摘要
目的:急性冠脉综合征(Acute Coronary Syndrome,ACS)是冠心病(Coronary Heart Disease,CHD)的最常见类型,包括不稳定型心绞痛(Unstable Angina Pectoris,UAP)、非ST段抬高型心肌梗死(non ST segment Elevation Myocardial Infarction,NSTE-MI)、ST段抬高型心肌梗死(ST segment Elevation Myocardial Infarction,STE-MI),三者在ACS中所占比例分别为12.86%,66.14%,21.00%。其中UAP和NSTE-MI又被称为非ST段抬高型急性冠脉综合征(non ST segment Elevation Acute Coronary Syndrome,NSTE-ACS),斑块破裂诱发非闭塞性血栓形成是NSTE-ACS的主要发病机制。UAP预后变化不定,可发展成急性心肌梗死(Acute Myocardial Infarction,AMI),也可转变为稳定型心绞痛(Stable Angina Pectoris,SAP)。如何在发病早期评价其发生心脏事件的危险性并及时给予正确干预,对改善疾病预后至关重要。心肌损伤标志物的检测对于ACS患者早期诊断、危险分层及处理具有重要的作用,目前临床中主要应用心肌型肌酸激酶同工酶(MB Isotype of Creatine Kinase,CK-MB)和心脏肌钙蛋白Ⅰ(Cardiac Troponin I,cTnI)联合检测的方法。本研究通过对NSTE-ACS患者入院早期(<48h)冠脉造影检查和CK-MB、cTnI的检测结果进行分析,探讨这些患者的临床特征及CK-MB、cTnI结果特点,评价CK-MB、cTnI在NSTE-ACS患者早期危险分层及处理中的作用,力求为临床中更加合理有效应用CK-MB、cTnI联合检测方法提供依据。
方法:检索2004年4月-2007年1月在武警医学院附属医院心内科住院治疗的患者病历,采用回顾性研究的方法,连续入选1074例NSTE-ACS患者,分析入院早期(<48h)冠脉造影结果,并采集症状发作至入院36h内cTnI和CK-MB检测值。以>正常值上限(Upper Limits of Normal,ULN)作为阳性结果,以≤ULN作为阴性结果,据此:
1.将入选患者分为4组:所有标志物阴性组(CK-MB~-/cTnI~-),CK-MB阳性和cTnI阴性组(CK-MB~+/cTnI~-),CK-MB阴性和cTnI阳性组(CK-MB~-/cTnI~+),所有标志物阳性组(CK-MB~+/cTnI~+)。评价组间结果一致与不一致的发生率及早期侵入性检查(<48h)应用情况,统计各组院内主要不良心脏事件(Major Adverse Cardiac Event,MACE)。
2.据cTnI是否阳性,将患者分为cTnI~+组和cTnI~-组,再次比较患者基本临床资料及冠脉造影、MACE,评价cTnI在NSTE-ACS患者危险分层中的作用。
3.据CK-MB是否阳性,对患者上述资料进行比较,评价CK-MB在NSTE-ACS患者危险分层中的作用,同时比较cTnI和CK-MB对NSTE-ACS危险分层的作用。
4.比较CK-MB~+/cTnI~-和CK-MB~-/cTnI~+两组间资料特征,评价这两组对NSTE-ACS危险分层的作用。
5.去除所有肾功能异常患者(Cr>132μmol/L),再次评价四组间基本资料,明确轻度肾功能异常对心肌损伤标志物的影响。
结果:
1.在最初纳入统计的1074名患者中,cTnI~+318人,CK-MB~+356人。两种标志物检测结果一致者共930人,其中CK-MB~-/cTnI~-664人(61.82%),CK-MB~+/cTnI~+患者266人(24.77%)。13.41%的患者CK-MB和cTnI结果不一致(n=90[8.38%]CK-MB~+/cTnI~-;n=54[5.03%]CK-MB/cTnI~+)。
2.在不考虑CK-MB情况下,cTnI~+组较cTnI~-组卒中史发生率(P=0.008)、尿蛋白阳性率(P=0.006)、白细胞(White Blood Corpuscle,WBC)计数异常比例(P=0.01)、冠脉病变支数(2支P=0.018;3支P=0.002)、冠脉病变心血管造影和介入治疗学会分型(Society forCardiac Angiography and Interventions,SCAI)Ⅱ型(P<0.001)、Ⅲ型(P=0.001)、Ⅳ型(P<0.001)病变发生率增多;左室射血分数(Left Ventricular Ejection Fraction,LVEF)值低(P=0.005);MACE发生率增加P<0.001)。
3.在不考虑cTnI的情况下,CK-MB~+组较CK-MB~-组男性比例(P=0.028)、高血压(P=0.001)、尿蛋白阳性(P<0.001)、中风史(P=0.008)、冠脉病变支数(2支P=0.018;3支P=0.004)、冠脉病变SCAI分型Ⅲ型(P=0.004)、Ⅳ型(P<0.001)病变增多;LVEF值低(P=0.033);院内MACE发生率无统计学差异(P=0.201)。
