sodium-nitrite and Myocardial-Infarction

Pre-clinical evidence suggests delivery of nitric oxide (NO) through administration of inorganic nitrite suppresses arrhythmias resulting from acute ischaemia and reperfusion (I/R). To date no assessment of whether inorganic nitrite might limit reperfusion arrhythmia has occurred in man, therefore we explored the effects on I/R-induced ventricular arrhythmias in the NITRITE-AMI cohort.. In the NITRITE-AMI cohort, Holter analysis was performed prior to and for 24 h after primary PCI in 80 patients who received either intra-coronary sodium nitrite (N = 40) or placebo (N = 40) during primary PCI for AMI.. Ventricular rhythm disturbance was experienced by 100% patients; however, there was no difference in the number between the groups, p = .2196. Non-sustained ventricular tachycardia (NSVT) occurred in 67.5% (27/40) of nitrite-treated patients compared to 89% (35/39) of those treated with placebo (p = .027). There was a significant reduction in both the number of runs (63%, p ≤.0001) and total beats of NSVT (64%, p = .0019) in the nitrite-treated patients compared to placebo. Post-hoc analyses demonstrate a direct correlation of occurrence of NSVT with infarct size, with the correlation stronger in the placebo versus the nitrite group initiating an independent nitrite effect (Nitrite: r = 0.110, p = .499, placebo: r = 0.527, p = .001, p for comparison: 0.004).. Overall no difference in ventricular rhythm disturbance was seen with intra-coronary nitrite treatment during primary PCI in STEMI patients, however nitrite treatment was associated with an important reduction in the incidence and severity of NSVT. In view of the sustained reduction of MACE seen, this effect warrants further study in a large-scale trial.

Topics: Cost of Illness; Double-Blind Method; Electrocardiography, Ambulatory; Female; Humans; Infusions, Intra-Arterial; Male; Middle Aged; Myocardial Infarction; Percutaneous Coronary Intervention; Postoperative Complications; Registries; Sodium Nitrite; Treatment Outcome; Ventricular Fibrillation

Recent work suggests that intracoronary nitrite reduces myocardial infarct size following primary percutaneous coronary intervention (PPCI) for acute myocardial infarction (AMI), although the exact mechanisms are unclear. We explored the effects of nitrite on reperfusion-induced inflammation, by assessing the levels of specific pro-inflammatory mediators, chemokines and adhesion molecules in plasma and circulating cell subtypes as exploratory end points in the NITRITE-AMI cohort.. Peripheral blood leucocyte subsets, cell adhesion molecules, high-sensitivity C reactive protein (hs-CRP), the monocyte and neutrophil chemoattractants CCL2 and CXCL1, CXCL5, respectively were measured in the blood of patients who received either intracoronary sodium nitrite (N=40) or placebo (N=40) during PPCI for AMI. Major adverse cardiac events were recorded at 3 years post-PPCI.. In the placebo-treated patients, total circulating neutrophil numbers and levels of hs-CRP were raised postreperfusion and then decreased over time; in nitrite-treated patients these changes were suppressed compared with placebo up to 6 months post-PPCI (p<0.01). This effect was associated with reduced expression of neutrophil CD11b, plasma CXCL1, CXCL5 and CCL2 levels (p<0.05). There were no differences in the number of other any other leucocyte population measured (monocytes and lymphocytes) or activation markers expressed by these cells between the treatment groups. These effects were associated with a reduction in both microvascular obstruction and infarct size.. Important reductions in neutrophil numbers and activation post-PPCI in patients with ST elevated myocardial infarction were associated with nitrite treatment, an effect we propose likely underlies, at least in part, the beneficial effects of nitrite upon infarct size.. NCT01584453.

