Elevated serum creatinine is associated with 1-year mortality after acute myocardial infarction

Background Cardiovascular mortality is high in individuals with end-stage renal disease. However, less is known about the prognostic importance of moderate renal insufficiency in patients with acute myocardial infarction. Methods We studied all patients with acute myocardial infarction admitted through the emergency department to an urban, academic hospital over 1 year. Patients were classified as having elevated (>133 μmol/L [1.5 mg/dL]) or normal (≤133 μmol/L) serum creatinine at presentation. Results Of 483 patients, 22% had elevated creatinine and 78% had normal creatinine. By 1 year, 46% of patients with elevated creatinine and 15% of patients with normal creatinine had died (P < .001). The unadjusted hazard ratio for 1-year mortality was increased in patients with elevated creatinine compared with those with normal creatinine (hazard ratio 3.85, 95% CI 2.61-5.67). After adjustment for baseline characteristics and treatment, the multivariable-adjusted hazard ratio for 1-year mortality remained increased in patients with elevated creatinine compared with those with normal creatinine (hazard ratio 2.40, 95% CI 1.55-3.72). There was an important modification of the prognostic value of creatinine by the presence of congestive heart failure at presentation (P value for interaction = .04). The adjusted hazard ratio for 1-year death associated with elevated creatinine compared with normal creatinine was 3.89 (95% CI 1.87-8.07) in patients without congestive heart failure and 1.92 (95% CI 1.10-3.36) in patients with congestive heart failure. Conclusions Elevated serum creatinine at presentation is associated with 1-year mortality after acute myocardial infarction. Further study is needed to optimize treatment after myocardial infarction in this high-risk group. (Am Heart J 2002;144:1003-1011.)     

Elevated factor XIII level and the risk of myocardial infarction in women

Factor XIII (FXIII) activity and antigen levels were determined in 955 patients investigated by coronary angiography. Patients were sub-grouped according to the presence or absence of coronary sclerosis (CS+, CS-) and a positive history of myocardial infarction (MI+, MI-). In females, but not in males, adjusted FXIII activity and antigen levels were significantly elevated in the CS+MI+ group compared to in the CS+MI- group. FXIII levels in the upper tertile were associated with significantly increased risk of MI in females, but not in males.     

Comparison of new point-of-care troponin assay with high sensitivity troponin in diagnosing myocardial infarction

Objectives

The aim of this study is to compare a new improved point of care cardiac troponin assay (new POC-cTnI) with 1. its predecessor (old POC-cTnI) and 2. a high sensitivity assay (hs-cTnI) for the diagnosis of acute myocardial infarction (AMI) and for major adverse cardiac events (MACE) by 30 days.

Methods

This is a single centre observational study, set in Christchurch Hospital, New Zealand. Patients presenting to the emergency department with non-traumatic chest pain underwent blood sampling at 0 h and 2 h post presentation for analysis with the 3 cTnI assays for the outcome of AMI and for analysis using an accelerated diagnostic protocol (ADP-normal 2 h troponins, normal electrocardiograms and Thrombolysis In Myocardial Infarction (TIMI) score of 0 or ≤ 1) for 30 day MACE.

Results

Of 962 patients, 220 (22.9%) had AMI. Old POC-cTnI was least sensitive at 70.0% (65.4–73.9%) by 2 h (p < 0.001). New POC-cTnI, sensitivity 93.6% (89.9–96.2%) had similar sensitivity to hs-cTnI, sensitivity 95.0% (91.5–97.3%) (p = 0.508). There were 231 (24.0%) patients with 30 day MACE. When used as part of the ADP, all assays had 100% (98.0–100%) sensitivity using TIMI = 0. Sensitivities of new POC-cTnI ADP, 98.3% (95.4–99.4%), old POC-cTnI, 96.5% (93.2–98.4%) and hs-cTnI, 98.7% (96.0–99.7%) were similar (p = 0.063–0.375) using TIMI ≤ 1.

Conclusions

A new POC-cTnI has improved sensitivity for AMI and MACE compared with its predecessor and comparable sensitivity to a high sensitivity assay. Now that sensitivities of the POC assay are improved, the new assay may be a useful alternative to central laboratory assays when rapid turn-around times are not possible.     