4.CK-MB~-/cTnI~+与CK-MB~+/cTnI~-两组间各指标比较无统计学差异。
5.无论是单独以cTnI作为标志物(cTnI~+组与cTnI~-组比较P=0.001)还是单独以CK-MB作为标志物(CK-MB~+组与CK-MB~-组比较P=0.003),WBC计数异常比例在阳性组与阴性组间均存在统计学差异。
结论:
1.在NSTE-ACS患者中,cTnI升高能够独立预测患者预后。
2.据入院时检测结果单独CK-MB~+预测价值与单独cTnI~+比较无明显差异。
3.cTnI既是一种心肌细胞损伤标志物,也是反映左室收缩功能受损程度的指标。
4.入院cTnI~+的患者较cTnI~-患者冠脉造影示冠脉病变重,院内MACE增多。
5.尿蛋白异常与NSTE-ACS患者cTnI升高有一定联系。轻度肾功能损害时,cTnI对NSTE-ACS患者预后判断的价值不受影响。
6.WBC计数对NSTE-ACS患者危险分层具有一定临床参考价值。
Objective
ACS (Acute Coronary Syndrome) is an important subtype of CHD(Coronary Heart Disease). It is composed of UAP (Unstable AnginaPectoris), NSTE-MI (non ST segment Elevation Myocardial Infarction),and STE-MI (ST segment Elevation Myocardial Infarction), and theproportion of each component is 12.86%, 66.14%, 21.00% respectively.UAP and NSTE-MI are also called NSTE-ACS (non ST segment ElevationAcute Coronary Syndrome). The main mechanism of ACS is rupture orerosion of the unstable atherosclerotic plaque and thereby incompleteocclusion of the coronary artery by thrombosis. The pathologicalevolution of UAP is uncertain, which can either develop into AMI or runto stable angina pectoris (SAP). Evaluation of the risks in ACS patientsand early initiation of proper therapy is very important for ameliorationof clinical outcome. The purpose of present study is to evaluate theassociation between markers of cardiac injury and early coronaryangiography results, in-hospital myocardial infarction, cardiac death,revascularization and treatment patterns in patients with NSTE-ACS, andto provide a rationale for the interpretation of double detection of cardiacbiomarkers in clinical settings.
Methods
1074 NSTE-ACS patients admitted in the division of cardiology,Medical College Affiliated Hospital of Chinese People's Armed PoliceForces (CPAPF) during Apr, 2004~Jul 2007, whose CK-MB and cTnI were measured within the first 36 hours from symptom onset afteradmission, were enrolled in the present study. All patients receivedcoronary angiography within 48h. Positive results were recorded ifbiomarker>1×upper limit of normal (ULN), and negative result wasrecorded when biomarker≤1×ULN.