Topics: Anti-Inflammatory Agents; Biomarkers; C-Reactive Protein; Cell Adhesion Molecules; Chemokines; Double-Blind Method; Female; Humans; Inflammation Mediators; Injections, Intra-Arterial; Kaplan-Meier Estimate; Leukocyte Count; London; Male; Middle Aged; Myocardial Infarction; Neutrophil Activation; Neutrophils; Percutaneous Coronary Intervention; Sodium Nitrite; Time Factors; Treatment Outcome

Preclinical evidence demonstrates that inorganic nitrite, after its in situ conversion to nitric oxide, attenuates consequent myocardial reperfusion injury.. We investigated whether intracoronary injection of nitrite during primary percutaneous coronary intervention might improve infarct size in ST-elevated myocardial infarction.. Patients undergoing primary percutaneous coronary intervention (n=80) were randomized to receive intracoronary (10 mL) sodium nitrite (1.8 μmol) or NaCl (placebo) before balloon inflation. The primary end point was infarct size assessed by measuring creatine kinase release. Secondary outcomes included infarct size assessed by troponin T release and by cardiac MRI on day 2. Baseline characteristics were similar between the groups. No evidence of differences in creatine kinase release (P=0.92), troponin T (P=0.85), or cardiac MRI-assessed infarct size (P=0.254) were evident. In contrast, there was an improvement [corrected] in myocardial salvage index (P=0.05) and reduction in [corrected] major adverse cardiac event at 1 year (2.6% versus 15.8%; P=0.04) in the nitrite group. In a 66-patient subgroup with thrombolysis in myocardial infarction ≤1 flow, there was reduced serum creatine kinase (P=0.030) and a 19% reduction in cardiac MRI-determined infarct size (P=0.034) with nitrite. No adverse effects of nitrite were detected.. In this phase II study, intracoronary nitrite infusion did not alter infarct size, although a trend to improved myocardial salvage index and a significant reduction in major adverse cardiac event was evident. In a subgroup of patients with thrombolysis in myocardial infarction flow ≤1, nitrite reduced infarct size and major adverse cardiac event and improved myocardial salvage index, indicating that a phase III clinical trial assessing intracoronary nitrite administration as an adjunct to percutaneous coronary intervention in ST-elevated myocardial infarction patients is warranted.. http://www.clinicaltrials.gov. Unique identifier: NCT01584453.

Topics: Aged; Female; Humans; Male; Middle Aged; Myocardial Infarction; Sodium Nitrite

Despite prompt revascularization of acute myocardial infarction (AMI), substantial myocardial injury may occur, in part a consequence of ischaemia reperfusion injury (IRI). There has been considerable interest in therapies that may reduce IRI. In experimental models of AMI, sodium nitrite substantially reduces IRI. In this double-blind randomized placebo controlled parallel-group trial, we investigated the effects of sodium nitrite administered immediately prior to reperfusion in patients with acute ST-elevation myocardial infarction (STEMI).. A total of 229 patients presenting with acute STEMI were randomized to receive either an i.v. infusion of 70 μmol sodium nitrite (n = 118) or matching placebo (n = 111) over 5 min immediately before primary percutaneous intervention (PPCI). Patients underwent cardiac magnetic resonance imaging (CMR) at 6-8 days and at 6 months and serial blood sampling was performed over 72 h for the measurement of plasma creatine kinase (CK) and Troponin I. Myocardial infarct size (extent of late gadolinium enhancement at 6-8 days by CMR-the primary endpoint) did not differ between nitrite and placebo groups after adjustment for area at risk, diabetes status, and centre (effect size -0.7% 95% CI: -2.2%, +0.7%; P = 0.34). There were no significant differences in any of the secondary endpoints, including plasma troponin I and CK area under the curve, left ventricular volumes (LV), and ejection fraction (EF) measured at 6-8 days and at 6 months and final infarct size (FIS) measured at 6 months.. Sodium nitrite administered intravenously immediately prior to reperfusion in patients with acute STEMI does not reduce infarct size.

