Sphingosine-1-phosphate receptor 3 promotes neointimal hyperplasia in mouse iliac-femoral arteries.

OBJECTIVE: The objective of this study was to define a role for sphingosine-1-phosphate receptor 3 (S1PR3) in intimal hyperplasia. METHODS AND RESULTS: A denudation model of the iliac-femoral artery in wild-type and S1PR3-null mice was used to define a role for S1PR3 in the arterial injury response because we found in humans and mice that expression of S1PR3 was higher in these arteries compared with carotid arteries. At 28 days after surgery, wild-type arteries formed significantly larger lesions than S1PR3-null arteries. Bromodeoxyuridine labeling experiments demonstrated that on injury, wild-type arteries exhibited higher medial as well as intimal proliferation than S1PR3-null arteries. Because S1PR3 expression in vitro was low, we expressed S1PR3 in S1PR3-null smooth muscle cells (SMCs) using retroviral-mediated gene transfer to study the effects of S1PR3 on cell functions and signaling. SMCs expressing S1PR3, but not vector-transfected controls, responded to sphingosine-1-phosphate stimulation with activation of Rac, Erk, and Akt. SMCs expressing S1PR3 also migrated more. CONCLUSIONS: In humans and mice, S1PR3 expression was higher in iliac-femoral arteries compared with carotid arteries. S1PR3 promoted neointimal hyperplasia on denudation of iliac-femoral arteries in mice, likely by stimulating cell migration and proliferation through activation of signaling pathways involving Erk, Akt, and Rac.

Use of a Real-Time Location System to Understand Resident Location in an Academic Medical Center.

BACKGROUND: There is great interest in understanding how residents spend their time in the hospital, but traditional time and motion studies are resource intensive and limited in scale. OBJECTIVE: We determined whether a real-time location system (RTLS) that uses infrared emitting badges can be used to track resident time and location. METHODS: Residents rotating on an internal medicine service in January 2018 were given the option to wear an RTLS badge. RTLS data were compared to the call schedule for each participating resident in a deidentified manner. Rules were created to identify work periods to be manually reviewed for data integrity. Reviewed work periods where there were extended periods of time without RTLS badge movement (eg, greater than 300 minutes) were excluded from analysis. RESULTS: Data were collected from 18 residents and included 236 work periods (2922 hours). Based on prespecified rules, 146 work periods were included, representing 83% of total eligible residents (n = 15) and 82% of total hours recorded (2397 hours). Residents spent the highest percentage of their time in physician workrooms (44%, SD 15%), followed by ward hallways (25%, SD 7%) and patient rooms (17%, SD 7%). Several work periods were excluded because residents left their RTLS badge in physician workrooms after the work period ended. CONCLUSIONS: This study demonstrates the potential utility of RTLS to measure resident time and location in the hospital.

Transient Secondary Hypothyroidism and Thyroid Hormone Replacement Therapy in Pediatric Postoperative Cardiopulmonary Bypass.

BACKGROUND: To develop an understanding of current practices in the management of transient secondary hypothyroidism in pediatric postoperative cardiopulmonary bypass (CPB) patients. METHODS: Electronic survey comprising a 10-item questionnaire was sent to sixty-four high volume pediatric heart centers in the United States and United Kingdom. Survey participants included cardiologists, intensivists, cardiothoracic surgeons, and advanced practice providers. A retrospective chart review was also performed at a large regional referral center in the Midwest on subjects 0-18 years old who underwent CPB from 2005-2015. Information obtained included a unique identifier, date of birth, age, procedure performed, CPB time, date of surgery and date and type of Thyroid Function Test (TFT) ordered. RESULTS: 1,153 individuals from 64 congenital heart centers were contacted via email to participate in the electronic survey. In the 3-month response window, 129 completed surveys were received from cardiologists (55%), intensivists (17%), surgeons (15%), "other" (8%), and advanced practice providers (5%). This yielded a response rate of 11.2%. Of the 129 respondents, only 10 providers routinely order TFTs prior to (n=7) and after (n=1) CPB or when clinically indicated (n=2). All 10 providers order thyroid stimulating hormone test, 7 order thyroxine, and 3 order triiodothyronine. Only 1 provider routinely treats children with prophylactic thyroid hormone replacement therapy after CPB. Our retrospective review included 502 CPB events with 442 unique patients. Of the events, 20 patients received preoperative TFT testing while 11 received postoperative testing. CONCLUSIONS: There is a general lack of uniformity in the evaluation, diagnosis, and treatment of transient secondary hypothyroidism in pediatric postoperative CPB patients.

Biventricular Repair of Pulmonary Atresia After Fontan Palliation.

Fontan palliation is used when biventricular repair (BVR) is not possible. Early outcomes are acceptable; however, the long-term sequelae include protein-losing enteropathy, declining functional status, increased pulmonary vascular resistance, heart failure, and hepatic and renal dysfunction. These adverse events are characteristic of persistent venous hypertension and may be avoided if restoring biventricular circulation is possible. Arrhythmias are a common adverse event, particularly in patients with an atriopulmonary connection, which may lead to acute decompensation and early death. We describe a 30-year-old woman who underwent successful BVR for pulmonary atresia with intact ventricular septum and demonstrate that where favorable anatomy exists with a failing Fontan, BVR should be considered.

Surgical Treatment of Neonate With Congenital Left Main Coronary Artery Atresia.

Left main coronary artery atresia (LMCAA) is a rare congenital malformation with a nonspecific and varied clinical presentation. Ventricular dysfunction and mitral insufficiency are expected ischemic consequences in the neonatal period. Left internal mammary artery (LIMA) bypass grafting (CABG) is uncommon because of the technical difficulties in performing this procedure in neonates. We describe LMCAA revascularization with a LIMA graft and mitral valve repair in a 7-week-old neonate with successful outcome 1 year postoperatively.