1. We examined relationships between results of four markercombinations (CK-MB~-/cTnI~-, CK-MB~+/cTnI~-, CK-MB~-/cTnI~+, andCK-MB~+/cTnI~+) and incidences of in-hospital myocardial infarction,cardiac death and early catheter-based interventions.
2. All patients were assigned to cTnI~+ group and cTnI~- groupaccording to level of cTnI. We examined the relationships between cTnIlevel with demographic and clinical data and incidence of in-hospitalmyocardial infarction, cardiac death and early catheter-basedinterventions.
3. All patients were re-analyzed according to the results of CK-MB.
4. We analyzed the data in CK-MB~+/cTnI~- group and CK-MB~-/cTnI~+group, and evaluated their roles in risk stratification of NSTE-ACS.
5. In another subset of analysis, patients with renal dysfunction(Cr>132μmol/L) were all excluded. Then we reevaluated the data in fourgroups, in order to identify the impact of slight renal functioninsufficiency on the level of cardiac biomarkers.
Results
1. Among 1074 NSTE-ACS patients, 318 were cTnI~+, and 356 wereCK-MB~+. Results from 930 patients were accordant in CK-MB and cTnIlevel, and the other 144 were discordant (n=90 [8.38%] CK-MB~+/cTnI~-;n=54 [5.03%] CK-MB~-/cTnI~+).
2. The incidences of stroke(P=0.008), proteinuria(P=0.006),WBC(White Blood Corpuscle)count(P=0.01), number of damagedcoronary artery(2, P=0.018; 3, P=0.002), SCAI(Society for CardiacAngiography and Interventions)typeⅡ(P<0.001),Ⅲ(P=0.001) and Ⅳ(P<0.001) coronary artery damage and MACE (Main Adverse CardiacEvent) were higher in cTnI~+ group regardless the level of CK-MB.
3. Except for the incidence of MACE (P=0.201), similarly resultswere observed from CK-MB group regardless the level of cTnI.
4. The number and types of damaged coronary artery and theincidence of MACE did not have statistical difference between theCK-MB~-/cTnI~+ and CK-MB~+/cTnI~- group.
5. WBC count was found effective in risk stratification, whetherpatients were grouped by cTnI or by CK-MB.
Conclusions
1. Elevation of cTnI alone can predict a higher risk of NSTE-ACSpatients.
2. Prognostic value of isolated CK-MB~+ is equal to isolated cTnI~+when the tests performed early after admission (<36h).
3. cTnI is considered as both a biomarker of cardiac injury and anindex for the severity of left ventricular systolic function.
4. Poor coronary angiographic and prognostic results seem to beassociated with elevated cTnI level and increased incidence of MACE.
5. The relationship between proteinuria and elevated level of cTnI isstill not very clear. Slight renal dysfunction does not affect the result ofcTnI in MI.
6. WBC count is of clinical importance in risk stratification of ACSpatients.
Recognition of these risk differences may contribute to moreappropriate early use of antithrombotic therapy and invasive managementfor all cTn~+ patients.
引文
[1]. Rosamond W, Flegal K, Friday G, et al. Heart disease and stroke statistics--2007 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2007;115(5):e69-171.
[2]. Ravkilde J. Creatine kinase isoenzyme MB mass, cardiac troponin T, and myosin light chain isotype 1 as serological markers of myocardial injury and their prognostic importance in acute coronary syndrome. Dan Med Bull. 1998;45(1):34-50.
[3]. Wollert KC, Kempf T, Peter T, et al. Prognostic value of growth-differentiation factor-15 in patients with non-ST-elevation acute coronary syndrome. Circulation. 2007;115(8):962-971.
[4]. Ohman EM, Armstrong PW, Christenson RH, et al. Cardiac troponin T levels for risk stratification in acute myocardial ischemia. GUSTO IIA Investigators. N Engl J Med. 1996;335(18):1333-1341.
[5]. Lindahl B, Toss H, Siegbahn A, et al. Markers of myocardial damage and inflammation in relation to long-term mortality in unstable coronary artery disease. FRISC Study Group. Fragmin during Instability in Coronary Artery Disease. N Engl J Med. 2000;343(16):1139-1147.
