Admission standard electrocardiogram for early risk stratification in patients with unstable coronary artery disease not eligible for acute revascularization therapy: a TRIM substudy. ThRombin Inhibition in Myocardial Infarction

Clinical Significance of Reciprocal ST-segment Changes in Patients With STEMI: A Cardiac Magnetic Resonance Imaging Study

INTRODUCTION AND OBJECTIVES

We sought to determine the association of reciprocal change in the ST-segment with myocardial injury assessed by cardiac magnetic resonance (CMR) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

METHODS

We performed CMR imaging in 244 patients who underwent primary PCI for their first STEMI; CMR was performed a median 3 days after primary PCI. The first electrocardiogram was analyzed, and patients were stratified according to the presence of reciprocal change. The primary outcome was infarct size measured by CMR. Secondary outcomes were area at risk and myocardial salvage index.

RESULTS

Patients with reciprocal change (n=133, 54.5%) had a lower incidence of anterior infarction (27.8% vs 71.2%, P < .001) and shorter symptom onset to balloon time (221.5±169.8 vs 289.7±337.3min, P=.042). Using a multiple linear regression model, we found that patients with reciprocal change had a larger area at risk (P=.002) and a greater myocardial salvage index (P=.04) than patients without reciprocal change. Consequently, myocardial infarct size was not significantly different between the 2 groups (P=.14). The rate of major adverse cardiovascular events, including all-cause death, myocardial infarction, and repeat coronary revascularization, was similar between the 2 groups after 2 years of follow-up (P=.92).

CONCLUSIONS

Reciprocal ST-segment change was associated with larger extent of ischemic myocardium at risk and more myocardial salvage but not with final infarct size or adverse clinical outcomes in STEMI patients undergoing primary PCI.

Short- and long-term prognostic significance of ST-segment elevation in lead aVR in patients with non-ST-segment elevation acute coronary syndrome

We sought to evaluate the prognostic significance of ST-segment elevation (STE) in lead aVR in unselected patients with non-STE acute coronary syndrome (NSTE-ACS). We enrolled 1,042 consecutive patients with NSTE-ACS. Patients were divided into 5 groups according to the following electrocardiographic (ECG) patterns on admission: (1) normal electrocardiogram or no significant ST-T changes, (2) inverted T waves, (3) isolated ST deviation (ST depression [STD] without STE in lead aVR or transient STE), (4) STD plus STE in lead aVR, and (5) ECG confounders (pacing, right or left bundle branch block). The main angiographic end point was left main coronary artery (LM) disease as the culprit artery. Clinical end points were in-hospital and 1-year cardiovascular death defined as the composite of cardiac death, fatal stroke, and fatal bleeding. Prevalence of STD plus STE in lead aVR was 13.4%. Rates of culprit LM disease and in-hospital cardiovascular death were 8.1% and 3.8%, respectively. On multivariable analysis, patients with STD plus STE in lead aVR (group 4) showed an increased risk of culprit LM disease (odds ratio 4.72, 95% confidence interval [CI] 2.31 to 9.64, p <0.001) and in-hospital cardiovascular mortality (odds ratio 5.58, 95% CI 2.35 to 13.24, p <0.001) compared to patients without any ST deviation (pooled groups 1, 2, and 5), whereas patients with isolated ST deviation (group 3) did not. At 1-year follow-up 127 patients (12.2%) died from cardiovascular causes. On multivariable analysis, STD plus STE in lead aVR was a stronger independent predictor of cardiovascular death (hazard ratio 2.29, 95% CI 1.44 to 3.64, p <0.001) than isolated ST deviation (hazard ratio 1.52, 95% CI 0.98 to 2.36, p = 0.06). In conclusion, STD plus STE in lead aVR is associated with high-risk coronary lesions and predicts in-hospital and 1-year cardiovascular deaths in patients with NSTE-ACS. Therefore, this promptly available ECG pattern could be useful to improve risk stratification and management of patients with NSTE-ACS.

Complementary prognostic values of ST segment deviation and Thrombolysis In Myocardial Infarction (TIMI) risk score in non-ST elevation acute coronary syndromes: Insights from the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) study

BACKGROUND

Although the Thrombolysis In Myocardial Infarction (TIMI) score incorporates ST deviation, it does not account for characteristics of the ST deviations. In the present study, it was hypothesized that the magnitude and characteristics of ST deviation may add to the prognostic values of the TIMI risk score in acute coronary syndrome (ACS) patients, particularly in lower-risk patients with a TIMI risk score of less than 5.

OBJECTIVE

To evaluate the prognostic value of combining the TIMI risk score and characteristics of ST deviation in patients with non-ST elevation ACS and a TIMI risk score of less than 5.

METHODS

The death/myocardial infarction (MI) rates of 1296 patients enrolled in the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) angiographic substudy were examined.

RESULTS

Patients without a TIMI risk score of 5 or greater, and without an ST deviation of 1 mm or greater had the lowest six-month rate of death/ MI (5%). In patients with a TIMI risk score of less than 5, the six-month death/MI rate was increased in those with ST depression of 2 mm or greater compared with patients with a similar TIMI risk score and without ST deviation of 1 mm or greater (24% versus 5%, P<0.001). The presence of ST deviation of 2 mm or greater identified an additional 15% of patients with an increased six-month death/MI rate in patients with a TIMI risk score of less than 5.

CONCLUSION

ST segment deviation of 2 mm or greater confers additional prognostic information in non-ST elevation ACS patients with a TIMI risk score of less than 5. Patients with a TIMI risk score of less than 5 and ST deviation of 2 mm or less had the lowest risk of six-month death/MI.

