Utilizing venous occlusion plethysmography to assess vascular effects: A study with buloxibutid, an angiotensin II type 2 receptor agonist.

Buloxibutid (also known as C21) is a potent and selective angiotensin II type 2 receptor (AT2R) agonist, in development for oral treatment of fibrotic lung disease. This phase I, open-label, pharmacodynamic study investigated vascular effects of buloxibutid in five healthy male volunteers. Subjects were administered intra-arterial infusions of buloxibutid for 5 min in ascending doses of 3, 10, 30, 100, and 200 µg/min, infused sequentially in the forearm. Infusions of sodium nitroprusside (SNP) solution in doses of 0.8-3.2 µg/min were administered as a positive control. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. Safety and tolerability of intra-arterial administrations of buloxibutid were evaluated. Following infusion of buloxibutid in doses of 3-200 µg/min, the range of increase in FBF was 27.8%, 17.2%, 37.0%, 28.5%, and 60.5%, compared to the respective baseline. The largest increase was observed in the highest dose group. Infusions of SNP as a positive control, increased FBF 230-320% compared to baseline. Three adverse events (AEs) of mild intensity, not related to buloxibutid or SNP, were reported for two subjects. Two of these AEs were related to study procedures. There were no clinically relevant changes in arterial blood pressure during the study period. Intra-arterial infusion of buloxibutid in low, ascending doses increased FBF, indicating that buloxibutid may be effective in conditions associated with endothelial dysfunction. Venous occlusion plethysmography was found to be a useful method to explore pharmacodynamic vascular effects of novel AT2R agonists, while avoiding systemic adverse effects.

The efficacy and safety of sodium nitroprusside in the treatment of schizophrenia: Protocol for an updated systematic review and meta-analysis.

BACKGROUND: Schizophrenia is a chronic persistent disease with high recurrence rate and high disability rate in the field of psychiatry. Sodium nitroprusside is a nitric oxide (NO) donor and considered a promising new compound for the treatment of schizophrenia. New high-quality clinical trials of sodium nitroprusside in the treatment of schizophrenia have been published in recent years. It is necessary to re-conduct the meta-analysis after the inclusion of these new clinical trials. Our study will conduct a systematic review and meta-analysis of the relevant literature in this field, so as to lay an evidence-based medicine foundation for the efficacy of sodium nitroprusside in the treatment of schizophrenia. METHODS AND ANALYSIS: Randomized controlled trials (RCTs) of sodium nitroprusside in the treatment of schizophrenia were searched through English databases (PubMed, Web of Science, Embase, and Cochrane Library) and Chinese databases (China Biology Medicine disc, VIP, WanFang Data, and CNKI). The extracted data will be inputted into Review Manager 5.3 for Meta-analysis. The included literature will be assessed for bias risk according to the bias risk assessment tools in the Cochrane Handbook for Systematic Reviews of Interventions. Funnel plots will be used to assess possible publication bias. Heterogeneity is tested by I2 and χ2 tests, and the existence of heterogeneity is defined as I2 ≥50% and P ≤0.1. If heterogeneity exists, the random-effect model will be used, and sensitivity analysis or subgroup analysis will be performed to further determine the source of heterogeneity. PROSPERO REGISTRATION NUMBER: CRD42022341681.

Sodium nitroprusside for advanced heart failure. A metanalysis of literature data.

Advanced heart failure (HF) is associated with a very poor prognosis and places a big burden on health-care services. The gold standard treatment, i.e. long-term mechanical circulatory support or heart transplantation, is precluded in many patients but observational studies suggest that the use of SNP might be associated with favourable long-term clinical outcomes. We performed a metanalysis of published studies that compared sodium nitroprusside (SNP) with optimal medical therapy to examine the safety and efficacy of SNP as part of the treatment regimen of patients hospitalized for advanced heart failure (HF). We searched PUBMED, EMBASE and WEB OF SCIENCE for studies that compared SNP with optimal medical therapy in advanced HF on July 2022. After screening 700 full-text articles, data from two original articles were included in a combined analysis. The analysis demonstrated a 66% reduction in the odds of death in advanced HF patients treated with SNP. The results show the potential importance of the inclusion of SNP in the treatment regimen of patients hospitalized because of advanced HF and underlines that controlled, randomized studies are still required in this condition.

