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.     

Prognostic value of troponins in patients with non-ST-segment elevation acute coronary syndromes and chronic kidney disease

BACKGROUND: The prognostic value of cardiac troponins (cTn) in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) and chronic kidney disease (CKD) is debated. HYPOTHESIS: We tested the performance of cTnI and cTnT for risk stratification in patients with CKD and evaluated the prognostic significance of cTnI and cTnT elevations by their magnitude across the range of CKD severity. METHODS: We examined correlations among cTn elevation, CKD, and in-hospital mortality in 31,586 high-risk patients with NSTE ACS included in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress ADverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines initiative (CRUSADE). Cardiac tropinins I and T levels were categorized as ratios of each site's upper limit of normal (ULN) for myocardial necrosis: normal (cTn ratio < or =1 x ULN), mild (cTn ratio > 1-3 x ULN), and major (cTn ratio > 3 x ULN) elevation. Estimated glomerular filtration rate (eGFR) was calculated using the abbreviated Modification of Diet in Renal Disease equation. Stages of CKD were categorized as normal to mild (eGFR > 60 mL/min), moderate (eGFR 30-60 mL/min), or severe (eGFR < 30 mL/min). RESULTS: Mortality increased more steeply across CKD stages (2.0%-12.9%) than across cTn ratio categories (2.7%-5.4%). In normal or mild CKD, mortality was low regardless of cTn elevations. In moderate CKD, mortality increased incrementally with cTnI (3.3% versus 5.4% versus 7.4%) and cTnT (3.7% versus 5.3% versus 7.3%) elevation. Among severe CKD patients, only major cTn elevations further distinguished risk (cTnI: 10.1% versus 9.7% versus 14.6%; cTnT: 7.0% versus 5.7% versus 14.0%). CONCLUSIONS: In patients with CKD, cTnI and cTnT perform equally in differentiating short-term prognosis following NSTE ACS; however, the prognostic impact of cTn is dependent upon the degree of CKD severity.     

Prognostic value of SPECT myocardial perfusion imaging in patients with elevated cardiac troponin I levels and atypical clinical presentation.

BACKGROUND: We determined the prognostic value of myocardial perfusion imaging (MPI) in patients with atypical clinical presentations and unexpected elevation of cardiac troponin I (cTnI) levels. METHODS AND RESULTS: In 156 consecutive patients with atypical presentations for acute coronary syndromes (ACS) and elevated cTnI levels undergoing MPI within 30 days, rates of all-cause mortality (100% follow-up; median follow-up, 611 days) and 6-month cardiac death and nonfatal myocardial infarction (96% follow-up; median follow-up, 167 days) were determined. The mean age of the patients was 68 +/- 14 years. The majority of the study cohort (96%) was at low to intermediate clinical risk for ACS (Thrombolysis in Myocardial Infarction score for unstable angina/non-ST-segment elevation myocardial infarction <5). The overall event rate was high, with 45 deaths (28.8%). There were 13 cardiac deaths/nonfatal myocardial infarctions in 6 months (8.3%). A normal MPI result was associated with a high event-free survival rate, whereas an abnormal MPI result was associated with a 3-fold and 7-fold higher risk of all-cause mortality and 6-month cardiac events, respectively. An abnormal MPI result was an independent predictor of all-cause death. CONCLUSIONS: In patients with cTnI elevation and a low to intermediate risk for ACS, a normal MPI result portends a good prognosis. Patients with abnormal MPI results have a higher 6-month cardiac event rate and a worse survival rate.     

Extent of ST-segment depression and cardiac events in non-ST-segment elevation acute coronary syndromes.