Usefulness of ST depression with T-wave inversion in leads V(4) to V(6) for predicting one-year mortality in non-ST-elevation acute coronary syndrome (from the Electrocardiographic Analysis of the Global Use of Strategies to Open Occluded Coronary Arteries IIB Trial)

ST-segment depression (ST-D) on the admission electrocardiogram of patients with non-ST-elevation acute coronary syndromes (NSTEACSs) is associated with higher mortality. However, few studies have evaluated the effect of location of ST-D and T-wave polarity on long-term prognosis of patients with NSTEACS. Electrocardiographic (ECG) and clinical data from 6,770 patients with NSTEACS randomly assigned in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) IIB trial were analyzed retrospectively. One-year mortality was correlated with location of ST-D (leads I and aVL; II, III, and aVF; V1 to V3; or V4 to V6) and T-wave polarity. ST-D in any of the ECG locations was associated with higher mortality compared with patients without ST-D. Patients with ST-D and T-wave inversion in leads V4 to V6 had the highest 1-year mortality rate of all groups (16.2%), significantly higher compared with patients with ST-D without T-wave inversion in those leads (9.0%, p=0.001). Logistic regression analysis showed that age, hyperlipidemia, Killip class>I, history of myocardial infarction, history of heart failure, history of angina pectoris, systolic blood pressure, heart rate, sum of ST-D (odds ratio 1.061, 95% confidence interval 1.035 to 1.087, p<0.001), and ST-D with T-wave inversion in leads V4 to V6 (odds ratio 1.374, 95% CI 1.023 to 1.844, p=0.035) were independent predictors of 1-year mortality. Conversely, ST-D without T-wave inversion in leads V4 to V6 or other ECG presentations were not independent predictors of high 1-year mortality. In conclusion, ST-D with T-wave inversion in leads V4 to V6 on the admission electrocardiogram in patients with NSTEACS identifies those with higher 1-year mortality than for patients with any other ECG presentation.

Prognostic value of continuous ST-segment monitoring in patients with non-ST-segment elevation acute coronary syndromes

BACKGROUND

Patients with non-ST-segment elevation acute coronary syndromes constitute a heterogeneous group concerning prognosis. The 12-lead ECG at rest is recommended for early risk stratification but is unable to reflect the dynamic nature of myocardial ischemia and coronary thrombosis. This study investigated whether continuous ST-segment monitoring provides early prognostic information in such patients.

METHODS

We prospectively studied 183 patients admitted due to chest pain at rest suggestive of an acute coronary syndrome. ST-segment monitoring was performed continuously for 24 hours from admission. Cardiac-specific troponin I levels were determined on admission and every 6 hours for the first 24 hours. The endpoint was defined as death or nonfatal myocardial infarction, whichever occurred first by 30 days follow-up.

RESULTS

ST episodes, defined as transient ST deviations of at least 0.1 mV, were detected in 50 patients (27.3%) and associated with worse 30-day outcome: 22.0% endpoint rate compared to 6.8% for patients without ST episodes (P = 0.003). In a multivariate analysis, the presence of ST episodes (hazard ratio, 3.07; 95% CI, 1.26 to 7.46; P = 0.014) and peak troponin I levels > 0.2 microg/L (hazard ratio, 2.65; 95% CI, 1.01 to 6.95; P = 0.048) were independent predictors of prognosis. The combination of ST-segment monitoring and peak troponin I identified patients at low (2.5%, n = 79), intermediate (14.5%, n = 76), and high (25.0%, n = 28) risk for the 30-day endpoint.

CONCLUSIONS

In patients with non-ST-segment elevation acute coronary syndromes, continuous ST-segment monitoring provides on-line early prognostic information, in addition to troponin I levels.

Short- and Long-Term Risk Stratification in Acute Coronary Syndromes

OBJECTIVES

The purpose of this study was to develop 30-day and 1-year risk stratification models for non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients that incorporate quantitative ST-segment depression and novel biomarkers.

BACKGROUND

Several novel biomarkers have changed the risk profile of ACS; thus, the reassessment of traditional indicators such as ST-segment depression in this new context is warranted.

METHODS

Multivariable logistic regression was used to identify significant predictors of 30-day death and death/myocardial infarction (MI) and 1-year mortality in 7,800 NSTE-ACS patients enrolled in the GUSTO-IV (Global Utilization of Strategies to Open Occluded Arteries-IV ACS) trial between 1998 and 2000.

RESULTS

Among all other predictors, the degree of ST-segment depression had the highest prognostic value for 30-day death, 30-day death/MI, and 1-year death. Troponin T (TnT), creatinine clearance, N-terminal pro-brain natriuretic peptide (NT-proBNP), heart rate, and age were also highly influential on adverse outcomes. Unlike TnT and NT-proBNP, C-reactive protein was only predictive of long-term death. In contrast to mortality, the contribution of TnT to predicting 30-day death/MI increased, whereas NT-proBNP's role was attenuated. The discriminatory power was excellent (c-index [adjusted for over-optimism]: 0.82 [30-day death]; 0.72 [30-day death/MI]; 0.81 [1-year]).

CONCLUSIONS

In this large contemporary study of NSTE-ACS patients, novel insights into risk stratification were observed-in particular, the utility of quantitative ST-segment depression and multiple biomarkers. Collection of these indicators in future NSTE-ACS populations is recommended to evaluate generalizability and clinical application of these findings.

The greatest benefit of enoxaparin over unfractionated heparin in acute coronary syndromes is achieved in patients presenting with ST-segment changes: the Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) Electrocardiogram Core Laboratory Substudy

BACKGROUND

We undertook a prospective electrocardiogram (ECG) substudy in the ESSENCE trial and hypothesized that patient subgroups with ST-segment deviation would experience greater benefit from enoxaparin, as compared with unfractionated heparin (UFH).

METHODS

Of the 3171 patients in the trial, 3087 had a qualifying ECG available for analysis by the core laboratory. Patients were divided into 4 mutually exclusive groups based upon the qualifying ECG: (1) ST-segment elevation, (2) ST-segment depression, (3) T-wave inversions, or (4) others.