S-Equol Protects Chondrocytes against Sodium Nitroprusside-Caused Matrix Loss and Apoptosis through Activating PI3K/Akt Pathway.

Osteoarthritis (OA) is a common chronic disease with increasing prevalence in societies with more aging populations, therefore, it is causing more concern. S-Equol, a kind of isoflavones, was reported to be bioavailable and beneficial to humans in many aspects, such as improving menopausal symptoms, osteoporosis and prevention of cardiovascular disease. This study investigated the effects of S-Equol on OA progress in which rat primary chondrocytes were treated with sodium nitroprusside (SNP) to mimic OA progress with or without the co-addition of S-Equol for the evaluation of S-Equol's efficacy on OA. Results showed treatment of 0.8 mM SNP caused cell death, and increased oxidative stress (NO and H2O2), apoptosis, and proteoglycan loss. Furthermore, the expressions of MMPs of MMP-2, MMP-3, MMP-9, and MMP-13 and p53 were increased. The addition of 30 µM S-Equol could lessen those caused by SNP. Moreover, S-Equol activates the PI3K/Akt pathway, which is an upstream regulation of p53 and NO production and is associated with apoptosis and matrix degradation. As a pretreatment of phosphoinositide 3-kinases (PI3K) inhibitor, all S-Equol protective functions against SNP decrease or disappear. In conclusion, through PI3K/Akt activation, S-Equol can protect chondrocytes against SNP-induced matrix degradation and apoptosis, which are commonly found in OA, suggesting S-Equol is a potential for OA prevention.

Characteristics of Heart Failure Patients With or Without Hypotension When Transitioning From Nitroprusside to Sacubitril-Valsartan.

BACKGROUND: Sacubitril-valsartan is an angiotensin receptor-neprilysin inhibitor indicated for the treatment of patients with symptomatic heart failure with reduced ejection fraction (HFrEF). Little is known about outcomes of HFrEF patients transitioned from sodium nitroprusside (SNP) to sacubitril-valsartan during an admission for acute decompensated heart failure. We sought to describe characteristics of patients initiated on sacubitril-valsartan while receiving SNP and, in particular, those patients who did and did not experience hypotension requiring interruption or discontinuation of sacubitril-valsartan. METHODS: We performed a retrospective case series of adult patients (>18 years) with HFrEF (left ventricular ejection fraction ≤40%) admitted to the University of Michigan cardiac intensive care unit between July 2018 to September 2020 who received sacubitril-valsartan while on SNP. RESULTS: A total of 15 patients with acute decompensated heart failure were initiated on sacubitril-valsartan while on SNP. The mean age was 57 ± 15.9 years. Seven (46.7%) patients experienced hypotension. The patients in the cohort who experienced hypotension were numerically older (60 ± 17 vs. 55 ± 15.5), and the majority were white (86%). Patients with hypotension had a numerically lower left ventricular ejection fraction (13 ± 4.2 vs. 18 ± 8.2) and higher serum creatinine (1.4 ± 0.54 vs. 0.88 ± 0.25). Seven (100%) patients received a diuretic on the day of sacubitril-valsartan initiation in those who experienced hypotension compared with 2 (25%) in those who did not experience hypotension. CONCLUSIONS: In almost half of patients admitted to the cardiac intensive care unit with acutely decompensated HFrEF, significant hypotension was seen when initiating sacubitril-valsartan while on SNP. Future studies should evaluate appropriate patients for this transition and delineate appropriate titration parameters.

Captopril Versus Hydralazine-Isosorbide Dinitrate Vasodilator Protocols in Patients With Acute Decompensated Heart Failure Transitioning From Sodium Nitroprusside.

