The Impact of a Machine Learning Early Warning Score on Hospital Mortality: A Multicenter Clinical Intervention Trial.

Objectives: To determine the impact of a machine learning early warning risk score, electronic Cardiac Arrest Risk Triage (eCART), on mortality for elevated-risk adult inpatients.

Design: A pragmatic pre- and post-intervention study conducted over the same 10-month period in 2 consecutive years.

Setting: Four-hospital community-academic health system.

Clinical Analytics Prediction Engine (CAPE): Development, electronic health record integration and prospective validation of hospital mortality, 180-day mortality and 30-day readmission risk prediction models.

Background: Numerous predictive models in the literature stratify patients by risk of mortality and readmission. Few prediction models have been developed to optimize impact while sustaining sufficient performance.

Objective: We aimed to derive models for hospital mortality, 180-day mortality and 30-day readmission, implement these models within our electronic health record and prospectively validate these models for use across an entire health system.

PDGF-induced vascular smooth muscle cell proliferation is associated with dysregulation of insulin receptor substrates.

In vascular smooth muscle cells (VSMCs), platelet-derived growth factor (PDGF) plays a major role in inducing phenotypic switching from contractile to proliferative state. Importantly, VSMC phenotypic switching is also determined by the phosphorylation state/expression levels of insulin receptor substrate (IRS), an intermediary signaling component that is shared by insulin and IGF-I. To date, the roles of PDGF-induced key proliferative signaling components including Akt, p70S6kinase, and ERK1/2 on the serine phosphorylation/expression of IRS-1 and IRS-2 isoforms remain unclear in VSMCs.

Nitrite consumption in ischemic rat heart catalyzed by distinct blood-borne and tissue factors.

Nitric oxide (NO) may limit myocardial ischemia-reperfusion injury by slowing the mitochondrial metabolism. We examined whether rat heart contains catalysts potentially capable of reducing nitrite to NO during an episode of regional myocardial ischemia produced by temporary coronary artery occlusion. In intact Sprague-Dawley rats, a 15-min coronary occlusion lowered the nitrite concentration of the myocardial regions exhibiting ischemic glucose metabolism to approximately 50% that of nonischemic regions (185 +/- 223 vs.

Measurement of thoracolumbar kyphosis after burst fracture: evaluation of intraobserver, interobserver, and variability of 4 measurement methods.

There are various methods for measuring kyphosis after thoracolumbar burst fracture. The reliability and reproducibility of these methods are not well defined. In the study reported here, we examined 4 commonly used measurement methods in order to determine intraobserver variability, interobserver variability, and variability between measurement methods.

Anomalous great cardiac vein.

Anomalous coronary venous anatomy is a little studied and rarely reported subject that is of crucial importance in interventions that rely upon the assumption of normal coronary venous anatomy. In particular, the recognition of coronary vein anomalies that disconnect large segments of the left ventricular myocardium from the main coronary sinus is critical for cardiothoracic surgeons who perform interventions involving retrograde cardioplegia and other forms of coronary venous retroperfusion. We present a rare case of an anomalous great cardiac vein that bypassed the coronary sinus to drain directly into the superior vena cava, and suggest a possible role for antecedent imaging of the coronary venous system in patients who might be expected to undergo such interventions.

Effect of simulated postprandial hyperglycemia on coronary blood flow in cardiac transplant recipients.

Patients with diabetes mellitus exhibit postprandial hyperglycemia, systemic oxidative stress, impaired endothelium-dependent, nitric oxide (NO)-mediated coronary artery dilatation, and an increased incidence of coronary events. Whether hyperglycemia causally mediates these associations is unknown. To test the hypothesis that postprandial hyperglycemia acutely impairs coronary endothelial function in humans, we compared the ability of the endothelium-dependent vasodilator acetylcholine to increase conduit coronary diameter (the macrovascular response) and coronary blood flow velocity (the microvascular response) in 12 cardiac transplant recipients without diabetes before and after blood glucose was raised from 6.

Effect of hyperoxia and vitamin C on coronary blood flow in patients with ischemic heart disease.

Pathological formation of reactive oxygen species within the coronary circulation has been hypothesized to mediate some clinical manifestations of ischemic heart disease (IHD) by interfering with physiological regulation of coronary tone. To determine the degree to which coronary tone responds to acute changes in ambient levels of oxidants and antioxidants in vivo in a clinical setting, we measured the effect of an acute oxidative stress (breathing 100% oxygen) on coronary capacitance artery diameter (quantitative angiography) and blood flow velocity through the coronary microcirculation (intracoronary Doppler ultrasonography) before and after treatment with the antioxidant vitamin C (3-g intravenous infusion) in 12 IHD patients undergoing a clinical coronary interventional procedure. Relative to room air breathing, 100% oxygen breathing promptly reduced coronary blood flow velocity by 20% and increased coronary resistance by 23%, without significantly changing the diameter of capacitance arteries.

