The predictive value of the bedside troponin T test for patients with acute chest pain

BACKGROUND: The evaluation of patients with acute chest pain is time consuming and complicated. In the present study, the role of the bedside troponin T (TnT) test was prospectively investigated for predicting the risk of death and acute heart failure (AHF) in patients with acute chest pain. METHODS: Five hundred two consecutive patients admitted in the 24 h after the onset of chest pain were enrolled in the study. Tests of bedside TnT, qualitative troponin I, myoglobin, creatine kinase and creatine kinase (muscle-brain), and electrocardiography were performed on these patients. RESULTS: For the bedside TnT test, 160 (31.9%) patients had positive results and 323 (64.3%) patients had negative results. During 30 days of follow-up, the differences between TnT-positive and TnT-negative patients were as follows: 139 (86.9%) positive patients and seven (2.2%) negative patients were diagnosed with acute myocardial infarction (AMI) (OR=298.8 for AMI in positive versus negative patients); 51 (31.9%) positive patients and 37 (11.5%) negative patients had AHF (OR=3.6 for AHF in positive versus negative patients); 39 (24.4%) positive patients and 15 (4.6%) negative patients died (OR=6.7 for all-cause death in positive versus negative patients); 31 (19.4%) positive patients and five (1.5%) negative patients died due to a cardiac event (OR=15.8 for cardiac death in positive versus negative patients). The sensitivity and specificity of the bedside TnT test for diagnosing AMI were 95.2% and 93.8%, respectively. CONCLUSIONS: The bedside TnT test is a powerful, independent and valuable tool for risk stratification in patients with acute chest pain.     

Differential impact of admission C-reactive protein levels on 28-day mortality risk in patients with ST-elevation versus non-ST-elevation myocardial infarction (from the Monitoring Trends and Determinants on Cardiovascular Diseases [MONICA]/Cooperative Health Research in the Region of Augsburg [KORA] Augsburg Myocardial Infarction Registry)

The present study investigated the association between C-reactive protein (CRP) on admission independently and in combination with troponin and short-term prognosis in an unselected sample of patients with acute myocardial infarction (AMI) from the community. The study population consisted of 1,646 patients aged 25 to 74 years who were consecutively hospitalized with AMI within 12 hours after symptom onset. They were divided into the 2 groups of CRP positive (n = 919) or CRP negative (n = 727) with respect to admission CRP (cutoff < or =0.3 mg/dl). CRP-positive patients had significantly more in-hospital complications and a higher 28-day case-fatality rate (9.6% vs 3.4%; p <0.0001). Troponin at admission (n = 1,419) also correlated with 28-day case-fatality rate (troponin-negative 3.4% vs troponin-positive patients 8.0%; p <0.002). Multivariable analysis showed that both troponin positivity and CRP positivity were associated with a 2-fold (adjusted odds ratio 1.99, 95% confidence interval 1.15 to 3.44; adjusted odds ratio 2.05, 95% confidence interval 1.09 to 3.84, respectively) increased risk of dying within 28 days after the acute event for all patients with AMI. Stratifying by AMI type showed that in patients with ST-elevation myocardial infarction (STEMI), troponin positivity, but not CRP positivity, independently predicted 28-day case fatality. In patients with non-STEMI, CRP positivity, but not troponin positivity, predicted outcome. In conclusion, admission CRP was a powerful parameter for risk stratification of patients with AMI. Stratification by AMI type and troponin showed that CRP was a better short-term risk predictor for patients with non-STEMI, and troponin was, for patients with STEMI.     

Impact of the revised criteria for acute myocardial infarction using cardiac troponins in a Japanese population with acute coronary syndromes.