BACKGROUND: The role of oral vasodilators in the management of acute decompensated heart failure (ADHF) is not clearly defined. We evaluated the use of captopril vs hydralazine-isosorbide dinitrate (H-ISDN) in the transition from sodium nitroprusside (SNP) in patients with ADHF. METHODS AND RESULTS: A retrospective chart review was performed of 369 consecutive adult patients in the intensive care unit with ADHF and reduced ejection fraction, who received either a captopril or an H-ISDN protocol to transition from SNP. Captopril patients were matched 1:2 to H-ISDN patients, based on serum creatinine and race (Black vs non-Black). Baseline demographics, serum chemistry and use of angiotensin converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) were similar in both groups. Time to SNP discontinuation (46.9 vs 40.4 hours, P = 0.11) and length of hospital stay (9.86 vs 7.99 days, P = 0.064) were similar in both groups. Length of hospital stay in the intensive care unit was statistically shorter in the H-ISDN group (4.11 vs 3.96 days, P = 0.038). Fewer H-ISDN protocol patients were discharged on ACEis/ARBs (82.9 % vs 69.9%, P = 0.003) despite similar kidney function at time of discharge (serum creatinine 1.1 vs 1.2, P = 0.113). No difference was observed in rates of readmission (40.7% vs 50%, P = 0.09) or mortality (16.3% vs 17.5 %, P = 0.77) at 1 year postdischarge. CONCLUSION: Similar inpatient and 1-year outcomes were observed between patients using H-ISDN vs ACEi when transitioning from SNP, even though fewer H-ISDN protocol patients were discharged taking ACEis/ARBs despite similar kidney function.

Pharmacologic Control of Blood Pressure in Infants and Children.

Alterations in blood pressure are common during the perioperative period in infants and children. Perioperative hypertension may be the result of renal failure, volume overload, or activation of the sympathetic nervous system. Concerns regarding end-organ effects or postoperative bleeding may mandate regulation of blood pressure. During the perioperative period, various pharmacologic agents have been used for blood pressure control including sodium nitroprusside, nitroglycerin, ß-adrenergic antagonists, fenoldopam, and calcium channel antagonists. The following manuscript outlines the commonly used pharmacologic agents for perioperative BP including dosing regimens and adverse effect profiles. Previously published clinical trials are discussed and efficacy in the perioperative period reviewed.

Incorporation of Nitroprusside on Silica Nanoparticles-A Strategy for Safer Use of This NO Donor in Therapy.

Silica-based nanoparticles have been developed as powerful platforms for drug delivery and might also prevent undesired side effects of drugs. Here, a fast method to synthesize positively charged mesoporous silica nanoparticles (ζ = 20 ± 0.5 mV, surface area = 678 m2 g-1, and 2.3 nm of porous size) was reported. This nanomaterial was employed to anchor sodium nitroprusside (SNP), a vasodilator drug with undesired cyanide release. A remarkable incorporation of 323.9 ± 7.55 µmol of SNP per gram of nanoparticle was achieved, and a series of studies of NO release were conducted, showing efficient release of NO along with major cyanide retention (ca. 64% bound to nanoparticle). Biological assays with mammalian cells showed only a slight drop in cell viability (13%) at the highest concentration (1000 µM), while SNP exhibited an LC50 of 228 µM. Moreover, pharmacological studies demonstrated similar efficacy for vasodilation and sGC-PKG-VASP pathway activation when compared to SNP alone. Altogether, this new SNP silica nanoparticle has great potential as an alternative for wider and safer use of SNP in medicine with lower cyanide toxicity.

Adverse events during intrahospital transport of critically ill patients in a large hospital. / Eventos adversos durante transporte intra-hospitalar de pacientes críticos em hospital de grande porte.

OBJECTIVE: To describe the incidence of clinical and non-clinical events during intrahospital transport of critically ill patients and to analyze the associated risk factors. METHODS: Cohort study with retrospective data collected from October 2016 to October 2017. All cases of intrahospital transport for diagnostic and therapeutic purposes in a large hospital with six adult intensive care units were analyzed, and the adverse events and related risk factors were evaluated. RESULTS: During the study period, 1,559 intrahospital transports were performed with 1,348 patients, with a mean age of 66 ± 17 years and a mean transport time of 43 ± 34 minutes. During transport, 19.8% of the patients were using vasoactive drugs; 13.7% were under sedation; and 10.6% were under mechanical ventilation. Clinical events occurred in 117 transports (7.5%), and non-clinical events occurred in 125 (8.0%) transports. Communication failures were prevalent; however, the multivariate analysis showed that the use of sedatives, noradrenaline and nitroprusside and a transport time greater than 36.5 minutes were associated with adverse clinical events. The use of dobutamine and a transport time greater than 36.5 minutes were associated with non-clinical events. At the end of transport, 98.1% of the patients presented unchanged clinical conditions compared with baseline. CONCLUSION: Intrahospital transport is related to a high incidence of adverse events, and transport time and the use of sedatives and vasoactive drugs were related to these events.

