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Lesión Renal Aguda , Procedimientos Quirúrgicos Cardíacos , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Humanos , Rosuvastatina Cálcica/efectos adversos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Lesión Renal Aguda/inducido químicamenteRESUMEN
BACKGROUND: Among patients having noncardiac surgery, perioperative hemodynamic abnormalities are associated with vascular complications. Uncertainty remains about what intraoperative blood pressure to target and how to manage long-term antihypertensive medications perioperatively. OBJECTIVE: To compare the effects of a hypotension-avoidance and a hypertension-avoidance strategy on major vascular complications after noncardiac surgery. DESIGN: Partial factorial randomized trial of 2 perioperative blood pressure management strategies (reported here) and tranexamic acid versus placebo. (ClinicalTrials.gov: NCT03505723). SETTING: 110 hospitals in 22 countries. PATIENTS: 7490 patients having noncardiac surgery who were at risk for vascular complications and were receiving 1 or more long-term antihypertensive medications. INTERVENTION: In the hypotension-avoidance strategy group, the intraoperative mean arterial pressure target was 80 mm Hg or greater; before and for 2 days after surgery, renin-angiotensin-aldosterone system inhibitors were withheld and the other long-term antihypertensive medications were administered only for systolic blood pressures 130 mm Hg or greater, following an algorithm. In the hypertension-avoidance strategy group, the intraoperative mean arterial pressure target was 60 mm Hg or greater; all antihypertensive medications were continued before and after surgery. MEASUREMENTS: The primary outcome was a composite of vascular death and nonfatal myocardial injury after noncardiac surgery, stroke, and cardiac arrest at 30 days. Outcome adjudicators were masked to treatment assignment. RESULTS: The primary outcome occurred in 520 of 3742 patients (13.9%) in the hypotension-avoidance group and in 524 of 3748 patients (14.0%) in the hypertension-avoidance group (hazard ratio, 0.99 [95% CI, 0.88 to 1.12]; P = 0.92). Results were consistent for patients who used 1 or more than 1 antihypertensive medication in the long term. LIMITATION: Adherence to the assigned strategies was suboptimal; however, results were consistent across different adherence levels. CONCLUSION: In patients having noncardiac surgery, our hypotension-avoidance and hypertension-avoidance strategies resulted in a similar incidence of major vascular complications. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research, National Health and Medical Research Council (Australia), and Research Grant Council of Hong Kong.
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Hipertensión , Hipotensión , Humanos , Antihipertensivos/uso terapéutico , Complicaciones Posoperatorias/epidemiología , Canadá , Hipotensión/etiología , Hipotensión/prevención & control , Hipertensión/tratamiento farmacológicoRESUMEN
BACKGROUND: For patients undergoing noncardiac surgery, bleeding and hypotension are frequent and associated with increased mortality and cardiovascular complications. Tranexamic acid (TXA) is an antifibrinolytic agent with the potential to reduce surgical bleeding; however, there is uncertainty about its efficacy and safety in noncardiac surgery. Although usual perioperative care is commonly consistent with a hypertension-avoidance strategy (i.e., most patients continue their antihypertensive medications throughout the perioperative period and intraoperative mean arterial pressures of 60 mmHg are commonly accepted), a hypotension-avoidance strategy may improve perioperative outcomes. METHODS: The PeriOperative Ischemic Evaluation (POISE)-3 Trial is a large international randomized controlled trial designed to determine if TXA is superior to placebo for the composite outcome of life-threatening, major, and critical organ bleeding, and non-inferior to placebo for the occurrence of major arterial and venous thrombotic events, at 30 days after randomization. Using a partial factorial design, POISE-3 will additionally determine the effect of a hypotension-avoidance strategy versus a hypertension-avoidance strategy on the risk of major cardiovascular events, at 30 days after randomization. The target sample size is 10,000 participants. Patients ≥45 years of age undergoing noncardiac surgery, with or at risk of cardiovascular and bleeding complications, are randomized to receive a TXA 1 g intravenous bolus or matching placebo at the start and at the end of surgery. Patients, health care providers, data collectors, outcome adjudicators, and investigators are blinded to the treatment allocation. Patients on ≥ 1 chronic antihypertensive medication are also randomized to either of the two blood pressure management strategies, which differ in the management of patient antihypertensive medications on the morning of surgery and on the first 2 days after surgery, and in the target mean arterial pressure during surgery. Outcome adjudicators are blinded to the blood pressure treatment allocation. Patients are followed up at 30 days and 1 year after randomization. DISCUSSION: Bleeding and hypotension in noncardiac surgery are common and have a substantial impact on patient prognosis. The POISE-3 trial will evaluate two interventions to determine their impact on bleeding, cardiovascular complications, and mortality. TRIAL REGISTRATION: ClinicalTrials.gov NCT03505723. Registered on 23 April 2018.