AIMS: We sought to determine whether the extent of myocardial ischaemia on the admission electrocardiogram (ECG) has independent predictive value for short-term risk stratification of patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). Although the presence of ischaemic ECG changes on admission has been shown to predict outcome, the relationship between the extent of ECG changes and the risk of cardiac events is still ill defined. METHODS AND RESULTS: We analysed the admission ECGs of 5192 ACS patients enrolled in the GUSTO-IIb trial, without an ECG indication for thrombolysis. ECG tracings showing one or more of the following were eligible: ST-segment depression >0.5 mm, T-wave inversion >1 mm, and ST-segment elevation >0.5 mm but <1 mm. ECG variables associated with unfavourable 30 day outcomes in a univariable analysis were further assessed in a multivariable logistic regression model including independent clinical predictors. In the multivariable clinical, enzymatic, and ECG model, the sum of ST-segment depression (in millimetres) in all leads was a powerful independent predictor of 30 day death (P<0.0001), with a continuous increase in risk with the extent of ST-segment depression. The sum of ST-segment depression (P<0.0001) and the presence of minimal inferior ST-segment elevation (P<0.0001) or anterior ST-segment elevation (P=0.0182) were also independent predictors of the composite of death and myocardial infarction or reinfarction. The extent of ST-segment depression showed a highly significant correlation with the prevalence of three-vessel (P<0.0001) or left main coronary disease (P<0.0001), and also with the peak levels of creatine kinase (P<0.0001) during the index episode of ACS. CONCLUSION: In patients with NSTE ACS, the sum of ST-segment depression in all ECG leads is a powerful predictor of all-cause mortality at 30 days, independent of clinical variables and correlates with the extent and severity of coronary artery disease. The presence of even minimal (<1 mm) ST-segment elevation in anterior or inferior leads is independently associated with adverse outcomes.     

Troponin T and quantitative ST-segment depression offer complementary prognostic information in the risk stratification of acute coronary syndrome patients

OBJECTIVES: Our primary objective was to examine the prognostic relationship between baseline quantitative ST-segment depression (ST) and cardiac troponin T (cTnT) elevation. The secondary objectives were to: 1) examine whether ST provided additional insight into therapeutic efficacy of glycoprotein IIb/IIIa therapy similar to that demonstrated by cTnT; and 2) explore whether the time to evaluation impacted on each marker's relative prognostic utility. BACKGROUND: The relationship between the baseline electrocardiogram (ECG) and cTnT measurements in risk-stratifying patients presenting with acute coronary syndromes (ACS) has not been evaluated comprehensively. METHODS: The study population consisted of 959 patients enrolled in the cTnT substudy of the Platelet IIb/IIIa Antagonism for the Reduction of Acute coronary syndrome events in a Global Organization Network (PARAGON)-B trial. Patients were classified as having no ST (n = 387), 1 mm ST (n = 433), and ST > or =2 mm (n = 139). Forty-percent (n = 381) were classified as cTnT-positive based on a definition of > or =0.1 ng/ml. RESULTS: Six-month death/(re)myocardial infarction rates were 8.4% among cTnT-negative patients with no ST and 26.8% among cTnT-positive patients with ST > or =2 mm. On ECGs done after 6 h of symptom onset, ST > or =2 mm was associated with higher risk compared to its presence on ECGs done earlier (odds ratio [OR] 7.3 vs. 2.1). In contrast, the presence of elevated cTnT within 6 h of symptom was associated with a higher risk of adverse events compared with elevations after 6 h (OR 2.4 vs. 1.5). CONCLUSIONS: Quantitative ST and cTnT status are complementary in assessing risk among ACS patients and both should be employed to determine prognosis and assist in medical decision making.     