OBJETIVO: Descrever a incidência de eventos clínicos e não clínicos durante o transporte intra-hospitalar de pacientes críticos e analisar os fatores de risco associados. MÉTODOS: Estudo de coorte, com coleta retrospectiva, no período de outubro de 2016 a outubro de 2017, tendo sido analisados todos os transportes intra-hospitalares para fins diagnósticos e terapêuticos em hospital de grande porte, que contava com seis unidades de terapia intensiva adulto, sendo avaliados os eventos adversos e os fatores de risco relacionados. RESULTADOS: No período, foram realizados 1.559 transportes intra-hospitalares, em 1.348 pacientes, com média de idade de 66 ± 17 anos, tempo médio de transporte de 43 ± 34 minutos. Durante o transporte, 19,8% dos pacientes estavam em uso de drogas vasoativas; 13,7% em uso de sedativos e 10,6% estavam sob ventilação mecânica. Eventos clínicos ocorreram em 117 transportes (7,5%) e não clínicos em 125 transportes (8,0%). Falhas de comunicação foram prevalentes, no entanto, aplicando-se análise multivariada, uso de sedativos, noradrenalina e nitroprussiato, e o tempo de transporte maior que 36,5 minutos estiveram associados a eventos adversos clínicos. Uso de dobutamina e tempo de transporte superior a 36,5 minutos estiveram associados a eventos não clínicos. Ao final do transporte, 98,1% dos pacientes apresentaram condições clínicas inalteradas em relação ao seu estado basal. CONCLUSÃO: Transportes intra-hospitalares estão relacionados à alta incidência de eventos adversos; o tempo de transporte e a utilização de sedativos e drogas vasoativas estiveram relacionados a esses eventos.

Efficacy and Tolerability of Adjunctive Intravenous Sodium Nitroprusside Treatment for Outpatients With Schizophrenia: A Randomized Clinical Trial.

Importance: Antipsychotic medications for the treatment of schizophrenia have limitations, and new treatments are needed. A prior pilot investigation suggested that adjunctive sodium nitroprusside (SNP) administered intravenously had rapid efficacy in the treatment of patients with schizophrenia. Objective: To determine the efficacy and tolerability of intravenous SNP infused at a rate of 0.5 µg/kg/min for 4 hours in patients with schizophrenia with some degree of treatment resistance. Design, Setting, and Participants: Multicenter, randomized, double-blind acute treatment study using a sequential parallel comparison design conducted in two 2-week phases at 4 academic medical centers beginning May 20, 2015, and ending March 31, 2017. Participants were adults 18 to 65 years of age with a diagnosis of schizophrenia as confirmed by the Structured Clinical Interview for DSM-IV, taking antipsychotic medication for at least 8 weeks, and had at least 1 failed trial of an antipsychotic medication within the past year. A total of 90 participants consented, 60 participants enrolled, and 52 participants were included in the analyses. A modified intent-to-treat analysis was used. Interventions: Participants were randomized in a 1:1:1 ratio to 1 of 3 treatment sequences: SNP and SNP, placebo and SNP, and placebo and placebo. The SNP and SNP group received SNP in phase 1 and SNP in phase 2 for the purpose of blinding, but the data from phase 2 were not included in the results. The placebo and SNP group received placebo in phase 1 and SNP in phase 2. If there was no response to placebo in phase 1, data from phase 2 were included in the analyses. The placebo and placebo group received placebo in both phases; if there was no response to placebo in phase 1, data from phase 2 were included in the analyses. Main Outcomes and Measures: Effectiveness of SNP compared with placebo in improving Positive and Negative Syndrome Scale (PANSS) total, positive, and negative scores across each 2-week phase. Results: Fifty-two participants (12 women and 40 men) were included in the study. In the SNP and SNP group, the mean (SD) age was 47.1 (10.5) years. In the placebo and SNP group, the mean (SD) age was 45.9 (12.3) years. In the placebo and placebo group, the mean (SD) age was 40.4 (11.0) years. There were no significant differences between the SNP and placebo groups at baseline or in change from baseline for PANSS-total (weighted ß = -1.04; z = -0.59; P = .57), PANSS-positive (weighted ß = -0.62; z = -0.93; P = .35), or PANSS-negative (weighted ß = -0.12; z = -0.19; P = .85) scores. No significant differences in safety or tolerability measures were identified. Conclusions and Relevance: Although intravenous SNP is well tolerated, it was not an efficacious adjunctive treatment of positive or negative symptoms of psychosis among outpatients with schizophrenia with prior history of treatment resistance. Trial Registration: ClinicalTrials.gov identifier: NCT02164981.