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Antifibrinolíticos , Hipotensión , Ácido Tranexámico , Antifibrinolíticos/efectos adversos , Pérdida de Sangre Quirúrgica/prevención & control , Humanos , Hipotensión/inducido químicamente , Hipotensión/diagnóstico , Hipotensión/prevención & control , Atención Perioperativa , Ácido Tranexámico/efectos adversosRESUMEN
BACKGROUND: Most patients who take antihypertensive medications continue taking them on the morning of surgery and during the perioperative period. However, growing evidence suggests this practice may contribute to perioperative hypotension and a higher risk of complications. This protocol describes an acute kidney injury substudy of the Perioperative Ischemic Evaluation-3 (POISE-3) trial, which is testing the effect of a perioperative hypotension-avoidance strategy versus a hypertension-avoidance strategy in patients undergoing noncardiac surgery. OBJECTIVE: To conduct a substudy of POISE-3 to determine whether a perioperative hypotension-avoidance strategy reduces the risk of acute kidney injury compared with a hypertension-avoidance strategy. DESIGN: Randomized clinical trial with 1:1 randomization to the intervention (a perioperative hypotension-avoidance strategy) or control (a hypertension-avoidance strategy). INTERVENTION: If the presurgery systolic blood pressure (SBP) is <130 mmHg, all antihypertensive medications are withheld on the morning of surgery. If the SBP is ≥130 mmHg, some medications (but not angiotensin receptor blockers [ACEIs], angiotensin receptor blockers [ARBs], or renin inhibitors) may be continued in a stepwise manner. During surgery, the patients' mean arterial pressure (MAP) is maintained at ≥80 mmHg. During the first 48 hours after surgery, some antihypertensive medications (but not ACEIs, ARBs, or renin inhibitors) may be restarted in a stepwise manner if the SBP is ≥130 mmHg. CONTROL: Patients receive their usual antihypertensive medications before and after surgery. The patients' MAP is maintained at ≥60 mmHg from anesthetic induction until the end of surgery. SETTING: Recruitment from 108 centers in 22 countries from 2018 to 2021. PATIENTS: Patients (~6800) aged ≥45 years having noncardiac surgery who have or are at risk of atherosclerotic disease and who routinely take antihypertensive medications. MEASUREMENTS: The primary outcome of the substudy is postoperative acute kidney injury, defined as an increase in serum creatinine concentration of either ≥26.5 µmol/L (≥0.3 mg/dL) within 48 hours of randomization or ≥50% within 7 days of randomization. METHODS: The primary analysis (intention-to-treat) will examine the relative risk and 95% confidence interval of acute kidney injury in the intervention versus control group. We will repeat the primary analysis using alternative definitions of acute kidney injury and examine effect modification by preexisting chronic kidney disease, defined as a prerandomization estimated glomerular filtration rate <60 mL/min/1.73 m2. RESULTS: Substudy results will be analyzed in 2022. LIMITATIONS: It is not possible to mask patients or providers to the intervention; however, objective measures will be used to assess acute kidney injury. CONCLUSIONS: This substudy will provide generalizable estimates of the effect of a perioperative hypotension-avoidance strategy on the risk of acute kidney injury.