Alterations in cardiac troponin subunits in myocardial infarction

1. Alterations in troponin subunits in myocardial infarction were studied in the dog heart by the analysis of troponin-tropomyosin complex, i.e, native tropomyoin, of total structural proteins in SDS gel electrophoresis, and by the measurement of degree of activation of actomyosin-ATPase by Ca++. 2. At 12 to 24 hours after coronary ligation, reductions in TN-C and tropomyosin were observed followed by a decrease in TN-I at 48 hours. The relative contents of these subunits were the lowest at 72 hours to 7 days falling to less than 10% of those in the non-ischemic myocardium. On the contrary, TN-T was preserved through the course of myocardial infarction. 3. Actomyosin-ATPase activity was increased at 12 to 24 hours after coronary ligation and then reduced rapidly at 24 to 48 hours together with the degradation of myosin. However, the activation of actomyosin-ATPase by Ca++-troponin-tropomyosin was reduced already at 12 hours simultaneously with the reduction in TN-C, and almost completely lost at 48 hours. 4. Troponin subunits and actomyosin-ATPase activity returned to those of the control myocardium at 28 days after coronary ligation indicating the recovery of infarcted tissue.     

Elevated troponin levels associated with hemolysis

A 75-year-old African American man with a history of gastroesophageal reflux reported chest pain during an episode of intravascular hemolysis. Although the electrocardiogram and echocardiogram were unchanged from baseline, cardiac troponin I was persistently elevated. Cardiac catheterization showed no critical disease, and the elevated troponin was attributed to interference by free hemoglobin and/or bilirubin. Hemoglobinemia and hyperbilirubinemia may produce either false-positive or false-negative troponin levels, depending on the assay used and the form or subunit of troponin measured. In the presence of hemolysis, troponin levels must be interpreted with caution.     

血浆同型半胱氨酸水平与心肌梗死的相关性

目的探讨血浆同型半胱氨酸(Hcy)水平与心肌梗死的关系。方法我院2012年1月至2013年12月间收治的40例心肌梗死患者作为心肌梗死组,选取同期行健康体检的正常人40例作为非心肌梗死组,比较两组血浆Hcy水平及治疗后心肌梗死组患者Hcy水平,分析心肌梗死危险因素。结果心肌梗死组患者血浆Hcy水平明显高于非心肌梗死组,治疗后,心肌梗死组Hcy水平较治疗前有明显下降,差异均具有统计学意义(P0.05);血浆Hcy高表达为心肌梗死独立危险因素。结论血浆Hcy水平与心肌梗死有一定的相关性,高Hcy为心肌梗死的独立危险因素。     

血清肌钙蛋白I诊断急性心肌梗塞的研究

用抗人心肌肌钙蛋白Ｉ（ｃＴｎＩ）单抗，建立酶联法检测血清ｃＴｎＩ，测健康人、室上性心动过速及陈旧性心梗患者的血清ｃＴｎＩ浓度为０～７μｇ／Ｌ（参照值）。重复检测差异小于８．７％，回收率１００．１％。６１例急性心肌梗塞（ＡＭＩ）病人血清ｃＴｎＩ均大于７μｇ／Ｌ。未溶栓患者胸痛后４～６小时血清ｃＴｎＩ上升，其峰值时间、上升曲线与ＣＫ－ＭＢ相似，峰值是参照值上限的２４倍。ｃＴｎＩ在血清中持续升高至少５天。溶栓治疗后血管再通病人血清ｃＴｎＩ峰值提前６小时，幅度增高。在溶栓治疗后８～１２小时，ｃＴｎＩ显著高于溶栓未通或未溶栓（未自溶）病人（Ｐ＜０．０５）。作者认为，用抗人ｃＴｎＩ单抗检测血清ｃＴｎＩ是诊断ＡＭＩ敏感与特异的指标之一。溶栓后连续检测ｃＴｎＩ还可能成为判断冠状动脉再通的指标之一。     

Diagnostic value of small concentrations of troponin in patients with myocardial infarction

We have reviewed here studies of measurement of small concentrations of troponin in patients with myocardial infarction conducted in 2010-2011 which were most significant for the clinic. Troponin is a most specific and sensitive cardiomarker appearance of which in blood serum evidence for a necrotic process in cardiac muscle. We discuss the problem of interpretation of small troponin concentrations by clinicians as well as the states in which appearance of the cardiomarker in blood serum has noncardiac origin. We also discuss novel possibilities of application of troponin as a prognostic marker in patients with stable or unstable angina after revascularization procedures.     

