Advances to diminish global newborn kernicterus mortality.

OBJECTIVE: Initiatives, "Every Newborn Action Plans" and "Sustainable Developmental Goals," are profoundly shaping global infant mortality trends. Concurrently, professional organizations recommended curricula to prevent extreme hyperbilirubinemia (EHB) sequelae. Therefore we assessed if these efforts have successfully decreased EHB-related mortality over time. STUDY DESIGN: We used the Global Burden of Diseases 2019 database to determine neonatal and infant mortality and the burden of kernicterus from 1990-2019. RESULTS: Globally, kernicterus accounted for 2.8 million infant deaths and trended downwards significantly from 1990 to 2019. By 2019, kernicterus-related mortality was 4 and 293 per million livebirths in high (HICs) and low income countries (LICs), respectively. 82% of deaths occurred in LICs and lower-middle income-countries. Average declines of mortality rates were 6.2% and 3.0% for HICs and LICs, respectively. CONCLUSIONS: Kernicterus-related mortality has been effectively reduced to <5 per million in HICs. Skills and knowledge transfer can potentially transform frontline services to bridge discordant kernicteric outcomes worldwide.

Georacial Epidemiological Estimates of Glucose-6-Phosphate Dehydrogenase Deficiency among Newborns in the United States.

OBJECTIVE: Glucose-6-phosphate dehydrogenase deficiency (G6PDd) is the most common inherited enzyme deficiency disorder worldwide and a major risk factor for the development of severe hyperbilirubinemia. Racial diversity of phenotypes and genotypes in affected individuals is likely to exist in the United States because of changing population demographics. The aim of the present study was to predict an empirical estimate of annual prevalence of G6PDd in newborns adjusted for geography (state of birth), maternal racial identity, and sex of the infant. STUDY DESIGN: Birth statistics (2019) from National Center for Vital Statistics and CDC-WONDER data and race-specific prevalence of G6PDd in the United States were evaluated from published sources. We developed Simpson's diversity index (DI) for each State and correlated these to rates of G6PDd in neonates. Descriptive statistics including modeled prevalence and its association with DI were assessed using the Spearman's rho correlation test. We modeled state-specific prevalence for six states (California, Washington DC, Illinois, Massachusetts, New York, and Pennsylvania) using population-level allele frequencies and race, based on Hardy-Weinberg equilibrium. RESULTS: We estimated 78,010 (95% confidence interval: 76,768-79,252) newborns had G6PDd at birth in 2019 with cumulative median prevalence of 17.3 (interquartile range: 12.4-23.2) per 1,000 live births for United States. A strong association was noted for DI and prevalence of G6PDd (p < 0.0005). Five states (Washington DC, Mississippi, Louisiana, Georgia, and Maryland) have the highest projected G6PDd prevalence, with a range of 35 to 48 per 1,000 live births. The probability of G6PDd for female heterozygotes, based on male prevalence, ranged from 1.1 to 7.5% for each cohort in the select six states. CONCLUSION: States with diverse populations are likely to have higher rates of G6PDd. These prevalence estimates exceeded by several-fold when compared with disorders screened by existing state mandated newborn screening panels. These discrepancies are further confounded by known risk of severe neonatal hyperbilirubinemia that results with G6PDd and the life-long risk of hemolysis. Combined universal newborn predischarge screening for G6PDd and bilirubin could alert and guide a clinician's practices for parental education and closer medical surveillance during the vulnerable neonatal time period. KEY POINTS: · G6PDd is a common X-linked disorder that can present with varied phenotypes among newborns.. · Prevalence of G6PDd and genotype distribution varies with sex, race, and ethnicity.. · We present regional race- and sex-based estimates of G6PDd in the United States..

Interstate Practice Variation and Factors Associated with Antibiotic Use for Suspected Neonatal Sepsis in the United States.

