Prospective CYP2C19 Genotyping to Guide Antiplatelet Therapy Following Percutaneous Coronary Intervention: A Pragmatic Randomized Clinical Trial.

BACKGROUND: CYP2C19 loss-of-function alleles impair clopidogrel effectiveness after percutaneous coronary intervention, but the clinical impact of implementing CYP2C19 genotyping in a real-world setting is unknown. The purpose of the study was to determine whether returning CYP2C19 genotype results along with genotype-guided pharmacotherapy recommendations using a rapid turnaround test would change antiplatelet prescribing following percutaneous coronary intervention.The primary outcome was the rate of prasugrel or ticagrelor prescribing in each arm. Secondary outcomes included agreement to the genotype-guided recommendations. METHODS: At the time of percutaneous coronary intervention, participants were randomly assigned to prospective rapid point-of-care genotyping of CYP2C19 major alleles (*2, *3, *17) via salivary swab (genotyped group) or no genotyping (usual care) to guide antiplatelet drug selection. Interventional cardiologists at 2 cardiac catheterization laboratories within the same health system were provided genotype information along with genotype-guided pharmacotherapy recommendations. RESULTS: A total of 504 participants were randomized, 249 to the genotyped and 255 to the usual care group. The participants were primarily men (73%); age, 63±10 years; and 50% had acute coronary syndromes. In the genotyped group, 28% were carriers of loss-of-function alleles (*2, *3). The use of prasugrel or ticagrelor was significantly higher in the genotyped group compared with the usual care group (30% versus 21%; odds ratio, 1.60 [95% CI, 1.07-2.42]; P=0.03). Within the genotyped group, 53% of loss-of-function allele carriers were started on prasugrel/ticagrelor, while 47% were started on clopidogrel. CONCLUSIONS: In a randomized controlled trial of clinical CYP2C19 genotyping implementation, pharmacogenetic test results significantly influenced antiplatelet drug prescribing; however, almost half of CYP2C19 loss-of-function carriers continued to receive clopidogrel. Interventional cardiologists consider both clinical and genetic factors when selecting antiplatelet therapy following percutaneous coronary intervention. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT02508116.

Non-invasive detection of divergent metabolic signals in insulin deficiency vs. insulin resistance in vivo.

The type 2 diabetic phenotype results from mixed effects of insulin deficiency and insulin resistance, but the relative contributions of these two distinct factors remain poorly characterized, as do the respective roles of the gluconeogenic organs. The purpose of this study was to investigate localized in vivo metabolic changes in liver and kidneys of contrasting models of diabetes mellitus (DM): streptozotocin (STZ)-treated wild-type Zucker rats (T1DM) and Zucker diabetic fatty (ZDF) rats (T2DM). Intermediary metabolism was probed using hyperpolarized (HP) [1-13C]pyruvate MRI of the liver and kidneys. These data were correlated with gene expression data for key mediators, assessed using rtPCR. Increased HP [1-13C]lactate was detected in both models, in association with elevated gluconeogenesis as reflected by increased expression of phosphoenolpyruvate carboxykinase. In contrast, HP [1-13C]alanine diverged between the two models, increasing in ZDF rats, while decreasing in the STZ-treated rats. The differences in liver alanine paralleled differences in key lipogenic mediators. Thus, HP [1-13C]alanine is a marker that can identify phenotypic differences in kidneys and liver of rats with T1DM vs. T2DM, non-invasively in vivo. This approach could provide a powerful diagnostic tool for characterizing tissue metabolic defects and responses to treatment in diabetic patients with ambiguous systemic manifestations.

Detection of localized changes in the metabolism of hyperpolarized gluconeogenic precursors 13 C-lactate and 13 C-pyruvate in kidney and liver.

