Short-term and long-term outcomes of cardiac arrhythmias in patients with cardiogenic shock.

INTRODUCTION: Cardiogenic shock is severe circulatory failure that results in significant in-hospital mortality, related morbidity, and economic burden. Patients with cardiogenic shock are at high risk for atrial and ventricular arrhythmias, particularly within the subset of patients with an overlap of cardiogenic shock and cardiac arrest. AREAS COVERED: This review article will explore the prevalence, definition, management, and outcomes of common arrhythmias in patients with cardiogenic shock. This review will describe the pathophysiology of arrhythmia in cardiogenic shock and the impact of inotropic agents on increased arrhythmogenicity. In addition to medical management, focused assessment of mechanical circulatory support, radiofrequency ablation, deep sedation, and stellate ganglion block will be provided. EXPERT OPINION: We will navigate the limited data and describe the prognostic impacts of arrhythmia. Finally, we will conclude the review with a discussion of prevention strategies, research limitations, and future research directions.

STAT: Mobile app helps clinicians manage inpatient emergencies.

In response to the unprecedented surge of patients with COVID-19, Massachusetts General Hospital created both repurposed and de-novo COVID-19 inpatient general medicine and intensive care units. The clinicians staffing these new services included those who typically worked in these care settings (e.g., medicine residents, hospitalists, intensivists), as well as others who typically practice in other care environments (e.g., re-deployed outpatient internists, medical subspecialists, and other physician specialties). These surge clinicians did not have extensive experience managing low frequency, high acuity emergencies, such as those that might result from COVID-19. Physician-innovators, in collaboration with key hospital stakeholders, developed a comprehensive strategy to design, develop, and distribute a digital health solution to address this problem. MGH STAT is an intuitive mobile application that empowers clinicians to respond to medical emergencies by providing immediate access to up-to-date clinical guidelines, consultants, and code-running tools at the point-of-care. 100% of surveyed physicians found STAT to be easy to use and would recommend it to others. Approximately 1100 clinicians have downloaded the app, and it continues to enjoy consistent use over a year after the initial COVID-19 surge. These results suggest that STAT has helped clinicians manage life threatening emergencies during and after the pandemic, although formal studies are necessary to evaluate its direct impact on patient care.

Rationale and design of the preserved versus reduced ejection fraction biomarker registry and precision medicine database for ambulatory patients with heart failure (PREFER-HF) study.

INTRODUCTION: Patients with heart failure (HF) are classically categorised by left ventricular ejection fraction (LVEF). Efforts to predict outcomes and response to specific therapy among LVEF-based groups may be suboptimal, in part due to the underlying heterogeneity within clinical HF phenotypes. A multidimensional characterisation of ambulatory patients with and without HF across LVEF groups is needed to better understand and manage patients with HF in a more precise manner. METHODS AND ANALYSIS: To date, the first cohort of 1313 out of total planned 3000 patients with and without HF has been enroled in this single-centre, longitudinal observational cohort study. Baseline and 1-year follow-up blood samples and clinical characteristics, the presence and duration of comorbidities, serial laboratory, echocardiographic data and images and therapy information will be obtained. HF diagnosis, aetiology of disease, symptom onset and clinical outcomes at 1 and 5 years will be adjudicated by a team of clinicians. Clinical outcomes of interest include all-cause mortality, cardiovascular mortality, all-cause hospitalisation, cardiovascular hospitalisation, HF hospitalisation, right-sided HF and acute kidney injury. Results from the Preserved versus Reduced Ejection Fraction Biomarker Registry and Precision Medicine Database for Ambulatory Patients with Heart Failure (PREFER-HF) trial will examine longitudinal clinical characteristics, proteomic, metabolomic, genomic and imaging data to better understand HF phenotypes, with the ultimate goal of improving precision medicine and clinical outcomes for patients with HF. ETHICS AND DISSEMINATION: Information gathered in this research will be published in peer-reviewed journals. Written informed consent for PREFER-HF was obtained from all participants. All study procedures were approved by the Mass General Brigham Institutional Review Board in Boston, Massachusetts and performed in accordance with the Declaration of Helsinki (Protocol Number: 2016P000339). TRIAL REGISTRATION NUMBER: PREFER-HF ClinicalTrials.gov identifier: NCT03480633.

Perioperative Physiotherapy in Total Knee Arthroplasty.

Total knee arthroplasty has a high success rate. In the interest of enhancing patient outcomes, numerous perioperative interventions have been studied, including preoperative education, preoperative rehabilitation, postoperative inpatient rehabilitation, continuous passive motion, postoperative outpatient rehabilitation, unsupervised in-home exercises, telerehabilitation, and various combinations of these. This comprehensive review analyzes the existing body of evidence on these perioperative interventions and examines some burgeoning opportunities in rehabilitation after total knee arthroplasty in the interest of improving patient outcomes and ensuring sustainable health care utilization for the future of total knee arthroplasty. [Orthopedics. 2017; 40(5):e765-e773.].