OBJECTIVE: This study aimed to estimate national time trends of overall and statewise antibiotic utilization (AU) rates for suspected neonatal sepsis (SNS) in the United States. STUDY DESIGN: In this cross-sectional study, we used retrospective linked birth cohort and vital records data from the Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research database for the years 2016 to 2020 and analyzed data containing antibiotic use for SNS. The primary outcome was proportional national and state-specific AU rates per 1,000 live births during the birth hospitalization. Secondary outcomes included overall trends and association between maternal education, race, sex, chorioamnionitis, mode of delivery, gestational age at birth, Apgar's scores, and insurance status with antibiotics exposure for SNS among newborns. Contingency tables, two-tailed t-test, and chi-square for independence tests were performed with statistical significance set at p < 0.05. RESULTS: For a birth cohort of >18 million, 2.2% of infants received antibiotics during birth hospitalization nationwide. There were wide variations in AU among U.S. states and territories, whereas overall treatment rates decreased by 16.1% (95% confidence interval [CI]: 15.2-17.0; p < 0.001). Compared with White newborns, Black newborns had higher AU rates (odds ratio [OR]: 1.33; 95% CI: 1.32-1.34), and Asians had the lowest rates (OR: 0.96; 95% CI: 0.95-0.97). There was a significant difference in mean AU rates by race (p < 0.001). Chorioamnionitis at birth significantly increased the odds for AU (OR: 14.5 ;95% CI: 14.4-14.6), although AU rates for chorioamnionitis showed a significant downward trend (OR: 0.52; 95% CI: 0.50-0.53) during the study period. CONCLUSION: Our findings suggest that there has been a gradual decline in AU for SNS in more than a third of states in last 5 years. While risk-based management approaches achieve widespread implementation, state- and nationwide quality improvement collaborates might have contributed to the relative decline in antibiotic use in newborns. Further studies are warranted to understand factors related to practice variation in the management of SNS in the United States KEY POINTS: · Early and prolonged use of antibiotics can lead to altered gut microbiome and adverse long-term neonatal outcomes.. · There is considerable clinical practice variation in antibiotic-prescribing practices for suspected neonatal sepsis.. · This cross-sectional study reports the differences in neonatal antibiotic usage patterns by region and maternal factors.. · Antibiotic use should be limited to newborns at high risk of infection and proven sepsis.. · Judicious use of antibiotics can be promoted by following evidence-based approaches to sepsis risk assessment..

Association of Survival at 22 Weeks' Gestation With Use of Antenatal Corticosteroids and Mode of Delivery in the United States.

This cross-sectional study reports recent trends in US national live births at 22 completed weeks' gestational age and analyzes the association of antenatal corticosteroid use and cesarean delivery with birth-linked survival at birth certificate reporting time, 27 days of life, and 364 days of life.

Prenatal choline supplementation improves biomarkers of maternal docosahexaenoic acid (DHA) status among pregnant participants consuming supplemental DHA: a randomized controlled trial.

BACKGROUND: Dietary methyl donors (e.g., choline) support the activity of the phosphatidylethanolamine N-methyltransferase (PEMT) pathway, which generates phosphatidylcholine (PC) molecules enriched in DHA that are exported from the liver and made available to extrahepatic tissues. OBJECTIVES: This study investigated the effect of prenatal choline supplementation on biomarkers of DHA status among pregnant participants consuming supplemental DHA. METHODS: Pregnant participants (n = 30) were randomly assigned to receive supplemental choline intakes of 550 mg/d [500 mg/d d0-choline + 50 mg/d deuterium-labeled choline (d9-choline); intervention] or 25 mg/d (25 mg/d d9-choline; control) from gestational week (GW) 12-16 until delivery. All participants received a daily 200-mg DHA supplement and consumed self-selected diets. Fasting blood samples were obtained at baseline, GW 20-24, and GW 28-32; maternal/cord blood was obtained at delivery. Mixed-effects linear models were used to assess the impact of prenatal choline supplementation on maternal and newborn DHA status. RESULTS: Choline supplementation (550 vs. 25 mg/d) did not achieve a statistically significant intervention × time interaction for RBC PC-DHA (P = 0.11); a significant interaction was observed for plasma PC-DHA and RBC total DHA, with choline supplementation yielding higher levels (+32-38% and +8-11%, respectively) at GW 28-32 (P < 0.05) and delivery (P < 0.005). A main effect of choline supplementation on plasma total DHA was also observed (P = 0.018); its interaction with time was not significant (P = 0.068). Compared with controls, the intervention group exhibited higher (P = 0.007; main effect) plasma enrichment of d3-PC (d3-PC/total PC). Moreover, the ratio of d3-PC to d9-PC was higher (+50-67%; P < 0.001) in the choline intervention arm (vs. control) at GW 20-24, GW 28-32, and delivery. CONCLUSIONS: Prenatal choline supplementation improves hepatic DHA export and biomarkers of DHA status by bolstering methyl group supply for PEMT activity among pregnant participants consuming supplemental DHA. This trial is registered at www.clinicaltrials.gov as NCT03194659.

