1
|
Segev A, Shechter M, Tsur AM, Belkin D, Cohen H, Sharon A, Morag NK, Grossman E, Maor E. Serum Magnesium Is Associated with Long-Term Survival of Non-ST-Elevation Myocardial Infarction Patients. Nutrients 2023; 15:4299. [PMID: 37836583 PMCID: PMC10574643 DOI: 10.3390/nu15194299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 10/05/2023] [Accepted: 10/07/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND Low serum magnesium (sMg) is associated with cardiovascular risk factors and atherosclerotic disease. OBJECTIVE To evaluate the association between sMg levels on admission and clinical outcomes in hospitalized non-ST-elevation myocardial infarction (NSTEMI) patients. METHODS A retrospective analysis of all patients admitted to a single tertiary center with a primary diagnosis of NSTEMI. Patients with advanced chronic kidney disease were excluded. Clinical data were collected and compared between lower sMg quartile patients (Q1; sMg < 1.9 mg/dL) and all other patients (Q2-Q4; sMg ≥ 1.9 mg/dL). RESULTS The study cohort included 4552 patients (70% male, median age 69 [IQR 59-79]) who were followed for a median of 4.4 (IQR 2.4-6.6) years. The median sMg level in the low sMg group was 1.7 (1.6-1.8) and 2.0 (2.0-2.2) mg/dL in the normal/high sMg group. The low sMg group was older (mean of 72 vs. 67 years), less likely to be male (64% vs. 72%), and had higher rates of comorbidities, including diabetes, hypertension, and atrial fibrillation (59% vs. 29%, 92% vs. 85%, and 6% vs. 5%; p < 0.05 for all). Kaplan-Meier survival analysis demonstrated significantly higher cumulative death probability at 4 years in the low sMg group (34% vs. 22%; p log rank <0.001). In a multivariable analysis model adjusted for sex, significant comorbidities, coronary interventions during the hospitalization, and renal function, the low sMg group exhibited an independent 24% increased risk of death during follow up (95% CI 1.11-1.39; p < 0.001). CONCLUSIONS Low sMg is independently associated with higher risk of long-term mortality among patients recovering from an NSTEMI event.
Collapse
Affiliation(s)
- Amitai Segev
- The Leviev Cardiothoracic & Vascular Center, Sheba Medical Center, Ramat Gan 5262504, Israel; (M.S.); (E.M.)
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
| | - Michael Shechter
- The Leviev Cardiothoracic & Vascular Center, Sheba Medical Center, Ramat Gan 5262504, Israel; (M.S.); (E.M.)
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
| | - Avishai M. Tsur
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
- Department of Medicine, Sheba Medical Center, Ramat Gan 5262504, Israel
- Israel Defense Forces, Medical Corps, Ramat Gan 5262504, Israel
| | - David Belkin
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
| | - Hofit Cohen
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Ramat Gan 5262504, Israel
| | - Amir Sharon
- The Leviev Cardiothoracic & Vascular Center, Sheba Medical Center, Ramat Gan 5262504, Israel; (M.S.); (E.M.)
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
| | - Nira Koren Morag
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
| | - Ehud Grossman
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
- Department of Medicine, Sheba Medical Center, Ramat Gan 5262504, Israel
| | - Elad Maor
- The Leviev Cardiothoracic & Vascular Center, Sheba Medical Center, Ramat Gan 5262504, Israel; (M.S.); (E.M.)
- The Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel (D.B.); (H.C.); (E.G.)
| |
Collapse
|
2
|
Voultsos P, Bazmpani MA, Papanastasiou CA, Papadopoulos CE, Efthimiadis G, Karvounis H, Kalogeropoulos AP, Karamitsos TD. Magnesium Disorders and Prognosis in Heart Failure: A Systematic Review. Cardiol Rev 2022; 30:281-285. [PMID: 34001688 DOI: 10.1097/crd.0000000000000397] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Magnesium is an essential mineral for the human body and plays an important role in cardiovascular health. Hypomagnesaemia has been linked with increased cardiovascular mortality in heart failure; however, previous studies have yielded conflicting results. Even fewer studies have addressed the association between hypermagnesemia and prognosis in heart failure. The aim of the present systematic review was to investigate the association of serum magnesium levels with cardiovascular and all-cause mortality in patients with heart failure and reduced ejection fraction (HFrEF). Cardiovascular morbidity, referring to heart failure rehospitalizations and ventricular arrhythmias, was also investigated. Eligible studies were identified by searching PubMed and Scopus. The Quality in Prognosis (QUIPS) tool was used to assess the quality of included studies. Eight studies (total of 13,539 patients with HFrEF) that assessed the effects of serum magnesium levels on cardiovascular mortality, all-cause mortality, and cardiovascular morbidity met inclusion criteria. In half of the studies, hypomagnesemia was found to be an independent risk factor for cardiovascular mortality, including sudden cardiac death. Only 1 study reported that hypermagnesemia (serum magnesium levels above 2.4 mg/dL) is a prognostic factor for noncardiac mortality suggesting that hypermagnesemia is more likely an indicator of comorbidities rather than a true independent prognostic marker. Finally, low serum magnesium levels were not associated with readmissions for heart failure or ventricular arrhythmias in patients with HFrEF.
Collapse
Affiliation(s)
- Petros Voultsos
- From the 1st Department of Cardiology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Maria-Anna Bazmpani
- From the 1st Department of Cardiology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Christos A Papanastasiou
- From the 1st Department of Cardiology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | | | - Georgios Efthimiadis
- From the 1st Department of Cardiology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Haralambos Karvounis
- From the 1st Department of Cardiology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Andreas P Kalogeropoulos
- Division of Cardiovascular Medicine, Stony Brook University, Stony Brook, NY
- Division of Cardiovascular Medicine, University of Patras, Rio, Greece
| | - Theodoros D Karamitsos
- From the 1st Department of Cardiology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| |
Collapse
|
3
|
Wang Q, Xu L, Helmholz H, Willumeit-Römer R, Luthringer-Feyerabend BJC. Effects of degradable magnesium on paracrine signaling between human umbilical cord perivascular cells and peripheral blood mononuclear cells. Biomater Sci 2020; 8:5969-5983. [PMID: 32975550 DOI: 10.1039/d0bm00834f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Human mesenchymal stem cells (MSC) interact with numerous immune cells that can promote regenerative processes and inhibit inflammatory responses. We hypothesised that the cross-talk between human umbilical cord perivascular cells (HUCPV; an alternative source of MSC) and peripheral blood mononuclear cells (PBMC) could be influenced by degradable transwell magnesium (Mg). To study the correlations between paracrine signaling and specific cellular behaviour during the host response to Mg, we used a transwell coculture system for up to 7 days. The proliferation and viability of both cell types were not significantly influenced by Mg. When HUCPV were cultured with degradable Mg, a moderate inflammation (e.g., lower secretions of pro-inflammatory interleukin 1 beta and IL2, and tumour necrosis factor alpha, interferon gamma, anti-inflammatory interleukins 4, 5, 10, 13, and 1 receptor antagonists and granulocyte colony stimulating factor), and an increased pro-healing M2 macrophage phenotype were observed. Moreover, when PBMC were cultured with degradable Mg, the expression of migration/wound healing related cytokines (interleukin 8, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant protein 1 and macrophage inflammatory protein 1α/β) was upregulated, accompanied by an increase in the migration ability of HUCPV (cell scratch assay). In addition, an increased pro-osteogenic potential was demonstrated via an increase of osteoblastic markers (e.g., alkaline phosphatase activity, specific gene expression and cytokine release). These results collectively imply that Mg possesses osteo-immunomodulatory properties. They also help to design Mg-based bone substitute biomaterials capable of exhibiting desired immune reactions and good clinical performance.
Collapse
Affiliation(s)
- Qian Wang
- Institute of Materials Research, Division for Metallic Biomaterials, Helmholtz-Zentrum Geesthacht (HZG), Geesthacht, Germany.
| | | | | | | | | |
Collapse
|
4
|
Study on the Mg-Li-Zn ternary alloy system with improved mechanical properties, good degradation performance and different responses to cells. Acta Biomater 2017; 62:418-433. [PMID: 28823717 DOI: 10.1016/j.actbio.2017.08.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/22/2017] [Accepted: 08/16/2017] [Indexed: 01/04/2023]
Abstract
Novel Mg-(3.5, 6.5wt%)Li-(0.5, 2, 4wt%)Zn ternary alloys were developed as new kinds of biodegradable metallic materials with potential for stent application. Their mechanical properties, degradation behavior, cytocompatibility and hemocompatibility were studied. These potential biomaterials showed higher ultimate tensile strength than previously reported binary Mg-Li alloys and ternary Mg-Li-X (X=Al, Y, Ce, Sc, Mn and Ag) alloys. Among the alloys studied, the Mg-3.5Li-2Zn and Mg-6.5Li-2Zn alloys exhibited comparable corrosion resistance in Hank's solution to pure magnesium and better corrosion resistance in a cell culture medium than pure magnesium. Corrosion products observed on the corroded surface were composed of Mg(OH)2, MgCO3 and Ca-free Mg/P inorganics and Ca/P inorganics. In vitro cytotoxicity assay revealed different behaviors of Human Umbilical Vein Endothelial Cells (HUVECs) and Human Aorta Vascular Smooth Muscle Cells (VSMCs) to material extracts. HUVECs showed increasing nitric oxide (NO) release and tolerable toxicity, whereas VSMCs exhibited limited decreasing viability with time. Platelet adhesion, hemolysis and coagulation tests of these Mg-Li-Zn alloys showed different degrees of activation behavior, in which the hemolysis of the Mg-3.5Li-2Zn alloy was lower than 5%. These results indicated the potential of the Mg-Li-Zn alloys as good candidate materials for cardiovascular stent applications. STATEMENT OF SIGNIFICANCE Mg-Li alloys are promising as absorbable metallic biomaterials, which however have not received significant attention since the low strength, controversial corrosion performance and the doubts in Li toxicity. The Mg-Li-Zn alloy in the present study revealed much improved mechanical properties higher than most reported binary Mg-Li and ternary Mg-Li-X alloys, with superior corrosion resistance in cell culture media. Surprisingly, the addition of Li and Zn showed increased nitric oxide release. The present study indicates good potential of Mg-Li-Zn alloy as absorbable cardiovascular stent material.