[6]. Lagerqvist B, Diderholm E, Lindahl B, et al. FRISC score for selection of patients for an early invasive treatment strategy in unstable coronary artery disease. Heart. 2005;91(8): 1047-1052.
[7]. James SK, Lindahl B, Siegbahn A, et al. N-terminal pro-brain natriuretic peptide and other risk markers for the separate prediction of mortality and subsequent myocardial infarction in patients with unstable coronary artery disease: a Global Utilization of Strategies To Open occluded arteries (GUSTO)-IV substudy. Circulation. 2003;108(3):275-281.
[8]. Haverkate F, Thompson SG, Pyke SD, et al. Production of C-reactive protein and risk of coronary events in stable and unstable angina. European Concerted Action on Thrombosis and Disabilities Angina Pectoris Study Group. Lancet. 1997;349(9050):462-466.
[9]. de Lemos JA, Morrow DA, Bentley JH, et al. The prognostic value of B-type natriuretic peptide in patients with acute coronary syndromes. N Engl J Med. 2001;345(14):1014-1021.
[10]. Cannon CP, Weintraub WS, Demopoulos LA, et al. Comparison of early invasive and conservative strategies in patients with unstable coronary syndromes treated with the glycoprotein IIb/IIIa inhibitor tirofiban. N Engl J Med. 2001;344(25):1879-1887.
[11]. Anavekar NS, McMurray JJ, Velazquez EJ, et al. Relation between renal dysfunction and cardiovascular outcomes after myocardial infarction. N Engl J Med. 2004;351(13):1285-1295.
[12]. Westerhout CM, Fu Y, Lauer MS, et al. Short- and long-term risk stratification in acute coronary syndromes: the added value of quantitative ST-segment depression and multiple biomarkers. J Am Coll Cardiol. 2006;48(5):939-947.
[13]. Kini AS, Lee P, Marmur JD, et al. Correlation of postpercutaneous coronary intervention creatine kinase-MB and troponin I elevation in predicting mid-term mortality. Am J Cardiol. 2004;93(1):18-23.
[14]. Jeremias A, Baim DS, Ho KK, et al. Differential mortality risk of postprocedural creatine kinase-MB elevation following successful versus unsuccessful stent procedures. J Am Coll Cardiol. 2004;44(6):1210-1214.
[15]. Mutlu B, Yilmaz A, Sonmez K, et al. Prognostic importance of predischarged troponin T levels in acute anterior myocardial infarction. Jpn Heart J. 2004;45(1):43-52.
[16]. Wu AH. The role of cardiac troponin in the recent redefinition of acute myocardial infarction. Clin Lab Sci. 2004;17(1):50-52.
[17]. Madsen LH, Christensen G, Lund T, et al. Time course of degradation of cardiac troponin I in patients with acute ST-elevation myocardial infarction: the ASSENT-2 troponin substudy. Circ Res. 2006;99(10):1141-1147.
[18]. Ohlmann P, Monassier JP, Michotey MO, et al. Troponin I concentrations following primary percutaneous coronary intervention predict large infarct size and left ventricular dysfunction in patients with ST-segment elevation acute myocardial infarction. Atherosclerosis. 2003;168(1):181-189.
[19]. Licka M, Zimmermann R, Zehelein J, et al. Troponin T concentrations 72 hours after myocardial infarction as a serological estimate of infarct size. Heart. 2002;87(6):520-524.
[20]. Lin JC, Apple FS, Murakami MM, et al. Rates of positive cardiac troponin I and creatine kinase MB mass among patients hospitalized for suspected acute coronary syndromes. Clin Chem. 2004;50(2):333-338.
[21]. Alpert JS, Thygesen K, Antman E, et al. Myocardial infarction redefined--a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. J Am Coll Cardiol. 2000;36(3):959-969.