RESULTS

The 30-day and 1-year primary outcomes (death, myocardial infarction, or recurrent angina) were significantly lower among patients with ST elevation or ST depression who received enoxaparin, as compared with UFH (20.8% vs 28.0%, P = .0019 and 32% vs 40.4%, P = .0011, respectively). The greatest absolute benefit of enoxaparin over UFH was seen in patients with ST depression (primary end point at 30 days, 24.6% vs 32.4%, P = .018; at 1 year, 35.5% vs 44.5%, P = .012).

CONCLUSION

Specific recognition of patients with ST-segment depression appears to identify those not only at high risk for adverse outcome, but also patients most likely to derive the greatest benefit from enoxaparin, as compared with UFH therapy.

Comparison of EASI-derived 12-lead electrocardiograms versus paramedic-acquired 12-lead electrocardiograms using Mason-Likar limb lead configuration in patients with chest pain

INTRODUCTION

Monitoring or serial 12-lead electrocardiogram (ECG) recordings are the accepted requirement for prehospital data acquisition in patients with chest pain. The purpose of this study was to determine whether waveforms and clinical triage decision are similar in EASI-derived ECGs and paramedic-acquired 12-lead ECGs using Mason-Likar limb lead configuration when compared with standard 12-lead ECGs (stdECG).

METHOD

Twenty patients with chest pain had a prehospital 12-lead ECG recorded in the ambulance, and paramedic-applied electrodes retained in place at hospital arrival. An ECG technician applied standard precordial and EASI electrodes in their correct positions. Twelve-lead ECGs were obtained from the paramedic-applied electrodes, using their Mason-Likar limb lead configuration, and derived from the EASI leads for comparison with the stdECG. Three computer-measured QRS-T waveform parameters were considered, and differences in waveform measurement between EASI and stdECG (EASIDeltastdECG) versus differences in waveform measurements between paramedic Mason-Likar and stdECG (PMLDeltastdECG) were calculated. Two physicians determined whether the EASI-derived or the paramedic Mason-Likar ECG contained information that would change their clinical triage decision from that indicated by the stdECG.

RESULTS

EASIDeltastdECG and PMLDeltastdECG were identical in 28%, whereas EASIDeltastdECG was more than PMLDeltastdECG in 35%, and PMLDeltastdECG was accurate (both time) than EASIDeltastdECG in 37% (P = .62). The physicians were more likely to change the level of patient care based on the EASI-derived ECGs compared with the paramedic ECGs; however, this difference was not statistically significant (P = .27), but this may only be caused by the small study population.

CONCLUSIONS

There are similar differences from stdECG waveforms in EASI-derived ECGs and those acquired via paramedic-applied precordial electrodes using Mason-Likar limb lead configuration. Either method can be used as a substitute for monitoring, but neither should be considered equivalent to the stdECG for diagnostic purposes.

Relation between baseline risk and treatment decisions in non-ST elevation acute coronary syndromes: an examination of international practice patterns

OBJECTIVES

To examine the interaction between ST segment depression on the baseline ECG and subsequent in-hospital revascularisation on six month mortality among patients with non-ST elevation acute coronary syndromes. To examine whether ST segment depression influenced clinical decision making and whether there was international variation in the use of cardiac procedures across ST segment depression categories.

METHODS

11 453 patients enrolled in GUSTO-IIB (global use of strategies to open occluded coronary arteries), PARAGON (platelet IIb/IIIa antagonism for the reduction of acute coronary syndrome events in a global organisation network) -A, and PARAGON-B were studied. Patients were categorised as having no ST segment depression, 1 mm ST segment depression in two contiguous leads, and ST segment depression > or = 2 mm in two contiguous leads. International practice across four geographic regions was examined: USA, Canada, Europe, and Australia/New Zealand.

RESULTS

Revascularisation appeared to have no impact on survival among patients with no ST segment depression; however, revascularisation was associated with a significant survival benefit among patients with ST segment depression > or = 1 mm. There was an inverse relation between the extent of ST segment depression and the use of angiography as well as angioplasty (p < 0.01). However, patients with ST segment depression > or = 2 mm were more likely to undergo bypass surgery. The only significant trend of increasing use of revascularisation procedures with increasing ST segment depression was observed in the USA.

CONCLUSIONS

International practice patterns in procedure use appear to be insensitive to the extent of ST segment depression. Major opportunities for more efficient delivery of care exist in all regions.

Risk stratification of patients with acute chest pain and normal troponin concentrations

OBJECTIVE

To investigate the outcome of patients with acute chest pain and normal troponin concentrations.

DESIGN

Prospective cohort design.

SETTING

Single centre study in a teaching hospital in Spain.

PATIENTS

609 consecutive patients with chest pain evaluated in the emergency department by clinical history (risk factors and a chest pain score according to pain characteristics), ECG, and early (< 24 hours) exercise testing for low risk patients with physical capacity (n = 283, 46%). All had normal troponin concentrations after serial determination.

MAIN OUTCOME MEASURES

Myocardial infarction or cardiac death during six months of follow up.

RESULTS

29 events were detected (4.8%). No patient with a negative early exercise test (n = 161) had events versus the 6.9% event rate in the remaining patients (p = 0.0001). Four independent predictors were found: chest pain score > or = 11 points (odds ratio (OR) 2.4, 95% confidence interval (CI) 1.1 to 5.5, p = 0.04), diabetes mellitus (OR 2.3, 95% CI 1.1 to 4.7, p = 0.03), previous coronary surgery (OR 3.1, 95% CI 1.3 to 7.6, p = 0.01), and ST segment depression (OR 2.8, 95% CI 1.3 to 6.3, p = 0.003). A risk score proved useful for patient stratification according to the presence of 0-1 (2.7% event rate), 2 (10.2%, p = 0.008), and 3-4 predictors (29.2%, p = 0.0001).

