Danicamtiv increases cardiac mechanical efficiency.

Danicamtiv is a recently developed cardiac-specific myosin activator that directly increases actomyosin interaction and, thereby, increases force. It is currently studied pre-clinically and has entered clinical trials. In this study, we provide the first assessment of its effects on cardiac energetics.

Metabolite-sensitive cross-bridge models of human atria reveal the impact of diabetes on muscle mechanoenergetics.

Type 2 diabetes is associated with a range of adverse health outcomes, including metabolic dysfunction and increased risk of heart failure. Although the interactions between diabetes and heart disease are complex and incompletely understood, they can be more effectively investigated using multiscale, biophysically based models of the underlying physiological processes. In this study, experimental data from non-diabetic and diabetic human atrial muscles were used to develop metabolite-sensitive cross-bridge models representing each group.

Comparison of In-Person and Virtual Integrated Vascular Surgery Residency Interviews from the Applicant's Perspective.

Background: The COVID-19 pandemic provoked an abrupt transition from in-person to virtual format interviews for integrated vascular surgery residency. Recently, 12 programs (15.8%) resumed in-person interviews in 2023-2024.

A prospective randomized trial of remote renal ischemic preconditioning for reducing nephropathy risk following fenestrated endovascular aortic aneurysm repair.

Objectives: We sought to evaluate whether remote renal ischemic preconditioning is effective for reducing postoperative acute kidney injury (AKI) and mid-term renal function decline in patients undergoing elective fenestrated endovascular aneurysm repair (FEVAR) of juxtarenal aortic aneurysms.

Methods: We performed a single-site, blinded, prospective randomized trial of a renal ischemic preconditioning intervention using arm ischemia via manual inflation of arm blood pressure cuff. We evaluated 30-day AKI, determined using the Risk, Injury, Failure, loss of Function, and End-stage (RIFLE) classification and 2-year freedom from renal function decline, defined as a >30% decrease in baseline estimated glomerular function rate.

Sex differences in cardiac energetics in the rat ventricular muscle.

Cardiac sex-difference functional studies have centred on measurements of twitch force and Ca dynamics. The energy expenditures from these two cellular processes: activation (Ca handling) and contraction (cross-bridge cycling), have not been assessed, and compared, between sexes. Whole-heart studies measuring oxygen consumption do not directly measure the energy expenditure of these activation-contraction processes.

Primary Sites and Clinicopathological Features of Corneal Melanoma: A Surveillance, Epidemiology, and End Results (SEER) Population-based Study of 29 Cases.

Purpose: Corneal melanoma (CM) is a rare malignancy that develops from melanocytes within the cornea, constituting a minority of all ocular tumors. In this study, we sought to investigate the clinicopathological characteristics correlated with the prognosis of CM patients.

Methods: We collected patients with CM between 1983 and 2018 from the Surveillance, Epidemiology, and End Results (SEER) database.

Sex Related Differences in Perioperative Outcomes after Complex Endovascular Aortic Aneurysm Repair.

Background: Prior studies suggest female sex is associated with worse outcomes after complex endovascular aortic aneurysm repair (EVAR) due to anatomic differences. Therefore, we aimed to compare 30-day perioperative and long-term outcomes after complex EVAR by sex.

Methods: A single-center retrospective review of consecutive elective and emergent complex EVAR with company-manufactured devices, laser fenestration, snorkel/periscope, or octopus technique was performed from 2012-2023.

A national census for the off-label treatment of complex aortic aneurysms.

Objective: Despite regulatory challenges, device availability, and rapidly expanding techniques, off-label endovascular repair of complex aortic aneurysms (cAAs) has expanded in the past decade. Given the lack of United States Food and Drug Administration-approved endovascular technology to treat cAAs, we performed a national census to better understand volume and current practice patterns in the United States.

Methods: Targeted sampling identified vascular surgeons with experience in off-label endovascular repair of cAAs.

Analysis of metabolite and strain effects on cardiac cross-bridge dynamics using model linearisation techniques.

Multi-scale models of cardiac energetics are becoming crucial in better understanding the prevalent chronic diseases operating at the intersection of metabolic and cardiovascular dysfunction. Computationally efficient models of cardiac cross-bridge kinetics that are sensitive to changes in metabolite concentrations are necessary to simulate the effects of disease-induced changes in cellular metabolic state on cardiac mechanics across disparate spatial scales. While these models do currently exist, deeper analysis of how the modelling of metabolite effects and the assignment of strain dependence within the cross-bridge cycle affect the properties of the model is required.

Methods for assessing cardiac myofilament calcium sensitivity.

Myofilament calcium (Ca) sensitivity is one of several mechanisms by which force production of cardiac muscle is modulated to meet the ever-changing demands placed on the heart. Compromised Ca sensitivity is associated with pathologies, which makes it a parameter of interest for researchers. Ca Sensitivity is the ratio of the association and dissociation rates between troponin C (TnC) and Ca.

An Instrument for High-throughput Testing of Heart Tissue In Vitro.