Topics: Biomarkers; Cardiotonic Agents; Double-Blind Method; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Myocardial Reperfusion Injury; Percutaneous Coronary Intervention; Sodium Nitrite; Treatment Outcome

Whilst advances in reperfusion therapies have reduced early mortality from acute myocardial infarction, heart failure remains a common complication, and may develop very early or long after the acute event. Reperfusion itself leads to further tissue damage, a process described as ischaemia-reperfusion-injury (IRI), which contributes up to 50% of the final infarct size. In experimental models nitrite administration potently protects against IRI in several organs, including the heart. In the current study we investigate whether intravenous sodium nitrite administration immediately prior to percutaneous coronary intervention (PCI) in patients with acute ST segment elevation myocardial infarction will reduce myocardial infarct size. This is a phase II, randomised, placebo-controlled, double-blinded and multicentre trial.. The aim of this trial is to determine whether a 5 minute systemic injection of sodium nitrite, administered immediately before opening of the infarct related artery, results in significant reduction of IRI in patients with first acute ST elevation myocardial infarction (MI). The primary clinical end point is the difference in infarct size between sodium nitrite and placebo groups measured using cardiovascular magnetic resonance imaging (CMR) performed at 6-8 days following the AMI and corrected for area at risk (AAR) using the endocardial surface area technique. Secondary end points include (i) plasma creatine kinase and Troponin I measured in blood samples taken pre-injection of the study medication and over the following 72 hours; (ii) infarct size at six months; (iii) Infarct size corrected for AAR measured at 6-8 days using T2 weighted triple inversion recovery (T2-W SPAIR or STIR) CMR imaging; (iv) Left ventricular (LV) ejection fraction measured by CMR at 6-8 days and six months following injection of the study medication; and (v) LV end systolic volume index at 6-8 days and six months. FUNDING, ETHICS AND REGULATORY APPROVALS: This study is funded by a grant from the UK Medical Research Council. This protocol is approved by the Scotland A Research Ethics Committee and has also received clinical trial authorisation from the Medicines and Healthcare products Regulatory Agency (MHRA) (EudraCT number: 2010-023571-26).. ClinicalTrials.gov: NCT01388504 and Current Controlled Trials: ISRCTN57596739.

Topics: Adolescent; Adult; Aged; Cardiotonic Agents; Double-Blind Method; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Infarction; Nitric Oxide; Percutaneous Coronary Intervention; Reperfusion Injury; Sodium Nitrite; United Kingdom; Young Adult

In the follow-up of patients in a trial of intracoronary sodium nitrite given during primary percutaneous coronary intervention (PCI) after acute myocardial infarction (AMI), we found a reduction in the incidence of major adverse cardiac events (MACEs). Specifically, MACE rates were 5.2% versus 25.0% with placebo at 3 years ( P = .013). Such MACE reductions should also be associated with economic benefit. Thus, we assessed the cost utility of sodium nitrite therapy versus standard primary PCI only.. We developed a model to simulate costs and quality-adjusted life years (QALYs) over the first 36 months after ST-Segment Elevation Myocardial Infarction (STEMI). Decision tree analysis was used to assess different potential cardiovascular outcomes after STEMI for patients in both treatment groups. Model inputs were derived from the NITRITE-AMI study. Cost of comparative treatments and follow-up in relation to cardiovascular events was calculated from the United Kingdom National Health Service perspective. Higher procedural costs for nitrite treatment were offset by lower costs for repeat revascularization, myocardial infarction, and hospitalization for heart failure compared to primary PCI plus placebo. Nitrite treatment was associated with higher utility values (0.91 ± 0.19 vs 0.82 ± 0.30, P = .041). The calculated incremental cost-effectiveness ratio of £2177 per QALY indicates a cost-effective strategy. Furthermore, positive results were maintained when input parameters varied, indicating the robustness of our model. In fact, based on the difference in utility values, the cost of nitrite could increase by 4-fold (£2006 per vial) and remain cost-effective.. This first analysis of sodium nitrite as a cardioprotective treatment demonstrates cost-effectiveness. Although more comparative analysis and assessment of longer follow-up times are required, our data indicate the considerable potential of nitrite-mediated cardioprotection.