[22]. Antman EM, Tanasijevic MJ, Thompson B, et al. Cardiac-specific troponin I levels to predict the risk of mortality in patients with acute coronary syndromes. N Engl J Med. 1996;335(18): 1342-1349.
[23]. Heeschen C, Hamm CW, Goldmann B, et al. Troponin concentrations for stratification of patients with acute coronary syndromes in relation to therapeutic efficacy of tirofiban. PRISM Study Investigators. Platelet Receptor Inhibition in Ischemic Syndrome Management. Lancet. 1999;354(9192):1757-1762.
[24]. Newby LK, Ohman EM, Christenson RH, et al. Benefit of glycoprotein IIb/IIIa inhibition in patients with acute coronary syndromes and troponin t-positive status: the paragon-B troponin T substudy. Circulation. 2001;103(24):2891-2896.
[25]. Yee KC, Mukherjee D, Smith DE, et al. Prognostic significance of an elevated creatine kinase in the absence of an elevated troponin I during an acute coronary syndrome. Am J Cardiol. 2003;92(12): 1442-1444.
[26]. Rao SV, Ohman EM, Granger CB, et al. Prognostic value of isolated troponin elevation across the spectrum of chest pain syndromes. Am J Cardiol. 2003;91(8):936-940.
[27]. Thompson PL, Fletcher EE, Katavatis V. Enzymatic indices of myocardial necrosis: influence on short- and long-term prognosis after myocardial infarction. Circulation. 1979;59(1):113-119.
[28]. Hamm CW, Ravkilde J, Gerhardt W, et al. The prognostic value of serum troponin T in unstable angina. N Engl J Med. 1992;327(3): 146-150.
[29]. Stubbs P, Collinson P, Moseley D, et al. Prospective study of the role of cardiac troponin T in patients admitted with unstable angia. Br Med J. 1996;313(7052):262-264.
[30]. Newby LK, Roe MT, Chen AY, et al. Frequency and clinical implications of discordant creatine kinase-MB and troponin measurements in acute coronary syndromes. J Am Coll Cardiol. 2006;47(2):312-318.
[31]. Bodor GS, Porter S, Landt Y, et al. Development of monoclonal antibodies for an assay of cardiac troponin-I and preliminary results in suspected cases of myocardial infarction. Clin Chem. 1992;38(11):2203-2214.
[32]. La Vecchia L, Mezzena G, Ometto R, et al. Detectable serum troponin I in patients with heart failure of nonmyocardial ischemic origin. Am J Cardiol. 1997;80(1):88-90.
[33]. Francis GS, McDonald K, Chu C, et al. Pathophysiologic aspects of end-stage heart failure. Am J Cardiol. 1995;75(3):11A-16A.
[34]. Missove E, Calzolari C, Pau B. High circulating levels of cardiac troponin-I in human congestive heart failure. J Am Coll Cardiol. 1996;27:338A.
[35]. Okazaki T, Tanaka Y, Nishio R, et al. Autoantibodies against cardiac troponin I are responsible for dilated cardiomyopathy in PD-1-deficient mice. Nat Med. 2003;9(12):1477-1483.
[36]. Bertrand ME, Simoons ML, Fox KA, et al. Management of acute coronary syndromes in patients presenting without persistent ST-segment elevation. Eur Heart J. 2002;23(23): 1809-1840.
[37]. Goser S, Andrassy M, Buss SJ, et al. Cardiac troponin I but not cardiac troponin T induces severe autoimmune inflammation in the myocardium. Circulation. 2006; 114(16): 1693-1702.
[38]. Benamer H, Steg PG, Benessiano J, et al. Elevated cardiac troponin I predicts a high-risk angiographic anatomy of the culprit lesion in unstable angina. Am Heart J. 1999; 137(5):815-820.
[39]. Okamatsu K, Takano M, Sakai S, et al. Elevated troponin T levels and lesion characteristics in non-ST-elevation acute coronary syndrome. Circulation. 2002;109(4):465-470.