BACKGROUND: The clinical implications of applying the new criteria of acute myocardial infarction (AMI) with cardiac troponins in terms of their diagnostic and prognostic impact in patients with suspected acute coronary syndromes (ACS) have not been well evaluated. METHODS AND RESULTS: The study group comprised 973 consecutive patients who were diagnosed as having ACS with or without ST elevation (STE). They were divided into 3 groups: unstable angina (UA) group (n=195) representing patients with no significant elevations of creatine kinase (CK) and troponin T (TnT); TnT-myocardial infarction (MI) group (n=170) with TnT elevation and no CK elevation (additionally detected AMI by the new criteria); CK-MI group (n=608) with significant elevation of CK (AMI by the old criteria). In the TnT-MI group, 140 (76%) patients had non-STE ACS. In-hospital mortality rates for STE ACS were 0%, 2.5% and 9.7% in the UA, TnT-MI and CK-MI groups, respectively. The corresponding values for non-STE ACS were 1.8%, 4.6%, and 16.5%, respectively (p<0.0001), suggesting a pivotal role of TnT. In multiple logistic regression analysis, significant CK elevation was selected as an independent predictor of in-hospital death in concurrence with age > or =75 years, prior MI, shock and low left ventricular ejection fraction in non-STE ACS. CONCLUSIONS: The new criteria result in a substantial increase in the diagnosis of AMI from non-STE ACS in particular. They assist greatly in detailed risk stratification of ACS patients, notably in cooperation with the old CK criteria.     

不稳定性心绞痛和急性心肌梗塞肌钙蛋白T变化的比较

目的 :比较不同急性冠状动脉综合征患者肌钙蛋白 T(Tn T)变化。　　方法 :不稳定性心绞痛 (UAP)、Q波型和非 Q波型急性心肌梗塞 (AMI)患者于急诊就诊时、住院后第 2、第 3和第 6日取血测定 Tn T水平。　　结果 :35 %的 UAP患者 Tn T表现为升高 ,其升高的幅度 (均 <3.0 ng/ ml)明显 <非 Q波型 AMI(2 4% >3.0 ng/ml)和 Q波型 AMI(90 % >3.0 ng/ ml) ,且一般 3天后即转为阴性 ,而 AMI患者 6天后多数仍为阳性。非 Q波型 AMI和Q波型 AMI急诊就诊时 Tn T的阳性率分别为 79.1%和 90 .7% ,住院后第 2日均达 10 0 % ,均明显高于同时间谷草转氨酶和肌酸激酶同工酶的阳性率 ,两组 Tn T阳性在持续时间上相似 ,但在升高幅度上有明显的区别。再灌注治疗可能会影响 Q波型 AMI患者 Tn T的自然变化规律。　　结论 :UAP患者 Tn T的变化与非 Q波型 AMI和 Q波型 AMI有显著的不同。     

Relationship Between Minor Myocardial Damage and Inflammatory Acute-Phase Reaction in Acute Coronary Syndromes

Background: In severe acute coronary syndromes (ACS) elevation of markers of inflammation and acute phase reaction (APR) like C-reactive protein (CRP) as well as a release of troponin have been reported.Using a high sensitivity troponin T (TnT) test we investigated whether an APR occurs in ACS only in the presence of ischemic myocardial damage. Methods: In 85 patients with ACS C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, thrombin antithrombin III complexes (TAT) and kallikrein were determined vs. high sensitive TnT (0.02 ng/ml) initially and 2 d later vs. 45 patients with stable angina pectoris and 42 controls. Results: In stable angina pectoris, markers of inflammation and coagulation were slightly elevated (p < 0.05). Initially in ACS elevations of CRP to 1.2 ± 0.3 mg/dl, SAA to 4.8 ± 2.6 mg/dl and fibrinogen to 448 ± 21 mg/dl (all p < 0.01 vs. controls) were found followed by a significant APR (p < 0.01).In the subgroup of TnT positive ACS patients, an APR with increased CRP (4.1 ± 1.3 mg/dl), SAA (20.4 ± 8.3 mg/dl), and fibrinogen (641 ± 45 mg/dl) was detectable (all p < 0.05 vs. TnT negative patients). In contrast, patients without TnT release showed APR markers comparable to patients with stable angina pectoris. Conclusion: Our findings demonstrate an association between myocardial injury in ACS and acute phase reaction as evidenced by several molecular markers. A highly sensitive TnT-test identified myocardial inury in about all patients with APR while a standard TnT cut-off (0.1 ng/ml) missed 32% of these patients. Thus, the APR in patients with ACS is strongly associated with at least minor ischemic myocardial damage and prior findings of an APR independent from myocardial injury are probably based on less sensitive troponin tests.     