Human and Economic Cost of Disease Burden Due to Congenital Hypothyroidism in India: Too Little, but Not Too Late.

Background: Congenital hypothyroidism (CH) is one of the most common preventable causes of mental retardation. Implementing newborn screening (NBS) in >52 countries enabled early detection and to initiate treatment of neonates with CH. India is yet to implement a national NBS program even though an estimated 5-15% of sick newborns suffer from genetic and metabolic disorders. Recent pilot studies confirm that the CH incidence rates range from 1 in 500 to 1 in 3,400 live births. Our objective was to estimate overall incidence rates of congenital hypothyroidism and to evaluate the costs and benefits of implementing universal NBS for CH in India. Methods: We used the best available epidemiological and cost data to synthesize incidence rates and screening costs for CH in India. We conducted a meta-analysis of country-specific published literature and included 14 studies to calculate baseline CH incidence rates. We used two models to estimate intellectual disability in unscreened cohorts. Disability-adjusted life years (DALY) were calculated to quantify burden of disease utilizing disability weights. Direct costs including screening, confirmatory tests, and treatment costs were obtained from public and private market sources. Economic benefits were calculated from lost DALY using human capital approach and value of statistical life methods, utilizing gross national income (GNI) per capita data and value of statistical life year (VSLY), respectively. Cost discounting was used to estimate the present value of future benefits over lifetime of affected newborns. Results: The incidence rate of CH in India is 72 (95% CI: 58, 85) cases per 100,000 live births. Based on this data, 1 in 1,388 (95% CI: 1166, 1714) infants were diagnosed with CH in India for the year 2018. The estimated annual incidence ranged from 14,000 to 20,730 cases, and those at risk for intellectual disability ranged from 5,397 to 13,929 cases. Estimated discounted and undiscounted lost DALYs were 57,640 and 410,000, respectively. Direct annual costs for universal screening for CH in India is around USD187 million. Based on current incidence and expected severity of sequelae, economic losses ranged from USD 159 million to 1.1 billion. Benefit-cost ratios ranged from 1.8 to 6. Conclusions: Universal NBS for CH is one of the healthcare interventions that is beneficial to prevent morbidity and cost saving. The cumulative economic benefits, derived from prevention of intellectual disability, assuming cost effectiveness threshold of three times of gross domestic product per capita, far outweigh the direct and indirect costs of screening, treatment, and surveillance throughout the life of the affected individuals. Our analysis strongly supports the argument for investing in NBS that provides good value for money and would yield substantial financial gains for the country.

Efficacy and Costs of Three Pharmacotherapies for Patent Ductus Arteriosus Closure in Premature Infants.