CONTEXTE: La plupart des patients qui prennent des médicaments antihypertenseurs continuent de les prendre le matin d'une intervention chirurgicale et pendant la période périopératoire. De plus en plus de preuves suggèrent que cette pratique pourrait entraîner l'hypotension périopératoire et augmenter le risque de complications. Ce protocole décrit une sous-étude sur l'insuffisance rénale aiguë (IRA) découlant de l'essai Perioperative Ischemic Evaluation-3 (POISE-3). Cet essai teste l'effet d'une stratégie d'évitement de l'hypotension périopératoire par rapport à une stratégie d'évitement de l'hypertension chez des patients qui subissent une chirurgie non cardiaque. OBJECTIFS: Cette sous-étude de l'essai POISE-3 vise à déterminer si une stratégie d'évitement de l'hypotension périopératoire réduit le risque d'IRA comparativement à la stratégie d'évitement de l'hypertension. TYPE D'ÉTUDE: Essai clinique randomisé à répartition 1:1 au groupe intervention (stratégie d'évitement de l'hypotension périopératoire) ou au groupe témoin (stratégie d'évitement de l'hypertension). GROUPE INTERVENTION: Si la pression artérielle systolique (PAS) avant l'opération est <130 mmHg, tous les médicaments antihypertenseurs sont suspendus le matin de la chirurgie. Si la PAS est ≥130 mmHg, certains médicaments (excluant les inhibiteurs de l'enzyme de conversion de l'angiotensine [IECA], les antagonistes du récepteur de l'angiotensine [ARA] ou les inhibiteurs de la rénine) peuvent être poursuivis de façon graduelle. Pendant la chirurgie, la pression artérielle moyenne (PAM) du patient est maintenue à ≥80 mmHg. Dans les 48 heures suivant l'intervention chirurgicale, certains médicaments antihypertenseurs (excluant les IECA, les ARA ou les inhibiteurs de la rénine) peuvent être réintroduits par étapes si la PAS est ≥130 mmHg. GROUPE TÉMOIN: Les patients reçoivent leurs médicaments antihypertenseurs habituels avant et après la chirurgie. La PAM du patient est maintenue à ≥60 mmHg de l'induction de l'anesthésie à la fin de l'intervention chirurgicale. CADRE: Recrutement à partir de 108 centres dans 22 pays entre 2018 à 2021. SUJETS: Des patients (~6 800) âgés de 45 ans et plus atteints d'athérosclérose, ou présentant un risque de l'être, devant subir une chirurgie non cardiaque et prenant des médicaments antihypertenseurs sur une base régulière. MESURES: Le principal critère d'évaluation de cette sous-étude est une IRA postopératoire définie par une hausse d'au moins 26,5 µmol/L (≥0,3 mg/dL) de la créatinine sérique dans les 48 heures suivant la randomisation ou d'au moins 50 % dans les 7 jours suivant la randomisation. MÉTHODOLOGIE: L'analyse primaire (par intention de traiter) examinera le risque relatif d'une IRA et l'intervalle de confiance à 95 % dans le groupe intervention par rapport au groupe témoin. Nous répéterons l'analyse primaire en utilisant d'autres définitions de l'IRA et nous examinerons la modification de l'effet en présence d'une insuffisance rénale préexistante (définie par un DFGe prérandomisation <60 ml/min/1,73 m2). RÉSULTATS: Les résultats de cette sous-étude seront analysés en 2022. LIMITES: Il n'est pas possible de procéder à l'insu des patients ou des prestataires de soins pour cette intervention; des mesures objectives seront toutefois utilisées pour évaluer l'IRA. CONCLUSION: Cette sous-étude fournira des estimations généralisables de l'effet d'une stratégie visant à éviter l'hypotension périopératoire sur le risque d'insuffisance rénale aiguë.
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AIMS: Systemic inflammation and increased activity of atrial NOX2-containing NADPH oxidases have been associated with the new onset of atrial fibrillation (AF) after cardiac surgery. In addition to lowering LDL-cholesterol, statins exert rapid anti-inflammatory and antioxidant effects, the clinical significance of which remains controversial. METHODS AND RESULTS: We first assessed the impact of cardiac surgery and cardiopulmonary bypass (CPB) on atrial nitroso-redox balance by measuring NO synthase (NOS) and GTP cyclohydrolase-1 (GCH-1) activity, biopterin content, and superoxide production in paired samples of the right atrial appendage obtained before (PRE) and after CPB and reperfusion (POST) in 116 patients. The effect of perioperative treatment with atorvastatin (80 mg once daily) on these parameters, blood biomarkers, and the post-operative atrial effective refractory period (AERP) was then evaluated in a randomized, double-blind, placebo-controlled study in 80 patients undergoing cardiac surgery on CPB. CPB and reperfusion led to a significant increase in atrial superoxide production (74% CI 71-76%, n = 46 paired samples, P < 0.0001) and a reduction in atrial tetrahydrobiopterin (BH4) (34% CI 33-35%, n = 36 paired samples, P < 0.01), and in GCH-1 (56% CI 55-58%, n = 26 paired samples, P < 0.001) and NOS activity (58% CI 52-67%, n = 20 paired samples, P < 0.001). Perioperative atorvastatin treatment prevented the effect of CPB and reperfusion on all parameters but had no significant effect on the postoperative right AERP, troponin release, or NT-proBNP after cardiac surgery. CONCLUSION: Perioperative statin therapy prevents post-reperfusion atrial nitroso-redox imbalance in patients undergoing on-pump cardiac surgery but has no significant impact on postoperative atrial refractoriness, perioperative myocardial injury, or markers of postoperative LV function. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT01780740.