Effects of supplemental oxygen administration on coronary blood flow in patients undergoing cardiac catheterization.

Patients with heart disease are frequently treated with supplemental oxygen. Although oxygen can exhibit vasoactive properties in many vascular beds, its effects on the coronary circulation have not been fully characterized. To examine whether supplemental oxygen administration affects coronary blood flow (CBF) in a clinical setting, we measured in 18 patients with stable coronary heart disease the effects of breathing 100% oxygen by face mask for 15 min on CBF (via coronary Doppler flow wire), conduit coronary diameter, CBF response to intracoronary infusion of the endothelium-dependent dilator ACh and to the endothelium-independent dilator adenosine, as well as arterial and coronary venous concentrations of the nitric oxide (NO) metabolites nitrotyrosine, NO(2)(-), and NO(3)(-).

Usefulness of temporary left ventricular pacing through the coronary sinus as an adjunct to transfemoral percutaneous coronary intervention.

In 10 patients who underwent percutaneous coronary intervention involving the right coronary artery, a new procedure for adjunctive temporary transfemoral pacing of the left ventricle through the coronary sinus was tested. The procedure was successful in 8 of 10 patients and could be performed in <5 minutes by experienced operators and supervised cardiology fellows.

Usefulness of hyperglycemia in predicting renal and myocardial injury in patients with diabetes mellitus undergoing percutaneous coronary intervention.

A retrospective analysis of 165 patients who had diabetes mellitus and underwent percutaneous coronary intervention (PCI) between 1998 and 2003 demonstrated that those whose plasma glucose levels were >/=200 mg/dl before PCI exhibited greater creatine phosphokinase release and serum creatinine increases after PCI. These observations identified hyperglycemia as a potentially modifiable mediator of myocardial and renal injuries in patients who have diabetes and have undergone PCI.

Diabetes mellitus and heart failure.

Type 2 diabetes mellitus substantially increases the lifetime risk of both developing and dying from heart failure. While this appears to be explained in part by the well-known association of diabetes with hypertension, dyslipidemia, and coronary atherosclerosis, additional pathophysiologic mechanisms linking type 2 diabetes and heart failure have recently been suggested. These include the potentially adverse effects of hyperglycemia on endothelial function and redox state, effects of excess circulating glucose and fatty acids on cardiomyocyte ultrastructure, intracellular signaling and gene expression, and the possibility that diabetes may impair recruitment of the myocardial insulin-responsive glucose transport system in response to ischemia.

Sterile inflammation associated with transradial catheterization and hydrophilic sheaths.

In 1999, we noted the development of inflammation and/or abscesses at the site of radial access in a group of patients. Over a 3-year period, we noted this inflammation in 33 patients out of 2,038 (1.6%) who had catheterization via the radial approach.

Natural history of inadvertent aorta-saphenous vein-coronary vein bypass graft.

Inadvertent distal anastomosis of an aortocoronary bypass graft to a coronary vein is a rare but potentially serious complication of coronary artery bypass surgery. We describe a patient in whom such a conduit was discovered only incidentally 17 years after its creation. This case illustrates the pertinent features of this anomaly and demonstrates that it can have a benign natural history.

Glucose and insulin management in the post-MI setting.

Despite dramatic advances in the treatment of acute myocardial infarction (AMI) in recent years, patients with diabetes mellitus continue to experience disproportionately high morbidity and mortality. A substantial body of experimental and clinical data suggest that the ability of the heart to augment its energetic metabolism of glucose in the acute setting is critical to survival and functional recovery after AMI. Emerging evidence also suggests that chronic hyperglycemia may predispose to post-AMI ischemia and heart failure via adverse effects on coronary endothelial function and myocardial ultrastructure, energy metabolism, and gene transcription.

Cardiac catheterization in morbidly obese patients.

The safety and findings of cardiac catheterization and coronary angiography in morbidly obese patients with suspected coronary heart disease (CHD) have not been fully examined in the modern era. From a database of 4,978 patients undergoing diagnostic cardiac catheterization, we identified 110 with morbid obesity (body mass > or = 145 kg and body mass index > or = 40 kg/m(2)). Relative to all the other patients in this database, morbidly obese patients had a lower prevalence of CHD (45% vs.