Collapse
|
5
|
Ahmadi Lakalayeh G, Rahvar M, Haririan E, Karimi R, Ghanbari H. Comparative study of different polymeric coatings for the next-generation magnesium-based biodegradable stents. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2017; 46:1380-1389. [PMID: 28838256 DOI: 10.1080/21691401.2017.1369424] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Development of next-generation bioabsorbable stents based on magnesium alloys is gaining lots of attention. However, finding an appropriate coating in order to enhance its corrosion resistance along with preserving other requirements is still a challenge. In this study, three FDA-approved polymers, namely poly(lactic acid), polycaprolactone and poly(lactic-co-glycolic acid), have been investigated as potential coatings for magnesium-based stents to enhance their corrosion resistance, biocompatibility and haemocompatibility. Potentiodynamic and electrochemical impedance spectroscopy results demonstrated that PLA and PLGA coating performed better in improving corrosion resistance in comparison with uncoated and other coated samples. Although all coated and bare samples displayed desirable results of haemocompatibility assays, PLA-coated samples showed better outcome in terms of biocompatibility. The results revealed that PLA can be considered as a potential coating material to enhance the main characteristics of magnesium-based bioabsorbable stents.
Collapse
Affiliation(s)
- Gholamreza Ahmadi Lakalayeh
- a Department of Medical Nanotechnology, Regenerative Nanomedicine Research Group, School of Advanced Technologies in Medicine , Tehran University of Medical Sciences , Tehran , Iran
| | - Mostafa Rahvar
- a Department of Medical Nanotechnology, Regenerative Nanomedicine Research Group, School of Advanced Technologies in Medicine , Tehran University of Medical Sciences , Tehran , Iran
| | - Esmaeil Haririan
- b Medical Biomaterial Research Center (MBRC) , Tehran University of Medical Sciences , Tehran , Iran
| | - Roya Karimi
- c Tissue Engineering Department, School of Advanced Technologies in Medicine , Tehran University of Medical Sciences , Tehran , Iran
| | - Hossein Ghanbari
- a Department of Medical Nanotechnology, Regenerative Nanomedicine Research Group, School of Advanced Technologies in Medicine , Tehran University of Medical Sciences , Tehran , Iran.,b Medical Biomaterial Research Center (MBRC) , Tehran University of Medical Sciences , Tehran , Iran.,d Research Center for Advanced Technologies in Cardiovascular Medicine , Tehran Heart Center, Tehran University of Medical Sciences , Tehran , Iran
| |
Collapse
|
6
|
Yuksel M, Isik T, Tanboga IH, Ayhan E, Erimsah ME, Topcu S, Demirelli S, Aksakal E, Sevimli S. The Importance of Magnesium Values in Patients With STEMI Admitted to the Emergency Department. Clin Appl Thromb Hemost 2016; 23:329-335. [PMID: 27418637 DOI: 10.1177/1076029616658119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
AIM The aim of this study is to examine the relationship between initial magnesium (Mg) levels, electrocardiographic no-reflow, and long-term mortality in patients who underwent primary percutaneous coronary intervention (pPCI) due to ST-segment elevation myocardial infarction (STEMI). METHODS A total of 111 patients with pPCI participated in the study. Magnesium and high-sensitive C-reactive protein (hs-CRP) were measured. The sum of ST-segment elevation was measured immediately before and 60 minutes after the restoration of coronary flow. The difference between the 2 measurements was taken as the amount of ST-segment resolution and defined as sum of ST-segment resolution (∑STR). The ∑STR <50% was determined as electrocardiographic sign of no-reflow phenomenon. After the patients were discharged, they were followed up for major adverse cardiac events for up to 51 months after discharge. RESULTS Forty patients in the no-reflow group and 71 patients in the normal-flow group were included in the study. Magnesium value ≤1.87 mg/dL initially measured had 77% sensitivity and 59% specificity in predicting no-reflow on receiver operating characteristic curve analysis. In multivariate analyses, Mg (odds ratio [OR]: 0.01, <95% confidence interval [CI]: 0.01-0.12; P = .004), hs-CRP (OR: 1.06, <95% CI: 1.00-1.14; P = .05), left anterior descending artery lesion (OR: 6.66, <95% CI: 1.45-3.05; P = .01), and reperfusion time (OR: 1.01, <95% CI: 1.00-1.01; P = .03) were still independent predictors of electrocardiographic no-reflow, and only Mg (OR: 0.08, <95% CI: 0.01-1.03; P = .05) was still an independent predictor of long-term mortality. CONCLUSION Serum Mg level is an independent predictor of electrocardiographic no-reflow and long-term mortality in patients with STEMI.
Collapse
Affiliation(s)
- Melih Yuksel
- 1 Department of Emergency Medicine, School of Medicine, Balikesir University, Balikesir, Turkey
| | - Turgay Isik
- 2 Department of Cardiology, School of Medicine, Balikesir University, Balikesir, Turkey
| | | | - Erkan Ayhan
- 2 Department of Cardiology, School of Medicine, Balikesir University, Balikesir, Turkey
| | - Mehmet Emre Erimsah
- 1 Department of Emergency Medicine, School of Medicine, Balikesir University, Balikesir, Turkey
| | - Selim Topcu
- 3 Department of Cardiology, School of Medicine, Ataturk University, Erzurum, Turkey
| | - Selami Demirelli
- 4 Department of Cardiology, Erzurum Education and Research Hospital, Erzurum, Turkey
| | - Enbiya Aksakal
- 3 Department of Cardiology, School of Medicine, Ataturk University, Erzurum, Turkey
| | - Serdar Sevimli
- 3 Department of Cardiology, School of Medicine, Ataturk University, Erzurum, Turkey
| |
Collapse
|
7
|
Study on the blood compatibility and biodegradation properties of magnesium alloys. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 47:204-10. [DOI: 10.1016/j.msec.2014.11.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/16/2014] [Accepted: 11/10/2014] [Indexed: 01/17/2023]
|
8
|
Mori K, Yamamoto T, Nakao Y, Miyazaki M, Iwata J, Tamura M, Shiroishi T. Novel neuroprotective effect of cisternal and intra-cerebral magnesium sulfate solution infusion on delayed cerebral death in rat hippocampal neurons after transient global ischemia. Brain Res 2012; 1480:72-80. [DOI: 10.1016/j.brainres.2012.07.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/15/2012] [Accepted: 07/19/2012] [Indexed: 11/16/2022]
|
9
|
Rhee E, Beiswenger T, Oguejiofor CE, James AH. The effects of magnesium sulfate on maternal and fetal platelet aggregation. J Matern Fetal Neonatal Med 2011; 25:478-83. [DOI: 10.3109/14767058.2011.584087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
10
|
Lu P, Cao L, Liu Y, Xu X, Wu X. Evaluation of magnesium ions release, biocorrosion, and hemocompatibility of MAO/PLLA-modified magnesium alloy WE42. J Biomed Mater Res B Appl Biomater 2010; 96:101-9. [DOI: 10.1002/jbm.b.31744] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
11
|
Hardy E, Heptinstall S, Rubin PC, Horn EH. Original article: Effects of Raised Extracellular Magnesium on Platelet Reactivity. Platelets 2009; 6:346-53. [DOI: 10.3109/09537109509078470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
12
|
Shrier I, Platt RW, Steele RJ. Mega-trials vs. meta-analysis: Precision vs. heterogeneity? Contemp Clin Trials 2007; 28:324-8. [PMID: 17188025 DOI: 10.1016/j.cct.2006.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 10/31/2006] [Accepted: 11/12/2006] [Indexed: 11/30/2022]
Abstract
In recent years, several authors have suggested there is a need for more very large or "mega-trials" (defined in this manuscript as a trial powered to address subgroup differences/interactions/secondary analyses) to answer important clinical questions. Because mega-trials are expensive and funding for clinical research is limited, increasing the number of mega-trials limits funding for other research. The advantages of this approach compared with funding more focused RCTs needs to be debated. Because there is no method to determine gold standard for which method gives the correct answer, we provide theoretical arguments that demonstrate that the two approaches are similar with respect to sample size requirements and the mega-trial approach provides a small advantage with respect to minimizing confounding by chance. However, the inherent heterogeneity in a series of smaller trials may represent a significant advantage over a single mega-trial.