Eventos adversos durante transporte intra-hospitalar de pacientes críticos em hospital de grande porte / Adverse events during intrahospital transport of critically ill patients in a large hospital

RESUMO Objetivo: Descrever a incidência de eventos clínicos e não clínicos durante o transporte intra-hospitalar de pacientes críticos e analisar os fatores de risco associados. Métodos: Estudo de coorte, com coleta retrospectiva, no período de outubro de 2016 a outubro de 2017, tendo sido analisados todos os transportes intra-hospitalares para fins diagnósticos e terapêuticos em hospital de grande porte, que contava com seis unidades de terapia intensiva adulto, sendo avaliados os eventos adversos e os fatores de risco relacionados. Resultados: No período, foram realizados 1.559 transportes intra-hospitalares, em 1.348 pacientes, com média de idade de 66 ± 17 anos, tempo médio de transporte de 43 ± 34 minutos. Durante o transporte, 19,8% dos pacientes estavam em uso de drogas vasoativas; 13,7% em uso de sedativos e 10,6% estavam sob ventilação mecânica. Eventos clínicos ocorreram em 117 transportes (7,5%) e não clínicos em 125 transportes (8,0%). Falhas de comunicação foram prevalentes, no entanto, aplicando-se análise multivariada, uso de sedativos, noradrenalina e nitroprussiato, e o tempo de transporte maior que 36,5 minutos estiveram associados a eventos adversos clínicos. Uso de dobutamina e tempo de transporte superior a 36,5 minutos estiveram associados a eventos não clínicos. Ao final do transporte, 98,1% dos pacientes apresentaram condições clínicas inalteradas em relação ao seu estado basal. Conclusão: Transportes intra-hospitalares estão relacionados à alta incidência de eventos adversos; o tempo de transporte e a utilização de sedativos e drogas vasoativas estiveram relacionados a esses eventos.

ABSTRACT Objective: To describe the incidence of clinical and non-clinical events during intrahospital transport of critically ill patients and to analyze the associated risk factors. Methods: Cohort study with retrospective data collected from October 2016 to October 2017. All cases of intrahospital transport for diagnostic and therapeutic purposes in a large hospital with six adult intensive care units were analyzed, and the adverse events and related risk factors were evaluated. Results: During the study period, 1,559 intrahospital transports were performed with 1,348 patients, with a mean age of 66 ± 17 years and a mean transport time of 43 ± 34 minutes. During transport, 19.8% of the patients were using vasoactive drugs; 13.7% were under sedation; and 10.6% were under mechanical ventilation. Clinical events occurred in 117 transports (7.5%), and non-clinical events occurred in 125 (8.0%) transports. Communication failures were prevalent; however, the multivariate analysis showed that the use of sedatives, noradrenaline and nitroprusside and a transport time greater than 36.5 minutes were associated with adverse clinical events. The use of dobutamine and a transport time greater than 36.5 minutes were associated with non-clinical events. At the end of transport, 98.1% of the patients presented unchanged clinical conditions compared with baseline. Conclusion: Intrahospital transport is related to a high incidence of adverse events, and transport time and the use of sedatives and vasoactive drugs were related to these events.

t-Resveratrol Protects against Acute High Glucose Damage in Endothelial Cells.

Postprandial hyperglycemia in diabetic and nondiabetic subjects is associated with endothelial dysfunction. Evidence shows that high glucose generates oxidative stress and a pro-inflammatory state promoting the development of cardiovascular diseases. trans-Resveratrol (t-RV) has been shown to reduce cardiovascular risk. To determine whether t-RV acts as a protector against acute high glucose (AHG)-induced damage, two in vitro models, rat aortic rings (RAR) and human umbilical vein endothelial cells (HUVEC) were used. RAR pretreated with AHG (25 mM D-glucose) for 3 h dramatically decreased the endothelium-dependent relaxation (EDR) induced by acetylcholine in phenylephrine (PE)-precontracted vessels. However, coincubation with t-RV significantly mitigated the damage induced by AHG on EDR. Pretreatment with AHG did not affect the vasodilation induced by sodium nitroprusside. HUVEC treated with t-RV decreased cytotoxicity and reduced radical oxygen species production induced by AHG. Taken together, these results suggest that t-RV can mitigate the AHG-induced EDR damage through a mechanism involving ROS scavenging and probably an increase in the bioavailability of NO.