The Erlanger chest pain evaluation protocol: a one-year experience with serial 12-lead ECG monitoring,two-hour delta serum marker measurements,and selective nuclear stress testing to identify and exclude acute coronary syndromes

STUDY OBJECTIVE: We determine the overall use of a 6-step accelerated chest pain protocol to identify and exclude acute coronary syndrome (ACS) and to confirm previous findings of the use of serial 12-lead ECG monitoring (SECG) in conjunction with 2-hour delta serum marker measurements to identify and exclude acute myocardial infarction (AMI). METHODS: A prospective observational study was conducted over a 1-year period from January 1, 1999, through December 31, 1999, in 2,074 consecutive patients with chest pain who underwent our accelerated evaluation protocol, which includes 2-hour delta serum marker determinations in conjunction with automated SECG for the early identification and exclusion of AMI and selective nuclear stress testing for identification and exclusion of ACS. In patients not undergoing emergency reperfusion therapy, physician judgment was used to determine patient disposition at the completion of the 2-hour evaluation period: admit for ACS, discharge or admit for non-ACS condition, or immediate emergency department nuclear stress scan for possible ACS. A positive protocol was defined as a positive result in 1 or more of the 6 incremental steps in our chest pain evaluation protocol: (1) initial ECG diagnostic of acute injury or reciprocal injury; (2) baseline creatine kinase (CK)-MB level of 10 ng/mL or greater and index of 5% or greater or cardiac troponin I level of 2 ng/mL or greater; (3) new/evolving injury or new/evolving ischemia on SECG; (4) increase in CK-MB level of +1.5 ng/mL or greater or cardiac troponin I level of +0.2 ng/mL or greater in 2 hours; (5) clinical diagnosis of ACS despite a negative 2-hour evaluation; and (6) reversible perfusion defect on stress scan compared with on resting scan. All patients were followed up for 30-day ACS, which was defined as myocardial infarction (MI), percutaneous coronary intervention/coronary artery bypass grafting, coronary arteriography revealing stenosis of major coronary artery of 70% or greater not amenable to percutaneous coronary intervention/coronary artery bypass grafting, life-threatening complication, or cardiac death within 30 days of ED presentation. RESULTS: Discharge diagnosis in the 2,074 study patients consisted of 179 (8.6%) patients with AMI, 26 (1.3%) patients with recent AMI (decreasing curve of CK-MB), and 327 (15.8%) patients with 30-day ACS. At 2 hours, sensitivity and specificity for MI (AMI or recent AMI) of SECG plus delta serum marker measurements was 93.2% and 93.9%, respectively (positive likelihood ratio 15.3; negative likelihood ratio 0.07). At the completion of the full ED evaluation protocol (positive result in >or=1 of the 6 incremental steps), sensitivity and specificity for 30-day ACS was 99.1% and 87.4%, respectively (positive likelihood ratio 7.9; negative likelihood ratio 0.01). CONCLUSION: An accelerated chest pain evaluation strategy consisting of SECG, 2-hour delta serum marker measurements, and selective nuclear stress testing in conjunction with physician judgment identifies and excludes MI and 30-day ACS during the initial evaluation of patients with chest pain.     

Troponin and C-reactive protein have different relations to subsequent mortality and myocardial infarction after acute coronary syndrome: a GUSTO-IV substudy

OBJECTIVES: We sought to evaluate C-reactive protein (CRP) and troponin T (TnT) as predictors of risk of the individual end points of mortality and myocardial infarction (MI) in a large cohort of patients with acute coronary syndrome (ACS). BACKGROUND: Both CRP and TnT predict risk of future coronary events in patients with ACS. However, the relationships between the levels of the markers and the individual end points are still unclear. METHODS: Baseline levels of CRP and TnT were determined in 7,108 patients with ACS not undergoing early revascularization in the Global Use of Strategies To Open occluded arteries trial IV (GUSTO-IV) trial and related to outcome at 30 days. RESULTS: Quartiles of TnT related to 30-day mortality, which was 1.1%, 3.7%, 3.7%, and 7.4% (p < 0.001) and to the rate of MI: 2.5%, 6.7%, 7.2%, and 5.6% (p < 0.001). Quartiles of CRP also related to 30-day mortality, which was 2.0%, 3.3%, 3.9%, and 6.3% (p < 0.001), whereas there was no relationship to the 30-day rate of MI: 5.6%, 4.7%, 5.2%, and 5.9% (p = 0.48). On multivariable analysis, both TnT and CRP were independent predictors of mortality, but only TnT was a predictor of MI. The combination of CRP and TnT provides an even better risk stratification of mortality, with 0.3% and 9.1% death rates, respectively, when both markers are in the bottom versus top quartiles. CONCLUSIONS: In ACS, baseline levels of TnT and CRP are independently related to 30-day mortality. Any detectable elevation of TnT, but not of CRP, is also associated with an increased risk of subsequent MI. Regarding mortality, the combination of both markers provides a better risk stratification than either one alone.     