非ST段抬高急性冠状动脉综合征的危险因素分析及早期干预

目的　探讨非ST段抬高急性冠状动脉综合征(ACS)的临床高危因素及早期有创干预的价值。方法　在 2001年 10月至 2003年 10月期间连续入院的非ST段抬高的ACS患者共 545例,随机分成早期保守治疗组与早期有创干预组;随访 30天与 6个月患者的复合心血管事件 (包括心脏性死亡、非致命性心肌梗死、非致命性心力衰竭、因反复缺血性心绞痛发作住院 )发生率,将患者一般临床特征及辅助检查指标对复合心血管事件做多变量回归分析,筛查主要的高危因素;评价早期保守治疗与早期有创干预对患者预后的影响。结果　随访 513例患者, 30天与 6个月的复合心血管事件发生率分别为 14 0%与 25 7%;多变量Logistic回归分析,显示ST段压低、肌钙蛋白Ⅰ (TnI)水平升高、高敏C反应蛋白(hs CRP)增高、左室射血分数(LVEF)值下降以及心肌梗死溶栓疗法(TIMI)危险评分高分者与 6个月的复合心血管事件增高密切相关,它们分别是患者复合心血管事件危险性增加的独立预测因子;与早期保守治疗组比较,早期有创干预组随访 30天时反复心绞痛发作住院率减少,复合心血管事件减少;随访 6个月时复合心血管事件也减少 (P均 <0 05)。结论　ST段压低、TnI水平升高、hs CRP增高、LVEF值下降或TIMI危险评分增高是非ST段抬高ACS患者的高危因素,早期有创干预能     

Implication of different cardiac troponin I levels for clinical outcomes and prognosis of acute chest pain patients

OBJECTIVES: We compared outcomes in patients with non-ST-segment elevation acute coronary syndromes (ACS) according to the degree of cardiac troponin I (cTnI) elevation. BACKGROUND: Controlled trials of high-risk patients have found that troponin elevations identify an even higher risk subset. It is unclear whether outcomes are similar among a lower risk, heterogeneous patient group. Also, few studies have reported outcomes other than myocardial infarction (MI) or death, based on the peak troponin value. METHODS: Consecutively, admitted patients without ST-segment elevation on the initial electrocardiogram underwent serial marker sampling using creatine kinase (CK), CK-MB fraction, and cTnI. Patients were grouped according to peak cTnI: negative = no detectable cTnI; low = peak greater than the lower limit of detectability but less than the optimal diagnostic value; intermediate = peak greater than or equal to the optimal diagnostic value but less than the manufacturer's suggested upper reference limit (URL); and high = peak greater than or equal to the URL. Thirty-day outcomes included cardiac death, MI based on CK-MB, revascularization, significant disease, and a reversible defect on stress testing. Six-month mortality was also determined. Negative evaluations for ischemia included nonsignificant disease, no reversible stress defect, and negative rest perfusion imaging. RESULTS: Of the 4,123 patients admitted, 893 (22%) had detectable cTnI values. Cardiac events and positive test results at 30 days and 6-month mortality increased significantly with increasing cTnI values. Negative evaluations for ischemia were significantly and inversely related to peak cTnI values. Although adverse events were significantly more common in patients with a low cTnI value than in those with negative cTnI, negative evaluations for ischemia were frequent. CONCLUSIONS: Increased cTnI values are associated with worse outcomes. Although low cTnI values are associated with adverse events, they do not have the same implication as higher cTnI values, and nonischemic evaluations are frequent.     

Cardiac troponin I levels and clinical outcomes in patients with acute coronary syndromes: the potential role of early percutaneous revascularization