CONCLUSIONS

A negative troponin result does not assure a good prognosis for patients coming to the emergency room with chest pain. Early exercise testing and clinical data should be carefully evaluated for risk stratification.

ST-segment depression on the initial electrocardiogram in acute myocardial infarction-prognostic significance and its effect on short-term mortality: A report from the National Registry of Myocardial Infarction (NRMI-2, 3, 4)

This study analyzed 255,256 patients who had acute myocardial infarction and were enrolled in the National Registry of Myocardial Infarction 2, 3, and 4 (1994 to 2002). The objective was to determine in-hospital mortality rate among patients who had ST-segment depression on the initial electrocardiogram. Patients who had ST-segment depression had an in-hospital mortality rate (15.8%) similar to that of patients who had ST-segment elevation or left bundle branch block (15.5%). After adjusting for observed differences, ST-segment depression was associated with only a slightly lower odds ratio (0.91) of mortality compared with ST-segment elevation or left bundle branch block.

Long-term prognosis of clinical variables, coronary reserve and extent of coronary disease in patients with a first episode of unstable angina

Clinical and ECG prognostic markers, ischemic threshold (IT) and extent of coronary disease were analyzed in 383 patients with unstable angina (UA) and correlated with long-term events. Patients >74 years or those with severe heart failure or previous revascularization procedures were excluded. There were 369 events in 245 patients: 87 deaths, 96 myocardial infarction (MI), 111 coronary artery bypass grafting (CABG), and 75 angioplasty procedures (PTCA). Follow-up was obtained in 367 hospital survivors (99%, 114 (44) months) and ST depression on admission ECG, a modest enzyme rise, refractory angina (>2 episodes), two to three vessel coronary disease and a reduced IT (<==130 beats/min) were each associated with cardiac events. A multivariate analysis, however, showed refractory angina (p<0.001) and multivessel disease (p<0.001) as most significant predictors. After their exclusion, IT was most relevant predictor (p<0.001). However, the predictive value of these markers was essentially centered on first-year events (249, 67%). Moreover, refractory angina, minor enzyme rise and admission ST depression were each highly correlated with a reduced IT (p<0.006) and with multivessel disease (p<0.0001). Therefore, these findings underscore that the prognostic value of conventional clinical markers in patients with UA is limited to first-year events and that their remarkable correlation with extensive coronary disease and reduced coronary reserve reveal the anatomical substrate of this prognostic significance.

Quantitative T-wave analysis predicts 1 year prognosis and benefit from early invasive treatment in the FRISC II study population

AIMS

To investigate the prognostic value of T-wave abnormalities in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS), and whether such ECG changes may predict benefit from an early coronary angiography. Although ST-segment changes are considered the most important ECG feature in NSTE-ACS, T-wave abnormalities are the most common ECG finding. We hypothesize that a new quantitative approach to T-wave analysis could improve the prognostic value of this ECG abnormality.

METHODS AND RESULTS

Quantitative T-wave analysis was performed on the admission ECG in 1609 patients with NSTE-ACS. Nine different categories of T-wave abnormality were analysed for their prognostic value concerning clinical outcome in patients not randomized to early coronary angiography. Also, the presence of one category (i.e. T-wave abnormality in > or =6 leads) was analysed for its predictive value concerning benefit from early coronary angiography. The combined study endpoint was death or myocardial infarction at 1 year follow-up. Patients with > or =6 leads with abnormal T-waves and concomitant ST-segment depression had a higher risk when not receiving early coronary angiography (24 vs. 12%, respectively; P=0.003), but could be brought to the same level of risk as the remaining patients with this treatment. For non-invasively treated patients five different categories of T-wave abnormality were significantly associated with an adverse outcome.

CONCLUSION

New quantitative T-wave analysis of the admission ECG gives additional predictive information concerning clinical outcome and identifies patients who benefit from early coronary angiography.

Predictors of short-term outcome in acute chest pain without ST-segment elevation

BACKGROUND

Management of acute chest pain in the emergency room constitutes a challenge.

METHODS

Seven hundred and one consecutive patients were evaluated by clinical history (chest pain score and risk factors), ECG, troponin I and early (<24 h) exercise testing in low risk patients (n=165). A composite end-point (recurrent unstable angina, acute myocardial infarction or cardiac death) was recorded during hospital stay or in ambulatory care settings for patients discharged after early exercise testing.

RESULTS

The end-point occurred in 122 patients (17%). Multivariate analysis identified the following predictors: chest pain score > or =11 points (OR=1.8, 2-2.8, 95% CI, P=0.007), age > or =68 (OR 1.6, 1.1-2.4 CI 95%, P=0.03), insulin-dependent diabetes mellitus (OR 1.9, 1.1-3.4 CI 95%, P=0.02), a history of coronary surgery (OR 3.3, 1.5-7.2 CI 95%, P=0.003), ST-segment depression (OR 1.9, 1.2-3.0 CI 95%, P=0.009) and troponin I elevation (OR 1.6, 1.1-2.5, CI 95%, P=0.05). ST-segment depression produced a high end-point increase (31 vs. 13%, P=0.0001). Troponin I elevation increased the risk in the subgroup without ST-segment depression (20 vs. 11%, P=0.006) but did not further modify the risk in the subgroup with ST depression (31 vs. 28%, ns). Nevertheless, the negative ECG and troponin I subgroup showed a non-negligible end-point rate (16% when pain score > or =11 or 7% when pain score <11, P=0.004). Finally, no patient with a negative exercise test presented events compared to 7% of those with a non-negative test (RR=2.5, 2.1-3.1 95% CI, P=0.01).