Prehospital troponin T testing in the diagnosis and triage of patients with suspected acute myocardial infarction

Prehospital electrocardiographic (ECG) diagnosis has improved triage and outcome in patients with acute ST-elevation myocardial infarction. However, many patients with acute myocardial infarction (AMI) present with equivocal ECG patterns making prehospital ECG diagnosis difficult. We aimed to investigate the feasibility and ability of prehospital troponin T (TnT) testing to improve diagnosis in patients with chest pain transported by ambulance. From June 2008 through September 2009, patients from the central Denmark region with suspected AMI and transported by ambulance were eligible for prehospital TnT testing with a qualitative point-of-care test (cutpoint 0.10 ng/ml). Quantitative TnT was measured at hospital arrival and after 8 and 24 hours (cutpoint 0.03 ng/ml). A prehospital electrocardiogram was recorded in all patients. Prehospital TnT testing was attempted in 958 patients with a 97% success rate. In 258 patients, in-hospital TnT values were increased (≥0.03 ng/ml) during admission. The prehospital test identified 26% and the first in-hospital test detected 81% of patients with increased TnT measurements during admission. A diagnosis of AMI was established in 208 of 258 patients with increased TnT. The prehospital test identified 30% of these patients, whereas the first in-hospital test detected 79%. Median times from symptom onset to blood sampling were 83 minutes (46 to 167) for the prehospital sample and 165 minutes (110 to 276) for the admission sample. In conclusion, prehospital TnT testing is feasible with a high success rate. This study indicates that prehospital implementation of quantitative tests, with lower detection limits, could identify most patients with AMI irrespective of ECG changes.     

Admission troponin T as a prognostic marker and it relationship to streptokinase treatment patients with acute myocardial infarction

The relationship between the admission troponinT (TnT) level and the response to streptokinase (SK) was examined in 76 patients with acute myocardial infarction (AMI). Of 27 TnT positive patients, 10 (37%) showed a response to SK as suggested by a non-invasive criterion for reperfusion, while 24 (49%) were 'responders' among 49 TnT negative patients. There appeared to be a trend towards a better response to SK in the TnT negative group but the difference lacked statistical power due to the small sample size. The mean time-interval between the onset of symptoms and thrombolytic treatment among TnT positive 'non-responders' was significantly (P < 0.005) higher than the TnT negative 'non-responders' (5.23 + 3.42 h versus 2.38 +/- 1.37 h). An 18 month follow up on 61 patients revealed a higher mortality (33%) among TnT positive patients than TnT negative patients (10%). Mortality among TnT positive 'non-responders' was significantly higher (P = 0.0494) than mortality among TnT-negative 'non-responders' (43% versus 9%), indicating that TnT positive patients, non-responsive to SK were at a greater risk of cardiac death. The data suggest that the admission TnT level can be of value in risk stratification of patients with AMI.     

Comparison of troponin T versus creatine kinase-MB in suspected acute coronary syndromes