[40]. Matetzky S, Sharir T, Domingo M, et al. Elevated troponin I level on admission is associated with adverse outcome of primary angioplasty in acute myocardial infarction. Circulation. 2000; 102(14): 1611-1616.
[41]. Morrow DA, Cannon CP, Rifai N, et al. Ability of minor elevations of troponins I and T to predict benefit from an early invasive strategy in patients with unstable angina and non-ST elevation myocardial infarction: results from a randomized trial. Jama. 2001 ;286(19):2405-2412.
[42]. Omland T, Aakvaag A, Bonarjee VV, et al. Plasma brain natriuretic peptide as an indicator of left ventricular systolic function and long-term survival after acute myocardial infarction. Comparison with plasma atrial natriuretic peptide and N-terminal proatrial natriuretic peptide. Circulation. 1996;93(11):1963-1969.
[43]. Antman EM, Tanasijevic MJ, Cannon CP, et al. Cardiac troponin I on admission predicts death by 24 days in unstable angina and improved survival with an early invasive strategy: results from TIMI IIIB. Circulation. 1999; 100 Suppl:I663.
[44]. Invasive compared with non-invasive treatment in unstable coronary-artery disease: FRISC II prospective randomised multicentre study. FRagmin and Fast Revascularisation during Instability in Coronary artery disease Investigators. Lancet. 1999;354(9180):708-715.
[45]. Freda BJ, Tang WH, Van Lente F, et al. Cardiac troponins in renal insufficiency: review and clinical implications. J Am Coll Cardiol. 2002;40(12):2065-2071.
[46]. De Zoysa JR. Cardiac troponins and renal disease. Nephrology (Carlton). 2004;9(2):83-88.
[47]. Muller-Bardorff M, Hallermayer K, Schroder A, et al. Improved troponin T ELISA specific for cardiac troponin T isoform: assay development and analytical and clinical validation. Clin Chem. 1997;43(3):458-466.
[48]. Benjamin MS, David AM. Troponin in Acute Coronary Syndromes. Progress in Cardiovascular Diseases. 2004;47(1): 177-188.
[49]. Apple FS, Murakami MM, Pearce LA, et al. Predictive value of cardiac troponin I and T for subsequent death in end-stage renal disease. Circulation. 2002;106(23):2941-2945.
[50]. Krumholz HM, Chen J, Wang Y, et al. Comparing AMI mortality among hospitals in patients 65 years of age and older: evaluating methods of risk adjustment. Circulation. 1999;99(23):2986-2992.
[51]. Barron HV, Harr SD, Radford MJ, et al. The association between white blood cell count and acute myocardial infarction mortality in patients > or =65 years of age: findings from the cooperative cardiovascular project. J Am Coll Cardiol. 2001 ;38(6): 1654-1661.
[52]. Cannon CP, McCabe CH, Wilcox RG, et al. Association of white blood cell count with increased mortality in acute myocardial infarction and unstable angina pectoris. OPUS-TIMI 16 Investigators. Am J Cardiol. 2001;87(5):636-639, A610.
[53]. Ott I, Neumann FJ, Kenngott S, et al. Procoagulant inflammatory responses of monocytes after direct balloon angioplasty in acute myocardial infarction. Am J Cardiol. 1998;82(8):938-942.
[1]. Rawles J. Magnitude of benefit from earlier thrombolytic treatment in acute myocardial infarction: new evidence from Grampian region early anistreplase trial (GREAT). Bmj. 1996;312(7025):212-215.
[2]. Arrell DK, Neverova I, Van Eyk JE. Cardiovascular proteomics: evolution and potential. Circ Res. 2001 ;88(8):763-773.
[3]. Anderson L. Candidate-based proteomics in the search for biomarkers of cardiovascular disease. J Physiol. 2005;563(Pt 1):23-60.
[4]. Jaffe AS, Katus H. Acute coronary syndrome biomarkers: the need for more adequate reporting. Circulation. 2004; 110(2): 104-106.