OBJECTIVES: To establish the role of early catheter-based coronary intervention among patients sustaining acute coronary syndromes (ACS) stratified according to admission plasma troponin I (Tn-I) levels. BACKGROUND: The impact of early revascularization strategy on the clinical outcomes in patients with ACS stratified by plasma Tn-I levels has not been established. METHODS: In-hospital complications and long-term outcomes were assessed in 1,321 consecutive patients with non-ST elevation ACS undergoing early (within 72 h) catheter-based coronary interventions. Patients were grouped according to admission Tn-I levels. Group I (n = 1,099) had no elevated plasma Tn-I (<0.15 ng/ml), Group II (n = 95) had Tn-I level between 0.15 to 0.45 ng/ml and Group III (n = 127) had Tn-I >0.45 ng/ml. In-hospital composite cardiac events (death, Q-wave MI, urgent in-hospital revascularization) and 8 months clinical outcomes (death, MI, repeat revascularization or any cardiac event) were compared between the three groups. RESULTS: The rate of in-hospital composite cardiac events was 6.1% among patients with Tn-I >0.45 ng/ml, 1.0% in patients with Tn-I between 0.15-0.45 ng/ml and 3.1% in patients without elevated admission Tn-I (p = 0.09 between groups). There was no difference in hospital mortality (p = 0.25). At eight months of follow-up, there was no difference in out-of-hospital death (3.5%, 3.8% and 1.8%, p = 0.17, respectively), MI (2.6%, 3.8% and 2.9%, p = 0.94) or target lesion revascularization (9.0%, 8.3% and 11.5%, p = 0.47), and cardiac event-free survival was also similar between groups (p = 0.66). By multivariate analysis, Tn-I >0.45 ng/ml was independently associated with in-hospital composite cardiac events [odds ratio (OR) = 2.4, p = 0.04] but not with out-of-hospital clinical events up to eight months. CONCLUSIONS: In patients with ACS, early (within 72 h) catheter-based coronary intervention may attenuate the adverse prognostic impact of admission Tn-I elevation during eight months of follow-up despite a trend towards increased in-hospital composite cardiac events.     

Circulating secretory phospholipase A2 activity predicts recurrent events in patients with severe acute coronary syndromes.

OBJECTIVES: The purpose of this study was to determine the prognostic value of circulating secretory phospholipase A2 (sPLA2) activity in patients with acute coronary syndromes (ACS). BACKGROUND: The plasma level of type IIA sPLA2 is a risk factor for coronary artery disease (CAD) and is associated with adverse outcomes in patients with stable CAD. The prognostic impact of sPLA2 in patients with ACS is unknown. METHODS: Secretory phospholipase A2 antigen levels and activity were measured in plasma samples of 446 patients with ACS, obtained at the time of enrollment. RESULTS: Baseline sPLA2 activity was associated with the risk of death and myocardial infarction (MI). The unadjusted rate of death and MI increased in a stepwise fashion with increasing tertiles of sPLA2 activity (p < 0.0001). The association remained significant in the subgroup of patients who had MI with ST-segment elevation (p = 0.014) and the subgroup of patients who had unstable angina or non-ST-segment elevation MI (p < 0.002). After adjustment for clinical and biological variables, the hazard ratios for the combined end point of death or MI in the third tertile of sPLA2 compared with the first and second tertiles was 3.08 (95% confidence interval, 1.37 to 6.91, p = 0.006). CONCLUSIONS: A single measurement of plasma sPLA2 activity at the time of enrollment provides strong independent information to predict recurrent events in patients with ACS.     

Identification of patients at risk by graded exercise testing in an emergency department chest pain center

The study applied a retrospective follow-up design to determine the prognostic effect of graded exercise testing (GXT) in patients with low- to moderate-risk chest pain evaluated in an emergency department 9-hour protocol chest pain center (CPC) from January 1, 1993 to August 1, 1996. The cohort of 1,209 patients were followed to the date of death or first adverse cardiac event up to 1 year after CPC admission. Cardiac events were defined as coronary artery bypass graft, percutaneous transluminal coronary angioplasty, cardiogenic shock, cardiac-related death, congestive heart failure admission, ventricular tachycardia/ventricular fibrillation arrest, and myocardial infarction. Patients with acute ST-segment elevation or depression of >1 mm, positive enzyme (creatine kinase myocardial band) testing, or unstable angina during their CPC evaluation were admitted without GXT testing. Statistical analysis included chi-square test for complication rates and Cox proportional-hazards modeling. Nine hundred fifty-eight of 1,209 patients underwent GXT testing. Patients with positive, inconclusive, and normal GXTs had complication rates of 36.8% (7 of 19), 3.4% (9 of 267), and 1.1% (5 of 456), respectively. After adjusting for age, sex, and race, the relative risk of complication was 38.9 (95% confidence interval 11.7 to 129.6) with a positive GXT, and 3.6 (95% confidence interval 1.2 to 10.7) with an inconclusive GXT compared with a normal GXT. The GXT is a good prognostic indicator of adverse cardiac events in low- to moderate-risk chest pain in patients evaluated in an emergency department CPC.     