Limitations of creatine kinase-MB (CK-MB) have led to alternative biochemical markers, including troponin T (TnT), to detect myocardial necrosis. Limited data are available regarding the predictive value of this new marker in patients with chest pain of uncertain etiology. Therefore, we prospectively compared CK-MB and TnT in a broad population with suspected acute coronary syndromes, including those admitted to a short-stay chest pain unit. CK-MB, quantitative TnT levels, and a rapid bedside assay were performed at 0, 4, 8, and 16 hours. Adverse events, including infarction, recurrent ischemia, coronary surgery, need for catheterization and/or intervention, stroke, congestive heart failure, or death, were identified by chart review and by follow-up phone call at 6 months. Of 707 patients, 104 were excluded for creatinine >2 mg/dl or incomplete data, leaving a total cohort of 603 patients. Coronary Care Unit admissions were 18%, intermediate care admissions were 14%, telemetry admissions is 21%, and admissions to 24-hour short-stay area were 47%. TnT (at 0.1 ng/ml) and CK-MB were positive in a similar proportion of patients (20.4% and 19.7%, respectively); however, the patients identified by TnT and CK-MB were not identical. In-hospital adverse events occurred in 37.1% with no differences in positive predictive value for the markers (p = NS). If CK-MB and TnT were negative, the early adverse event rate was 27%. No cardiac marker was positive by 16 hours in 54.9% of patients with an adverse event. Six-month follow-up was obtained in 576 of the 603 patients (95.5%). One hundred fifty-five late adverse events occurred in 134 patients (23.3%) at an average of 3.3+/-2.5 months after discharge. If both markers were negative, the late event rate was 20.2% and did not increase in patients with positive CK-MB or TnT >0.2 ng/ml. However, the late event rate was substantially higher (52.9%) in those with intermediate TnT levels of 0.1 to 0.2 ng/ml (p = 0.002). Thus, TnT is a suitable alternative to CK-MB in patients with suspected acute coronary syndromes. The rapid bedside assay is comparable to quantitative TnT and may enable early diagnosis and triage. A negative cardiac marker value (TnT or CK-MB) does not necessarily confer a low risk of complication in patients presenting with acute chest pain to an emergency department.     

C-reactive protein in patients with acute coronary syndrome: correlation with diagnosis, myocardial damage, ejection fraction and angiographic findings

BACKGROUND: C-reactive protein (CRP) plasmatic levels increase in patients with acute coronary syndromes (ACS). Correlations between CRP levels, myocardial functional damage and cardiomyocyte lysis remain to be defined. METHODS: 192 consecutive patients with acute coronary syndromes (64.97 +/- 11.08 mean age, 71.35% male gender) were included in the study; 138 patients (71.87%) were discharged with an acute myocardial infarction (AMI) diagnosis (28 with non Q-wave AMI) and 54 with an unstable angina (UA) diagnosis (28.13%). In all patients CRP, CK, LDH, CK-MB and troponin I plasmatic concentrations were evaluated every 6 h for 48 h and every 24 h for the following 2 days from the onset of symptoms. Ejection fraction was estimated by bidimensional echocardiography and extension of myocardial lysis by cardiac enzymes plasmatic release. 92 patients (67 with AMI, 25 with UA) underwent coronary-angiography. Incidence of adverse cardiac events was recorded in a 6 months follow up. RESULTS: Mean CRP levels in Q-wave MI showed a statistically significant increase in the different blood samples with baseline. Mean CRP levels of the three groups were not statistically different at baseline and after 6, 12, and 18 h. Q-wave AMI CRP levels showed a statistically significant difference as against non Q-wave AMI at 36 (p < 0.05), 48 (p < 0.05) and 72 h (p < 0.05) and UA at 24 (p < 0.01), 30 (p < 0.01), 48 (p < 0.0001), 72 (p = 0.0001) and 96 h (p = 0.0003); non Q-wave AMI CPR levels showed a statistically significant difference as against UA at 48 h (p < 0.01). CRP peak mean levels were significantly different when comparing Q-wave AMI patients with UA patients (8.21 +/- 7.85 vs. 2.75 +/- 3.33 mg/dl, p < 0.001). In patients with Q-wave AMI there was a correlation between CRP peak concentrations and CK (r = 0.264, p = 0.008) and LDH (r = 0.32, p = 0.001), while correlation with CK-MB peak concentrations was not statistically significant (r = 0.196, p = 0.051). In the same patient group, there was also a correlation between CRP plasmatic concentrations and troponin I plasmatic concentrations from the 30th to 96th h after the onset of symptoms (r = 0.38-0.53, p < 0.05). No correlation was found between CRP levels and ejection fraction and angio-coronarography findings (number of stenotic vessels, culprit lesions, ruptured plaques). Peak CRP levels were associated in a 6 months follow up with an increased incidence of major adverse cardiac events (MACEs) in patients with Q-wave AMI (HR 1.1649, 95% C.I. 1.0197-1.3307, p < 0.05). CONCLUSIONS: CRP plasmatic concentrations showed a different release curve in patients with Q-wave AMI in comparison with patients with non Q-wave AMI and with patients with UA. CRP peak concentrations did not correlate with ejection fraction and angiographic findings, but correlate with incidence of MACE. The increase in CRP levels during Q-wave MI seems to be linked to the extension of myocardial damage rather than pre-existing inflammation.     