Angina intensity is not different in diabetic and non-diabetic patients with acute myocardial infarction

BACKGROUND: Diabetic patients with acute myocardial infarction (AMI) may have diminished pain or a higher frequency of asymptomatic infarctions. This appears to be a common clinical perception. METHODS: Data from two registries of AMI patients presenting in hospital (MITRA PLUS with 18786 patients; North German Registry, NGR, 1042 patients with detailed symptom interviews) were analyzed concerning symptoms of acute myocardial infarction in patients with diabetes mellitus (DM) and without diabetes (non-DM). RESULTS: DM patients were significantly older and more often female than non-DM. There were no differences in the frequency of pre-infarction angina between DM and non-DM (Mitra Plus). In NGR, severe angina during AMI occurred in 49.8% of DM and 46.3% of non-DM (n. s.). No chest pain was reported in 16.9% of DM and 15.0% of non-DM (n. s.). Extra-thoracic pain, dizziness, nausea, sweating, palpitations, radiation of angina and localization of radiating pain was not different between DM and non-DM patients. Severe dyspnea occurred in 29.5% of DM and 19.5% of non-DM patients (p = 0.003). CONCLUSIONS: Apart from a higher frequency of severe dyspnea in diabetics, there appears to be no difference in the clinical symptoms of AMI patients with and without diabetes mellitus. AMI with little or no angina was also frequently found in non-diabetics. In the hospital, diabetics with suspected AMI do not appear to need a special judgement of symptoms. This could accelerate access of diabetics to standard therapeutic procedures.     

Elevated skin tissue cholesterol levels and myocardial infarction

BACKGROUND: Skin cholesterol has been associated with coronary artery disease, extent of angiographic disease and inflammatory markers such as hs-CRP. Based on these findings we sought to determine whether skin cholesterol was associated with myocardial infarction (MI). METHODS: Patients (N = 649) underwent diagnostic catheterization and concurrent skin cholesterol measurement. History of MI was determined at the time of hospitalization. RESULTS: Patients with a history of MI (n = 225, 35%) had significantly higher skin cholesterol than those without MI (127+/-29 versus 120+/-20, p = 0.002). The odds ratio for high skin cholesterol (for MI) was 1.6 (95% CI = 1.1, 2.6; p = 0.01) after adjustment for traditional risk and extent of angiographic disease. CONCLUSION: Skin cholesterol may indicate increased risk of coronary-related events rather than simply the presence of angiographic narrowing.     

Cardiac troponin T is not increased in patients with hypothyroidism

Patients with hypothyroidism often have increased creatine kinase (CK) levels. It is possible that there is increased production of CK, but other mechanisms, such as an increased cell membrane permeability or decreased enzyme clearance were also proposed. Recently, troponins T and I have been extensively studied because of their cardiac specificity. Cardiac troponins are sensitive and specific markers of cardiac injury. The objective of the study was to measure cardiac troponin T (cTnT) levels in patients with hypothyroidism. Twenty-five patients with primary hypothyroidism were evaluated (thyroid-stimulating hormone (TSH) >30 mU/L and low FT₄). In all patients thyrotropin (TSH), free thyroxine (FT₄), CK, CK-MB and cTnT were measured.There were 3 men and 22 women with a mean age of 47.5 ± 12.4 years. TSH levels ranged from 31 to 75 mIU/L and mean FT₄ levels were 4.5 ± 1.9 pmol/L. CK was normal in 11 patients and increased in 14. CK levels ranged between 86 and 1221 U/L (normal levels <170 in women, <195 in men) with a mean of 322 U/L ± 279. CK-MB was increased in 4 patients (16%) and normal in 21. All 25 patients had normal cTnT levels, < 0.01 ng/mL (normal levels 0–0.1 μg/L). Increase in CK and its MB fraction are common in patients with hypothyroidism but cTnT levels are not, even in patients with increased CK-MB. Therefore, cTnT is a reliable marker of cardiac injury even in the hypothyroid patient.     

