Background Diagnosis of significant coronary artery disease (CAD) in at risk patients can be challenging, typically including non-invasive imaging modalities and ultimately the gold standard of coronary angiography. Previous studies suggested that peripheral blood gene expression can reflect the presence of CAD. Objective To validate a previously developed 23-gene expression-based classifier for diagnosis of obstructive CAD in non-diabetic patients. Design Multi-center prospective trial with blood samples drawn prior to coronary angiography. Setting Thirty-nine US centers. Patients An independent validation cohort of 526 non-diabetic patients clinically-indicated for coronary angiography Intervention None. Measurements Receiver-operator characteristics (ROC) analysis of classifier score measured by real-time polymerase chain reaction (RT-PCR), additivity to clinical factors, and reclassification of patient disease likelihood vs disease status defined by quantitative coronary angiography (QCA). Obstructive CAD defined as ≥50% stenosis in ≥1 major coronary artery by QCA. Results The overall ROC curve area (AUC) was 0.70 ±0.02, (p<0.001); the classifier added to clinical variables (Diamond-Forrester method) (AUC 0.72 with classifier vs 0.66 without, p = 0.003). Net reclassification was improved by the classifier over Diamond-Forrester and an expanded clinical model (both p<0.001). At a score threshold corresponding to 20% obstructive CAD likelihood (14.75), the sensitivity and specificity were 85% and 43%, yielding NPV of 83% and PPV 46%, with 33% of patient scores below this threshold. Limitations The study excluded patients with chronic inflammatory disorders, elevated white blood counts or cardiac protein markers, and diabetes. Conclusions This non-invasive whole blood test, based on gene expression and demographics, may be useful for assessment of obstructive CAD in non-diabetic patients without known CAD. Primary Funding Source CardioDx, Inc.

Despite superior outcomes and lower associated costs, relatively few patients with end-stage renal disease undergo self-care or home hemodialysis. Few studies have examined patient- and physician-specific barriers to self-care and home hemodialysis in the modern era. The degree to which innovative technology might facilitate the adoption of these modalities is unknown. We surveyed 250 patients receiving in-center hemodialysis and 51 board-certified nephrologists to identify key barriers to adoption of self-care and home hemodialysis. Overall, 172 (69%) patients reported that they were "likely" or "very likely" to consider self-care hemodialysis if they were properly trained on a new hemodialysis system designed for self-care or home use. Nephrologists believed that patients were capable of performing many dialysis-relevant tasks, including: weighing themselves (98%), wiping down the chair and machine (84%), clearing alarms during treatment (53%), taking vital signs (46%), and cannulating vascular access (41%), but thought that patients would be willing to do the same in only 69%, 34%, 31%, 29%, and 16%, respectively. Reasons that nephrologists believe patients are hesitant to pursue self-care or home hemodialysis do not correspond in parallel or by priority to reasons reported by patients. Self-care and home hemodialysis offer several advantages to patients and dialysis providers. Overcoming real and perceived barriers with new technology, education and coordinated care will be required for these modalities to gain traction in the coming years.

Introduction Home hemodialysis has not been widely adopted despite superior outcomes relative to conventional in-center hemodialysis. Patients receiving home hemodialysis experience high rates of technique failure owing to machine complexity, training burden, and the inability to master treatments independently. Methods We conducted human factors testing on 15 health care professionals (HCPs) and 15 patients upon release of the defined training program on the Tablo™ Hemodialysis System. Each participant completed one training and one testing session conducted in a simulated clinical environment. Training sessions lasted <3 hours for HCPs and <4 hours for patients, with an hour break between sessions for knowledge decay. During the testing session, we recorded participant behavior and data according to standard performance and safety-based criteria. Findings Of 15 HCPs, 10 were registered nurses and five patient care technicians, with a broad range of dialysis work experience and no limitations other than visual correction. Of 15 patients (average age 48 years), 13 reported no limitations and two reported modest limitations-partial deafness and blindness in one eye, respectively. The average error rate was 4.4 per session for HCPs and 2.9 per session for patients out of a total possible 1,710 opportunities for errors. Despite having received minimal training, neither HCPs nor patients committed safety-related errors that required mitigation; rather, we noted only minor errors and operational difficulties. Discussion The Tablo™ Hemodialysis System is easy to use, and may help to enable self-care and home hemodialysis in settings heretofore associated with high rates of technique failure.

Purpose: Better methods are needed to assess patients presenting with symptoms suggestive of obstructive coronary artery disease (CAD). We hypothesized that the use of a gene expression score (GES) would lead to a change in the diagnostic evaluation.Methods: The Primary Care Providers Use of a Gene Expression Test in Coronary Artery Disease Diagnosis (IMPACT-PCP) trial (clinical trial identifier NCT01594411, clinicaltrials.gov) was a prospective study of stable, nonacute, nondiabetic patients presenting with chest pain and related symptoms at 4 primary care practices. All patients underwent GES testing, with clinicians documenting their planned diagnostic strategy both before and after GES. The GES was derived from a peripheral blood draw measuring expression of 23 genes and has been shown to have a 96% negative predictive value for excluding the diagnosis of obstructive CAD.Results: Of the 251 study patients, 140 were women (56%); the participants had a mean age of 56 years (standard deviation, 13.0) and a mean body mass index of 30 mg/kg 2 (standard deviation, 6.7). The mean GES was 16 (range, 1-38), and 127 patients (51%) had a low GES ([ltqeu]15). A change in the diagnostic testing pattern before and after GES testing was noted in 145 of 251 patients (58% observed vs. 10% predefined expected change; P < .001).Conclusions