CONCLUSIONS

Emergency room evaluation of chest pain should not focus on a single parameter; on the contrary, the clinical history, ECG, troponin and early exercise testing must be globally analysed.

Relevance of multivessel disease in the development of in-hospital refractory angina and myocardial infarction in patients with unstable angina

We investigated the relationship between clinical, electrocardiographic and angiographic characteristics with development of refractory angina and acute myocardial infarction (AMI) in 976 consecutive patients with unstable angina (UA). AMI occurred in 63 (6%) and recurrent angina in 384 (39%), 201 of whom had >2 episodes (refractory, 21%). Patients with AMI were older (P<0.001) and had a higher rate of smoking (P<0.02), previous cerebrovascular accident (P<0.02), abnormal ST segment on admission (P<0.002), refractory angina (P<0.001) and multivessel disease (P<0.005) than those without AMI. Patients with refractory angina were older (P<0.001) and showed a higher incidence of abnormal ST segment on admission (P<0.001) and multivessel disease (P<0.001) than those without. A multivariate analysis, however, showed that refractory angina (P<0.0001), and multivessel disease (P<0.001) were the strongest predictors of AMI while age and multivessel disease were the strongest predictors of refractory angina (P<0.003). Thus, multivessel disease was the most frequent substrate of refractory angina and AMI in patients with UA. These findings may suggest that significant coronary stenosis in non-culprit arteries may facilitate recurrence of ischemia/AMI perhaps by reacting in concert with the culprit lesion and causing a further reduction of the ischemic threshold.

[Emergency room risk stratification of patients with chest pain without ST segment elevation]

OBJECTIVES

To investigate the prognostic factors in patients who come to the emergency room with chest pain but without ST segment elevation.

PATIENTS AND METHOD

743 consecutive patients were evaluated by recording clinical history, electrocardiogram and troponin I determination, and early (<24 h) exercise testing was done for the low-risk subgroup of patients (n=203). All patients were followed during 3 months for major events (acute myocardial infarction or death).

RESULTS

Major events occurred in 71 patients (9.6%). Multivariate analysis (C statistic=0.79; 95% CI 0.73-0.84; p=0.0001) identified the following predictors: age > or =72 years (OR=1.7; 95% CI, 1.0-2.9; p=0.05), insulin-dependent diabetes mellitus (OR=2.9; 95% CI, 1.5-5.4; p=0.001), previous ischemic heart disease (OR=1.9; 95% CI, 1.1-3.2; p=0.02), ST depression (OR=2.1; 95% CI, 1.2-3.8; p=0.01) and troponin I elevation (OR=2.9; 95% CI, 1.5-5.3; p=0.001). These five predictors were used to construct a risk score based on their odds ratios, which allowed event rate stratification by quartiles of the score: 0-2 points (1.6% events), 3-4 points (8.1% events), 5-7 points (11.9% events) and > or =8 points (26.2% events); p=0.0001. No patient with negative findings in the early exercise testing had major events.

CONCLUSIONS

In patients with chest pain, the combination of clinical, electrocardiographic and biochemical data available on admission to the emergency service allows rapid prognostic stratification. Early exercise testing is advisable for the final stratification of low risk patients.

A new scoring system to stratify risk in unstable angina

BACKGROUND

We performed this study to develop a new scoring system to stratify different levels of risk in patients admitted to hospital with a diagnosis of unstable angina (UA), which is a complex syndrome that encompasses different outcomes. Many prognostic variables have been described but few efforts have been made to group them in order to enhance their individual predictive power.

METHODS

In a first phase, 473 patients were prospectively analyzed to determine which factors were significantly associated with the in-hospital occurrence of refractory ischemia, acute myocardial infarction (AMI) or death. A risk score ranging from 0 to 10 points was developed using a multivariate analysis. In a second phase, such score was validated in a new sample of 242 patients and it was finally applied to the entire population (n = 715).

RESULTS

ST-segment deviation on the electrocardiogram, age > or = 70 years, previous bypass surgery and troponin T > or = 0.1 ng/mL were found as independent prognostic variables. A clear distinction was shown among categories of low, intermediate and high risk, defined according to the risk score. The incidence of the triple end-point was 6 %, 19.2 % and 44.7 % respectively, and the figures for AMI or death were 2 %, 11.4 % and 27.6 % respectively (p < 0.001).

CONCLUSIONS

This new scoring system is simple and easy to achieve. It allows a very good stratification of risk in patients having a clinical diagnosis of UA. They may be divided in three categories, which could be of help in the decision-making process.

Prognostic value of lead aVR in patients with a first non-ST-segment elevation acute myocardial infarction

BACKGROUND

ST-segment elevation in lead aVR has been associated with severe coronary artery lesions in patients with acute coronary syndromes, but the prognostic significance of this finding is unknown.

METHODS AND RESULTS

We analyzed the initial ECG in 775 consecutive patients admitted to our center with a first acute myocardial infarction without ST-segment elevation in leads other than aVR or V1. The rates of in-hospital death in patients without (n=525) and with 0.05 to 0.1 mV (n=116) or > or =0.1 mV (n=134) of ST-segment elevation in lead aVR were 1.3%, 8.6%, and 19.4%, respectively (P<0.001). After adjustment for the baseline clinical predictors and for ST-segment depression on admission, the odds ratios for death in the last 2 groups were, respectively, 4.2 (95% CI, 1.5 to 12.2) and 6.6 (95% CI, 2.5 to 17.6). The rates of recurrent ischemic events and heart failure during hospital stay also increased in a stepwise fashion among the groups, whereas creatine kinase-MB levels were similar. Among the 437 patients that were catheterized within 6 months, the prevalence of left main or 3-vessel coronary artery disease in the 3 groups was 22.0%, 42.6%, and 66.3%, respectively (P<0.001).