Collapse
Affiliation(s)
- Ian Shrier
- Centre for Clinical Epidemiology and Community Studies, SMBD-Jewish General Hospital, McGill University, 3755 Cote Ste-Catherine Road, Montreal, Quebec, Canada H3T 1E2.
| | | | | |
Collapse
|
13
|
Brenn BR, Theroux MC, Dabney KW, Miller F. Clotting parameters and thromboelastography in children with neuromuscular and idiopathic scoliosis undergoing posterior spinal fusion. Spine (Phila Pa 1976) 2004; 29:E310-4. [PMID: 15284525 DOI: 10.1097/01.brs.0000132513.88038.64] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An unblinded comparison of laboratory values between patients with idiopathic and neuromuscular scoliosis. OBJECTIVES To compare standard tests of coagulation and thromboelastography (TEG) parameters between two groups of patients undergoing posterior spinal fusion (PSF). SUMMARY OF BACKGROUND DATA Children with neuromuscular scoliosis such as cerebral palsy have more intraoperative blood loss than children with idiopathic scoliosis during PSF. Various reasons suggested for this include nutritional deficiencies, altered tissue integrity, hepatic dysfunction, and use of antiepileptic medications that can cause poor hemostasis and altered coagulation. We have observed alterations in coagulation factor levels in patients with cerebral palsy due to spastic quadriplegia with moderate blood volume loss (25% estimated blood volume). METHODS In a prospective analysis, we compared standard tests of coagulation (prothrombin time [PT], partial thromboplastin time [PTT], platelet count, fibrinogen levels) and TEG at baseline and at a blood loss of 15% estimated blood volume in patients with idiopathic scoliosis and cerebral palsy undergoing PSF. RESULTS There were no differences between the groups in terms of gender distribution and age. There was a significant difference between the baseline PT and PTT values, although both groups were within laboratory norms. After 15% blood volume loss, there were differences seen in the PT, PTT, maximum amplitude on the TEG, ionized calcium, and serum magnesium levels (P < 0.05). CONCLUSIONS Children with cerebral palsy undergoing PSF have increased bleeding that starts earlier in the procedure than it does for patients with idiopathic scoliosis undergoing PSF. We found that, even though children with spastic quadriplegia had baseline PT and PTT values within normal limits, they were significantly different when compared with normal patients.
Collapse
Affiliation(s)
- B Randall Brenn
- Department of Anesthesiology and Critical Care, Nemours Children's Clinic-Wilmington, Alfred I. duPont Hospital for Children, Wilmington, DE 19899, USA.
| | | | | | | |
Collapse
|
14
|
Al-Delaimy WK, Rimm EB, Willett WC, Stampfer MJ, Hu FB. Magnesium intake and risk of coronary heart disease among men. J Am Coll Nutr 2004; 23:63-70. [PMID: 14963055 DOI: 10.1080/07315724.2004.10719344] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Our aim in this study was to assess the relationship between magnesium intake and risk of coronary heart disease (CHD) among men. METHODS A total of 39,633 men in the Health Professionals Follow-up Study who returned a dietary questionnaire in 1986 were followed up for 12 years. Intakes of magnesium, zinc and potassium and other nutrients were assessed in 1986, 1990 and 1994. Total CHD incidence (nonfatal myocardial infarction (MI) and fatal CHD) was ascertained by biennial questionnaire and mortality surveillance confirmed by medical record review. Standard CHD risk factors were recorded biennially. RESULTS During 12 years of follow-up (414,285 person-years), we documented 1,449 cases of total CHD (1,021 non-fatal MI cases, and 428 fatal CHD). The age-adjusted relative risk (RR) of developing CHD in the highest quintile (median intake = 457 mg/day) compared with the lowest quintile (median intake = 269 mg/day) was 0.73 (95% CI 0.62-0.87, p for trend <0.0001). After controlling for standard CHD risk factors and dietary factors, the RR for developing CHD among men in the highest total magnesium intake quintile compared with those in the lowest was 0.82 (95% CI 0.65-1.05, p for trend = 0.08). For supplemental magnesium intake, the RR comparing the highest quintile to non-supplement users was 0.77 (95% CI 0.56-1.06, p for trend = 0.14). CONCLUSIONS These results suggest that intake of magnesium may have a modest inverse association with risk of CHD among men.
Collapse
Affiliation(s)
- Wael K Al-Delaimy
- Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
| | | | | | | | | |
Collapse
|
15
|
Jian W, Su L, Yiwu L. The effects of magnesium prime solution on magnesium levels and potassium loss in open heart surgery. Anesth Analg 2003; 96:1617-1620. [PMID: 12760983 DOI: 10.1213/01.ane.0000065444.21593.23] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
UNLABELLED In this study, we examined the effects of magnesium supplementation in the cardiopulmonary bypass (CPB) prime solution on pediatric patients' magnesium levels and potassium loss with open heart surgery. Forty pediatric patients undergoing heart surgery were randomly assigned either magnesium sulfate (magnesium group, n = 20; 0.25 mmol/kg) or saline (placebo group; n = 20) supplementation to the prime solution. Ionized magnesium (IMg) and urinary magnesium and potassium were measured at defined time points during and after CPB. In the magnesium group, IMg concentration was larger during CPB but not after CPB. IMg decreased in the early stages of CPB in the placebo group and decreased to an even smaller level 24 h after CPB. Urinary magnesium levels in the magnesium group were larger than those in the placebo group during and after CPB, and urinary potassium concentrations reached significantly smaller levels 24 h after CPB (44.2 +/- 2.9 versus 60.9 +/- 2.6 mmol/L; P < 0.01). We conclude that the addition of magnesium into prime solution maintains normal IMg levels and prevents potassium flux during the perioperative period. IMPLICATIONS In our study, we demonstrate that a magnesium prime solution can prevent hypomagnesemia during and after cardiopulmonary bypass (CPB) and decrease the urinary potassium loss after CPB in pediatric patients undergoing open heart surgery.
Collapse
Affiliation(s)
- Wang Jian
- Department of Cardiac Surgery, Second Hospital of Hebei Medical University, Shijiazhuang, People's Republic of China
| | | | | |
Collapse
|
16
|
Abstract
Hypomagnesemia is common in hospitalized patients, especially in elderly patients with coronary artery disease (CAD) and/or those with chronic heart failure. Hypomagnesemia is associated with increased all cause mortality and mortality from CAD. Magnesium supplementation improves myocardial metabolism, inhibits calcium accumulation and myocardial cell death; it improves vascular tone, peripheral vascular resistance, afterload and cardiac output, reduces cardiac arrhythmias and improves lipid metabolism. Magnesium also reduces vulnerability to oxygen-derived free radicals, improves endothelial function and inhibits platelet function, including platelet aggregation and adhesion, which potentially confers upon magnesium physiologic and natural effects similar to adenosine-diphosphate inhibitors such as clopidogrel. However, data regarding the use of magnesium in patients with acute myocardial infarction (AMI) are conflicting. Although some previous relatively small randomized clinical trials demonstrated a remarkable reduction in mortality when intravenous magnesium was administered to relatively high risk AMI patients, two recently published large-scale randomized clinical trials (the Fourth International Study of Infarct Survival [ISIS 4] and Magnesium in Coronaries [MAGIC]) were unable to demonstrate any advantage of intravenous magnesium over placebo. Nevertheless, the theoretical benefits of magnesium supplementation as a cardio-protective agent in CAD patients, promising results from animal and human studies, its relatively low-cost and ease of handling requiring no special expertise, together with its excellent tolerability, gives magnesium a place in treating CAD patients, especially in those at high risk, such as CAD patients with heart failure, the elderly and hospitalized patients with hypomagnesemia. Furthermore, magnesium therapy is indicated in life-threatening ventricular arrhythmias such as torsades de pointes and intractable ventricular tachycardia.
Collapse
Affiliation(s)
- Michael Shechter
- Heart Institute, Chaim Sheba Medical Center and Sackler School of Medicine, Tel-Aviv University, Israel.
| |
Collapse
|
17
|
Abstract
Magnesium exhibits a range of neuronal and vascular actions that may ameliorate ischaemic CNS insults, including stroke. Significant neuroprotection with magnesium has been observed in different models of focal cerebral ischaemia in many laboratories, with infarct volume reductions between 25 and 61%. Maximal neuroprotection is evident at readily attainable serum concentrations, and neuroprotection is still seen when administration is delayed up to 6 hours after onset of ischaemia. Clinical use of magnesium in pre-eclampsia and acute myocardial infarction confirms its safety and tolerability. Five small trials in acute stroke have reported reduced odds of death or dependence with administration of magnesium, but confidence intervals are wide, and definitive data from ongoing large trials are awaited.
Collapse
Affiliation(s)
- K W Muir
- University Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, Scotland, UK.
| |
Collapse
|
18
|
Ravn HB, Lassen JF, Bergenhem N, Kristensen AT. Intravenous magnesium does not influence the activity of the coagulation cascade. Blood Coagul Fibrinolysis 2001; 12:223-8. [PMID: 11460004 DOI: 10.1097/00001721-200106000-00001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Experimental arterial thrombus formation is reduced during intravenous magnesium infusion. It is well documented that magnesium reduces platelet reactivity, but the antithrombotic effect could also originate from anticoagulant properties or increased fibrinolysis. We therefore evaluated the effect of intravenous magnesium on prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin III complex (TAT) concentrations, and fibrin degradation products (FbDP) in a randomized, cross-over study in 14 healthy volunteers. Citrated blood samples were collected at 0, 30, and 180 min. An additional in vitro study on magnesium's effect on the activity of different coagulation factors was carried out. A transient increase was seen in F1 + 2 and TAT after 30 min but without any significant difference between the placebo and magnesium period. FbDP did not change significantly between the two treatments. Increasing concentrations of magnesium dose-dependently decreased binding of activated factor X to activated factor VII (FVIIa), but the decrease was slight and probably without any significance for coagulation at the concentrations tested. No effect was observed on the activity of FVIIa or activated factor VIII. In conclusion, no significant differences were observed on markers of coagulation or fibrinolytic activity during intravenous magnesium infusion. These results indicate that the observed antithrombotic effect of magnesium is more likely to arise from the previously observed platelet inhibition.