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Atorvastatina/uso terapéutico , Fibrilación Atrial/prevención & control , Función del Atrio Derecho/efectos de los fármacos , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Puente Cardiopulmonar/efectos adversos , Atrios Cardíacos/efectos de los fármacos , Compuestos Nitrosos/metabolismo , Periodo Refractario Electrofisiológico/efectos de los fármacos , Potenciales de Acción/efectos de los fármacos , Atorvastatina/efectos adversos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/metabolismo , Fibrilación Atrial/fisiopatología , Biopterinas/análogos & derivados , Biopterinas/metabolismo , Método Doble Ciego , Inglaterra , Atrios Cardíacos/metabolismo , Atrios Cardíacos/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , NADPH Oxidasas/metabolismo , Óxido Nítrico Sintasa/metabolismo , Oxidación-Reducción , Superóxidos/metabolismo , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Kinase oxidation is a critical signaling mechanism through which changes in the intracellular redox state alter cardiac function. In the myocardium, PKARIα (type-1 protein kinase A) can be reversibly oxidized, forming interprotein disulfide bonds in the holoenzyme complex. However, the effect of PKARIα disulfide formation on downstream signaling in the heart, particularly under states of oxidative stress such as ischemia and reperfusion (I/R), remains unexplored. METHODS: Atrial tissue obtained from patients before and after cardiopulmonary bypass and reperfusion and left ventricular (LV) tissue from mice subjected to I/R or sham surgery were used to assess PKARIα disulfide formation by immunoblot. To determine the effect of disulfide formation on PKARIα catalytic activity and subcellular localization, live-cell fluorescence imaging and stimulated emission depletion super-resolution microscopy were performed in prkar1 knock-out mouse embryonic fibroblasts, neonatal myocytes, or adult LV myocytes isolated from "redox dead" (Cys17Ser) PKARIα knock-in mice and their wild-type littermates. Comparison of intracellular calcium dynamics between genotypes was assessed in fura2-loaded LV myocytes, whereas I/R-injury was assessed ex vivo. RESULTS: In both humans and mice, myocardial PKARIα disulfide formation was found to be significantly increased (2-fold in humans, P=0.023; 2.4-fold in mice, P<0.001) in response to I/R in vivo. In mouse LV cardiomyocytes, disulfide-containing PKARIα was not found to impact catalytic activity, but instead led to enhanced AKAP (A-kinase anchoring protein) binding with preferential localization of the holoenzyme to the lysosome. Redox-dependent regulation of lysosomal two-pore channels by PKARIα was sufficient to prevent global calcium release from the sarcoplasmic reticulum in LV myocytes, without affecting intrinsic ryanodine receptor leak or phosphorylation. Absence of I/R-induced PKARIα disulfide formation in "redox dead" knock-in mouse hearts resulted in larger infarcts (2-fold, P<0.001) and a concomitant reduction in LV contractile recovery (1.6-fold, P<0.001), which was prevented by administering the lysosomal two-pore channel inhibitor Ned-19 at the time of reperfusion. CONCLUSIONS: Disulfide modification targets PKARIα to the lysosome, where it acts as a gatekeeper for two-pore channel-mediated triggering of global calcium release. In the postischemic heart, this regulatory mechanism is critical for protection from extensive injury and offers a novel target for the design of cardioprotective therapeutics.
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Calcio/metabolismo , Subunidad RIalfa de la Proteína Quinasa Dependiente de AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Daño por Reperfusión Miocárdica/terapia , Animales , Humanos , Ratones , Oxidación-ReducciónRESUMEN
BACKGROUND: Complications after cardiac surgery are common and lead to substantial increases in morbidity and mortality. Meta-analyses of small randomized trials have suggested that perioperative statin therapy can prevent some of these complications. METHODS: We randomly assigned 1922 patients in sinus rhythm who were scheduled for elective cardiac surgery to receive perioperative rosuvastatin (at a dose of 20 mg daily) or placebo. The primary outcomes were postoperative atrial fibrillation within 5 days after surgery, as assessed by Holter electrocardiographic monitoring, and myocardial injury within 120 hours after surgery, as assessed by serial measurements of the cardiac troponin I concentration. Secondary outcomes included major in-hospital adverse events, duration of stay in the hospital and intensive care unit, left ventricular and renal function, and blood biomarkers. RESULTS: The concentrations of low-density lipoprotein cholesterol and C-reactive protein after surgery were lower in patients assigned to rosuvastatin than in those assigned to placebo (P<0.001). However, the rate of postoperative atrial fibrillation did not differ significantly between the rosuvastatin group and the placebo group (21.1% and 20.5%, respectively; odds ratio 1.04; 95% confidence interval [CI], 0.84 to 1.30; P=0.72), nor did the area under the troponin I-release curve (102 ng×hour per milliliter and 100 ng×hour per milliliter, respectively; between-group difference, 1%; 95% CI, -9 to 13; P=0.80). Subgroup analyses did not indicate benefit in any category of patient. Rosuvastatin therapy did not result in beneficial effects on any of the secondary outcomes but was associated with a significant absolute (±SE) excess of 5.4±1.9 percentage points in the rate of postoperative acute kidney injury (P=0.005). CONCLUSIONS: In this trial, perioperative statin therapy did not prevent postoperative atrial fibrillation or perioperative myocardial damage in patients undergoing elective cardiac surgery. Acute kidney injury was more common with rosuvastatin. (Funded by the British Heart Foundation and others; STICS ClinicalTrials.gov number, NCT01573143.).