CONCLUSIONS

Lead aVR contains important short-term prognostic information in patients with a first non-ST-segment elevation acute myocardial infarction. Because the poorer outcome predicted by ST-segment elevation in lead aVR seems to be related to a more severe coronary artery disease, an early invasive approach might be especially beneficial in patients presenting with this finding.

The relative accuracies of ECG precordial lead waveforms derived from EASI leads and those acquired from paramedic applied standard leads

Accurate precordial electrode placement can be difficult in emergency situations leading either to loss of time or diminished accuracy. A possible solution is the quasi-orthogonal EASI lead system, with only five electrodes and easily defined landmarks to provide a derived 12-lead electrocardiogram (ECG). The purpose of this study was to test the hypothesis that precordial waveforms in EASI-derived ECGs have no greater deviation from those in gold standard ECGs, than do the precordial waveforms in paramedic acquired standard ECGs. Twenty paramedics applied the standard precordial electrodes employing the routine procedure. A certified ECG technician applied the 6 standard precordial electrodes in their correct gold standard positions, and the EASI electrodes. 12-lead ECGs were obtained from the paramedics' standard leads, and derived from the EASI leads, for comparison with the gold standard ECG. In each precordial lead recording, 6 computer-measured QRS-T waveform parameters were considered. Differences between deltaEASI-gold standard versus deltaparamedic-gold standard were calculated for every waveform in every lead resulting in 720 comparisons. EASI and paramedic results were "equally accurate" in 47%, the paramedic was more accurate in 31%, and EASI was more accurate in the remaining 22%. The differences from gold standard recording of precordial waveforms in ECGs derived from the EASI leads and those acquired via paramedic-applied standard electrodes are similar. The results suggest that the EASI lead system may provide an alternative to the standard ECG precordial leads to facilitate data acquisition and possibly save valuable time in emergency situations.

[Risk stratification using combined ECG, clinical, and biochemical assessment in patients with chest pain without ST-segment elevation. How long should we wait? ]

INTRODUCTION

We use clinical, ECG, and biochemical data to stratify risk in patients with chest pain without ST segment elevation. However, the prognostic performance of these studies in relation to time from onset of symptoms is unknown.

PATIENTS AND METHOD

In a single-center, prospective study, 321 consecutive patients who had been admitted in the emergency room with a suspected acute coronary syndrome without ST segment elevation were included in the study. Blood samples were collected for CK, CK-MB mass, myoglobin, and cardiac troponin T analysis 6, 12 and 18 hours after the onset of pain and other clinical and ECG data were recorded. Univariate and multivariate analysis was used to identify independent prognostic predictors 6 and 12 hours after the onset of chest pain.

RESULTS

Five variables were independent predictors of the recurrence of ischemia. The model correctly classified 82% of the patients. Age, history of coronary artery disease, prolonged chest pain at rest in the preceding 15 days, pain, ST-segment changes with pain, and cardiac troponin T in excess of 0.1 ng/m 12 hours after the onset of chest pain were identified by logistic regression. A similar model was analyzed at 6 hours, after changing the cutoff point for cardiac troponin T. Cardiac troponin T was considered positive with values of 0.04 ng/ml 6 hours after the onset of chest pain.

CONCLUSIONS

More than 80% of the patients admitted to the emergency room with chest pain without ST segment elevation can be correctly classified for new ischemic recurrences using clinical, ECG, and biochemical parameters 6 hours after the onset of pain.

Quantitative analysis of the admission electrocardiogram identifies patients with unstable coronary artery disease who benefit the most from early invasive treatment

OBJECTIVES

The aim of the present study was to evaluate whether the effect of an early invasive treatment strategy differed between patients sub-grouped according to their severity of myocardial ischemia, as evaluated by quantitative electrocardiographic (ECG) analysis at the time of presentation. The present study is a sub-study of the previously published Fast Revascularization during InStability in Coronary artery disease trial (FRISC-II).

BACKGROUND

An early invasive treatment strategy has been shown to be the preferable treatment for non-ST-segment elevation acute coronary syndromes (ACS). The population of patients with unstable coronary artery disease is heterogeneous regarding both the underlying pathology and prognosis. Early risk stratification is important to select patient subgroups that will benefit the most from a given treatment.

METHODS

In 2,201 patients with non-ST-segment elevation ACS, the ischemic burden at hospital admission was determined by quantitative measurements of ST-T-segment deviations on the ECG. The patients were subsequently sub-grouped in tertiles based on the amount of ST-segment deviation. The primary end point for this analysis was death or myocardial infarction (MI) within one year after study inclusion.

RESULTS

The invasive treatment strategy produced a reduction of approximately 50% in death or MI among the patients with intermediate or major ST-segment deviation. The findings were independent of age, gender, or troponin T status. The patients with confounding factors precluding ST analysis had a poor outcome regardless of the treatment strategy.

CONCLUSIONS

Ischemic burden on the admission ECG identifies patients with ACS who benefit the most from an invasive treatment strategy. When the standard ECG is scrutinized with complete quantitative measurements, it provides independent information on prognosis and benefit of treatment.

Cumulative risk assessment in unstable angina: clinical, electrocardiographic, autonomic, and biochemical markers

OBJECTIVES

To determine the incremental value of clinical data, troponin T, ST segment monitoring, and heart rate variability for predicting outcome in patients with non-ST elevation acute coronary syndromes.

METHODS

Prospective cohort study of 304 consecutive patients. Baseline clinical and electrocardiographic data were recorded, serial blood samples were obtained for troponin T assay, and 48 hour Holter monitoring was performed for ST segment and heart rate variability analysis. End points were cardiac death and non-fatal myocardial infarction during 12 months' follow up.