BACKGROUND: The hemodynamic impact of persistent patent ductus arteriosus (PDA) is associated with neonatal morbidities and mortality in preterm newborns. While there has been considerable debate about optimal management of PDA and its impact on clinical outcomes, there is widespread variation in practice, such as using different pharmacotherapies to achieve closure of hemodynamically significant PDA during the first week of life in very low birth weight infants. AIMS: The objective was to estimate the efficacy of acetaminophen, ibuprofen, and indomethacin with regard to ductal closure and to compare the costs of these three commonly used medications to treat PDA in preterm infants. METHODS: PubMed, Embase, and Cochrane Registry were searched for trials from the years 2010-2020. We identified 17 randomized clinical trials (RCTs) and 14 case series that enrolled preterm infants < 37 weeks gestational age for inclusion. Pooled estimates of closure rates for acetaminophen (n = 630), ibuprofen (n = 694), and indomethacin (n = 312) were analyzed using the weighted proportion ratio using a Mantel­Haenszel random effects model. The chi-squared test of proportions was used to determine significance between groups. We accessed cost estimates of pharmacotherapy from the Lexi-Comp average wholesale price database and utilized a decision tree model to appraise cost benefits for the outcome measure of successful PDA closure. RESULTS: The pooled proportional point estimates of closure rates from RCTs for acetaminophen, ibuprofen, and indomethacin were 70.1% (95% confidence interval [CI] 60-80), 63.4% (95% CI 52.8-74.1), and 71.5% (95% CI 62.3-80.7), respectively. There was no significant statistical difference in closure rates when RCTs and uncontrolled case series were combined. Pairwise comparisons showed both acetaminophen and indomethacin were each more effective in closing PDA than ibuprofen (acetaminophen vs indomethacin: p = 0.01; ibuprofen vs indomethacin: p = 0.02; acetaminophen vs indomethacin: p = 0.93). Comparing costs for successful closure of PDA, at the average wholesale price of different medications, suggested that treatment with acetaminophen costs significantly less, with a mean of $1487 (95% CI 1300-1737), compared to ibuprofen, with a mean of $2585 (95% CI 2214-3104), and indomethacin, with a mean of $2661 (95% CI 2358-3052), per course of treatment. CONCLUSIONS: Our meta-analysis suggests acetaminophen is non-inferior to both indomethacin and ibuprofen, and costs relatively less for successful PDA constriction in premature infants. Further clinical trials are warranted to compare acetaminophen's safety, along with short- and long-term effects, to help resolve the clinical conundrum of the necessity of early treatment in the management of PDA, and the optimal pharmacological course, if indicated.

Trends in hospitalizations of newborns with hyperbilirubinemia and kernicterus in United States: an epidemiological study.

BACKGROUND: Hyperbilirubinemia is one of the most common diagnosis in newborn nurseries in United States. Universal pre-discharge bilirubin screening decreased the incidence of extreme hyperbilirubinemia and risk of kernicterus. OBJECTIVES: We sought to assess temporal population trends of hyperbilirubinemia, kernicterus and usage of phototherapy, intravenous immunoglobulin (IVIG), and exchange transfusion. DESIGN/METHODS: Data from Healthcare Cost and Utilization Project (HCUP)-the Kids' Inpatient Database (KID) obtained for years 1997-2012. All neonatal discharges with ICD-9 codes for neonatal jaundice (774.2, 774.6), kernicterus (773.4, 774.7) and procedure codes for phototherapy (99.83), IVIG infusion (99.14), exchange transfusion (99.01) were extracted. We compared the trends of diagnosis of hyperbilirubinemia, kernicterus, use of phototherapy, IVIG, and exchange transfusion. RESULTS: During the study period, the proportion of infants diagnosed with hyperbilirubinemia increased by 65% (9.4% vs. 15.5%; p<.001) in term infants and 34.5% (33.5% vs. 45%; p<.001) in preterm infants, respectively. Rate of kernicterus discharges significantly reduced from 7 to 1.9 per 100,000 newborns. Overall, the number of exchange transfusions has decreased by 67% during study period while phototherapy and IVIG use increased by 83% and 170%, respectively. CONCLUSIONS: In last two decades, there was a significant decrease in neonatal discharges with a history of exchange transfusion or with a diagnosis of kernicterus. However, there was a significant increase in number of neonates discharged home with a history of phototherapy during birth hospitalization and decreased number of exchange transfusions were observed during the study period. Incremental implementation of universal predischarge bilirubin screening and treatments based on 2004 AAP recommended risk-based strategies might have contributed to timely interventions in infants with significant hyperbilirubinemia.

Economic evaluation of point of care universal newborn screening for glucose-6-Phosphate dehydrogenase deficiency in United States.