Collapse
Affiliation(s)
- H B Ravn
- Department of Anaesthesia and Intensive Care Medicine, Skejby Sygehus, Aarhus University Hospital, Aarhus, Denmark.
| | | | | | | |
Collapse
|
19
|
Toft G, Ravn HB, Hjortdal VE. Intravenously and topically applied magnesium in the prevention of arterial thrombosis. Thromb Res 2000; 99:61-9. [PMID: 10904104 DOI: 10.1016/s0049-3848(00)00215-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Magnesium (Mg) has been shown to reduce platelet aggregation both in vitro and ex vivo, and this antiplatelet effect may be advantageous in the prevention of arterial thrombosis. Previous animal studies have shown an antithrombotic effect of Mg also in vivo, but mainly with higher Mg concentrations ( approximately 3.0-4.0 mM). The objectives of the present study were to evaluate the antithrombotic effect of (1) intravenous Mg at a lower and clinically more relevant concentration and (2) topically applied Mg. The study comprised 30 male rats, randomly assigned into 3 groups: (1) placebo group, (2) intravenous Mg group, and (3) topical Mg group. A thrombogenic lesion was established by making a standardised arteriotomy in the right femoral artery. The vessel was transilluminated and thrombus formation was visualised dynamically by in vivo microscopy and recorded on videotapes. Thrombus area was measured after ended experiment by computer-assisted image analysis. Intravenously administered Mg, elevating the S-Mg level to 2.2 mmol/L, significantly reduced the mean thrombus area (p<0.05) compared to the control group. Topically applied Mg significantly decreased the maximum thrombus area, without any increase in S-Mg level (p<0.05). The Mg-treated groups showed no increase in bleeding complications. A transient fall in blood pressure was seen in the systemic Mg group, but blood pressures were not significantly different between any of the groups at the end of the experiment. In conclusion, topically as well as intravenously infused Mg reduce arterial thrombus formation in this in vivo rat model without compromising haemostasis.
Collapse
Affiliation(s)
- G Toft
- Institute of Experimental Clinical Research, Skejby Hospital, Aarhus University Hospital, Aarhus, Denmark
| | | | | |
Collapse
|
20
|
Dorman BH, Sade RM, Burnette JS, Wiles HB, Pinosky ML, Reeves ST, Bond BR, Spinale FG. Magnesium supplementation in the prevention of arrhythmias in pediatric patients undergoing surgery for congenital heart defects. Am Heart J 2000; 139:522-8. [PMID: 10689268 DOI: 10.1016/s0002-8703(00)90097-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND The efficacy of magnesium in the prevention of arrhythmias in pediatric patients after heart surgery remains unknown. Therefore we prospectively examined the effect of magnesium treatment on the incidence of postoperative arrhythmias in pediatric patients undergoing surgical repair of congenital heart defects. METHODS AND RESULTS Twenty-eight pediatric patients undergoing heart surgery with cardiopulmonary bypass were prospectively, randomly assigned in a double-blind fashion to receive intravenous magnesium (magnesium group, n = 13; 30 mg/kg) or saline (placebo group, n = 15) immediately after cessation of cardiopulmonary bypass. Magnesium, potassium, and calcium levels were measured at defined intervals during surgery and 24 hours after surgery. Continuous electrocardiographic documentation by Holter monitor was performed for 24 hours after surgery. Magnesium levels were significantly decreased below the normal reference range for patients in the placebo group compared with the magnesium group on arrival in the intensive care unit and for 20 hours after surgery. Magnesium levels remained in the normal range for patients in the magnesium group after magnesium supplementation. In 4 patients in the placebo group (27%), junctional ectopic tachycardia developed within the initial 20 hours in the intensive care unit. No junctional ectopic tachycardia was observed in the magnesium group (P =.026). CONCLUSIONS Although this study was originally targeted to include 100 patients, the protocol was terminated because of the unacceptable incidence of hemodynamically significant junctional ectopic tachycardia that was present in the placebo group. Thus low magnesium levels in pediatric patients undergoing heart surgery are associated with an increased incidence of junctional ectopic tachycardia in the immediate postoperative period.
Collapse
MESH Headings
- Arrhythmias, Cardiac/blood
- Arrhythmias, Cardiac/diagnosis
- Arrhythmias, Cardiac/prevention & control
- Calcium/blood
- Cardiac Surgical Procedures/adverse effects
- Cardiopulmonary Bypass/adverse effects
- Child, Preschool
- Digitalis/therapeutic use
- Double-Blind Method
- Electrocardiography, Ambulatory/drug effects
- Female
- Heart Defects, Congenital/drug therapy
- Heart Defects, Congenital/surgery
- Humans
- Infusions, Intravenous
- Magnesium/administration & dosage
- Magnesium/blood
- Magnesium Deficiency/blood
- Magnesium Deficiency/diagnosis
- Magnesium Deficiency/prevention & control
- Male
- Phytotherapy
- Plants, Medicinal
- Plants, Toxic
- Postoperative Complications/blood
- Postoperative Complications/prevention & control
- Potassium/blood
- Prospective Studies
- Tachycardia, Ectopic Junctional/blood
- Tachycardia, Ectopic Junctional/etiology
- Tachycardia, Ectopic Junctional/prevention & control
- Treatment Outcome
Collapse
Affiliation(s)
- B H Dorman
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, South Carolina, USA.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Magnesium Therapy for Acute Myocardial Infarction. J Thromb Thrombolysis 1999; 2:93-94. [PMID: 10608010 DOI: 10.1007/bf01064375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The use of magnesium therapy for acute myocardial infarction remains controversial despite recent clinical trials such as ISIS-4. Magnesium has numerous beneficial effects in the setting of myocardial infarction, including inhibitory effects on platelet aggregation. Clinical trials of magnesium therapy for myocardial infarction have yielded conflicting results that may be related to the difference in the timing of magnesium administration. Moreover, magnesium may have salutary effects in patients who are ineligible for thrombolytic therapy. Further clinical trials are still needed to elucidate definitively the role of magnesium therapy for myocardial infarction.
Collapse
|
22
|
Raghu C, Peddeswara Rao P, Seshagiri Rao D. Protective effect of intravenous magnesium in acute myocardial infarction following thrombolytic therapy. Int J Cardiol 1999; 71:209-15. [PMID: 10636525 DOI: 10.1016/s0167-5273(99)00125-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The role of intravenous magnesium therapy in patients with acute myocardial infarction (AMI) who received thrombolytic therapy is controversial. The results from previous clinical trials were not in consonance. We therefore conducted a prospective, randomized, double-blind, placebo controlled study in 350 patients with confirmed AMI during the period January 1994 to December 1996. The role of intravenous magnesium sulphate therapy (2 g over 5 min followed by 16 g over 24 h) was evaluated in patients with AMI who received thrombolytic therapy. Study group consisted of 169 patients who were administered magnesium sulphate. Control group comprised of 181 patients who were given isotonic saline. Among those in the magnesium group, 70% received magnesium within 6 h after the onset of symptoms. All patients received magnesium immediately after the completion of thrombolytic therapy. Patients were followed up for 30 days after AMI. The number of deaths in the study group was 6 (3.5%) compared with control arm in which 18 patients (9.9%) died (P value <0.01 95% Confidence intervals [CI] 1.2 to 11.6). Ventricular arrhythmias were also less in the magnesium arm; 27 patients (13%) compared with 83 patients (48.6%) in the control arm (P value 0.00001 95% Cl 26.7 to 44.5). In the magnesium group 15 patients (8.8%) had re-infarction compared with 23 patients (12.7%) in the placebo arm (P value not significant). Post myocardial infarction angina was observed in 47 patients (27.8%) in the magnesium arm compared with 60 patients (33.1%) in the placebo arm (P value not significant). The main side effect of intravenous magnesium was transient flushing observed in 152 (90%) patients. Intravenous magnesium sulphate in patients with AMI is a safe and useful adjunct to thrombolytic therapy in reducing the short-term mortality and ventricular arrhythmias after AMI.
Collapse
Affiliation(s)
- C Raghu
- Division of Cardiology, Nizam's Institute of Medical Sciences, Hyderabad, India.
| | | | | |
Collapse
|
23
|
Ames WA, McDonnell N, Potter D. The effect of ionised magnesium on coagulation using thromboelastography. Anaesthesia 1999; 54:999-1001. [PMID: 10540068 DOI: 10.1046/j.1365-2044.1999.00647.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Magnesium is an ionised mineral with therapeutic uses. There is laboratory evidence that it may have an anticoagulant activity although recent research has been to the contrary. The clinical implications of the effect of a therapeutic dose of magnesium on coagulation have yet to be resolved conclusively. In our study, 10 healthy volunteers were given 4 g of magnesium sulphate intravenously. Thromboelastographs were recorded and blood analysed for haematological indices, before and after the infusion. All variables associated with coagulation remained unchanged except the alpha angle on the thromboelastograph which increased significantly. We conclude that in our in vivo study, the effect of magnesium sulphate on coagulation is not clinically significant.