RESULTS

After 12 months, 7 patients had died and 21 had had non-fatal myocardial infarction. The risk of an event was increased by troponin T > 0.1 microg/l, T wave inversion on the presenting ECG, Holter ST shift, and a decrease in the standard deviation of 5 minute mean RR intervals. Positive predictive values of individual multivariate risk were low; however, analysis of all multivariate risk markers permitted calculation of a cumulative risk score, which increased the positive predictive value to 46.9% while retaining a negative predictive value of 96.9%.

CONCLUSION

A cumulative approach to risk stratification in non-ST elevation coronary syndromes successfully identifies a group in whom the risk of cardiac death or non-fatal myocardial infarction approaches 50%.

A combination of troponin T and 12-lead electrocardiography: a valuable tool for early prediction of long-term mortality in patients with chest pain without ST-segment elevation

BACKGROUND

Electrocardiography (ECG) obtained on admission and a troponin T (tn-T) level measured early after admission are simple and accessible methods for predicting outcome in patients with suspected unstable angina or myocardial infarction without persistent ST-elevations. However, there are few studies about the combination of these 2 methods as a means of predicting long-term outcome.

METHODS

ECG was obtained on admission, and a tn-T level was analyzed on admission and after 6 hours in 710 consecutive patients admitted because of chest pain and no ST-elevations. Patients were observed for a median time of 40 months for death.

RESULTS

ST-segment depressions > or =0.05 mV were present in 266 patients (37%). These patients had a 9.7-fold increased risk of death, compared with patients with normal ECG results. Isolated T-Wave inversions or pathological signs other than ST-T changes were present in 196 patients (28%), who had a 4.5-fold increased risk of death compared with patients who had normal ECG results. At 6 hours after admission, 169 patients (24%) had at least 1 sample of tn-T > or =0.10 microg/L, which resulted in an 3.7-fold increased risk of death. In a multivariate analysis, both ECG on admission and tn-T level came out as independent predictors of outcome. When these methods were combined, patients could be divided into low- (tn-T level <0.10 microg/L and no ST-segment depression), intermediate- (tn-T level > or =0.10 microg/L or ST-segment depression), and high-risk groups (tn-T level > or =0.10 microg/L and ST-segment depression).

CONCLUSIONS

ECG and tn-T level are valuable tools to quickly risk stratify patients with chest pain. The combination of these methods is superior to either one alone.

[Prognostic factors in unstable angina with dynamic electrocardiographic changes. Value of fibrinogen]

INTRODUCTION AND OBJECTIVES

The prognosis of unstable angina varies between series depending on the inclusion criteria and management protocol used. The aim of this study was to analyze in-hospital events and their predictors in a homogeneous single-center series of patients with unstable angina.

MATERIAL AND METHODS

A total of 246 patients with the following inclusion criteria were studied: 1) resting anginal pain, 2) transient electrocardiographic changes during anginal pain, 3) normal CK-MB levels and 4) exclusion of postinfarction angina. All patients were treated with aspirin and enoxaparin (1 mg/kg/12 h). Coronary angiography was performed in the case of recurrent angina or ischemia in Bruce I-II stage during the predischarge effort stress test. The variables recorded were risk factors, history of ischemic heart disease, history of coronary surgery, ECG upon admission, and fibrinogen.

RESULTS

During the hospital stay the following events were recorded: 36% recurrent angina, 58% cardiac catheterization, and 5,7% major events (infarction or death). Multivariate analysis found recurrent angina to be more frequent in patients with a history of coronary bypass surgery (p = 0.004. OR = 22; CI 95%, 3-182), ST-segment changes (p = 0.01. OR = 4.7, CI 95%; 1.4-15.9) and higher fibrinogen (p = 0.002. OR = 1,4, CI 95%; 1.1-1.7). Fibrinogen was the only variable related to cardiac catheterization (p = 0,009. OR = 1.3. CI 95%, 1.1-1.6) and major events (p = 0.001. OR = 2.0. CI 95%, 1.4-3.1).

CONCLUSIONS

1) Unstable angina with electrocardiographic changes was associated to a high rate of in-hospital events. 2) Fibrinogen was related to any event, and previous by-pass surgery and ST changes were related to recurrent angina.

[2002 Update of the Guidelines of the Spanish Society of Cardiology for Unstable Angina/Without ST-Segment Elevation Myocardial Infarction]

Since the Spanish Society of Cardiology Clinical Practice Guidelines on Unstable Angina/Non-Q-Wave Myocardial Infarction were released in 1999, the conclusions of several studies that have been published make it advisable to update current clinical recommendations. The main findings are related to the developing role of Chest Pain Units in the management and early risk stratification of acute coronary syndromes in the emergency department; new information concerning the efficacy of glycoprotein IIb/IIIa inhibitors, clopidogrel and low-molecular-weight heparins in the pharmacological treatment of acute coronary syndromes without ST-segment elevation; and the role of early invasive strategy in improving the prognosis of these patients. The published evidence is reviewed and the corresponding clinical recommendations for the management of acute coronary syndromes without persistent ST-segment elevation are updated.

[Is troponin I useful for predicting in-hospital risk for unstable angina patients in a community hospital? Results of a prospective study]

INTRODUCTION AND OBJECTIVES

Before including troponin I detection in the daily practice of our hospital we performed a prospective study to determine its real usefulness and to establish the best cut-off point.

METHODS

We studied 82 consecutive patients admitted with unstable angina to a community hospital. Troponin I was determined (> 10 h after chest pain). Patients were referred to a tertiary hospital for catheterization/revascularization if clinical events developed.