升高的单核细胞/淋巴细胞比值与老年急性心肌梗死患者住院期间死亡风险相关

目的]探讨升高的单核细胞/淋巴细胞比值(MLR)与老年急性心肌梗死(AMI)患者住院期间死亡风险之间是否相关。 [方法]回顾性收集2015年12月─2021年12月在大连医科大学附属第二医院心血管内科住院治疗的老年AMI患者的病史资料,共1 550例,其中发生住院期间死亡的患者共132例。主要包括性别、年龄、身高、体质量、血常规、血脂相关指标、空腹血糖、心肌酶、心肌梗死类型、估算的肾小球滤过率(eGFR)、住院期间结局、心力衰竭、糖尿病和高血压患病情况以及住院期间他汀类药物、抗血小板药物的使用情况。根据ROC曲线分析结果,将MLR＞0.342的患者定义为高MLR组(n＝699),MLR≤0.342的患者则定义为低MLR组(n＝851)。 [结果]高MLR组患者的年龄、白细胞计数、单核细胞计数、MLR、心肌肌钙蛋白I(cTnI)、空腹血糖(FBG)、eGFR＜60 mL/(min·1.73 m²)、男性患者、心力衰竭、住院期间发生全因死亡人数的比例均高于低MLR组(P＜0.05),体质指数(BMI)、淋巴细胞计数、低密度脂蛋白胆固醇(LDLC)、eGFR＞60 mL/(min·1.73 m²)、高血压、使用抗血小板类药物的人数均低于低MLR组(P＜0.05)。多因素逻辑回归结果显示,高MLR与老年AMI患者住院期间死亡风险独立相关(OR＝1.812,95%CI:1.106～2.969,P＝0.018)。ROC曲线分析结果显示,MLR联合cTnI或FBG后其预测能力显著提升,ROC曲线下面积分别为0.789和0.739。限制性立方样条(RCS)分析结果显示,MLR与老年AMI患者住院结局之间存在线性的剂量-反应关系。 [结论]升高的MLR与老年AMI患者住院期间死亡风险独立相关,临床医生可在日常诊疗中考虑使用MLR指标对这类患者进行风险分层和相关处置以改善其短期预后。     

Plasma troponin levels after cardiac surgery vs after myocardial infarction

Raised plasma troponin, a diagnostic marker for myocardial infarction, usually occurs after cardiac surgery, leading to difficulties in diagnosing postoperative myocardial infarction. To ascertain whether the same processes influence troponin elevation in both conditions, a literature search was performed for plasma troponin elimination curves after myocardial infarction, myocardial infarction with reperfusion, and cardiac surgery. From 70 studies, 11 curves using the Stratus immunoassay kit were analyzed: 5 post-cardiac surgery (412 patients), 2 after myocardial infarction with reperfusion (169 patients), and 4 after myocardial infarction (640 patients). For each group, a new plot was formulated from the mean troponin level at each time interval. While the up-slope of the cardiac surgery curve was much steeper than that of myocardial infarction, resembling that of myocardial infarction with reperfusion, its down-slope was significantly more gentle than that of both other groups (-0.91 vs -5.31, t = 3.47, df = 8, p < 0.01). This suggests that postoperative troponin elevation involves enhanced cell permeability as seen after ischemia reperfusion rather than permanent cellular damage. The gentler down-slope may point to surgery-induced impaired troponin removal from the circulation. Due to the different mechanisms proposed, implications from post-myocardial infarction troponin levels may not be conferred on post-cardiac surgery patients.     

Glycoprotein Ia 807TT/873AA genotype is not associated with myocardial infarction.

OBJECTIVE: The glycoprotein Ia/IIa complex is a major platelet collagen receptor. Its surface expression is influenced by two linked single nucleotide polymorphisms (C807T and G873A) in the glycoprotein Ia (GPIa) gene. In this study we aimed to determine the frequency of GPIa C807T/G873A genotype in patients with myocardial infarction (MI) and healthy controls in Turkish population and association between these dimorphisms and risk factors of MI. METHODS: We examined GPIa (C807T/G873A) genotypes in 158 patients with MI and 145 healthy controls. Distributions of the C807T and G873A dimorphisms were investigated by genotyping DNA using multiplexed allele-specific PCR. RESULTS: There was no association between GPIa genotypes and MI. We further analysed each group for all known risk factors such as plasma lipid levels, cigarette smoking, diabetes, hypertension, gender, age, MI history and body mass index. When compared with other two genotypes for glycoprotein Ia (GT/GA and CC/GG), TT/AA showed an association with higher high-density lipoprotein (HDL) -cholesterol levels in the healthy control group, but none in the group with MI. CONCLUSION: The 807TT/873AA genotype of the GPIa gene alone or in combination with risk factors had no major effect on MI, however, it appears to be associated with higher HDL-cholesterol levels in healthy subjects.     

Cardiac troponin T in ST-segment elevation acute myocardial infarction revisited

Cardiac troponins not only allow for risk stratification and guidance of therapy in unstable angina and non-Q-wave acute myocardial infarction but also may be useful in the diagnostic workup and monitoring of patients with ST-segment elevation myocardial infarction. In clinical practice, troponins are used for confirmation and monitoring of myocardial infarction, noninvasive prediction of reperfusion success after thrombolytic therapy, and noninvasive estimation of infarct size. Accumulating evidence suggests that the measurement of cardiac troponins on admission may represent a relatively novel application that is useful for early risk stratification and prediction of reperfusion success after thrombolysis or primary percutaneous coronary interventions. Potential mechanisms of the predictive power of cardiac troponins are discussed.