Collapse
Affiliation(s)
- W A Ames
- St. Thomas' Hospital, London, UK
| | | | | |
Collapse
|
24
|
Shibata M, Ueshima K, Harada M, Nakamura M, Hiramori K, Endo S, Sato N, Mukaida H, Suzuki T, Suzuki T, Inada K. Effect of magnesium sulfate pretreatment and significance of matrix metalloproteinase-1 and interleukin-6 levels in coronary reperfusion therapy for patients with acute myocardial infarction. Angiology 1999; 50:573-82. [PMID: 10431997 DOI: 10.1177/000331979905000707] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Magnesium (Mg) inhibits the influx of calcium in vascular smooth muscle cells. The purposes of this study were to test the hypothesis that an intravenous administration of magnesium might effect the complement response and to determine the effects of a magnesium pretreatment of patients with acute myocardial infarction (AMI) on the incidence of reperfusion injuries. Thirty-eight AMI patients were treated with coronary reperfusion therapy within 6 hours of onset. They were randomly divided into two groups: group pretreated with intravenous magnesium sulfate (0.27 mmol/kg) (magnesium group, n = 19), and nonpretreated controls (placebo group). The reperfusion injuries observed within 1 hour after the coronary reperfusion included arrhythmias, aggravated chest pain, and ST segment elevation in 12-lead electrocardiograms. Coronary recanalization was performed in 36 patients. The incidence of reperfusion arrhythmia was significantly lower in the magnesium group than in the placebo group (17% vs 78%, p<0.001). At the postreperfusion stage, there was a tendency for the degree of ST segment reelevation in the magnesium group lower than in the placebo group (2.5 +/- 2.3 mm vs 4.7 +/- 3.8 mm, p = 0.07). No marked difference was observed in the incidence of chest pain aggravation between the two groups (67% vs 73%, ns). The peak serum levels of interleukin-6 (IL-6) were significantly lower in the magnesium group than those in the placebo group (38.9 +/- 25.0 vs 92.3 +/- 76.5 pg/mL, p = 0.016). The peak serum levels of matrix metalloproteinase-1 (MMP-1) were lower than those in the placebo group (16.2 +/- 4.8 vs 19.7 +/- 9.0 ng/mL, p = 0.09), but the difference was not significant. A positive correlation was observed between the peak MMP-1 values and the peak IL-6 values (r = 0.57, p = 0.001) in all patients. Increased serum ionized Mg2+ may inhibit arrhythmic recurrence and the production of IL-6 and MMP-1 after reperfusion and prevent the increase of myocardial lesions caused by calcium overload on myocytes. The increased IL-6 production may induce MMP-1, leading to tissue organ injury. Pretreatment with magnesium sulfate may protect the myocardium of AMI patients from reperfusion injuries.
Collapse
Affiliation(s)
- M Shibata
- Iwate Medical University, Morioka, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Ravn HB, Moeldrup U, Brookes CI, Ilkjaer LB, White P, Chew M, Jensen L, Johnsen S, Birk-Soerensen L, Hjortdal VE. Intravenous magnesium reduces infarct size after ischemia/reperfusion injury combined with a thrombogenic lesion in the left anterior descending artery. Arterioscler Thromb Vasc Biol 1999; 19:569-74. [PMID: 10073959 DOI: 10.1161/01.atv.19.3.569] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Experimental studies have demonstrated that intravenous magnesium (Mg) can protect the ischemic myocardium and has an antithrombotic effect. In patients with myocardial infarction, the reperfusion injury is complicated by the presence of a thrombogenic area in the affected coronary artery that may cause repetitive thrombus formation and embolization. We investigated the effect of Mg on infarct size in a randomized study in pigs. Myocardial infarction was induced by a 50-minute mechanical occlusion of the left anterior descending artery combined with an arterial injury, which stimulated a dynamic thrombus formation with emboli shedding on reperfusion. Magnesium sulfate (6 mmol/20 min plus 3 mmol/h) or saline was started at 30 minutes after coronary occlusion. Real-time ventricular pressure-volume loops were generated from the left ventricle by using a microtip pressure manometer and a conductance catheter. Platelet accumulation in the myocardium was evaluated by using 111In-labeled platelets. After 4 hours of reperfusion, the infarct size/area at risk ratio in the placebo group was 46+/-0.06% (n=8) compared with 22+/-0.07% (n=6) in the Mg-treated animals (P=0. 03). Ejection fraction decreased significantly in the control group but not in the Mg-treated animals (P=0.03). Platelet accumulation in the myocardium did not change significantly between the Mg- and placebo-treated animals (placebo group, 191+/-19%; Mg group, 177+/-29%; NS). The present study demonstrates that intravenous Mg infusion is able to reduce infarct size by >50% and preserve the ejection fraction in this model where ischemia/reperfusion injury was evaluated in the presence of a thrombogenic area in the nutrient artery.
Collapse
Affiliation(s)
- H B Ravn
- Institute of Experimental and Clinical Research, Aarhus University, Aarhus, Denmark.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Pearson PJ, Evora PR, Seccombe JF, Schaff HV. Hypomagnesemia inhibits nitric oxide release from coronary endothelium: protective role of magnesium infusion after cardiac operations. Ann Thorac Surg 1998; 65:967-72. [PMID: 9564911 DOI: 10.1016/s0003-4975(98)00020-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Postoperative hypomagnesemia is common in patients who have undergone cardiac operations and is associated with clinically significant morbidity resulting from atrial and ventricular dysrhythmias. Magnesium supplementation may increase the cardiac index in the early postoperative period. METHODS The action of the magnesium cation on coronary vascular reactivity was studied. Segments of canine epicardial coronary artery were suspended in organ chambers to measure isometric force (95% O2/5% CO2, 37 degrees C). RESULTS In coronary segments constricted with prostaglandin F2alpha (2 x 10[-6] mol/L), acetylcholine and adenosine diphosphate (10[-9] to 10[-4] mol/L) induced vasodilation in arteries with endothelium (n=10, each group; p < 0.05). Acetylcholine-mediated vasodilation was blocked by NG-monomethyl-L-arginine (10[-4] mol/L) and NG-nitro-L-arginine (10[-4] mol/L), two inhibitors of nitric oxide synthesis from L-arginine (n=10, p < 0.05). The removal of magnesium from the organ chamber solution impaired vasodilation in response to acetylcholine and adenosine diphosphate. However, normal endothelium-dependent vasodilation could be restored by return of magnesium to the bathing solution. Vascular relaxation in response to bradykinin (10[-9] to 10[-6] mol/L), which was found to induce endothelium-dependent vasodilation independent of nitric oxide production, was unaffected by magnesium removal (n=10). CONCLUSIONS Hypomagnesemia selectively impaired the release of nitric oxide from the coronary endothelium. Because nitric oxide is a potent endogenous nitro-vasodilator and inhibitor of platelet aggregation and adhesion, hypomagnesemia could promote vasoconstriction and coronary thrombosis in the early postoperative period.
Collapse
Affiliation(s)
- P J Pearson
- Section of Cardiovascular Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA
| | | | | | | |
Collapse
|
27
|
Ravn HB, Kristensen SD, Hjortdal VE, Thygesen K, Husted SE. Early administration of intravenous magnesium inhibits arterial thrombus formation. Arterioscler Thromb Vasc Biol 1997; 17:3620-5. [PMID: 9437213 DOI: 10.1161/01.atv.17.12.3620] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
An antiplatelet effect of magnesium has been demonstrated in vitro and ex vivo, and this effect may be advantageous in patients with acute myocardial infarction to inhibit reocclusion after coronary angioplasty or thrombolysis. We investigated the antithrombotic in vivo effect of intravenous magnesium in a placebo-controlled, blinded study in 46 male Wistar rats. Thrombus formation was induced by standardized arteriotomy of the femoral artery and partial inversion of the vessel wall to produce a thrombogenic area. The vessel was transilluminated and visualized dynamically by in vivo microscopy. Thrombus area was measured every minute for 30 minutes after removal of the vessel clamp by image analysis techniques, and the number of visible emboli was registered. Animals were randomized into three groups: groups 1 and 2 received saline (control group, n = 15) or MgSO4 (Mg-early group, n = 15), respectively, during the entire infusion period. In group 3 intravenous saline was given during preparation of the arteriotomy followed by infusion of MgSO4 (Mg-late group, n = 16) from 10 minutes after removal of the vessel clamp. Thrombus area was significantly reduced by 75% in the Mg-early group (P < .005) but not in the Mg-late group compared with the control group. Mean number of emboli was reduced during magnesium infusion. The serum magnesium level increased to 2.2 (2.1 to 2.5) and 3.5 (3.0 to 4.2) mmol/L after infusion in the Mg-late and the Mg-early group, respectively. In the present study, intravenous infusion of MgSO4 significantly reduced thrombus formation in vivo but only when it was given before reperfusion. The antithrombotic effect of magnesium may be utilized in patients with acute myocardial infarction to reduce the rate of reocclusion. Magnesium infusion may also be of value in elective arterial angioplasty, but this option has not been investigated in clinical trials. However, correct timing of magnesium administration is critical to obtain an efficient antithrombotic effect.