[5]. Alpert JS, Thygesen K, Antman E, et al. Myocardial infarction redefined—a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. J Am Coll Cardiol. 2000;36(3):959-969.
[6]. Myocardial infarction redefined--a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. Eur Heart J. 2000;21(18):1502-1513.
[7]. Jaffe AS, Ravkilde J, Roberts R, et al. It's time for a change to a troponin standard. Circulation. 2000; 102(11): 1216-1220.
[8]. Panteghini M, Pagani F, Yeo KT, et al. Evaluation of imprecision for cardiac troponin assays at low-range concentrations. Clin Chem. 2004;50(2):327-332.
[9]. Panteghini M, Gerhardt W, Apple FS, et al. Quality specifications for cardiac troponin assays. Clin Chem Lab Med. 2001 ;39(2): 175-179.
[10]. Eriksson S, Hellman J, Pettersson K. Autoantibodies against cardiac troponins. N Engl J Med. 2005;352(1):98-100.
[11]. Novis DA, Jones BA, Dale JC, et al. Biochemical markers of myocardial injury test turnaround time: a College of American Pathologists Q-Probes study of 7020 troponin and 4368 creatine kinase-MB determinations in 159 institutions. Arch Pathol Lab Med. 2004; 128(2): 158-164.
[12]. Eggers KM, Oldgren J, Nordenskjold A, et al. Diagnostic value of serial measurement of cardiac markers in patients with chest pain: limited value of adding myoglobin to troponin I for exclusion of myocardial infarction. Am Heart J. 2004;148(4):574-581.
[13]. Apple FS, Murakami MM. Cardiac troponin and creatine kinase MB monitoring during in-hospital myocardial reinfarction. Clin Chem. 2005;51(2):460-463.
[14]. Ohman EM, Armstrong PW, Christenson RH, et al. Cardiac troponin T levels for risk stratification in acute myocardial ischemia. GUSTO IIA Investigators. N Engl J Med. 1996;335(18):1333-1341.
[15]. Stubbs P, Collinson P, Moseley D, et al. Prognostic significance of admission troponin T concentrations in patients with myocardial infarction. Circulation. 1996;94(6):1291-1297.
[16]. Giannitsis E, Muller-Bardorff M, Lehrke S, et al. Admission troponin T level predicts clinical outcomes, TIMI flow, and myocardial tissue perfusion after primary percutaneous intervention for acute ST-segment elevation myocardial infarction. Circulation. 2001;104(6):630-635.
[17]. Ohman EM, Armstrong PW, White HD, et al. Risk stratification with a point-of-care cardiac troponin T test in acute myocardial infarction. GUSTOIII Investigators. Global Use of Strategies To Open Occluded Coronary Arteries. Am J Cardiol. 1999;84(11): 1281-1286.
[18]. Giannitsis E, Lehrke S, Wiegand UK, et al. Risk stratification in patients with inferior acute myocardial infarction treated by percutaneous coronary interventions: the role of admission troponin T. Circulation. 2000;102(17):2038-2044.
[19]. Morrow DA, Antman EM, Tanasijevic M, et al. Cardiac troponin I for stratification of early outcomes and the efficacy of enoxaparin in unstable angina: a TIMI-11B substudy. J Am Coll Cardiol. 2000;36(6): 1812-1817.
[20]. Newby LK, Ohman EM, Christenson RH, et al. Benefit of glycoprotein IIb/IIIa inhibition in patients with acute coronary syndromes and troponin t-positive status: the paragon-B troponin T substudy. Circulation. 2001;103(24):2891-2896.
[21]. Morrow DA, Cannon CP, Rifai N, et al. Ability of minor elevations of troponins I and T to predict benefit from an early invasive strategy in patients with unstable angina and non-ST elevation myocardial infarction: results from a randomized trial. Jama. 2001;286(19):2405-2412.
[22]. Yusuf S, Zhao F, Mehta SR, et al. Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation. N Engl J Med. 2001;345(7):494-502.