PURPOSE: The purpose of this study was to characterize tissue-specific alterations in metabolism of hyperpolarized (HP) gluconeogenic precursors 13 C-lactate and 13 C-pyruvate by rat liver and kidneys under conditions of fasting or insulin-deprived diabetes. METHODS: Seven normal rats were studied by MR spectroscopic imaging of both HP 13 C-lactate and 13 C-pyruvate in both normal fed and 24 h fasting states, and seven additional rats were scanned after induction of diabetes by streptozotocin (STZ) with insulin withdrawal. Phosphoenolpyruvate carboxykinase (PEPCK) expression levels were also measured in liver and kidney tissues of the STZ-treated rats. RESULTS: Multiple sets of significant signal modulations were detected, with graded intensity in general between fasting and diabetic states. An approximate two-fold reduction in the ratio of 13 C-bicarbonate to total 13 C signal was observed in both organs in fasting. The ratio of HP lactate-to-alanine was markedly altered, ranging from a liver-specific 54% increase in fasting, to increases of 69% and 92% in liver and kidney, respectively, in diabetes. Diabetes resulted in a 40% increase in renal lactate signal. STZ resulted in 5.86-fold and 2.73-fold increases in PEPCK expression in liver and kidney, respectively. CONCLUSION: MRI of HP 13 C gluconeogenic precursors may advance diabetes research by clarifying organ-specific roles in abnormal diabetic metabolism. Magn Reson Med 77:1429-1437, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Multiband spectral-spatial RF excitation for hyperpolarized [2-13 C]dihydroxyacetone 13 C-MR metabolism studies.

PURPOSE: To develop a specialized multislice, single-acquisition approach to detect the metabolites of hyperpolarized (HP) [2-13 C]dihydroxyacetone (DHAc) to probe gluconeogenesis in vivo, which have a broad 144 ppm spectral range (∼4.6 kHz at 3T). A novel multiband radio-frequency (RF) excitation pulse was designed for independent flip angle control over five to six spectral-spatial (SPSP) excitation bands, each corrected for chemical shift misregistration effects. METHODS: Specialized multiband SPSP RF pulses were designed, tested, and applied to investigate HP [2-13 C]DHAc metabolism in kidney and liver of fasted rats with dynamic 13 C-MR spectroscopy and an optimal flip angle scheme. For comparison, experiments were also performed with narrow-band slice-selective RF pulses and a sequential change of the frequency offset to cover the five frequency bands of interest. RESULTS: The SPSP pulses provided a controllable spectral profile free of baseline distortion with improved signal to noise of the metabolite peaks, allowing for quantification of the metabolic products. We observed organ-specific differences in DHAc metabolism. There was two to five times more [2-13 C]phosphoenolpyruvate and about 19 times more [2-13 C]glycerol 3-phosphate in the liver than in the kidney. CONCLUSION: A multiband SPSP RF pulse covering a spectral range over 144 ppm enabled in vivo characterization of HP [2-13 C]DHAc metabolism in rat liver and kidney. Magn Reson Med 77:1419-1428, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Monitoring acute metabolic changes in the liver and kidneys induced by fructose and glucose using hyperpolarized [2-13 C]dihydroxyacetone.

PURPOSE: To investigate acute changes in glucose metabolism in liver and kidneys in vivo after a bolus injection of either fructose or glucose, using hyperpolarized [2-13 C]dihydroxyacetone. METHODS: Spatially registered, dynamic, multislice MR spectroscopy was acquired for the metabolic products of [2-13 C]dihydroxyacetone in liver and kidneys. Metabolism was probed in 13 fasted rats at three time points: 0, 70, and 140 min. At 60 min, rats were injected intravenously with fructose (n = 5) or glucose (n = 4) at 0.8 g/kg to initiate acute response. Controls (n = 4) did not receive a carbohydrate challenge. RESULTS: Ten minutes after fructose infusion, levels of [2-13 C]phosphoenolpyruvate and [2-13 C]glycerol-3-phosphate halved in liver: 51% (P = 0.0010) and 47% (P = 0.0001) of baseline, respectively. Seventy minutes later, levels returned to baseline. The glucose challenge did not alter the signals significantly, nor did repeated administration of the dihydroxyacetone imaging bolus. In kidneys, no statistically significant changes were detected after sugar infusion other than a 20% increase of the glycerol-3-phosphate signal between 10 and 80 min after fructose injection (P = 0.0028). CONCLUSION: Hyperpolarized [2-13 C]dihydroxyacetone detects a real-time, transient metabolic response of the liver to an acute fructose challenge. Observed effects possibly include ATP depletion and changes in the unlabeled pool sizes of glycolytic intermediates. Magn Reson Med 77:65-73, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Initial clinical predictors of significant coronary lesions after resuscitation from cardiac arrest.