BACKGROUND AND OBJECTIVES: Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency is frequent inherited enzymopathy that poses potentially preventable risk for extreme hyperbilirubinemia (EHB) which can, rarely, lead to acute bilirubin encephalopathy, childhood kernicterus and death. We aimed to estimate quality adjusted life years (QALY) lost due to G6PD deficiency associated with EHB and economic costs to best estimate value of universal pre-discharge screening. METHODS: We did a cost utility analysis for US birth cohort utilizing pre-discharge screening decision tree model to estimate population burden and EHB outcomes, based on literature search and expert opinions. Employing human capital approach, we measured health benefits in terms of QALYs and economic losses. QALYs and costs were discounted at 3%; one-way sensitivity analysis was used for decision variables. RESULTS: We determined for USA live births of 3.86 million in 2017, 1464 cases of EHB were estimated to be due to G6PD deficiency (CI 95%; range: 1270-1656) and contributed 2 deaths (CI 95%; range 1.3-3.2) and 14 (CI 95%; range: 9.1-21.5) cases of kernicterus. Over lifetime horizon, the model predicted undiscounted and discounted gains of 165 (102-252) life years; 241 (183-433) QALYs and 16 (9.9-24.5) life years; 89 (67.9-160.5) QALYs, respectively. Assuming 50% effectiveness, benefit cost ratios ranged from 0.19 to 3.42 for diverse operational settings. The cost to prevent a single case of kernicterus was $2.7 to 6.8 million per annum with cost per QALY gained at $35,946 to $89,159. CONCLUSION: At incremental cost-effective threshold of $100,000/life year, pre-discharge screening would be expected to prove cost effective in preventing EHB related morbidities and mortality attributed to G6PD deficiency.

Choline metabolome response to prenatal choline supplementation across pregnancy: A randomized controlled trial.

Pregnancy places a unique stress upon choline metabolism, requiring adaptations to support both maternal and fetal requirements. The impact of pregnancy and prenatal choline supplementation on choline and its metabolome in free-living, healthy adults is relatively uncharacterized. This study investigated the effect of prenatal choline supplementation on maternal and fetal biomarkers of choline metabolism among free-living pregnant persons consuming self-selected diets. Participants were randomized to supplemental choline (as choline chloride) intakes of 550 mg/d (500 mg/d d0-choline + 50 mg/d methyl-d9-choline; intervention) or 25 mg/d d9-choline (control) from gestational week (GW) 12-16 until Delivery. Fasting blood and 24-h urine samples were obtained at study Visit 1 (GW 12-16), Visit 2 (GW 20-24), and Visit 3 (GW 28-32). At Delivery, maternal and cord blood and placental tissue samples were collected. Participants randomized to 550 (vs. 25) mg supplemental choline/d achieved higher (p < .05) plasma concentrations of free choline, betaine, dimethylglycine, phosphatidylcholine (PC), and sphingomyelin at one or more study timepoint. Betaine was most responsive to prenatal choline supplementation with increases (p ≤ .001) in maternal plasma observed at Visit 2-Delivery (relative to Visit 1 and control), as well as in the placenta and cord plasma. Notably, greater plasma enrichments of d3-PC and LDL-C were observed in the intervention (vs. control) group, indicating enhanced PC synthesis through the de novo phosphatidylethanolamine N-methyltransferase pathway and lipid export. Overall, these data show that prenatal choline supplementation profoundly alters the choline metabolome, supporting pregnancy-related metabolic adaptations and revealing biomarkers for use in nutritional assessment and monitoring during pregnancy.