Topics: Clinical Decision-Making; Cost Savings; Cost-Benefit Analysis; Drug Costs; Heart Failure; Hospital Costs; Humans; Models, Economic; Myocardial Infarction; Myocardial Reperfusion Injury; Percutaneous Coronary Intervention; Progression-Free Survival; Quality-Adjusted Life Years; Retreatment; Sodium Nitrite; ST Elevation Myocardial Infarction; State Medicine; Time Factors; United Kingdom; Vasodilator Agents

Acute myocardial infarction is the leading cause of mortality in the industrialized world. While it is essential to attempt an early reperfusion of ischemic myocardial territories, reperfusion itself adds damage to the heart, the ischemia-reperfusion (I/R) injury. Particularly the injury resulting from the very first minutes of reperfusion remains incompletely understood. MicroRNAs (miRNAs) are dynamic regulators in I/R injury. Nitric oxide (•NO) signaling, in turn, interacts with miRNA signaling. Our previous investigations showed that •NO signaling in I/R could be modulated by nitrite. We therefore sought to investigate the role of miRNAs in nitrite cardioprotection with focus on the first few minutes of reperfusion. The study was conducted in mice in vivo with 30 min of ischemia and 5 min of reperfusion. Mice received a single-dose of nitrite or saline intracardially 5 min prior to reperfusion. We identified nine miRNAs to be up-regulated after 5 min of reperfusion. The up-regulation of almost half of those miRNAs (miR-125a-5p, miR-146b, miR-339-3p, miR-433) was inhibited by nitrite treatment, perpetuating baseline values. In silico analysis revealed the Irak-M gene to be a target of miR-146b and miR-339-3p. Correspondingly, a rise in Irak-M transcript and protein levels occurred by nitrite treatment within the early phase of reperfusion. The results demonstrate that already a very short phase of reperfusion is sufficient for significant dysregulation in cardiac miRNAs expression and that nitrite preserves baseline values of miRNAs in the scale of only a few minutes. These findings hint at a potential novel cardioprotective mechanism of nitrite signaling.

Topics: Animals; Apoptosis; Gene Expression; Gene Expression Regulation; Gene Ontology; Male; Mice; MicroRNAs; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Oxidative Phosphorylation; Signal Transduction; Sodium Nitrite

Chronic heart failure (CHF) reduces nitric oxide (NO) bioavailability and impairs skeletal muscle vascular control during exercise. Reduction of NO2 (-) to NO may impact exercise-induced hyperemia, particularly in muscles with pathologically reduced O2 delivery. We tested the hypothesis that NO2 (-) infusion would increase exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats with a preferential effect in muscles composed primarily of type IIb + IId/x fibers. CHF (coronary artery ligation) was induced in adult male Sprague-Dawley rats. After a >21-day recovery, mean arterial pressure (MAP; carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% incline) with and without NO2 (-) infusion. The myocardial infarct size (35 ± 3%) indicated moderate CHF. NO2 (-) infusion increased total hindlimb skeletal muscle VC (CHF: 0.85 ± 0.09 ml·min(-1)·100 g(-1)·mmHg(-1) and CHF + NO2 (-): 0.93 ± 0.09 ml·min(-1)·100 g(-1)·mmHg(-1), P < 0.05) without changing MAP (CHF: 123 ± 4 mmHg and CHF + NO2 (-): 120 ± 4 mmHg, P = 0.17). Total hindlimb skeletal muscle BF was not significantly different (CHF: 102 ± 7 and CHF + NO2 (-): 109 ± 7 ml·min(-1)·100 g(-1) ml·min(-1)·100 g(-1), P > 0.05). BF increased in 6 (∼21%) and VC in 8 (∼29%) of the 28 individual muscles and muscle parts. Muscles and muscle portions exhibiting greater BF and VC after NO2 (-) infusion comprised ≥63% type IIb + IId/x muscle fibers. These data demonstrate that NO2 (-) infusion can augment skeletal muscle vascular control during exercise in CHF rats. Given the targeted effects shown herein, a NO2 (-)-based therapy may provide an attractive "needs-based" approach for treatment of the vascular dysfunction in CHF.