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Fibrilación Atrial/prevención & control , Procedimientos Quirúrgicos Cardíacos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Complicaciones Posoperatorias/prevención & control , Rosuvastatina Cálcica/uso terapéutico , Lesión Renal Aguda/inducido químicamente , Anciano , Proteína C-Reactiva/análisis , LDL-Colesterol/sangre , Procedimientos Quirúrgicos Electivos , Femenino , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Masculino , Persona de Mediana Edad , Atención Perioperativa , Rosuvastatina Cálcica/efectos adversos , Troponina I/sangreRESUMEN
Atrial fibrillation (AF) is a growing public health burden, and its treatment remains a challenge. AF leads to electrical remodeling of the atria, which in turn promotes AF maintenance and resistance to treatment. Although remodeling has long been a therapeutic target in AF, its causes remain poorly understood. We show that atrial-specific up-regulation of microRNA-31 (miR-31) in goat and human AF depletes neuronal nitric oxide synthase (nNOS) by accelerating mRNA decay and alters nNOS subcellular localization by repressing dystrophin translation. By shortening action potential duration and abolishing rate-dependent adaptation of the action potential duration, miR-31 overexpression and/or disruption of nNOS signaling recapitulates features of AF-induced remodeling and significantly increases AF inducibility in mice in vivo. By contrast, silencing miR-31 in atrial myocytes from patients with AF restores dystrophin and nNOS and normalizes action potential duration and its rate dependency. These findings identify atrial-specific up-regulation of miR-31 in human AF as a key mechanism causing atrial dystrophin and nNOS depletion, which in turn contributes to the atrial phenotype begetting this arrhythmia. miR-31 may therefore represent a potential therapeutic target in AF.
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Arritmias Cardíacas/metabolismo , Fibrilación Atrial/metabolismo , Distrofina/metabolismo , Atrios Cardíacos/metabolismo , MicroARNs/metabolismo , Óxido Nítrico Sintasa de Tipo I/metabolismo , Potenciales de Acción/genética , Potenciales de Acción/fisiología , Animales , Regulación de la Expresión Génica , Cabras , Humanos , Ratones , MicroARNs/genética , Miocitos Cardíacos/metabolismo , Regulación hacia ArribaRESUMEN
BACKGROUND: The mechanism responsible for left ventricular dysfunction after cardiac surgery is only partly understood. In isolated rat hearts subjected to an ischaemia-reperfusion protocol, left ventricular dysfunction was associated with uncoupling of endothelial nitric oxide synthase (NOS) activity secondary to oxidation of the NOS cofactor, tetrahydrobiopterin (BH4). Here we investigated the effect of cardiopulmonary bypass and reperfusion on myocardial nitroso-redox balance in patients undergoing cardiac surgery. METHODS: From 116 patients who underwent elective cardiac surgery on cardiopulmonary bypass, paired samples of the right atrial appendages were obtained before venous cannulation of the right atrium and after myocardial reperfusion. Superoxide production from atrial samples was measured by lucigenin (5 µmol/L) enhanced chemiluminescence and 2-hydroxyethidium (2-OHE) detection by high-performance liquid chromatography (HPLC). BH4, oxidised biopterins, GTP-cyclohydrolase 1 (GTPCH-1, the rate-limiting enzyme in BH4 synthesis), and NOS activity ((14)C L-arginine to L-citrulline conversion) were measured by HPLC. FINDINGS: Atrial superoxide production increased significantly after reperfusion (from mean 37·83 relative light units per s per mg [SE 3·71] before cannulation to 65·02 [6·01] after reperfusion, p<0·0001; n=46 samples from 23 patients) due to increased mitochondrial and NOX2 oxidase activity (by 309% and 149%; p=0·002 and p=0·0002, respectively) and uncoupling of NOS activity. Atrial content of BH4 after perfusion was reduced (by 32%, p=0·001), as was activity of GTPCH1 (50%, p<0·0001). NOS activity decreased significantly after reperfusion (60%, p=0·0005) and this reduction was not affected by BH4 supplementation (10 µM) or NOX2 inhibition ex vivo. Instead, we identified increased endothelial NOS s-glutathionylation as the main mechanism for NOS uncoupling after reperfusion. Reversing NOS s-glutathionylation with dithiothreitol (100 µmol/L) completely restored NOS activity after reperfusion (p=0·34). INTERPRETATION: Our findings suggest that NOS s-glutathionylation, rather than BH4 depletion, accounts for NOS dysfunction in patients after cardiac surgery and cardiopulmonary bypass. FUNDING: British Heart Foundation.