Collapse
Affiliation(s)
- H B Ravn
- Department of Medicine and Cardiology, Aarhus Amtssygehus, Aarhus University Hospital, Denmark.
| | | | | | | | | |
Collapse
|
28
|
Thämer V, Grunert S, Bier F, Schlack W. [Effect of magnesium on infarct size after coronary occlusion. Animal experiment studies]. Herz 1997; 22 Suppl 1:35-9. [PMID: 9333590 DOI: 10.1007/bf03042653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In addition to its antiarrhythmic and antithrombotic effects magnesium is said to have a beneficial effect in patients with acute myocardial infarction. Magnesium can protect myocardial tissue after coronary occlusion and reduces infarct size in experimental models of ischaemia and reperfusion, though the given doses of magnesium are relatively high and differ from clinically reachable serum concentrations. We tested 2 hypotheses in a dog model of ischaemia-reperfusion: 1. The protective effect may be due to a direct, local influence of magnesium on myocardial reperfusion injury. 2. Systemic magnesium treatment with low doses comparable to clinical study regiments may reduce myocardial infarct size. Anaesthetized open chest dogs underwent 1 h of left anterior descending artery occlusion followed by 6 h of reperfusion. 1. Ten animals received intracoronary magnesium aspartate (Mg i.c.) or vehicle infusion (control i.c.) for the first hour of reperfusion to increase regional Mg-concentration by 2 mmol/l. 2. Fourteen animals received intravenous infusion with magnesium potassium aspartate (Mg-K i.v.) or vehicle infusion (control i.v.), beginning 1 h before occlusion until the end of the 6 h reperfusion period. Regional magnesium concentration in the Mg i.c.-group increased to 2.7 +/- 1.00 mmol/l at 45 min of reperfusion. Intravenous infusion raised serum magnesium from 0.71 +/- 0.03 mmol/l to 1.29 +/- 0.14 mmol/l in the Mg-K i.v. group (5 min of reperfusion, p < 0.01 vs. baseline). Infarct size after 6 h reperfusion (TTC staining) was similar in both groups of intracoronary treatment (Mg i.c., 20.6 +/- 5.0; control, 24.4 +/- 8.7% of area at risk; p = n.s.) and intravenous treatment (Mg-K i.v. 18.1 +/- 14.8; control 14.1 +/- 12.2% of area at risk; p = n.s.). Neither regional nor systemic magnesium leads to a clinically relevant reduction of infarct size in the regional ischaemic-reperfused dog heart when it is given in clinically usable doses. The beneficial action of systemic Mg is probably not due to an early direct protective effect on ischaemic-reperfused myocardium but to its antiarrhythmic and antithrombotic effects. Possibly only to high doses of Mg applied under experimental conditions can reduce infarct size.
Collapse
Affiliation(s)
- V Thämer
- Institut für Herz- und Kreislaufphysiologie, Heinrich-Heine-Universität, Düsseldorf
| | | | | | | |
Collapse
|
29
|
Abstract
Intravenous magnesium has been suggested as a treatment for certain emergency conditions for more than 60 years. It is currently proposed to be beneficial in treating asthma, preeclampsia, eclampsia, myocardial infarction, and cardiac arrhythmias. The use and efficacy of the drug, however, are controversial. This article discusses the current state of magnesium sulfate research and therapy.
Collapse
Affiliation(s)
- M A Frakes
- Douglas County Division of EMS, Lawrence, KS, USA
| | | |
Collapse
|
30
|
Wiles ME, Wagner TL, Weglicki WB. Effect of acute magnesium deficiency (MgD) on aortic endothelial cell (EC) oxidant production. Life Sci 1996; 60:221-36. [PMID: 9000647 DOI: 10.1016/s0024-3205(96)00619-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Magnesium deficiency (MgD) has been associated with production of reactive oxygen species, cytokines, and eicosanoids, as well as vascular compromise in vivo. Although MgD-induced inflammatory change occurs during "chronic" MgD in vivo, acute MgD may also affect the vasculature and consequently, predispose endothelial cells (EC) to perturbations associated with chronic MgD. As oxyradical production is a significant component of chronic MgD, we examined the effect of acute MgD on EC oxidant production in vitro. In addition we determined EC; pH, mitochondrial function, lysosomal integrity and general cellular antioxidant capacity. Decreasing Mg2+ (< or = 250microM) significantlyincreased EC oxidant production relative to control Mg2+ (1000microM). MgD-induced oxidant production, occurring within 30min, was attenuated by EC treatment with oxyradical scavengers and inhibitors of eicosanoid biosynthesis. Coincident with increased oxidant production were reductions in intracellular glutathione (GSH) and corresponding EC alkalinization. These data suggest that acute MgD is sufficient for induction of EC oxidant production, the extent of which may determine, at least in part, the extent of EC dysfunction/injury associated with chronic MgD.
Collapse
Affiliation(s)
- M E Wiles
- The George Washington University Medical Center, Division of Experimental Medicine, Washington, D.C., USA.
| | | | | |
Collapse
|
31
|
Hennekens CH, Albert CM, Godfried SL, Gaziano JM, Buring JE. Adjunctive drug therapy of acute myocardial infarction--evidence from clinical trials. N Engl J Med 1996; 335:1660-7. [PMID: 8929364 DOI: 10.1056/nejm199611283352207] [Citation(s) in RCA: 158] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- C H Hennekens
- Department of Medicine, Brigham and Women's Hospital, Boston, MA 02215-1204, USA
| | | | | | | | | |
Collapse
|
32
|
Abstract
Magnesium possesses numerous salutary effects for the treatment of acute myocardial infarction (AMI). It is a coronary vasodilator, calcium antagonist, afterload reducer, antiarrhythmic, and antiplatelet drug that modulates autonomic function and limits reperfusion injury when administered early in infarction. Various clinical trials of magnesium therapy for AMI have proffered conflicting results as to the efficacy of magnesium therapy because of significant differences in the timing of magnesium administration. Additional clinical trials that focus on early administration of magnesium are warranted to delineate the role of magnesium therapy for AMI.
Collapse
Affiliation(s)
- L E Rabbani
- Columbia University College of Physicians and Surgeons, Presbyterian Hospital, New York, New York, USA
| | | |
Collapse
|
33
|
Elwood PP. Magnesium and coronary heart disease. NUTR BULL 1996. [DOI: 10.1111/j.1467-3010.1996.tb00851.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
34
|
Shechter M, Hod H, Kaplinsky E, Rabinowitz B. The rationale of magnesium as alternative therapy for patients with acute myocardial infarction without thrombolytic therapy. Am Heart J 1996; 132:483-6; discussion 496-502. [PMID: 8694008 DOI: 10.1016/s0002-8703(96)90340-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Only one third of hospitalized patients with acute myocardial infarction receive thrombolytic therapy despite its proven benefits on outcomes. Elderly patients, for example, have a greater risk of death after myocardial infarction, but studies demonstrate that thrombolytic therapy is less likely to be used in older patients. Intravenous magnesium supplementation, both theoretically and experimentally, has been demonstrated to decrease myocardial damage and reduce the mortality rate in subsets of patients, including the elderly and/or patients not suitable for thrombolysis, if it is administered before reperfusion occurs. The aim of this study is to review the rationale for patients with acute myocardial infarction without thrombolytic therapy.
Collapse
Affiliation(s)
- M Shechter
- Heart Institute, Sheba Medical Center, Tel Hashomer, Israel
| | | | | | | |
Collapse
|
35
|
Gawaz M, Ott I, Reininger AJ, Heinzmann U, Neumann FJ. Agglutination of isolated platelet membranes. Arterioscler Thromb Vasc Biol 1996; 16:621-7. [PMID: 8963718 DOI: 10.1161/01.atv.16.5.621] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Platelet membrane glycoproteins play a central role in platelet aggregation and thus in primary hemostasis. To investigate mechanisms of platelet-platelet interaction in the absence of cellular activation events, we studied immunological and functional aspects of isolated platelet membranes. Platelet membranes contained significant amounts of the inducible fibrinogen receptor, glycoprotein (GP) IIb-IIIa, which exposes conformation-dependent LIBS1 and PMI-1 epitopes in response to fibrinogen-mimetic peptides GRGDSP and HHLG-GAKQAGDV. In the presence of soluble fibrinogen, membrane-coated latex beads showed Ca(2+)-dependent agglutination that could be partially inhibited by GRGDSP but not by the biologically inactive peptide GRGESP. Thrombospondin enhanced agglutination of membrane-coated beads, which could be inhibited by polyvalent anti-thrombospondin Fab fragments and anti-thrombospondin monoclonal antibody MA-II. Mg2+ inhibited both GPIIb-IIIa- and thrombospondin-mediated agglutination of membranes in a dose-dependent manner. The results of the present study indicate that isolated platelet membranes are a useful tool to study regulation of GPIIb-IIIa- and thrombospondin-mediated platelet-platelet interaction.
