patients that benefit from revascularization. METHODS: Fifty consecutive patients who were referred for consideration of TAVR and underwent a stress PET study were retrospectively identified. We assessed major adverse cardiac events and significant decreases in systolic blood pressure. The percentage of jeopardized myocardium was determined by combining ischemic and hibernating myocardium. RESULTS: Our patients were high risk with a mean Society of Thoracic Surgeons mortality score of 11.4% and had severe AS with a moderately reduced left ventricular ejection fraction (EF) (mean aortic valve area of 0.78 ± 0.25 cm(2) and mean EF of 39 ± 16%). There were no major adverse events during testing. Transient hypotension occurred in 16% of the patients. Revascularization was performed in 44% of patients, and 91% of these patients had revascularization to territories jeopardized on PET. These patients had substantial jeopardized myocardium (median 19%), and only 3 patients underwent revascularization despite less than 10% jeopardized myocardium. CONCLUSIONS: Stress cardiac PET with regadenoson can be performed safely in patients with severe AS. Results of the PET study can accurately direct subsequent revascularization.

The effect of aspirin on endothelial progenitor cell biology: preliminary investigation of novel properties.

UNLABELLED: Atherosclerosis develops in an environment of endothelial injury and inflammation. Circulating endothelial progenitor cells (EPCs) are required for vascular repair and restoration of normal endothelial function. We tested the hypothesis that the nonselective cyclooxygenase (COX) inhibitor aspirin (ASA) exerts an effect on circulating EPCs. METHODS: As part of a larger study evaluating the effect of aspirin dose in primary and secondary prevention, subjects (n=32) were assigned randomly to either 81 mg or 325 mg aspirin daily for two months, and circulating mononuclear cells were enumerated at the beginning of the study and after 2 months using fluorescent antibodies against CD34 and CD133 as well as based on aldehyde dehydrogenase (ALDH) activity. Brachial artery endothelial function via flow-mediated dilation (BAFMD) and light transmittance platelet aggregometry in response to physiologic agonists was also determined. RESULTS: Subjects taking aspirin at the time of study entry had a lower numbers of CD133+/34+ cells compared to those not previously exposed (0.01% vs. 0.05% of MNCs, P<0.03). After 2 months, subjects randomized to 81 vs. 325 mg of ASA had no significant differences in the median numbers of EPCs, although mean numbers trended lower in the high dose group. Patients on chronic ASA therapy continued to have lower numbers of EPCs. Similar effects were observed in CD34 and CD 133 single-positive cells, as well as ALDH(br) cells. BAFMD did not differ nor change significantly over time between aspirin dose groups. All patients had decreased ex vivo platelet aggregation in response to arachidonic acid and ADP stimulation. CONCLUSIONS: Our preliminary studies suggest that aspirin exerts a time-dependent effect on circulating EPCs. Short-term exposure to differing doses of ASA had indeterminate effects on EPCs levels, suggesting that time of ASA exposure may play a more important role than dose. Determining the responsible mechanism(s) and the overall clinical relevance of these findings will require further investigation.

The FGF14(F145S) mutation disrupts the interaction of FGF14 with voltage-gated Na+ channels and impairs neuronal excitability.

Fibroblast growth factor 14 (FGF14) belongs to the intracellular FGF homologous factor subfamily of FGF proteins (iFGFs) that are not secreted and do not activate tyrosine kinase receptors. The iFGFs, however, have been shown to interact with the pore-forming (alpha) subunits of voltage-gated Na+ (Na(v)) channels. The neurological phenotypes seen in Fgf14-/- mice and the identification of an FGF14 missense mutation (FGF14(F145S)) in a Dutch family presenting with cognitive impairment and spinocerebellar ataxia suggest links between FGF14 and neuronal functioning. Here, we demonstrate that the expression of FGF14(F145S) reduces Na(v) alpha subunit expression at the axon initial segment, attenuates Na(v) channel currents, and reduces the excitability of hippocampal neurons. In addition, and in contrast with wild-type FGF14, FGF14(F145S) does not interact directly with Na(v) channel alpha subunits. Rather, FGF14(F145S) associates with wild-type FGF14 and disrupts the interaction between wild-type FGF14 and Na(v) alpha subunits, suggesting that the mutant FGF14(F145S) protein acts as a dominant negative, interfering with the interaction between wild-type FGF14 and Na(v) channel alpha subunits and altering neuronal excitability.