Estimated disease burden and lost economic productivity due to glucose-6-phosphate dehydrogenase deficiency in Nigerian newborns.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency rarely manifests as extreme hyperbilirubinemia [EHB, total serum/plasma bilirubin > 25 mg/dL (428 µmol/L)]. It is a major preventable cause of newborn morbidity and mortality. In resource-constrained communities of Nigeria, experts have observed its significant clinical burden. We accessed a previously published pooled model of G6PD deficiency and determined its prevalence, subsequent risk of EHB, kernicterus, and death to be 26.4% [95% confidence interval (CI): 19.5, 33.2%]; 33.3% (95%CI: 16.6, 50%); and 22.7% (95% CI: 16.5, 28.9%), respectively. The total number of disability-adjusted life years (DALYs) lost to symptomatic G6PD deficiency was 54,251 (95% CI: 6,039, 189,149). Estimated national average economic deficits due to mortality and disability ranged from $309 to $584 million. G6PD deficiency, when symptomatic in Nigerian newborns, is a significant disease burden, placing 1% of annual births at increased risks of neonatal mortality and morbidity, which contribute to significant economic productivity losses.

A Unique Genomic Variant of HDR Syndrome in Newborn.

BACKGROUND: HDR syndrome (also known as Barakat syndrome) is a rare genetic disorder due to deletions/mutations on specific regions of zinc-finger transcription factor (GATA3) gene. CASE CHARACTERISTICS: A male preterm infant presented with multiple dysmorphic features characterized by small for gestational age, hypognathia and facial abnormalities. OBSERVATION: Investigations revealed hypocalcemia and low parathyroid hormone levels and bilateral sensorineural deafness. OUTCOME: Chromosomal microarray analysis revealed a combination of deletion on chromosome 10p (10p15.3p14) with loss of GATA3 gene and duplication of chromosome 20p (20p13p12.3) as a result of unbalanced 10:20 translocation. MESSAGE: Detecting this syndrome at neonatal age is very important because it allows early intervention to minimize future clinical problems.

Infantile hemangiomas and retinopathy of prematurity: possible association.

OBJECTIVE: The goal was to study the clinical association between infantile hemangiomas and retinopathy of prematurity in preterm infants. METHODS: A retrospective study of preterm neonates weighing /=1 cm in size. Univariate analyses showed lower gestational age, lower birth weight, and postnatal steroid use to be predictors of retinopathy of prematurity, whereas prenatal steroid use, race, and gender were not significantly related. In multivariate logistic regression analyses controlling for gestational age and postnatal steroid use, infantile hemangiomas were found to be independently associated with any stage of retinopathy of prematurity. Neither the number nor the size of infantile hemangiomas showed any association with the severity of retinopathy of prematurity. CONCLUSIONS: Infantile hemangiomas are associated with the development of retinopathy of prematurity in infants weighing

Sildenafil augments early protective transcriptional changes after ischemia in mouse myocardium.

Recently, targeting cyclic-GMP specific phosphodiesterase-5 (PDE5) has attracted much interest in several cardiopulmonary diseases, in particular myocardial ischemia (MI). Although multiple mechanisms were postulated for these beneficial effects at cellular level, early transcriptional changes were unknown. The aim of present study was to examine gene expression profiles in response to MI after 24 h of ischemia in murine model and compare transcriptional modulation by sildenafil, a popular phosphodiesterase 5 (PDE5) inhibitor. Mice were divided into four groups: Control sham (C), Sildenafil sham (S), Control MI (CMI) and Sildenafil MI (SMI). Sildenafil was given at a dose of 0.7 mg/kg intraperitoneally 30 min before LAD occlusion. cDNA microarray analysis of peri-infarct tissue was done using a custom cloneset and employing a looped dye swap design. Replicate signals were median averaged and normalized using LOWESS algorithm. R/MAANOVA analysis was used and false discovery rate corrected permutation p-values <0.005 were employed as significance thresholds. 156 genes were identified as significantly regulated demonstrating fold difference >1.5 in at least one of the four groups. 52 genes were significantly upregulated in SMI compared to CMI. For a randomly chosen subset of genes (9), microarray data were confirmed through real time RT-PCR. The differentially expressed genes could be classified into following groups based on their function: phosphorylation/dephosphorylation, apoptosis, differentiation, ATP binding. Our results suggest that sildenafil treatment might regulate early genetic reprogramming strategy for preservation of the ischemic myocardium.

Ex vivo and in vivo approaches to study mechanisms of cardioprotection targeting ischemia/reperfusion (i/r) injury: useful techniques for cardiovascular drug discovery.