Role of cardiac troponin T in the long-term risk stratification of patients undergoing percutaneous coronary intervention.

AIMS: To investigate the long-term prognostic significance of pre- and post-procedure troponin T (TnT) elevations in patients undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS: TnT and CK-MB were measured pre- and post-procedure in 212 patients undergoing PCI. Major adverse events (composite of death, myocardial infarction and revascularization) were ascertained 6 years later. Pre-procedural TnT was a significant independent predictor of time to major events (hazard ratio [HR] 1.75, 95% confidence interval [CI] 1.16-2.64) and death or myocardial infarction. Post-procedural TnT elevation above normal was the only independent predictor of the primary end-point at 1 year (HR 2.39, 95% CI 1.09-5.26) but was not significantly related to event-free survival throughout follow-up. Post-PCI elevation of TnT 5x above normal, however, did significantly predict time to events during the entirety of follow-up. By contrast, CK-MB was not an independent predictor in any of the analyses. CONCLUSIONS: Our study confirms the long-term prognostic value of pre-procedural TnT elevation in patients undergoing PCI, and demonstrates the superior predictive ability of a post-procedural increase in TnT 5x normal for long-term adverse events. Whether the prognostic significance of smaller post-procedural TnT elevations extends beyond the intermediate-term awaits further investigation.     

Predictors of hospital mortality in the global registry of acute coronary events

BACKGROUND: Management of acute coronary syndromes (ACS) should be guided by an estimate of patient risk. OBJECTIVE: To develop a simple model to assess the risk for in-hospital mortality for the entire spectrum of ACS treated in general clinical practice. METHODS: A multivariable logistic regression model was developed using 11 389 patients (including 509 in-hospital deaths) with ACS with and without ST-segment elevation enrolled in the Global Registry of Acute Coronary Events (GRACE) from April 1, 1999, through March 31, 2001. Validation data sets included a subsequent cohort of 3972 patients enrolled in GRACE and 12 142 in the Global Use of Strategies to Open Occluded Coronary Arteries IIb (GUSTO-IIb) trial. RESULTS: The following 8 independent risk factors accounted for 89.9% of the prognostic information: age (odds ratio [OR], 1.7 per 10 years), Killip class (OR, 2.0 per class), systolic blood pressure (OR, 1.4 per 20-mm Hg decrease), ST-segment deviation (OR, 2.4), cardiac arrest during presentation (OR, 4.3), serum creatinine level (OR, 1.2 per 1-mg/dL [88.4- micro mol/L] increase), positive initial cardiac enzyme findings (OR, 1.6), and heart rate (OR, 1.3 per 30-beat/min increase). The discrimination ability of the simplified model was excellent with c statistics of 0.83 in the derived database, 0.84 in the confirmation GRACE data set, and 0.79 in the GUSTO-IIb database. CONCLUSIONS: Across the entire spectrum of ACS and in general clinical practice, this model provides excellent ability to assess the risk for death and can be used as a simple nomogram to estimate risk in individual patients.     

Implications of diabetes in patients with acute coronary syndromes. The Global Registry of Acute Coronary Events