Diversity of the elevation of serum cardiac troponin I levels in patients during their first visit to the emergency room.

BACKGROUND: Although measurement of serum creatine kinase levels, as well as myoglobin levels, has been used for screening patients with acute coronary syndrome (ACS), the specificity of both is low. Measurement of cardiac troponin levels is now extensively used for the diagnosis of ACS because of their superior cardiac specificity. However, troponin levels are reportedly elevated not only in patients with ACS but also in those with other diseases. METHODS AND RESULTS: The clinical characteristics of 1,023 patients (mean age: 63.5+/-16.3 years; males: 665, females: 358) whose serum cardiac troponin I (cTnI) levels had been measured at the initial visit to the emergency room of Toyota Memorial Hospital between April 2004 and March 2005 were retrospectively analyzed. A positive elevation of cTnI was defined as cTnI > or =0.03 ng/ml. There were 432 patients (42.2%) with positive cTnI levels. The cTnI levels (8.48+/-2.64 ng/ml) in patients with acute myocardial infarction (AMI) were greater than those (0.25+/-0.07 ng/ml) in patients with unstable angina pectoris (AP), as well as those (0.04+/-0.01 ng/ml) in patients with stable AP. In terms of the diagnosis of AMI, the sensitivity was high enough (94.6%), but its specificity was relatively low (61.9%). Furthermore, the differentiation between AMI and unstable AP by the cTnI value alone was impossible. The cTnI levels were elevated in patients with a variety of diseases other than ACS, including heart failure, cardiomyopathies, myocarditis, renal failure, tachyarrhythmias, and pulmonary embolism. CONCLUSIONS: Elevation of the cTnI level is frequently observed in patients in the emergency room with common diseases other than ACS.     

高敏肌钙蛋白T与常规肌钙蛋白T在急性冠状动脉综合征中的对比研究

目的对比分析急性冠状动脉综合征(ACS)患者血清高敏肌钙蛋白T(hs-cTnT)与常规肌钙蛋白T(cTnT)早期诊断急性心肌梗死(AMI)的价值。方法连续入选拟诊ACS患者215例,依据诊断分为AMI组59例,不稳定性心绞痛(UAP)组103例,非冠状动脉粥样硬化(非CHD)组53例。入院即刻测定血清cTnT、hs-cTnT水平。应用ROC曲线比较hs-cTnT、常规cTnT对AMI早期诊断的敏感性和特异性。结果 AMI组血清hs-cTnT和常规cTnT均高于UAP组和非CHD组(P<0.05)。hs-cTnT与常规cTnT诊断AMI的ROC曲线下面积分别为0.936、0.880(P=0.000);hs-cTnT敏感性为88.1%,特异性为84.6%,cTnT分别为76.3%、99.4%。hs-cTnT水平与Gensini积分呈正相关(P<0.05),与冠状动脉病变支数无关(P>0.05)。结论 ACS患者中,hs-cTnT对早期诊断AMI可能较常规cTnT更敏感,可尽早检测出更多的AMI患者。     

Troponina I por Percentil 99 da Definição Universal de Infarto do Miocárdio versus Ponto de Corte de Melhor Acurácia em Síndromes Coronárias Agudas

Background Contemporary diagnosis of ACS and risk stratification are essential for appropriate management and reduction of mortality and recurrent ischemic events, in the acute phase of disease and after hospitalization. The Universal Definition of Myocardial Infarction recommends the detection of troponin levels above the 99^th percentile.Objectives To evaluate the occurrence of early death and acute myocardial infarction (AMI) in patients without elevation of troponin (<0.034 ng/mL), patients with mild elevation (above the 99^th percentile [>0.034 ng/mL and <0.12 ng/mL)], and patients with significant elevation of troponin (above the diagnostic cutoff for AMI defined by the troponin kit (≥0.12 ng/mL)]; and to analyze the impact of troponin on the indication for invasive strategy and myocardial revascularization.Methods Cross-sectional cohort study of patients with ACS with assessment of peak troponin I, risk score, prospective analysis of 30-day clinical outcomes and two-sided statistical tests, with statistical significance set at p<0.05.Results A total of 494 patients with ACS were evaluated. Troponin > 99^th percentile and below the cutoff point, as well as values above the cutoff, were associated with higher incidence of composite endpoint (p<0.01) and higher rates of percutaneous or surgical revascularization procedures (p<0.01), without significative difference in 30-day mortality.Conclusions Troponin levels above the 99^th percentile defined by the universal definition of AMI play a prognostic role and add useful information to the clinical diagnosis and risk scores by identifying those patients who would most benefit from invasive risk stratification and coronary revascularization procedures.     