Collapse
Affiliation(s)
- M Gawaz
- I Medizinische Klinik, Technische Universität München, Germany
| | | | | | | | | |
Collapse
|
36
|
|
37
|
Bhargava B, Chandra S, Agarwal VV, Kaul U, Vashishth S, Wasir HS. Adjunctive magnesium infusion therapy in acute myocardial infarction. Int J Cardiol 1995; 52:95-9. [PMID: 8749868 DOI: 10.1016/0167-5273(95)02455-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Intravenous magnesium therapy in acute myocardial infarction (MI) has been shown to be beneficial in many studies. However, these effects are not consistent from one trial to another, and their clinical significance is often questionable. A total of 78 consecutive patients were included in a prospective placebo controlled, randomized study of the effects of intravenous magnesium sulfate infusion in acute MI. Of these, 52 (66%) received intravenous streptokinase and the rest belonged to a non-thrombolysed group. These patients were randomized to receive magnesium sulfate infusion (8 mmol over 5 min followed by 65 mmol over 24 h) or placebo. The end points were serious arrhythmias, left ventricular ejection fraction (LVEF) and death during hospital stay and at the end of 28 days. LVEF measured by radionuclide ventriculography at discharge (9 +/- 5 days) was similar in two groups (41 +/- 11 vs. 39 +/- 10; magnesium vs. placebo respectively, P = 0.40). However, the LVEF of the placebo-treated thrombolysed group was higher than the non-thrombolysed group (42 +/- 10 vs. 37 +/- 0, P = 0.02). Incidence of nonsustained ventricular tachycardia (NSVT) was higher with placebo than with magnesium (50% vs. 23% respectively, P < 0.02, odds ratio = 0.29; 95% confidence intervals (CI) 0.1-0.85). Mortality during hospital stay and at the end of 28 days was also similar in both the groups. Thus, the administration of magnesium infusion as an adjunct to thrombolytic therapy remains to be of questionable benefit.
Collapse
Affiliation(s)
- B Bhargava
- Cardiothoracic Sciences Centre, All India Institute of Medical Sciences, New Delhi
| | | | | | | | | | | |
Collapse
|
38
|
Haigney MC, Silver B, Tanglao E, Silverman HS, Hill JD, Shapiro E, Gerstenblith G, Schulman SP. Noninvasive measurement of tissue magnesium and correlation with cardiac levels. Circulation 1995; 92:2190-7. [PMID: 7554201 DOI: 10.1161/01.cir.92.8.2190] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Intracellular magnesium ([Mg]i) plays an important role in the regulation of myocardial metabolism, contractility, and the maintenance of transsarcolemmal and intracellular ionic gradients. An understanding of the role of magnesium in the clinical setting, however, is hampered by the lack of an assay of intracellular tissue magnesium levels. METHODS AND RESULTS We used energy-dispersive x-ray analysis to measure [Mg]i in sublingual epithelial cells and to correlate the level with those in atrial biopsy specimens from the same patients during cardiopulmonary bypass. Levels were also measured in acute myocardial infarction (AMI) patients before and after intravenous magnesium sulfate administration and compared with those from intensive care unit (ICU) patients and healthy individuals. A strong correlation between sublingual epithelial cell (mean, 32.1 +/- 0.3 mEq/L) and atrial tissue (mean, 32.1 +/- 0.3 mEq/L) [Mg]i was present in 18 cardiac surgery patients (r = .68, P < .002). Epithelial and atrial [Mg]i levels were lower than in healthy individuals (33.7 +/- 0.5 mEq/L, P < .01) studied at that time and correlated poorly with serum magnesium. Mean [Mg]i in 22 AMI patients was 30.7 +/- 0.4 mEq/L, which was significantly lower than in 21 ICU patients and 15 healthy individuals (35.0 +/- 0.5 mEq/L and 34.5 +/- 0.7 mEq/L, respectively, P < .001). Intravenous magnesium sulfate was administered to most of the AMI patients (mean dose, 36 +/- 6 mmol). [Mg]i rose significantly in the AMI patients over the first 24 hours, and the magnitude of the increase was greater in those who received higher doses of intravenous magnesium sulfate. CONCLUSIONS Sublingual epithelial cell [Mg]i correlates well with atrial [Mg]i but not with serum magnesium. [Mg]i levels are low in patients undergoing cardiac surgery and those with AMI. Intravenous magnesium sulfate corrects low [Mg]i levels in AMI patients. Energy-dispersive x-ray analysis determination of sublingual cell [Mg]i may expedite the investigation of the role of magnesium deficiency in heart disease.
Collapse
Affiliation(s)
- M C Haigney
- Department of Medicine, Johns Hopkins Medical Institutions
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Schlack W, Bier F, Schäfer M, Uebing A, Schäfer S, Borchard U, Thämer V. Intracoronary magnesium is not protective against acute reperfusion injury in the regional ischaemic-reperfused dog heart. Eur J Clin Invest 1995; 25:501-9. [PMID: 7556368 DOI: 10.1111/j.1365-2362.1995.tb01736.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Intravenous magnesium lowers mortality in patients with suspected myocardial infarction. We tested the hypothesis that the protective effect may be due to a direct, local influence of magnesium on myocardial reperfusion injury in a dog model of ischaemia/reperfusion. Ten anaesthetized open chest dogs underwent 1 h of left anterior descending artery (LAD) occlusion and 6 h of reperfusion. The animals received intracoronary (i.c.) magnesium aspartate (Mg, n = 5) or vehicle infusion (n = 5) for the first hour of reperfusion. Mg infusion was adapted to actual LAD flow (ultrasonic flow probe) to increase regional plasma concentration by 4 mmol L-1. Regional myocardial function was measured as percent systolic wall thickening (sWTh, sonomicrometry). Intracoronary Mg increased LAD flow during application (at 15 min reperfusion; Mg, 194 +/- 44 (mean +/- SD); control, 116 +/- 41 mL min-1 100 g-1, P < 0.01). sWTh decreased during coronary occlusion from 14.3 +/- 7.1% to -4.7 +/- 2.7% in the control group and from 14.8 +/- 2.5% to -4.1 +/- 3.1% in the Mg group. Throughout the reperfusion period wall function remained depressed in both groups to a similar degree (control, -3.5 +/- 1.8%; Mg, -3.0 +/- 1.9% at 6 h reperfusion). Global haemodynamics were not different. Infarct size after 6 h reperfusion (TTC staining) was similar in both groups (Mg, 20.6 +/- 5.0; control, 24.4 +/- 8.7% of area at risk). Regional magnesium application (i.c.) to post-ischaemic reperfused myocardium had no influence on infarct size or post-ischaemic regional wall function in this model.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- W Schlack
- Abt. für Herz- und Kreislaufphysiologie, Heinrich-Heine-Universität, Dusseldorf, Germany
| | | | | | | | | | | | | |
Collapse
|
40
|
Shechter M, Hod H, Chouraqui P, Kaplinsky E, Rabinowitz B. Magnesium therapy in acute myocardial infarction when patients are not candidates for thrombolytic therapy. Am J Cardiol 1995; 75:321-3. [PMID: 7856520 DOI: 10.1016/s0002-9149(99)80546-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Thrombolytic therapy reduces in-hospital mortality. However, 70% to 80% of patients do not receive thrombolysis and their in-hospital mortality is high. During the last decade some clinical trials demonstrated that magnesium sulfate reduced in-hospital mortality. The aim of this study was to evaluate the effects of magnesium sulfate in patients with acute myocardial infarction (AMI) who were considered unsuitable for thrombolytic therapy. Intravenous magnesium sulfate was evaluated in 194 patients with AMI ineligible for thrombolytic therapy in a randomized, double-blind, placebo-controlled study. Group I consisted of 96 patients who received 48-hour intravenous magnesium. Group II consisted of 98 patients who received isotonic glucose as a placebo. Magnesium reduced the incidence of arrhythmias, congestive heart failure, and conduction disturbances compared with placebo (27% vs 40%, p = 0.04; 18% vs 23%, p = 0.27; 10% vs 15%, p = 0.21, respectively). Left ventricular ejection fraction 72 hours and 1 to 2 months after admission was higher in patients who received magnesium sulfate than in those taking placebo (49% vs 43% and 52% vs 45%; p = 0.01, respectively). In-hospital mortality was significantly reduced in patients receiving magnesium sulfate than in those receiving placebo (4% vs 17%; p < 0.01), and also in the subgroup of elderly patients (> 70 years) (9% vs 23%; p = 0.09). In conclusion, magnesium sulfate should be considered as an alternative therapy to thrombolysis in patients with AMI.
Collapse
Affiliation(s)
- M Shechter
- Heart Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | | | | | | | | |
Collapse
|
41
|
Affiliation(s)
- P C Elwood
- MRC Epidemiology Unit, Llandough Hospital, Penarth, South Glamorgan
| |
Collapse
|
42
|
Woods KL, Fletcher S. Long-term outcome after intravenous magnesium sulphate in suspected acute myocardial infarction: the second Leicester Intravenous Magnesium Intervention Trial (LIMIT-2). Lancet 1994; 343:816-9. [PMID: 7908076 DOI: 10.1016/s0140-6736(94)92024-9] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The second Leicester Intravenous Magnesium Intervention Trial (LIMIT-2) examined the effect of an intravenous regimen of magnesium sulphate in 2316 patients with suspected acute myocardial infarction. Treatment, according to a double-blind randomised protocol, was started with a loading injection, before any thrombolytic therapy, and continued with a maintenance infusion for a further 24 h. Cause-specific mortality of randomised patients has now been examined over 1.0-5.5 (mean 2.7) years of follow-up. Mortality rate from ischaemic heart disease was reduced by 21% (95% CI 5-35%, p = 0.01) and all-cause mortality rate reduced by 16% (2-29%, p = 0.03) in magnesium-treated patients. Magnesium protects the contractile function of the myocardium from reperfusion injury ("stunning") in experimental models; this observation accords with the 25% (7-39%, p = 0.009) reduction in early left ventricular failure in the magnesium group of LIMIT-2. For such protection to occur, magnesium must be raised by the time of reperfusion since the injury is immediate. In the clinical context the timing of magnesium treatment in relation to thrombolytic therapy or spontaneous reperfusion is likely to be critical. The early benefits of this simple and safe intervention are reflected in improved long-term survival.