BACKGROUND: There are limited data describing the presenting characteristics, management, and outcomes of diabetic and nondiabetic patients with an acute coronary syndrome (ACS). OBJECTIVE: To examine differences in these factors, patients with ST-segment elevation acute myocardial infarction, non-ST-segment elevation acute myocardial infarction, and unstable angina were enrolled in a large multinational coronary disease registry. METHODS: The Global Registry of Acute Coronary Events is a prospective observational study of patients hospitalized with an ACS at 94 hospitals in 14 countries. The study sample consisted of 5403 patients with ST-segment elevation acute myocardial infarction, 4725 with non-ST-segment elevation acute myocardial infarction, and 5988 with unstable angina. RESULTS: Approximately 1 in 4 patients presented to participating hospitals with a history of diabetes. Patients with diabetes were older, more often women, with a greater prevalence of comorbidities, and they were less likely to be treated with effective cardiac therapies than nondiabetic patients. Patients with diabetes who developed an ACS were at increased risk for each hospital outcome examined including heart failure, renal failure, cardiogenic shock, and death. These differences remained after adjustment for potentially confounding prognostic factors. CONCLUSIONS: A considerable proportion of patients with an ACS has diabetes and is at increased risk for adverse outcomes compared with patients without diabetes. There are certain proven therapeutic strategies that remain underused in the diabetic population. A more widespread awareness of this increased risk and a more diligent use of proven cardiac treatment approaches are indicated for patients with diabetes who develop an ACS.     

Regional left ventricular perfusion and function in patients presenting to the emergency department with chest pain and no ST-segment elevation.

AIMS: We hypothesized that the assessment of left ventricular regional function (RF) and myocardial perfusion (MP) will provide incremental value over routine evaluation in patients who present to the emergency department (ED) with chest pain (CP) and no ST-segment elevation. METHODS AND RESULTS: In addition to routine clinical evaluation, patients with suspected cardiac CP and no ST-segment elevation were evaluated in the ED for RF and MP using contrast echocardiography (CE). Cardiac-related death, acute myocardial infarction, unstable angina pectoris, congestive heart failure (CHF), and revascularization were considered as events within 48 h (early). Of the 1017 patients studied, 166 (16.3%) had early events. Adding RF increased the prognostic information of clinical and EKG variables significantly (Bonferroni corrected P<0.0001) for predicting these events. When MP was added, significant additional prognostic information was obtained (Bonferroni corrected P=0.0002). All patients were followed for a median of 7.7 months (25th-75th percentiles: 2.7-12.5) Of these, 292 (28.7%) had events. Adding RF increased the prognostic information of clinical and EKG variables for determining the risk of events significantly (Bonferroni corrected P<0.0001), which was further increased by adding MP (Bonferroni corrected P<0.0001). CONCLUSION: Early assessment of RF on CE adds significant diagnostic and prognostic value to routine evaluation in patients presenting to the ED with suspected cardiac CP and no ST-segment elevation. MP provides additional significant value. CE could be a valuable tool in the early triage and management of CP patients presenting to the ED.     

ST-segment monitoring with continuous 12-lead ECG improves early risk stratification in patients with chest pain and ECG nondiagnostic of acute myocardial infarction.

OBJECTIVES: The purpose of this study was to evaluate the prognostic importance of ischemic episodes detected by ST-segment monitoring with continuous 12-lead electrocardiography (ECG) in a nonselected coronary care unit (CCU) population with chest pain and ECG nondiagnostic of acute myocardial infarction (AMI). BACKGROUND: Patients with chest pain and ECG nondiagnostic of AMI constitute a heterogeneous group concerning both diagnosis and prognosis. Continuous 12-lead ECG is a rather new method not thoroughly studied in this population. METHODS: The ST-segment monitoring with continuous 12-lead ECG was performed for 12 h in 630 consecutive patients admitted to CCU due to chest pain and a nondiagnostic ECG, i.e., no ST-segment elevations. An ST-episode was defined as a transient ST-segment depression or elevation of at least 0.10 mV. The median follow-up time was six months. RESULTS: A total of 176 ST-episodes occurred in 100 (15.9%) patients. The median duration and maximal ST-segment deviation in patients with ST-episodes were 80 min and 0.20 mV, respectively. Presence of ST-episodes predicted worse outcome concerning cardiac death and cardiac death or myocardial infarction (MI) (log-rank p < 0.001). At 30 day follow-up procedure, 10% versus 1.5% died from cardiac causes or had an MI in the group with and without ST-episodes, respectively. In a multivariate analysis, only troponin T > or = 0.10 microg/l and the presence of ST-episodes came out as independent predictors of cardiac death or MI. CONCLUSIONS: Continuous 12-lead ECG monitoring provides prognostic information on-line and considerably improves early risk stratification in patients with ECG nondiagnostic of AMI and symptoms suggestive of acute coronary syndrome.     