Curcumin protects rabbit articular chondrocytes against sodium nitroprusside-induced apoptosis in vitro.

The preventive and therapeutic effects of curcumin on degeneration of articular (joint) cartilage diseases have rarely been investigated. In the present study, the protective effects of curcumin against sodium nitroprusside (SNP)-induced chondrocyte apoptosis were evaluated and the underlying molecular mechanisms were elucidated. Curcumin was used to as a co-treatment with SNP in chondrocytes, and changes occurring in the cells were observed and evaluated. It was shown using a cell counting kit-8 (CCK-8) assay that curcumin protected the viability of chondrocytes against SNP damage. NO (nitric oxide) from SNP could be scavenged by curcumin. Flow cytometry and Hoechst 33342 staining showed that curcumin not only inhibited the cell apoptosis in a concentration-dependent pattern but also ameliorated the SNP-induced nuclear chromatin damage and reduction of the mitochondrial membrane potential in chondrocytes. In SNP-treated chondrocytes, curcumin downregulated the expression of Bax and cleaved caspase-3 but upregulated the expression of Bcl-2, as shown by western blot. Meanwhile, curcumin administration also protected extracellular matrix (ECM) synthesis and prevented its degradation. Taken together, these results support the hypothesis that curcumin exerts its protective effect on chondrocytes against SNP-induced apoptosis, at least partly, via blocking the mitochondrial-dependent apoptotic pathway and maintaining the metabolic balance of ECM. Thus, curcumin may be a potential candidate to be used as a unique biological agent for the prevent and treatment of osteoarthritis (OA).

Resveratrol protects against sodium nitroprusside induced nucleus pulposus cell apoptosis by scavenging ROS.

Oxidative stress induced disc cell apoptosis plays an important role in intervertebral disc (IVD) degeneration. The present study aims to investigate effects of resveratrol (RV), a natural polyphenol compound, on sodium nitroprusside (SNP) induced nucleus pulposus (NP) cell apoptosis and related mechanism. Rat NP cells were pretreated with RV, N-acetyl cysteine (NAC) and carboxy-PTIO (PTIO) before SNP treatment. Cell Counting Kit-8 assay was carried out for cell viability evaluation. Annexin V/propidium iodide (PI), Hoechst 33258 and Actin­Tracker Green and Tubulin-Tracker Red staining were conducted to detect NP cell apoptosis and apoptotic structural changes. Mitochondrial membrane potential (ΔΨm) was analyzed with tetramethylrhodamine methyl ester staining. DCFH-DA and DAF-FM DA staining was used to determine intracellular reactive oxygen species (ROS) and nitric oxide (NO) levels. An ex vivo experiment was also carried out followed by TUNEL assay of sections of discs. SNP induced NP cell apoptosis, excessive production of intracellular ROS and NO, reduction of ΔΨm as well as disruption of cytoskeletal and morphological structure. Meanwhile, organ culture results showed that SNP induced NP cell apoptosis ex vivo. RV and NAC siginificantly inhibited SNP induced NP cell apoptosis, production of intracellular ROS, deline of ΔΨm as well as disruption of cytoskeletal and morphological structure, while RV did not suppress NO production. RV and NAC could also suppress SNP induced NP cell apoptosis ex vivo. However, PTIO did not prevent SNP induced NP cell apoptosis, though it scavenged NO significantly. In conclusion, RV protects against SNP induced NP cell apoptosis by scavenging ROS but not NO, suggesting a promising prospect of RV in IVD degeneration retardation.

Comparison of regadenoson and nitroprusside to adenosine for measurement of fractional flow reserve: A systematic review and meta-analysis.