PSMA-targeted stably linked "dendrimer-glutamate urea-methotrexate" as a prostate cancer therapeutic.

One of the important criteria for achieving efficient nanoparticle-based targeted drug delivery is that the drug is not prematurely released at off-target sites. Here we report the preclinical evaluation of a serum-stable dendrimer-based drug conjugate capable of actively targeting into prostate cancer (PC) cells, delivered through the prostate-specific membrane antigen (PSMA). Multiple molecules of PSMA-binding small molecule glutamate urea (GLA; targeting agent) and the drug methotrexate (MTX) were conjugated to generation 5 PAMAM dendrimer (G5) through Cu-free "click" chemistry. The GLA was conjugated through a stable amide bond, and the MTX was conjugated either through ester (Es)- or amide (Am)-coupling, to generate G5-GLA(m)-(Es)MTX(n) and G5-GLA(m)-(Am)MTX(n), respectively. In serum-containing medium, free MTX was slowly released from "G5-GLA(m)-(Es)MTX(n)", with ~8% MTX released from the dendrimer in 72 h, whereas the MTX on G5-GLA(m)-(Am)MTX(n) was completely stable. The G5-GLA(m)-(Am)MTX(n) bound and internalized into PSMA-expressing LNCaP cells, but not into PSMA-negative PC3 cells. The conjugate-inhibited recombinant dihydrofolate reductase and induced potent cytotoxicity in the LNCaP cells, but not in the PC3 cells. Similar to the action of free GLA, stable amide-linked dendrimer-GLA was capable of inhibiting the enzyme N-acetylated α-linked acidic dipeptidase (NAALADase) activity of PSMA. The G5-GLA(m)-MTX(n) may serve as a serum-stable nanoparticle conjugate to specifically and effectively target and treat PSMA-overexpressing prostate tumors.

Design and in vitro validation of multivalent dendrimer methotrexates as a folate-targeting anticancer therapeutic.

Design of cancer-targeting nanotherapeutics relies on a pair of two functionally orthogonal molecules, one serving as a cancer cell-specific targeting ligand, and the other as a therapeutic cytotoxic agent. The present study investigates the validity of an alternative simplified strategy where a dual-acting molecule which bears both targeting and cytotoxic activity is conjugated to the nanoparticle as cancer-targeting nanotherapeutics. Herein, we demonstrate that methotrexate is applicable for this dual-acting strategy due to its reasonable affinity to folic acid receptor (FAR) as a tumor biomarker, and cytotoxic inhibitory activity of cytosolic dihydrofolate reductase. This article describes design of new methotrexate-conjugated poly(amidoamine) (PAMAM) dendrimers, each carrying multiple copies of methotrexate attached through a stable amide linker. We evaluated their dual biological activities by performing surface plasmon resonance spectroscopy, a cell-free enzyme assay and cell-based experiments in FAR-overexpressing cells. This study identifies the combination of an optimal linker framework and multivalency as the two key design elements that contribute to achieving potent dual activity.

Polyvalent dendrimer-methotrexate as a folate receptor-targeted cancer therapeutic.

Our previous studies have demonstrated that a generation 5 dendrimer (G5) conjugated with both folic acid (FA) and methotrexate (MTX) has a higher chemotherapeutic index than MTX alone. Despite this, batch-to-batch inconsistencies in the number of FA and MTX molecules linked to each dendrimer led to conjugate batches with varying biological activity, especially when scaleup synthesis was attempted. Since the MTX is conjugated through an ester linkage, there were concerns that biological inconsistency could also result from serum esterase activity and differential bioavailability of the targeted conjugate. In order to resolve these problems, we undertook a novel approach to synthesize a polyvalent G5-MTX(n) conjugate through click chemistry, attaching the MTX to the dendrimer through an esterase-stable amide linkage. Surface plasmon resonance binding studies show that a G5-MTX(10) conjugate synthesized in this manner binds to the FA receptor (FR) through polyvalent interaction showing 4300-fold higher affinity than free MTX. The conjugate inhibits dihydrofolate reductase, and induces cytotoxicity in FR-expressing KB cells through FR-specific cellular internalization. Thus, the polyvalent MTX on the dendrimer serves the dual role as a targeting molecule as well as a chemotherapeutic drug. The newly synthesized G5-MTX(n) conjugate may serve as a FR-targeted chemotherapeutic with potential for cancer therapy.