Urgent coronary angiography following cardiac arrest is an important consideration as part of a therapeutic hypothermia/postresuscitation care bundle. Few data exist to guide the selection of patients who should receive postarrest angiography. This investigation sought to evaluate patient-level variables on initial postarrest presentation and their association with significant coronary lesions on subsequent angiography. Clinical and angiographic data were collected on consecutive postarrest patients from July 2007 to April 2012 who underwent coronary angiography during hospitalization. Univariate and multivariable analyses were performed to determine the relationship between patient characteristics, clinical data, and the outcome measure, defined as the presence of at least one coronary lesion with >75% stenosis. Of 527 cardiac arrest patients, 267 achieved return of spontaneous circulation; 106 of these initial survivors received coronary angiography. This cohort had a mean age of 58.1±13.5 years and a survival to discharge of 73/106 (69%), with therapeutic hypothermia utilized in 79/106 (75%) patients. Significant coronary lesions were found on angiography in 68/106 (64%) patients. Multivariable adjusted analysis demonstrated that significant lesions were associated with a prior known history of coronary disease and/or prior myocardial infarction (odds ratio [OR] 6.2, 95% confidence interval [CI] 1.6-24.4, p=0.009), and with initial rhythm of ventricular fibrillation/ventricular tachycardia (OR 2.9, 95% CI 1.1-7.7, p=0.033), but not with hypertension, tobacco use, age, or initial troponin measurements. Prior known history of coronary disease and a shockable arrest rhythm were associated with significant coronary lesions on subsequent angiography. Normal initial troponin values and younger age did not exclude clinically relevant lesions postarrest.

Tracing the footsteps of glomerular insulin signaling in diabetic kidney disease.

Insufficient insulin secretion and insulin resistance are hallmarks of diabetes. Recent studies indicate that insulin plays an important role in maintaining the glomerular filtration barrier. Mima et al. report that glomeruli of diabetic and obese rats suffer from insulin resistance and altered insulin signaling. Protein kinase C inhibitors are able to overcome insulin resistance, offering new hopes for the treatment of the condition.

Suspicion and treatment of the macrosomic fetus: a review.

OBJECTIVE: To review the prevalence of and our ability to identify macrosomic (birthweight >4000 g) fetuses. Additionally, based on the current evidence, propose an algorithm for treatment of suspected macrosomia. STUDY DESIGN: A review. RESULTS: According to the National Vital Statistics, in the United States, the prevalence of newborns weighing at least 4000 g has decreased by 10% in seven years (10.2% in 1996 and 9.2% in 2002) and 19% for newborns with weights >5000 g (0.16% and 0.13%, respectively). Bayesian calculations indicates that the posttest probability of detecting a macrosomic fetus in an uncomplicated pregnancy is variable, ranging from 15% to 79% with sonographic estimates of birth weight, and 40 to 52% with clinical estimates. Among diabetic patients the post-test probability of identifying a newborn weighing >4000 g clinically and sonographically is over 60%. Among uncomplicated pregnancies, there is sufficient evidence that suspected macrosomia is not an indication for induction or for primary cesarean delivery. For pregnancies complicated by diabetes, with a prior cesarean delivery or shoulder dystocia, delivery of a macrosomic fetus increases the rate of complications, but there is insufficient evidence about the threshold of estimated fetal weight that should prompt cesarean delivery. CONCLUSION: Due to the inaccuracies, among uncomplicated pregnancies suspicion of macrosomia is not an indication for induction or for primary cesarean delivery.

Functional characterization of neostatins, the MMP-derived, enzymatic cleavage products of type XVIII collagen.