Antibodies to chlamydial lipopolysaccharides in unstable angina pectoris

Patients with coronary artery disease frequently have elevated antibody titers against Chlamydia pneumoniae, but whether antichlamydial antibody titers are correlated with prognosis in unstable angina remains unclear. We therefore investigated the sera of 1,096 patients with unstable angina regarding immunoglobulin (Ig) IgG, IgA, and IgM antibody titers against chlamydial lipopolysaccharides (LPS) and the concentrations of C-reactive protein (CRP) and troponin T (TnT). Anti-LPS IgG titers were increased in 45% of patients at enrollment and in 48% of patients at discharge (p <0.0001). Anti-LPS IgA titers were increased in 27% of patients at enrollment and in 33% of patients at discharge (p <0.0001). Patients who subsequently died had significantly lower IgM titers at enrollment than patients without events (p = 0.016). IgG, IgA, or IgM titers did not correlate with concentrations of CRP or TnT. In this large-scale study of patients with unstable angina, we frequently found elevated antichlamydial antibody titers. Patients with low IgM anti-LPS titers were at risk for subsequent death. However, there was no correlation between antichlamydial antibody titers and CRP or TnT.     

不稳定性心绞痛患者C-反应蛋白与肌钙蛋白T的变化

目的探讨不稳定性心绞痛患者血清C-反应蛋白(CRP)及肌钙蛋白T(TnT)的变化.方法选择92例不稳定性心绞痛患者(实验组),28例稳定性心绞痛患者(对照组),分别取血测定CRP和TnT.结果实验组中TnT为阳性30例(32.6%),TnT为阴性62例(67.4%);对照组则均为阴性.实验组TnT阳性患者的CRP显著高于TnT阴性患者及对照组,有非常显著性差异(P＜0.001).结论实验组约1/3可出现TnT升高,其CRP亦显著高于TnT阴性的患者,且CRP与TnT呈正的直线相关(γ=0.489,P＜0.01).     

Influence of the new definition of acute myocardial infarction on coronary care unit admission, discharge diagnosis, management and outcome in patients with non-ST elevation acute coronary syndromes: a national survey

BACKGROUND: Major changes occurred recently in the definition and recommended management of non-ST segment elevation acute coronary syndromes (NSTE ACS). The impact of these changes on the coronary care unit (CCU) is incompletely characterized. METHODS: ACSIS is a national survey gathering data every other year among all ACS patients in all CCUs in Israel. We compared case load, baseline variables, management, outcome and distribution of diagnoses among NSTE ACS patients admitted before (during 2000 [N = 729]) and after (during 2002 [N = 970]) the widespread introduction of troponin and the new AMI definition. RESULTS: The number of NSTE ACS patients in 2002 increased by 33% compared to 2000, with no change in the number of beds, while the number of ST elevation ACS patients remained unchanged. The rate of AMI rose by 16% and hospital stay decreased by 1 day (p = 0.005). The availability of troponin values increased from 20% in 2000 to 60% in 2002; The proportion of patients given the diagnosis of NSTE AMI rose significantly more in centers with high utilization of troponin (p = 0.023). During 2002 significant increases occurred in the utilization of guideline-recommended medications, as in the use of coronary angiography and intervention. Mortality at 30 days decreased by 35%. CONCLUSIONS: This is the first large registry of ACS to describe the significant actual changes which occurred in the CCU following the introduction of troponin and the new AMI definition. We observed a substantial increase in the burden of NSTE ACS coupled with a shortened length of stay. These changes may impact significantly upon patient care and resource utilization.     