[23]. Wiviott SD, Cannon CP, Morrow DA, et al. Differential expression of cardiac biomarkers by gender in patients with unstable angina/non-ST-elevation myocardial infarction: a TACTICS-TIMI 18 (Treat Angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction 18) substudy. Circulation. 2004;109(5):580-586.
[24]. Hamm CW, Goldmann BU, Heeschen C, et al. Emergency room triage of patients with acute chest pain by means of rapid testing for cardiac troponin T or troponin I. N Engl J Med. 1997;337(23):1648-1653.
[25]. deFilippi CR, Tocchi M, Parmar RJ, et al. Cardiac troponin T in chest pain unit patients without ischemic electrocardiographic changes: angiographic correlates and long-term clinical outcomes. J Am Coll Cardiol. 2000;35(7):1827-1834.
[26]. Henrikson CA, Howell EE, Bush DE, et al. Prognostic usefulness of marginal troponin T elevation. Am J Cardiol. 2004;93(3):275-279.
[27]. Muller-Bardorff M, Hallermayer K, Schroder A, et al. Improved troponin T ELISA specific for cardiac troponin T isoform: assay development and analytical and clinical validation. Clin Chem. 1997;43(3):458-466.
[28]. Januzzi JL, Cannon CP, DiBattiste PM, et al. Effects of renal insufficiency on early invasive management in patients with acute coronary syndromes (The TACTICS-TIMI 18 Trial). Am J Cardiol. 2002;90(11): 1246-1249.
[29]. deFilippi C, Wasserman S, Rosanio S, et al. Cardiac troponin T and C-reactive protein for predicting prognosis, coronary atherosclerosis, and cardiomyopathy in patients undergoing long-term hemodialysis. Jama. 2003;290(3):353-359.
[30]. Apple FS, Murakami MM, Pearce LA, et al. Predictive value of cardiac troponin I and T for subsequent death in end-stage renal disease. Circulation. 2002;106(23):2941-2945.
[31]. Ooi DS, Isotalo PA, Veinot JP. Correlation of antemortem serum creatine kinase, creatine kinase-MB, troponin I, and troponin T with cardiac pathology. Clin Chem. 2000;46(3):338-344.
[32]. Miller WL, Garratt KN, Burritt MF, et al. Baseline troponin level: key to understanding the importance of post-PCI troponin elevations. Eur Heart J. 2006;27(9):1061-1069.
[33]. Selvanayagam JB, Petersen SE, Francis JM, et al. Effects of off-pump versus on-pump coronary surgery on reversible and irreversible myocardial injury: a randomized trial using cardiovascular magnetic resonance imaging and biochemical markers. Circulation. 2004;109(3):345-350.
[34]. Dokainish H, Pillai M, Murphy SA, et al. Prognostic implications of elevated troponin in patients with suspected acute coronary syndrome but no critical epicardial coronary disease: a TACTICS-TIMI-18 substudy. J Am Coll Cardiol. 2005;45(1):19-24.
[35]. Yamagishi M, Nissen SE, Booth DC, et al. Coronary reactivity to nitroglycerin: intravascular ultrasound evidence for the importance of plaque distribution. J Am Coll Cardiol. 1995;25(1):224-230.
[36]. Devaraj S, Du Clos TW, Jialal I. Binding and internalization of C-reactive protein by Fcgamma receptors on human aortic endothelial cells mediates biological effects. Arterioscler Thromb Vasc Biol. 2005;25(7):1359-1363.
[37]. Khera A, McGuire DK, Murphy SA, et al. Race and gender differences in C-reactive protein levels. J Am Coll Cardiol. 2005;46(3):464-469.
[38]. Shlipak MG, Katz R, Fried LF, et al. Cystatin-C and mortality in elderly persons with heart failure. J Am Coll Cardiol. 2005;45(2):268-271.
[39]. Sarnak MJ, Katz R, Stehman-Breen CO, et al. Cystatin C concentration as a risk factor for heart failure in older adults. Ann Intern Med. 2005;142(7):497-505.