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There are significant variations in critical care practices, costs, and reimbursements in various countries. Of note, there is a paucity of reliable information on remuneration and reimbursement models for intensivists in India. This review article aims to analyze the existing reimbursement models in United States and United Kingdom and propose a frame-work model that may be applicable in India.
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Myocardial constitutive No production depends on the activity of both endothelial and neuronal NOS (eNOS and nNOS, respectively). Stimulation of myocardial ß(3)-adrenergic receptor (ß(3)-AR) produces a negative inotropic effect that is dependent on eNOS. We evaluated whether nNOS also plays a role in ß(3)-AR signaling and found that the ß(3)-AR-mediated reduction in cell shortening and [Ca(2+)](i) transient amplitude was abolished both in eNOS(-/-) and nNOS(-/-) left ventricular (LV) myocytes and in wild type LV myocytes after nNOS inhibition with S-methyl-L-thiocitrulline. LV superoxide (O(2)(·-)) production was increased in nNOS(-/-) mice and reduced by L-N(ω)-nitroarginine methyl ester (L-NAME), indicating uncoupling of eNOS activity. eNOS S-glutathionylation and Ser-1177 phosphorylation were significantly increased in nNOS(-/-) myocytes, whereas myocardial tetrahydrobiopterin, eNOS Thr-495 phosphorylation, and arginase activity did not differ between genotypes. Although inhibitors of xanthine oxidoreductase (XOR) or NOX2 NADPH oxidase caused a similar reduction in myocardial O(2)(·-), only XOR inhibition reduced eNOS S-glutathionylation and Ser-1177 phosphorylation and restored both eNOS coupled activity and the negative inotropic and [Ca(2+)](i) transient response to ß(3)-AR stimulation in nNOS(-/-) mice. In summary, our data show that increased O(2)(·-) production by XOR selectively uncouples eNOS activity and abolishes the negative inotropic effect of ß(3)-AR stimulation in nNOS(-/-) myocytes. These findings provide unequivocal evidence of a functional interaction between the myocardial constitutive NOS isoforms and indicate that aspects of the myocardial phenotype of nNOS(-/-) mice result from disruption of eNOS signaling.
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Señalización del Calcio/fisiología , Proteínas Musculares/metabolismo , Miocardio/enzimología , Miocitos Cardíacos/enzimología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Óxido Nítrico Sintasa de Tipo I/metabolismo , Animales , Arginasa/genética , Arginasa/metabolismo , Señalización del Calcio/efectos de los fármacos , Citrulina/análogos & derivados , Citrulina/farmacología , Inhibidores Enzimáticos/farmacología , Ventrículos Cardíacos/citología , Ventrículos Cardíacos/enzimología , Isoenzimas/antagonistas & inhibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Noqueados , Proteínas Musculares/antagonistas & inhibidores , Proteínas Musculares/genética , Miocardio/citología , Miocitos Cardíacos/citología , NADPH Oxidasa 2 , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa de Tipo I/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo I/genética , Óxido Nítrico Sintasa de Tipo III/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo III/genética , Fosforilación/efectos de los fármacos , Fosforilación/fisiología , Receptores Adrenérgicos beta 3/genética , Receptores Adrenérgicos beta 3/inmunología , Superóxidos/metabolismo , Tiourea/análogos & derivados , Tiourea/farmacología , Xantina Deshidrogenasa/genética , Xantina Deshidrogenasa/metabolismoRESUMEN
OBJECTIVES: The purpose of this study was to evaluate the role of the myocardial redox state in the development of in-hospital complications after cardiac surgery and the effect of statins on the myocardial redox state. BACKGROUND: Statins improve clinical outcome after cardiac surgery, but it is unclear whether they exert their effects by modifying the myocardial redox state. METHODS: We quantified myocardial superoxide anion (O(2)(-)) and peroxynitrite (ONOO(-)) and their enzymatic sources in samples of the right atrial appendage (RAA) from 303 patients undergoing cardiac surgery who were followed up until discharge, and in 42 patients who were randomized to receive 3-day treatment with atorvastatin 40 mg/d or placebo before surgery. The mechanisms by which atorvastatin modifies myocardial redox state were investigated in 26 RAA samples that were exposed to atorvastatin ex vivo. RESULTS: Atrial O(2)(-) (derived mainly from nicotinamide adenine dinucleotide phosphate [NADPH] oxidases) and ONOO(-) were independently associated with increased risk of atrial fibrillation, the need for post-operative inotropic support, and the length of hospital stay. Pre-operative atorvastatin treatment suppressed atrial NADPH oxidase activity and myocardial O(2)(-) and ONOO(-) production. Ex vivo incubation of RAA samples with atorvastatin induced a mevalonate-reversible and Rac1-mediated inhibition of NADPH oxidase. CONCLUSIONS: There is a strong independent association between myocardial O(2)(-)/ONOO(-) and in-hospital complications after cardiac surgery. Both myocardial O(2)(-) and ONOO(-) are reduced by pre-operative statin treatment, through a Rac1-mediated suppression of NADPH oxidase activity. These findings suggest that inhibition of myocardial NADPH oxidases may contribute to the beneficial effect of statins in patients undergoing cardiac surgery. (Effects of Atorvastatin on Endothelial Function, Vascular and Myocardial Redox State in High Cardiovascular Risk Patients; NCT01013103).