Predictors of recurrent ischemic events and death in unstable coronary artery disease after treatment with combination antithrombotic therapy

BACKGROUND: Patients with non-Q-wave acute coronary syndromes (ACS) have substantial rates of recurrent ischemic events, but prognostic studies have been small or preceded the routine use of aggressive combination antithrombotic therapy. We sought to identify predictors of these events after antithrombotic treatment of non-Q-wave ACS. METHODS: We assessed 30-day rates of a composite triple end point (death, infarction, or refractory angina) and double end point (death or infarction) among 3171 patients with non-ST-segment elevation ACS randomly assigned to enoxaparin or heparin, plus aspirin, for 2 to 8 days. We created multivariable regression models to predict these end points from baseline factors. RESULTS: Overall, 682 patients (21%) reached the triple end point and 220 (6.8%) reached the double end point. Independent predictors of the triple end point were admission with myocardial necrosis, ST-segment depression, prior angina severity, symptom duration, and allocation to enoxaparin treatment in patients with ST-segment depression (significant interaction). Independent predictors of the double end point were admission with myocardial necrosis, ST-segment depression, enrollment region, age >75 years, prior angina severity, and rales. By deciles, the average predicted risk for the double end point ranged from 2% to 20%: a patient aged <75 years with no risk factors had a 3.5% risk, whereas a patient aged >75 years with 2 additional high-risk features (myonecrosis and ST depression) had a risk of death or reinfarction of 26%. CONCLUSIONS: Patients with non-ST-segment elevation ACS exhibit a broad range of risk of adverse recurrent ischemic events. The predictive power of the model for the triple end point, using baseline variables, was modest. However, a subgroup at very low risk of the double end point (average 2%) can be identified with baseline variables.     

联合检测肌钙蛋白T、高敏C反应蛋白和B型钠尿肽对非ST段抬高的急性冠状动脉综合征预后诊断的价值

目的探讨联合检测肌钙蛋白T、高敏C反应蛋白、B型钠尿肽对非ST段抬高的急性冠状动脉综合征预后诊断的价值。方法检测145例经冠状动脉造影证实的非ST段抬高的急性冠状动脉综合征患者肌钙蛋白T、高敏C反应蛋白、B型钠尿肽的水平。随访急性冠状动脉综合征患者12个月，观察终点为心肌梗死新发或再发和心源性死亡。结果多因素logistic回归分析发现肌钙蛋白T、高敏C反应蛋白、B型钠尿肽可独立预测非ST段抬高急性冠状动脉综合征患者远期预后。经过已知的临床危险因素校正后，心脏生化标志物异常的数目仍然是其心血管事件重要危险因子。结论联合检测肌钙蛋白T、高敏C反应蛋白、B型钠尿肽对急性冠状动脉综合征患者长期预后有重要的临床价值。     

Labor- und EKG-Parameter als Prädiktoren für die Größe und Transmuralität einer myokardialen Narbe

Background

The size and transmurality of a myocardial scar have a high prognostic value with regard to mortality in acute coronary syndrome (ACS). We investigated the predictive value of the classic ECG parameters and the standard laboratory parameters for the size and transmurality of a myocardial scar in cardiac MRI.

Methods

A total of 96 patients after ACS with subsequent intervention underwent cardiac MRI. The statistical relationship between laboratory and ECG parameters and the size and transmurality of a myocardial scar was analyzed.

Results

There was no correlation between the presence of ST-segment elevation myocardial infarction (STEMI) and the size and transmurality of a scar. Likewise there was no significant correlation with the presence of Pardee Q wave. However, a positive correlation with the levels of CK, CK-MB, and LDH was noted. The positive significant correlation was determined for the size and transmurality. The troponin level upon admittance showed no correlation.