Topics: Animals; Chronic Disease; Disease Models, Animal; Exercise Tolerance; Heart Failure; Hemodynamics; Hindlimb; Infusions, Intra-Arterial; Male; Muscle Contraction; Muscle Fatigue; Muscle Fibers, Fast-Twitch; Muscle, Skeletal; Myocardial Infarction; Nitric Oxide; Physical Exertion; Rats, Sprague-Dawley; Regional Blood Flow; Sodium Nitrite; Time Factors

We evaluated the role of SH-groups in improvement of endothelial dysfunction with ACE-inhibitors in experimental heart failure. To this end, we compared the vasoprotective effect of chronic treatment with zofenopril (plus SH-group) versus lisinopril (no SH-group), or N-acetylcysteine (only SH-group) in myocardial infarcted (MI) heart failure rats. After 11 weeks of treatment, aortas were obtained and studied as ring preparations for endothelium-dependent and -independent dilatation in continuous presence of indomethacin to avoid interference of vasoactive prostanoids, and the selective presence of the NOS-inhibitor L-NMMA to determine NO-contribution. Total dilatation after receptor-dependent stimulation with acetylcholine (ACh) was attenuated (-49%, P<0.05) in untreated MI (n=11), compared to control rats with no-MI (n=8). This was in part due to impaired NO-contribution in MI (-50%, P<0.05 versus no-MI). At the same time the capacity for generation of biologically active NO after receptor-independent stimulation with A23187 remained intact. Chronic treatment with n-acetylcysteine (n=8) selectively restored NO-contribution in total dilatation to ACh. In contrast, both ACE-inhibitors fully normalized total dilatation to ACh, including the part mediated by NO (no significant differences between zofenopril (n=10) and lisinopril (n=8)). Zofenopril, but not lisinopril, additionally potentiated the effect of endogenous NO after A23187-induced release from the endothelium (+100%) as well as that of exogenous NO provided by nitroglycerin (+22%) and sodium nitrite (+36%) (for all P<0.05 versus no-MI). We conclude that ACE-inhibition with a SH-group has a potential advantage in improvement of endothelial dysfunction through increased activity of NO after release from the endothelium into the vessel wall. Furthermore, this is the first study demonstrating the selective normalizing effect of N-actylcysteine on NO-contribution to ACh-induced dilatation in experimental heart failure.

Topics: Acetylcholine; Acetylcysteine; Angiotensin-Converting Enzyme Inhibitors; Animals; Aorta, Thoracic; Blood Pressure; Body Weight; Calcimycin; Captopril; Endothelium, Vascular; Heart Diseases; In Vitro Techniques; Lisinopril; Male; Myocardial Infarction; Nitrates; Nitrites; Nitroglycerin; omega-N-Methylarginine; Rats; Rats, Wistar; Sodium Nitrite; Sulfhydryl Compounds; Vasodilation; Vasodilator Agents