Fibroblast growth factor 14 is an intracellular modulator of voltage-gated sodium channels.

Genetic ablation of the fibroblast growth factor (Fgf) 14 gene in mice or a missense mutation in Fgf14 in humans causes ataxia and cognitive deficits. These phenotypes suggest that the neuronally expressed Fgf14 gene is essential for regulating normal neuronal activity. Here, we demonstrate that FGF14 interacts directly with multiple voltage-gated Na(+) (Nav) channel alpha subunits heterologously expressed in non-neuronal cells or natively expressed in a murine neuroblastoma cell line. Functional studies reveal that these interactions result in the potent inhibition of Nav channel currents (I(Na)) and in changes in the voltage dependence of channel activation and inactivation. Deletion of the unique amino terminus of the splice variant of Fgf14, Fgf14-1b, or expression of the splice variant Fgf14-1a modifies the modulatory effects on I(Na), suggesting an important role for the amino terminus domain of FGF14 in the regulation of Na(v) channels. To investigate the function of FGF14 in neurones, we directly expressed Fgf14 in freshly isolated primary rat hippocampal neurones. In these cells, the addition of FGF14-1a-GFP or FGF14-1b-GFP increased I(Na) density and shifted the voltage dependence of channel activation and inactivation. In fully differentiated neurones, FGF14-1a-GFP or FGF14-1b-GFP preferentially colocalized with endogenous Nav channels at the axonal initial segment, a critical region for action potential generation. Together, these findings implicate FGF14 as a unique modulator of Nav channel activity in the CNS and provide a possible mechanism to explain the neurological phenotypes observed in mice and humans with mutations in Fgf14.

Thioredoxin reductase regulates AP-1 activity as well as thioredoxin nuclear localization via active cysteines in response to ionizing radiation.

A recently identified class of signaling factors uses critical cysteine motif(s) that act as redox-sensitive 'sulfhydryl switches' to reversibly modulate specific signal transduction cascades regulating downstream proteins with similar redox-sensitive sites. For example, signaling factors such as redox factor-1 (Ref-1) and transcription factors such as the AP-1 complex both contain redox-sensitive cysteine motifs that regulate activity in response to oxidative stress. The mammalian thioredoxin reductase-1 (TR) is an oxidoreductase selenocysteine-containing flavoprotein that also appears to regulate multiple downstream intracellular redox-sensitive proteins. Since ionizing radiation (IR) induces oxidative stress as well as increases AP-1 DNA-binding activity via the activation of Ref-1, the potential roles of TR and thioredoxin (TRX) in the regulation of AP-1 activity in response to IR were investigated. Permanently transfected cell lines that overexpress wild type TR demonstrated constitutive increases in AP-1 DNA-binding activity as well as AP-1-dependent reporter gene expression, relative to vector control cells. In contrast, permanently transfected cell lines expressing a TR gene with the active site cysteine motif deleted were unable to induce AP-1 activity or reporter gene expression in response to IR. Transient genetic overexpression of either the TR wild type or dominant-negative genes demonstrated similar results using a transient assay system. One mechanism through which TR regulates AP-1 activity appears to involve TRX sub-cellular localization, with no change in the total TRX content of the cell. These results identify a novel function of the TR enzyme as a signaling factor in the regulation of AP-1 activity via a cysteine motif located in the protein.

Ataxia and paroxysmal dyskinesia in mice lacking axonally transported FGF14.

Fibroblast growth factor 14 (FGF14) belongs to a distinct subclass of FGFs that is expressed in the developing and adult CNS. We disrupted the Fgf14 gene and introduced an Fgf14(N-beta-Gal) allele that abolished Fgf14 expression and generated a fusion protein (FGF14N-beta-gal) containing the first exon of FGF14 and beta-galactosidase. Fgf14-deficient mice were viable, fertile, and anatomically normal, but developed ataxia and a paroxysmal hyperkinetic movement disorder. Neuropharmacological studies showed that Fgf14-deficient mice have reduced responses to dopamine agonists. The paroxysmal hyperkinetic movement disorder phenocopies a form of dystonia, a disease often associated with dysfunction of the putamen. Strikingly, the FGF14N-beta-gal chimeric protein was efficiently transported into neuronal processes in the basal ganglia and cerebellum. Together, these studies identify a novel function for FGF14 in neuronal signaling and implicate FGF14 in axonal trafficking and synaptosomal function.