Conclusions

The classic ECG parameters (Q wave, ST-segment elevation) exhibited no significant correlation with the size and transmurality of the scar. In contrast, the maximum levels of CK, CK-MB, and LDH represent the only reliable predictors of size and transmurality of a myocardial scar.     

非ST段抬高急性冠状动脉综合征的预后危险因素与危险评分

目的：探讨非 ST 段抬高急性冠状动脉综合征的预后危险因素及不同危险评分的预测预后价值。方法：2003年1月至2004年4月期间,连续入院且资料完整的非 ST 段抬高急性冠状动脉综合征患者337例,随访 30天与1年的终点事件(心原性死亡和非致命性心肌梗死)。根据入院时的临床指标分别计算每例患者的心肌梗死溶栓治疗临床试验(TIMI)评分和全球急性冠状动脉事件注册(GRACE)评分,进行多变量回归分析,筛查30天和1年时心血管事件的预测危险因素(根据有无终点事件发生分为30天事件组、30天无事件组和1年事件组、1年无事件组)；分析 TIMI 评分和 GRACE 评分的预后价值,以及与血运重建的相互关系。结果：随访1年共发生终点事件57例(16.9%)。死亡19例(5.6%),非致死性心肌梗北38例(11.3%)。预测危险因素包括：年龄、血肌酐升高、入院时心率、左心室射血分数＜0.40和高血压。TIMI 评分和 GRACE 评分方法预测30天终点事件的敏感性和特异性相似,但 GRACE 评分预测1年终点事件的敏感性和特异性优于 TIMI 评分,GRACE 评分＞ 133分的患者进行血运重建治疗后远期终点事件发生率明显下降(P=0.01)。结论：除传统危险因素外,血肌酐水平升高是非 ST 段抬高急性冠状动脉综合征患者预后的重要危险因素；GRACE 评分较 TIMI 评分能更好的预测非 ST 段抬高急性冠状动脉综合征患者1年的终点事件危险,GRACE 评分＞133分的患者进行血运重建的获益更多。     

Myonecrosis After Revascularization Procedures

The detection of elevated cardiac enzyme levels and the occurrence of electrocardiographic (ECG) abnormalities after revascularization procedures have been the subject of recent controversy. This report represents an effort to achieve a consensus among a group of researchers with data on this subject. Creatine kinase (CK) or CK-MB isoenzyme (CK-MB) elevations occur in 5% to 30% of patients after a percutaneous intervention and commonly during coronary artery bypass graft surgery (CABG). Although Q wave formation is rare, other ECG changes are common. The rate of detection is highly dependent on the intensity of enzyme and ECG measurement. Because most events occur without the development of a Q wave, the ECG will not definitively diagnose them; even the ECG criteria for Q wave formation signifying an important clinical event have been variable. At least 10 studies evaluating >10,000 patients undergoing percutaneous intervention have demonstrated that elevation of CK or CK-MB is associated not only with a higher mortality, but also with a higher risk of subsequent cardiac events and higher cost. Efforts to identify a specific cutoff value below which the prognosis is not impaired have not been successful. Rather, the risk of adverse outcomes increases with any elevation of CK or CK-MB and increases further in proportion to the level of intervention. This information complements similar previous data on CABG. Obtaining preprocedural and postprocedural ECGs and measurement of serial cardiac enzymes after revascularization are recommended. Patients with enzyme levels elevated more than threefold above the upper limit of normal or with ECG changes diagnostic for Q wave myocardial infarction (MI) should be treated as patients with an MI. Patients with more modest elevations should be observed carefully. Clinical trials should ensure systematic evaluation for myocardial necrosis, with attention paid to multivariable analysis of risk factors for poor long-term outcome, to determine the extent to which enzyme elevation is an independent risk factor after considering clinical history, coronary anatomy, left ventricular function and clinical evidence of ischemia. In addition, tracking of enzyme levels in clinical trials is needed to determine whether interventions that reduce periprocedural enzyme elevation also improve mortality.