The last few decades have seen significant advancement in the therapy of Ischemic Heart Diseases (IHD). This is a direct outcome of the increasing knowledge of the molecular mechanisms involved during an ischemic insult of the myocardium. Even then there is still a major unmet need for better strategies or drug therapies to reduce ventricular remodeling and improve post-ischemic myocardial function. The ex-vivo isolated working heart model and the in vivo myocardial infarction model are the best known techniques to elucidate the contribution of a drug therapy to confer cardioprotection in the event of an ischemic insult/reperfusion. Our review aims to provide an insight into the state of the art techniques that lay the foundations for cardiovascular drug discovery and present the prospects for further development from a preclinical perspective. The first section of the review provides an overview of the rat/mouse ex-vivo and in vivo models of myocardial ischemia. The following section will then present various applications of these clinically relevant models in characterizing cardiac functions, screening for drugs and identifying the drug induced changes in cardiac functions. Finally the role of these models in drug development is discussed with respect to functional relevance of drug treatment on heart rate, aortic flow, coronary flow, infarct size and the mechanisms by which these drugs promote myocardial protection. This review may serve as a basic knowledge for researchers who intend to study the efficacy of a drug in the treatment of ischemic heart diseases.

Sildenafil-mediated neovascularization and protection against myocardial ischaemia reperfusion injury in rats: role of VEGF/angiopoietin-1.

Sildenafil citrate (SC), a drug for erectile dysfunction, is now emerging as a cardiopulmonary drug. Our study aimed to determine a novel role of sildenafil on cardioprotection through stimulating angiogenesis during ischaemia (I) reperfusion (R) at both capillary and arteriolar levels and to examine the role of vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) in this mechanistic effect. Rats were divided into: control sham (CS), sildenafil sham (SS), control+IR (CIR) and sildenafil+IR (SIR). Rats were given 0.7 mg/kg, (i.v) of SC or saline 30 min. before occlusion of left anterior descending artery followed by reperfusion (R). Sildenafil treatment increased capillary and arteriolar density followed by increased blood flow (2-fold) compared to control. Treatment with sildenafil demonstrated increased VEGF and Ang-1 mRNA after early reperfusion. PCR data were validated by Western blot analysis. Significant reduction in infarct size, cardiomyocyte and endothelial apoptosis were observed in SC-treated rats. Increased phosphorylation of Akt, eNOS and expression of anti-apoptotic protein Bcl-2, and thioredoxin, hemeoxygenase-1 were observed in SC-treated rats. Echocardiography demonstrated increased fractional shortening and ejection fraction following 45 days of reperfusion in the treatment group. Stress testing with dobutamine infusion and echocardiogram revealed increased contractile reserve in the treatment group. Our study demonstrated for the first time a strong additional therapeutic potential of sildenafil by up-regulating VEGF and Ang-1 system, probably by stimulating a cascade of events leading to neovascularization and conferring myocardial protection in in vivo I/R rat model.

Sildenafil induces angiogenic response in human coronary arteriolar endothelial cells through the expression of thioredoxin, hemeoxygenase and vascular endothelial growth factor.

This study was undertaken to investigate the effect of phosphodiesterase-5 (PDE5) inhibitor, sildenafil, on angiogenic response in human coronary arteriolar endothelial cells (HCAEC). The cells exposed to sildenafil (1-20 microM) demonstrated significantly accelerated tubular morphogenesis with the induction of thioredoxin-1 (Trx-1), hemeoxygenase-1 (HO-1) and VEGF. Sildenafil induced VEGF and angiopoietin specific receptors such as KDR, Tie-1 and Tie-2. This angiogenic response was repressed by tinprotoporphyrin IX (SnPP), an inhibitor of HO-1 enzyme activity. Sildenafil below 1 muM has no angiogenic effect as evidenced by reduced tuborogenesis. Sildenafil along with SnPP inhibited both VEGF and Angiopoietin-1 (Ang-1) protein expression. Therefore our results demonstrated for the first time that sildenafil is a very potent pro-angiogenic factor.