Collapse
Affiliation(s)
- K L Woods
- Department of Medicine and Therapeutics, University of Leicester, UK
| | | |
Collapse
|
43
|
Bashir Y, Sneddon JF, Staunton HA, Haywood GA, Simpson IA, McKenna WJ, Camm AJ. Effects of long-term oral magnesium chloride replacement in congestive heart failure secondary to coronary artery disease. Am J Cardiol 1993; 72:1156-62. [PMID: 8237806 DOI: 10.1016/0002-9149(93)90986-m] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Magnesium deficiency frequently develops in patients with congestive heart failure and may increase susceptibility to lethal arrhythmias and sudden death via multiple pathophysiologic mechanisms. The effects of peroral magnesium supplementation were investigated in a randomized, double-blind, crossover trial involving 21 patients with stable congestive heart failure secondary to coronary artery disease. All were receiving long-term loop diuretics, and had normal renal function, and low or normal serum magnesium concentrations. Subjects alternately received enteric-coated magnesium chloride (15.8 mmol magnesium per day) and placebo for 6 weeks. Magnesium therapy increased serum magnesium from 0.87 +/- 0.07 to 0.92 +/- 0.05 mmol/liter (p < 0.05), serum potassium from 4.0 +/- 0.3 to 4.3 +/- 0.4 mmol/liter (p < 0.01) and urinary magnesium excretion from 2.82 +/- 0.96 to 4.74 +/- 2.38 mmol/24 hours (p = 0.001). There was no significant change in heart rate or Doppler cardiac index, but mean arterial pressure decreased from 91 +/- 10 to 87 +/- 10 mm Hg (p < 0.05) and systemic vascular resistance from 1,698 +/- 367 to 1,613 +/- 331 dynes s cm-5 (p = 0.047). The frequency of isolated ventricular premature complexes was reduced by 23% (95% confidence interval [CI] 6 to 37%; p < 0.02), couplets by 52% (95% CI 30 to 65%; p < 0.001) and nonsustained ventricular tachycardia episodes by 24% (95% CI 15 to 49%; p < 0.01). Plasma epinephrine decreased from 447 +/- 535 to 184 +/- 106 pg/ml (p = 0.02), but there was no corresponding change in plasma norepinephrine or heart rate variability.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- Y Bashir
- Department of Cardiological Sciences, St. George's Hospital Medical School, London, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
44
|
Yusuf S, Teo K, Woods K. Intravenous magnesium in acute myocardial infarction. An effective, safe, simple, and inexpensive intervention. Circulation 1993; 87:2043-6. [PMID: 8504519 DOI: 10.1161/01.cir.87.6.2043] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
|
45
|
Affiliation(s)
- M A Arsenian
- Department of Internal Medicine, Cape Ann Medical Center, Gloucester, MA 01930
| |
Collapse
|
46
|
Horner SM. Efficacy of intravenous magnesium in acute myocardial infarction in reducing arrhythmias and mortality. Meta-analysis of magnesium in acute myocardial infarction. Circulation 1992; 86:774-9. [PMID: 1387591 DOI: 10.1161/01.cir.86.3.774] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND To ascertain the effect of the intravenous administration of magnesium in acute myocardial infarction on the frequency of arrhythmias and mortality, a meta-analysis of randomized controlled trials was performed. METHODS AND RESULTS The study included 930 patients with acute myocardial infarction admitted to primary referral hospitals. Administration of magnesium in acute myocardial infarction was associated with a 49% reduction in ventricular tachycardia and fibrillation. The incidence of cardiac arrest was reduced by 58%. The frequency of supraventricular tachycardias was also lower. Overall, there was a 54% reduction in mortality. CONCLUSIONS Intravenous magnesium is a safe and effective method of reducing the frequency of arrhythmias and mortality in acute myocardial infarction.
Collapse
Affiliation(s)
- S M Horner
- Department of Cardiology, Middlesex Hospital, London, UK
| |
Collapse
|
47
|
Woods KL, Fletcher S, Roffe C, Haider Y. Intravenous magnesium sulphate in suspected acute myocardial infarction: results of the second Leicester Intravenous Magnesium Intervention Trial (LIMIT-2). Lancet 1992; 339:1553-8. [PMID: 1351547 DOI: 10.1016/0140-6736(92)91828-v] [Citation(s) in RCA: 310] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The cardiovascular actions of the magnesium ion at pharmacological concentrations include coronary and systemic vasodilatation, platelet inhibition, and antiarrhythmic effects. Magnesium has also been reported to protect myocardial tissue in experimental models of ischaemia and reperfusion. Several small clinical trials in suspected acute myocardial infarction have suggested that early mortality can be reduced by intravenous infusion of magnesium salts in the acute phase, but none has been of sufficient size to be conclusive. We therefore conducted a randomised, double blind, placebo controlled study in 2316 patients with suspected acute myocardial infarction who received either intravenous magnesium sulphate (8 mmol over 5 min followed by 65 mmol over 24 h) or physiological saline. The primary outcome measure was 28-day mortality, which was ascertained in 99.3% of patients. The groups were well balanced for prognostic factors. By intention-to-treat analysis mortality from all causes was 7.8% in the magnesium group and 10.3% in the placebo group (2p = 0.04), a relative reduction of 24% (95% confidence interval 1-43%). Within the coronary care unit the incidence of left ventricular failure was reduced by 25% (7-39%) in the magnesium group (2p = 0.009). There was no significant difference between the groups in the incidence of heart block or the use of antiarrhythmic drugs, direct-current cardioversion, or temporary pacing. Myocardial infarction was confirmed in 65% of each group, with closely similar rises in cardiac enzymes. The side-effects of magnesium treatment were transient flushing, related to speed of injection of the loading dose, and an increased incidence of sinus bradycardia (2p = 0.02). Exploratory subgroup analyses of 28-day mortality did not indicate any effect modification by thrombolysis or aspirin, or by previous treatment with beta blockers, calcium antagonists, or diuretics. Intravenous magnesium sulphate is a simple, safe, and widely applicable treatment. Its efficacy in reducing early mortality of myocardial infarction is comparable to, but independent of, that of thrombolytic or antiplatelet therapy.
Collapse
Affiliation(s)
- K L Woods
- Department of Pharmacology and Therapeutics University of Leicester, UK
| | | | | | | |
Collapse
|
48
|
Izumi Y, Roussel S, Pinard E, Seylaz J. Reduction of infarct volume by magnesium after middle cerebral artery occlusion in rats. J Cereb Blood Flow Metab 1991; 11:1025-30. [PMID: 1939380 DOI: 10.1038/jcbfm.1991.170] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effects of magnesium, an endogenous inhibitor of calcium entry into neurons, upon ischemic brain damage were investigated using a well-characterized model of focal cerebral ischemia in rats. Infarct volumes were determined by 2,3,5-triphenyltetrazolium chloride transcardiac perfusion 48 h after middle cerebral artery (MCA) occlusion. The area of ischemic damage was quantified by image analysis in coronal sections taken every 0.5 mm. MgCl2 (1 mmol/kg) was injected intraperitoneally just after MCA occlusion and again 1 h later. Posttreatment with MgCl2 (16 control and 16 treated rats) significantly reduced the cortical infarct volume. Compensation for the hyperglycemic effect of MgCl2 with insulin (17 rats) further reduced the infarct volume in the neocortex. No systemic effects of either treatment could account for the observed neuroprotection.
Collapse
Affiliation(s)
- Y Izumi
- Laboratoire de Recherches Cérébrovasculaires, CNRS UA 641, Université Paris VII, France
| | | | | | | |
Collapse
|
49
|
Affiliation(s)
- K L Woods
- Department of Pharmacology and Therapeutics, University of Leicester
| |
Collapse
|
50
|
Becker RC, Gore JM. Adjunctive use of beta-adrenergic blockers, calcium antagonists and other therapies in coronary thrombolysis. Am J Cardiol 1991; 67:25A-31A. [PMID: 1671315 DOI: 10.1016/0002-9149(91)90085-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The availability of thrombolytic agents for use in the treatment of acute myocardial infarction is an important step in the management of a common, often debilitating, and potentially lethal disorder. However, despite the proven benefits of coronary thrombolysis, the importance of adjunctive treatment modalities is being increasingly recognized. Beta-adrenergic blockers, calcium antagonists, nitrates, magnesium, and angiotensin-converting enzyme inhibitors each exert favorable cardiovascular properties that may offer additional benefits. Clinical trials combining thrombolytic and adjunctive pharmacologic agents offer hope for further advances in the treatment of acute myocardial infarction.
Collapse
Affiliation(s)
- R C Becker
- Division of Cardiovascular Medicine, University of Massachusetts Medical School, Worcester 01655
| | | |
Collapse
|