The effects of superoxide dismutase (SOD) alone or in combination with acidified sodium nitrite (NaNO2), a liberator of nitric oxide were examined in dogs after ischemia and reperfusion. Animals were divided into five groups. Left anterior descending coronary artery was occluded for 90 min followed by 4 hours of reperfusion with or without therapeutic interventions given preceding reperfusion. Left ventricular end diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP) and ECG changes were monitored throughout the study. Area at risk was defined by Evans blue and area of infarction by incubation in triphenyltetrazolium. Myocardial tissue lipid peroxidation was measured in ischemic and non-ischemic zones. There was no evidence of infarction until ninety minutes of ischemia. Percentage area of necrosis vis-a-vis area at risk percentage necrosis in left vertricular mass was significantly low in animals treated with combination of SOD and NaNO2 in comparison with isolated treatment with saline, SOD or NaNO2. LVEDP increased significantly following ischemia and remained unchanged during saline reperfusion. Treatment with SOD, NaNO2 in isolation or its combination significantly lowered LVEDP. Maximum increase in tissue lipid peroxidation was observed in saline and NaNO2 treated animals. SOD alone or in combination with NaNO2 significantly lowered the lipid peroxidation. The results clearly demonstrate that reperfusion can cause necrosis in ischemic myocardium. Combined treatment with SOD and NaNO2 offers significant cardioprotection against oxidative stress.

Topics: Animals; Blood Pressure; Dogs; Drug Interactions; Heart; Male; Myocardial Infarction; Myocardium; Protective Agents; Reperfusion Injury; Sodium Nitrite; Superoxide Dismutase; Ventricular Function, Left

Unenhanced hypothermic cardioplegia does not prevent postischemic endothelial and contractile dysfunction in hearts subjected to antecedent regional or global ischemia. This study tested the hypothesis that supplementing blood cardioplegic solution and reperfusion with the nitric oxide precursor L-arginine would preserve endothelial function, reduce infarct size, and reverse postcardioplegia regional contractile dysfunction by the L-arginine-nitric oxide pathway. In 23 anesthetized dogs, the left anterior descending coronary artery was ligated for 90 minutes, after which total bypass was established for surgical "revascularization." In 10 dogs, unsupplemented multidose hypothermic blood cardioplegic solution was administered for a total of 60 minutes of cardioplegic arrest. In eight dogs, L-arginine was given intravenously (4 mg/kg per minute) and in blood cardioplegic solution (10 mmol) during arrest. In five dogs, the nitric oxide synthesis blocker N omega-nitro-L-arginine (1 mmol) was used to block the L-arginine-nitric oxide pathway during cardioplegia and reperfusion. Infarct size (triphenyltetrazolium chloride) as percent of the area at risk was significantly reduced by L-arginine compared with blood cardioplegic solution (28.2% +/- 4.1% versus 40.5% +/- 3.5%) and was reversed by N omega-nitro-L-arginine to 68.9% +/- 3.0% (p < 0.05). Postischemic regional segmental work in millimeters of mercury per millimeter (sonomicrometry) was significantly better with L-arginine (92 +/- 15) versus blood cardioplegic solution (28 +/- 3) and N omega-nitro-L-arginine (26 +/- 6). Segmental diastolic stiffness was significantly lower with L-arginine (0.46 +/- 0.06) compared with blood cardioplegic solution (1.10 +/- 0.11) and was significantly greater with N omega-nitro-L-arginine (2.70 +/- 0.43). In ischemic-reperfused left anterior descending coronary arterial vascular rings, maximum relaxation responses to acetylcholine, the stimulator of endothelial nitric oxide, was depressed in the blood cardioplegic solution group (77% +/- 4%) and was significantly reversed by L-arginine (92% +/- 3%). Smooth muscle function was unaffected in all groups. We conclude that cardioplegic solution supplemented with L-arginine reduces infarct size, preserves postischemic systolic and diastolic regional function, and prevents arterial endothelial dysfunction via the L-arginine-nitric oxide pathway.

Topics: Acetylcholine; Amino Acid Oxidoreductases; Animals; Arginine; Blood; Calcimycin; Coronary Vessels; Creatine Kinase; Dogs; Heart; Heart Arrest, Induced; Hemodynamics; Hypothermia, Induced; In Vitro Techniques; Myocardial Contraction; Myocardial Infarction; Myocardial Reperfusion; Myocardial Reperfusion Injury; Myocardium; Nitric Oxide; Nitric Oxide Synthase; Nitroarginine; Peroxidase; Sodium Nitrite; Vasodilation