Response of high-sensitivity C-reactive protein to percutaneous coronary intervention in patients with acute coronary syndrome

Percutaneous coronary intervention (PCI) provokes an inflammatory reaction, as shown by increased concentrations of plasma C-reactive protein (CRP) after PCI. However, the changes of CRP levels after PCI in patients with acute coronary syndrome (ACS) have not been well evaluated. We evaluated the characteristics of the patients with elevated CRP response after PCI and whether an increase in CRP after PCI predicts long-term prognosis in patients with ACS. We studied consecutive 360 patients with ACS who underwent elective coronary stenting. Inflammatory response to PCI was calculated as the difference between the peak postprocedural hsCRP level and the preprocedural hsCRP level (ΔCRP). Twelve months follow-up data were obtained and clinical outcomes were compared with ΔCRP. In receiver operating characteristics analyses, the cutoff point of ΔCRP for major adverse cardiac events (MACE) was 3.0 mg/l, which yielded sensitivity of 61.7% and specificity of 69.7%. The patients with ΔCRP > 3 mg/l revealed higher incidence of myocardial infarction (37.7 vs 14.6%, P < 0.001), and ACC/AHA type B2/C lesion (81.5 vs 68.7%, P = 0.006) than in patients with low ΔCRP. White blood cell count, low-density lipoprotein cholesterol, peak creatinine kinase-MB, and peak troponin T were significantly elevated in patients with ΔCRP > 3 mg/l than in those with ≤3 mg/l. There was significant correlation between ΔCRP and the changes in troponin T after PCI (r = 0.210, P < 0.001). An increase in hsCRP > 3 mg/l after PCI had a higher predictive value for the occurrence of MACE than low hsCRP elevation (hazard ratio 2.1, P = 0.005). In multivariate analysis, ΔCRP and peak troponin T were independent predictors of MACE (P < 0.001 and P = 0.013, respectively). In conclusion, postprocedural hsCRP elevation >3 mg/l was associated with higher incidence of MACE in patients with ACS. ΔCRP determinations may be of value for risk stratification after PCI.     

The prognostic value of troponin in patients with non-ST elevation acute coronary syndromes: a meta-analysis

OBJECTIVES: This study was designed to compare the prognostic value of an abnormal troponin level derived from studies of patients with non-ST elevation acute coronary syndromes (ACS). BACKGROUND: Risk stratification for patients with suspected ACS is important for determining need for hospitalization and intensity of treatment. METHODS: We identified clinical trials and cohort studies of consecutive patients with suspected ACS without ST-elevation from 1966 through 1999. We excluded studies limited to patients with acute myocardial infarction and studies not reporting mortality or troponin results. RESULTS: Seven clinical trials and 19 cohort studies reported data for 5,360 patients with a troponin T test and 6,603 with a troponin I test. Patients with positive troponin (I or T) had significantly higher mortality than those with a negative test (5.2% vs. 1.6%, odds ratio [OR] 3.1). Cohort studies demonstrated a greater difference in mortality between patients with a positive versus negative troponin I (8.4% vs. 0.7%, OR 8.5) than clinical trials (4.8% if positive, 2.1% if negative, OR 2.6, p = 0.01). Prognostic value of a positive troponin T was also slightly greater for cohort studies (11.6% mortality if positive, 1.7% if negative, OR 5.1) than for clinical trials (3.8% if positive, 1.3% if negative, OR 3.0, p = 0.2) CONCLUSIONS: In patients with non-ST elevation ACS, the short-term odds of death are increased three- to eightfold for patients with an abnormal troponin test. Data from clinical trials suggest a lower prognostic value for troponin than do data from cohort studies.     

急性冠状动脉综合征患者C-反应蛋白升高与远期死亡率和心力衰竭的相关性分析

目的评估C-反应蛋白(CRP)与急性冠状动脉综合征(ACS)患者远期预后的相关性。方法收集我院急诊ACS患者的资料并检测其CRP水平。入选患者随访3年,内容包括死亡,因急性心肌梗死(AMI)和充血性心力衰竭(CHF)而再次住院情况。结果共有446名患者入选,CRP升高的患者的死亡率和因CHF的再次住院率均高于CRP正常的患者(P<0.05)。校正心肌肌钙蛋白T(cTnT)水平后,急性期CRP>7.44 mg/L与发病后3年内的死亡率和因CHF再住院的风险增加仍显著相关。结论在胸痛早期就出现CRP升高的ACS患者的晚期死亡率和CHF风险增加。