BACKGROUND: FFR is useful in defining the physiological significance of intermediate coronary stenosis and requires induction of maximal hyperemia and measurement of pressure proximal and distal to the stenosis. Hyperemia normally is induced by either IV or IC adenosine, a medication associated with short-term side effects. IV regadenoson and IC nitroprusside have been suggested as viable alternatives. This meta-analysis aims to identify all studies comparing use of intravenous (IV) regadenoson or intracoronary (IC) nitroprusside with IV adenosine to determine differences related to the agent utilized for assessment of fractional flow reserve (FFR). METHODS: We searched PubMed, EMBASE, Web of Science, SCOPUS, ClinicalTrials.gov and the Cochrane Library databases for studies comparing IV regadenoson or IC nitroprusside to IV adenosine for FFR assessment. The main outcome was difference in mean FFR measurement. The main secondary outcomes were composite side-effect profile and reclassification of lesions. RESULTS: Seven studies were included in the analysis, with a total of 375 patients. Compared to IV adenosine, there was no difference in the mean FFR derived from IV regadenoson (p=1.0) or IC nitroprusside (p=0.48). IV regadenoson was associated with 53% lower risk of pooled side effects compared to IV adenosine (p=0.05). IC nitroprusside was associated with 97% lower risk of pooled side effects compared to IV adenosine (p<0.001). CONCLUSIONS: IV regadenoson and IC nitroprusside produce similar pressure-derived FFR measurements compared to IV adenosine and have a favorable side effect profile. Both can be considered as alternative agents to IV adenosine for FFR measurement. Further clinical validation is warranted.

Metformin Exposure During Pregnancy and Lactation Did Not Cause Vascular Reactivity Alteration in Adult Male Offsprings.

Metformin has been used for the treatment of some metabolic diseases during gestation and the beneficial effects of metformin to the vascular system have been described in diabetic and obese animal models. Nevertheless, the long-term consequences to the vascular system of offsprings maternally exposed to metformin have not yet been characterized. Therefore, we want to test the hypothesis that gestational and lactational exposure to metformin would be safe for the vascular reactivity of male adult offsprings. Wistar female rats were treated with metformin 293 mg·kg·d, by gavage, from gestational day (GD) 0 to GD 21 (METG) or GD 0 until postnatal day 21 (METGL). Control dams received water by gavage in the same periods (CTRG and CTRGL). In male offsprings (75 days), the aortic reactivity to phenylephrine, acetylcholine, and sodium nitroprusside in the presence or absence of endothelium were evaluated. The results demonstrated that aortic contraction and relaxation were similar between groups. These data showed that metformin exposure during pregnancy and lactation did not interfere with aortic reactivity, suggesting that metformin exposure during gestational and lactation are safe for the offsprings' vascular system.

Protective effects of melatonin on the activity of SOD, CAT, GSH-Px and GSH content in organs of mice after administration of SNP.

Sodium nitroprusside (SNP) is an antihypertensive drug with proven dose-dependent toxic effects attributed mainly to the production of cyanide but also excesive nitric oxide (NO) and derived reactive species. The present study evaluated whether melatonin administration would have time-dependent protective effect against SNP−induced toxicity. Male Swiss mice were used in this study. Control mice were treated with 0.9% NaCl; the second group was injected with 10 mg melatonin (MEL)/kg body weight (b.w.); the third group was given SNP at the dose of 3,6 mg/kg b.w.; the fourth group received both MEL and SNP at the same doses. In homogenates of brain, liver and kidneys, activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were estimated after 3, 6 and 24 h of drugs administration. The concentration of reduced glutathione (GSH) was also evaluated in the blood, brain, liver and kidneys of mice at the same time intervals. In animals receiving MEL, the highest levels of GSH were observed in all the organs as compared to the control after 3, 6 h. Meanwhile, SNP decreased GSH concentration in the blood, brain, liver and kidneys in all time intervals. Administration of MEL in combination with SNP increased the GSH levels in all organs, as compared to the administration of SNP alone; this effect was observed after 3, 6 and 24 h. The activity of SOD, CAT and GSH-Px in the MEL-treated group increased after 3 h in all the organs, while in liver and kidney the increase was also observed after 6 h. Conversely, the SNP intoxication caused a decrease of the activity of enzymes in the tested organs in all intervals, while administration of MEL + SNP resulted in increased activities of SOD, CAT and GSH-Px in all the organs after 3 h and 6 h. The investigation carried out in the present study provide new data to add to the study of antioxidant properties of MEL and SNP-induced oxidative stress with regard to time-dependent properties in different types of tissues.