Several anti-angiogenic factors are derived from proteolytic processing of large molecules including endostatin from type XVIII collagen and angiostatin from plasminogen. In previous studies we showed that neostatin-7, the C-terminal 28kDa endostatin-spanning proteolytic fragment, is generated from the proteolytic action of matrix metalloproteinase matrilysin (MMP)-7 on type XVIII collagen. Now, we report a second member of the neostatin family of proteins, neostatin-14. Given the small quantities of neostatin-7 and -14 generated by the breakdown of naturally occurring collagen XVIII (using MMP-7 and -14, respectively), we used two other approaches to characterize the anti-angiogenic properties of these molecules: murine recombinant neostatin in vitro, and gene therapy. We demonstrate that murine recombinant neostatin-7 inhibits calf pulmonary artery endothelial cell proliferation and that microinjection of neostatin-7 and neostatin-14 naked DNA into the corneal stroma of mice results in significant reduction of basic fibroblast growth factor-induced corneal neovascularization. These results provide supportive evidence of the possible anti-angiogenic effect of neostatins.

Percutaneous patent foramen ovale and atrial septal defect closure in adults: results and device comparison in 100 consecutive implants at a single center.

Closure of interatrial septal defects with percutaneous devices is increasingly common. However, the indications for closure and techniques for device implantation are diverse. We reviewed our first 100 consecutive implants to assess and compare the indications, results, complications, and evolution of techniques for percutaneous patent foramen ovale (PFO) and atrial septal defect (ASD) closure. The mean age of patients was 52 years and 70% were female. Paradoxical embolism was the predominant indication (94%) for PFO closure and significant left-to-right shunt was the most frequent indication (89%) for ASD closure. Implantation success was 94% with major complications in 3 patients (2.8%). Transesophageal echocardiography was utilized in the initial 27 procedures and then replaced by intracardiac echocardiography in subsequent ones, with an associated reduction in procedure and physician time. During 6 months of follow-up, 3 patients were readmitted for atrial arrhythmias (2 patients) and an MRI-negative neurologic event (1 patient). Echocardiography at 6 months in 83% of the PFO patients revealed moderate and severe positive contrast studies for right-to-left shunting in one third of patients, with differences between devices and insertion techniques. This single-center experience with percutaneous device closure of PFO and ASD in adults demonstrates excellent results with few complications.

Effect of atorvastatin on postcardiac transplant increase in low-density lipoprotein cholesterol reduces development of intimal hyperplasia and progression of endothelial dysfunction.

Following cardiac transplantation, accelerated coronary disease limits long-term survival. Because statins may reduce the progression of the disease in part by their anti-inflammatory effects, this study was designed to assess if atorvastatin prevented neointimal hyperplasia and endothelial dysfunction independently of baseline cholesterol levels. Patients were randomized to usual therapy (n = 13) or to 10 to 20 mg of atorvastatin (n = 12). Control subjects received niacin when their low-density lipoprotein (LDL) cholesterol levels were >130 mg/dl (n = 4). Neointimal hyperplasia by intracoronary ultrasonography, endothelial dependent vascular reactivity, and coronary flow reserve were measured at baseline and 1 year. Control group total cholesterol (203 +/- 11 to 200 +/- 13 mg/dl) and LDL (116 +/- 10 to 119 +/- 11 mg/dl) remained stable, whereas there was a nonsignificant reduction at 12 months in the atorvastatin group (total cholesterol 216 +/- 28 to 178 +/- 21 mg/dl; LDL 126 +/- 17 to 100 +/- 18 mg/dl). At 2 to 3 months there was a significant increase in total cholesterol and LDL cholesterol that was reduced with atorvastatin. At 1 year, patients taking atorvastatin showed a decrease in new or progressing lesions (2.5 +/- 1.7 vs 4.2 +/- 1.8 lesions/patient, p = 0.02), progression of maximal intimal thickness (0.12 +/- 0.07 vs 0.52 +/- 0.17 mm, p = 0.04), and percent area stenosis (5.9 +/- 2.2% vs 19.0 +/- 5.5%, p = 0.04). Atorvastatin ameliorated progressive endothelial dysfunction, whereas coronary flow reserve was unchanged in both groups. Atorvastatin administered to patients with normal or mild hypercholesterolemia in the initial year after transplant reduced the initial increase in LDL cholesterol, and, by doing so, prevented the development and progression of coronary artery lesions and endothelial dysfunction with only mild long-term decreases in cholesterol levels.