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Procedimientos Quirúrgicos Cardíacos/métodos , Ácidos Heptanoicos/administración & dosificación , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Oxidación-Reducción/efectos de los fármacos , Pirroles/administración & dosificación , Anciano , Atorvastatina , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/mortalidad , Intervalos de Confianza , Puente de Arteria Coronaria/efectos adversos , Puente de Arteria Coronaria/métodos , Puente de Arteria Coronaria/mortalidad , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Estudios de Seguimiento , Mortalidad Hospitalaria/tendencias , Humanos , Estimación de Kaplan-Meier , Peroxidación de Lípido/efectos de los fármacos , Masculino , Persona de Mediana Edad , Miocardio/metabolismo , Complicaciones Posoperatorias/prevención & control , Valor Predictivo de las Pruebas , Cuidados Preoperatorios/métodos , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: An altered nitric oxide-redox balance has been implicated in the pathogenesis of atrial fibrillation (AF). Statins inhibit NOX2-NADPH oxidases and prevent postoperative AF but are less effective in AF secondary prevention; the mechanisms underlying these findings are poorly understood. METHODS AND RESULTS: By using goat models of pacing-induced AF or of atrial structural remodeling secondary to atrioventricular block and right atrial samples from 130 patients undergoing cardiac surgery, we found that the mechanisms responsible for the NO-redox imbalance differ between atria and with the duration and substrate of AF. Rac1 and NADPH oxidase activity and the protein level of NOX2 and p22phox were significantly increased in the left atrium of goats after 2 weeks of AF and in patients who developed postoperative AF in the absence of differences in leukocytes infiltration. Conversely, in the presence of longstanding AF or atrioventricular block, uncoupled nitric oxide synthase activity (secondary to reduced BH4 content and/or increased arginase activity) and mitochondrial oxidases accounted for the biatrial increase in reactive oxygen species. Atorvastatin caused a mevalonate-reversible inhibition of Rac1 and NOX2-NADPH oxidase activity in right atrial samples from patients who developed postoperative AF, but it did not affect reactive oxygen species, nitric oxide synthase uncoupling, or BH4 in patients with permanent AF. CONCLUSIONS: Upregulation of atrial NADPH oxidases is an early but transient event in the natural history of AF. Changes in the sources of reactive oxygen species with atrial remodeling may explain why statins are effective in the primary prevention of AF but not in its management.
Asunto(s)
Antiarrítmicos/uso terapéutico , Fibrilación Atrial/prevención & control , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Especies Reactivas de Oxígeno/metabolismo , Anciano , Anciano de 80 o más Años , Animales , Arginasa/metabolismo , Bloqueo Atrioventricular/metabolismo , Modelos Animales de Enfermedad , Femenino , Cabras , Atrios Cardíacos/efectos de los fármacos , Atrios Cardíacos/metabolismo , Humanos , Masculino , Glicoproteínas de Membrana/biosíntesis , Persona de Mediana Edad , Mitocondrias/enzimología , NADPH Oxidasa 2 , NADPH Oxidasas/biosíntesis , NADPH Oxidasas/metabolismo , Oxidorreductasas/metabolismo , Proteína de Unión al GTP rac1/metabolismoRESUMEN
A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether patients with haemophilia undergoing cardiac surgery have good surgical outcomes. Haemophilia A and haemophilia B are sex-linked recessive inherited diseases affecting males only, with females acting as carriers. The conditions result in various degrees of factor VIII or factor IX deficiency, respectively. The life expectancy of haemophilia patients is increasing and now approaches that of the general male population, and they are confronted with age-related co-morbidity, including ischaemic cardiovascular disease. Replacement of the deficient factor (VIII for haemophilia A and IX for haemophilia B) is the cornerstone of treatment; other therapeutic options include tranexamic acid, desmopressin and aprotinin. Recently, the advent of recombinant factor VIII and IX has eliminated the infective risk of using factor concentrates, such as prothrombin complex concentrate or fresh frozen plasma. A total of 84 papers were found using the reported search criteria, and out of this 25 papers, selected with reference to a more modern date range, provided the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results were tabulated. We conclude that there is lack of good-quality evidence and that, in all probability, these papers are subject to publication bias as poor outcomes are unlikely to have been reported. However, all the reported series showed that good outcomes are possible in this specific subgroup of patients given the correct approach. The data accrued from these studies (a total of 30 adults and three children) suggest that routine cardiac surgery can be performed safely in patients with haemophilia, with minimal morbidity and mortality. We identified the following key points to achieve this result: a team approach, a factor replacement protocol and perioperative monitoring of factor levels. Intraoperative plasma factor levels can be easily measured before heparin and after protamine sulphate administration, whereas during cardiopulmonary bypass this will require a chromogenic method. Exposure to factor concentrates early in the life might predispose a patient with severe haemophilia to the development of inhibitors. Moreover, the absence of inhibitors should be confirmed before any surgical procedure.
Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Cardiopatías/cirugía , Hemofilia A/complicaciones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Benchmarking , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/mortalidad , Medicina Basada en la Evidencia , Cardiopatías/complicaciones , Cardiopatías/mortalidad , Hemofilia A/mortalidad , Humanos , Lactante , Masculino , Persona de Mediana Edad , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
We describe a case of cerebral venous thrombosis presenting in a patient with Lane-Hamilton syndrome and coeliac disease epilepsy cerebral calcification syndrome. This is a first reported occurrence of this combination. Delayed anticoagulation with early external ventricular drain insertion for life-threatening raised intracranial pressure resulted in a successful outcome.
Asunto(s)
Encefalopatías Metabólicas , Calcinosis , Enfermedad Celíaca/cirugía , Hemosiderosis/complicaciones , Trombosis Intracraneal/cirugía , Enfermedades Pulmonares/complicaciones , Adulto , Enfermedad Celíaca/complicaciones , Enfermedad Celíaca/diagnóstico por imagen , Epilepsia , Femenino , Humanos , Trombosis Intracraneal/diagnóstico por imagen , Trombosis Intracraneal/etiología , Síndrome , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
BACKGROUND: Randomized controlled trials (RCTs) in surgery can provide valuable evidence of the efficacy of interventions if they are well-designed, appropriately executed, and adequately reported. Adequate reporting of methodology in surgical RCTs is known to be poor, and adverse-event reporting in surgical research is inconsistent. The Consolidated Standards of Reporting Trials (CONSORT) statement is a framework to help authors report their findings in a transparent manner. Extensions to the CONSORT statement have been published recently to address deficiencies in adverse-event reporting and in reporting of specific criteria related to nonpharmacologic treatments. The aim of this study was to assess the quality of reporting of trial methodology and adverse events in a sample of general surgical RCTs published in high-quality surgical journals using the criteria specified in the CONSORT statements. STUDY DESIGN: We used impact factor to identify the top three ranked surgical journals in 2004. We then obtained information on all RCTs published in these journals in the 2005 calendar year. We assessed quality of reporting using Jadad score, compared the quality of RCTs from CONSORT-endorsing journals with nonendorsers, and assessed the number of RCTs adequately reporting key generic methodologic, adverse-event-related, and specific nonpharmacologic criteria. RESULTS: Of 42 RCTs analyzed, only 40% (17 of 42) had a Jadad score > or = 3. There was no significant difference in the number of high-quality RCTs published in CONSORT-endorsing journals compared with nonendorsers (p = 0.3). The median percentage of RCTs adequately reporting generic methodologic, adverse-event-related, and specific nonpharmacologic criteria was 32.5%, 17%, and 36.5%, respectively. CONCLUSIONS: Quality of reporting of generic methodologic, adverse-event-related, and specific nonpharmacologic criteria in surgical RCTs is poor. Increased attention to quality of reporting of surgical RCTs is required if studies are to meet published criteria.
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Cirugía General , Factor de Impacto de la Revista , Periodismo Médico/normas , Registros Médicos/normas , Publicaciones Periódicas como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Proyectos de Investigación , Bibliometría , Humanos , MEDLINE , Publicaciones Periódicas como Asunto/normas , Proyectos de Investigación/normasRESUMEN
Critical care is often described as expensive care. However, standardized methodology that would enable determination and international comparisons of cost is currently lacking. This article attempts to review this important issue and develop a framework through which cost of critical care in India could be analyzed.