Efficacy and safety of intracoronary verapamil versus sodium nitroprusside for the prevention of microvascular obstruction during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction.

OBJECTIVE: The aim of this study was to compare the role of intracoronary (IC) verapamil versus sodium nitroprusside (SNP) in the prevention of microvascular obstruction (MVO) during a primary percutaneous coronary intervention (pPCI). BACKGROUND: A head-to-head comparison between verapamil and SNP in the prevention of MVO lacks evidence. PATIENTS AND METHODS: Sixty patients with ST-segment elevation myocardial infarction were randomized to receive IC verapamil (n=30) versus SNP (n=30) during pPCI. The primary outcome was the incidence of angiographic MVO as defined by Thrombolysis In Myocardial Infarction flow less than 3 or Thrombolysis In Myocardial Infarction flow 3 with myocardial blush grade less than 2. The secondary outcomes were the percentage of ST-segment resolution on 12-lead ECG, left ventricular ejection fraction and wall motion score index by two-dimensional echocardiography at 3-5 days after pPCI, as well as major adverse cardiovascular events at 30 days. Safety outcomes were the incidence of hypotension and/or bradycardia during pPCI. RESULTS: Verapamil was associated with lower incidence of angiographic MVO compared with SNP (13.3 vs. 40%, respectively; P=0.02), as well as superior ST-segment resolution greater than or equal to 70% (33.3 vs. 6.7%, respectively; P=0.01). There was a trend towards improved left ventricular ejection fraction with verapamil (42.6±4.9 vs. 40.4±4.7%, respectively; P=0.09), but with similar wall motion score index (1.43±0.1 vs. 1.45±0.2, respectively; P=0.14). Both groups had similar 30-day major adverse cardiovascular events (3.3 vs. 6.7%, respectively; P=0.55). Verapamil was associated with lower incidence of hypotension compared with SNP (3.3 vs. 20%, respectively; P=0.04). CONCLUSION: In pPCI, IC verapamil results in significant improvements in MVO with a better safety profile compared with SNP. Larger trials should be conducted to confirm these results.

Thiocyanate Accumulation in Critically Ill Patients Receiving Nitroprusside Infusions.

PURPOSE: This study evaluated thiocyanate concentrations and factors associated with thiocyanate accumulation in intensive care unit patients receiving nitroprusside with and without sodium thiosulfate coadministration. MATERIALS AND METHODS: This retrospective study evaluated critically ill adults who received nitroprusside infusions and had at least one thiocyanate concentration. Patients with thiocyanate accumulation (concentrations ≥30 µg/mL) were compared to patients without accumulation. Factors associated with accumulation were determined by Spearman correlation and multivariate regression. RESULTS: Thiocyanate concentrations (n = 192) were obtained from 87 patients. Fourteen of the 87 (16%) patients experienced thiocyanate accumulation with a mean (SD) thiocyanate concentration of 44 ± 11 µg/mL. Patients with accumulation had received greater cumulative nitroprusside doses (28 vs 8.2 mg/kg, P < .01), greater cumulative sodium thiosulfate doses (16.8 vs 10.1 mg/kg, P < .01), and longer infusion durations (10.9 vs 6.0 days, P < .01), compared to patients without accumulation. Sodium thiosulfate coadministration resulted in greater thiocyanate concentrations (22.8 ± 16.7 vs 16.8 ± 14.9 µg/mL, P = .01), despite utilization of lower cumulative nitroprusside doses (10.2 vs 14.6 mg/kg, P = .03). Cumulative nitroprusside dose ( r2 .44, P < .001) and cumulative sodium thiosulfate dose ( r2 .32, P < .001) demonstrated a significant correlation with measured thiocyanate concentrations. Thiocyanate accumulation was independently associated with cumulative nitroprusside dose in mg/kg (regression coefficient 0.75, 95% CI 0.63-0.89; P < .01). No clinically significant adverse effects of cyanide or thiocyanate toxicity were observed. CONCLUSIONS: Cumulative nitroprusside dose was independently associated with thiocyanate accumulation. Despite elevated thiocyanate levels in 16% of patients, there was no clinical evidence of cyanide or thiocyanate toxicity. Routine monitoring of thiocyanate concentrations appears most warranted in patients receiving higher cumulative doses of nitroprusside.