Cardiac trabeculae are small samples of heart muscle tissue that can be dissected and studied in vitro to better understand the underlying physiology of cardiac muscle. However, instruments for such experimentation often (1) involve delicate mounting of the muscle, (2) constrain investigations to one muscle at a time and, thus, (3) cannot retain the muscle in the same experimental configuration for post-experimental assessment including imaging analysis. Here, we present a novel device that allows trabeculae to be secured by a visible-light photo-initiated hydrogel, manipulated via a force sensor, and stimulated while being imaged.

Measuring and Modelling the Effect of Inorganic Phosphate on Cross-bridge Mechanics in Human Cardiac Muscle.

Many common chronic diseases operate at the intersection of metabolic and cardiovascular dysfunction. In order to model the effects of these diseases and investigate underlying causes we are developing a cardiomyocyte model which incorporates both the mechanics and metabolic factors that underlie work done by the heart. In this paper we present the first experimental results from our study measuring mechanical properties in human cardiac trabeculae, including the effect of inorganic phosphate (Pi) on the complex modulus at 37 °C.

Resolving an inconsistency in the estimation of the energy for excitation of cardiac muscle contraction.

In the excitation of muscle contraction, calcium ions interact with transmembrane transporters. This process is accompanied by energy consumption and heat liberation. To quantify this activation energy or heat in the heart or cardiac muscle, two non-pharmacological approaches can be used.

Validity of the Global Vascular Guidelines in Predicting Outcomes Based on First-Time Revascularization Strategy.

Background: The Global Vascular Guidelines (GVG) recommend selecting an endovascular versus open-surgical approach to revascularization for chronic limb-threatening ischemia (CLTI), based on the Global Limb Anatomic Staging System (GLASS) and wound, ischemia, and foot infection (WIfI) classification systems. We assessed the utility of GVG-recommended strategies in predicting clinical outcomes.

Methods: We conducted a single-center, retrospective review of first-time lower-extremity revascularizations within a comprehensive limb-preservation program from 2010 to 2018.

Most privately insured patients do not receive federally recommended abdominal aortic aneurysm screening.

Objective: Since 2005, the United States Preventative Services Task Force has recommended abdominal aortic aneurysm (AAA) ultrasound screening for 65- to 75-year-old male ever-smokers. Integrated health systems such as Kaiser Permanente and the Veterans Affairs (VA) health care system report 74% to 79% adherence, but compliance rates in the private sector are unknown.

Methods: The IBM Marketscan Commercial and Medicare Supplemental databases (2006-2017) were queried for male ever-smokers continuously enrolled from age 65 to 75 years.

Uncovering cross-bridge properties that underlie the cardiac active complex modulus using model linearisation techniques.

The properties underlying cardiac cross-bridge kinetics can be characterised by a muscle's active complex modulus. While the complex modulus can be described by a series of linear transfer functions, the biophysical mechanisms underlying these components are represented inconsistently among existing cross-bridge models. To address this, we examined the properties commonly implemented in cross-bridge models using model linearisation techniques and assessed their contributions to the complex modulus.

SBML to bond graphs: From conversion to composition.

The Systems Biology Markup Language (SBML) is a popular software-independent XML-based format for describing models of biological phenomena. The BioModels Database is the largest online repository of SBML models. Several tools and platforms are available to support the reuse and composition of SBML models.

Large Fenestrations Versus Scallops for the Superior Mesenteric Artery during Fenestrated Endovascular Aneurysm Repair: Does it Matter?

Background: Fenestrated endovascular aneurysm repair is an established customized treatment for aortic aneurysms with 3 current commercially available configurations for the superior mesenteric artery (SMA)-a single-wide scallop, large fenestration, or small fenestration, with the scallop or large fenestration most utilized. Outcomes comparing SMA single-wide scallops to large fenestrations with the Zenith fenestrated (ZFEN) device are scarce. As large fenestrations have the benefit of extending the proximal seal zone compared to scalloped configurations, we sought to determine the differences in seal zone and sac regression outcomes between the 2 SMA configurations.

Cardiac efficiency and Starling's Law of the Heart.

The formulation by Starling of The Law of the Heart states that 'the [mechanical] energy of contraction, however measured, is a function of the length of the muscle fibre'. Starling later also stated that 'the oxygen consumption of the isolated heart … is determined by its diastolic volume, and therefore by the initial length of its muscular fibres'. This phrasing has motivated us to extend Starling's Law of the Heart to include consideration of the efficiency of contraction.

Female sex is independently associated with reduced inpatient mortality after endovascular repair of blunt thoracic aortic injury.

Background: Female sex has been associated with decreased mortality after blunt trauma, but whether sex influences the outcomes of thoracic endovascular aortic repair (TEVAR) for traumatic blunt thoracic aortic injury (BTAI) is unknown.

Methods: In this retrospective study of a prospectively maintained database, the Vascular Quality Initiative registry was queried from 2013 to 2020 for patients undergoing TEVAR for BTAI. Univariate Student's t-tests and χ tests were performed, followed by multivariate logistic regression for variables associated with inpatient mortality.