RESULTS

Twenty-five patients (31%) suffered events during admission: recurrent angina in 23 cases (28%); heart failure in 5 (6%); exitus in 3 (4%); myocardial infarction in 1 (1%). The cut-off point for troponin I that best predicted events was 0.1 ng/ml. Patients with troponin I > 0.1 (34 patients, 42%) experienced more events [47 vs. 19%; OR = 3.8 (1.4-10.4); p = 0.01] and had higher rates of recurrent angina (42 vs. 19%), heart failure (12 vs. 2%) and exitus (9 vs 0%). Patients with ECG changes and troponin I > 0.1 showed a significantly higher percentage of events (63%) than those with ECG changes alone (23%) or troponin I > 0.1 alone (15%) or those without ECG changes and troponin I < 0.1 (17%) (p < 0.0001).

CONCLUSIONS

Troponin I elevation is useful for predicting in-hospital risk for unstable angina patients admitted to a community hospital. A low cut-off value (0.1 ng/ml) predicts events. The association of ECG changes and high troponin I identifies a population at very high risk; however, the absence of both variables in patients with a diagnosis of unstable angina does not preclude the development of events.

Clinical significance of abnormal T waves in patients with non-ST-segment elevation acute coronary syndromes

T-wave abnormalities are common electrocardiographic occurrences in patients with non-ST-segment elevation acute coronary syndromes. Although these abnormalities are considered relatively benign, physicians use them to guide therapies. The study objective was to examine the prognostic predictive information of T-wave abnormalities in the setting of unstable coronary artery disease. The T-wave abnormality criterion was based on a new set of normal T-wave amplitude limits differentiated by gender, age, electrocardiographic lead, and QRS axis. Four hundred sixty-eight patients suspected of an acute ischemic incident and considered ineligible for reperfusion therapy were included. Thirteen categories of T-wave abnormalities were tested prospectively. The primary 30-day end point was the combination of refractory angina, myocardial infarction, or death. Quantitative T-wave analysis in an electrocardiographic core laboratory revealed 6 of 13 prespecified categories of T-wave abnormalities that were significantly associated with an adverse outcome. T-wave abnormalities had no prognostic value when ST-segment depression was also present, but this occurred in only 7.9% of patients. T-wave abnormalities as the sole manifestation of ischemia were common (74.4%). Patients with abnormal T waves in > or =1 of 6 selected abnormality categories (70.3%) had a significantly higher risk of death, acute myocardial infarction, and refractory angina (11% vs 3%; p = 0.018). Thus, T-wave abnormalities in patients presenting with non-ST-segment elevation acute coronary syndromes are common and should not automatically be regarded as benign phenomena. Quantitative T- wave analysis provides optimal risk stratification.

Risk stratification in non-ST segment elevation acute coronary syndromes with special focus on recent guidelines

Patients with unstable angina or non-ST segment elevation (non-Q-wave) myocardial infarction are a heterogeneous group with respect to their risk of developing clinically significant adverse events such as subsequent myocardial infarction and death. Recent guidelines promote risk stratification of these patients, targeting high-risk patients for maximal antithrombotic and antiischemic therapy and low-risk patients for early discharge. We reviewed current and future modalities for risk stratification of patients and the predictive value of these methods in context with available pharmacologic agents. Unfortunately, most of the data identifying a particular pharmacologic regimen as beneficial in high-risk patients are retrospectively derived from large trials. Until prospective studies that use markers to guide therapy are available, clinicians should be familiar with the use of these risk markers and their application to the role of a given management strategy, including pharmacologic therapy.

Angiographic correlates of a positive troponin T test in patients with unstable angina

OBJECTIVE

To study the angiographic correlates of cardiac troponin T (cTnT)-positive and -negative patients with unstable angina pectoris.

BACKGROUND

A positive cTnT test identifies a high-risk subgroup of unstable angina pectoris patients. Only the high-risk cTnT-positive patients seem to benefit from a more aggressive antithrombotic treatment regimen. The underlying coronary pathology in cTnT-positive and -negative patients that explains the predictive power of cTnT on prognosis and response to antithrombotic therapy is largely unknown.

METHODS

A total of 197 subsequently admitted patients with unstable angina pectoris underwent cTnT testing by a rapid bedside assay and early qualitative and quantitative angiography. Long-term follow-up was 12 months.

RESULTS

Patients with cTnT-positive tests revealed more critical stenoses of culprit lesions (p =.041), more severe reductions of thrombolysis in myocardial infarction flow grades (p <.037), a higher prevalence of intracoronary thrombus (p =.079), and a poorer left ventricular function (p =.047). The odds ratio of cTnT was 5.8 (p <.0001) for presence of thrombus, reduced thrombolysis in myocardial infarction flow, and/or critical stenosis (>90%), and was 3.1 (p =.005) for presence of three-vessel disease, left main disease, and/or reduced left ventricular ejection fraction. Coronary bypass grafting was more frequently performed in the cTnT-positive group. However, event-free survival was not different in our cohort characterized by a high rate of percutaneous coronary interventions.

CONCLUSIONS

A positive cTnT test in patients with unstable angina pectoris indicates presence of more severe coronary artery disease and poorer left ventricular function. This finding could explain the differences in short- and long-term outcome and treatment responses to antithrombotic regimens.

The correlation between presenting ST-segment depression and the final size of acute myocardial infarcts in patients with acute coronary syndromes

The use of reperfusion therapy in patients with ST elevation acute coronary syndromes had been established. However, reperfusion therapy is usually considered contra-indicated in those with ST depression, despite the knowledge that regional posterior infarction is typically indicated by ST depression maximal in leads V1 to V3 and nonregional subendocardial infarction is typically indicated by marked ST depression maximal in other leads. This study of patients with non-ST-elevation acute coronary syndromes investigates the quantitative relationship between presenting ST depression and final QRS changes in both of these subgroups. The final QRS score was significantly higher (2.44 points) than that of a control group with not ST depression, (1.55 points) in the group with maximal ST depression in V1 to V3 (P = 0.04). However, in the entire population, there was a highly significant correlation (P = .003) between the sum of the presenting ST depression and the final QRS score. Trials of reperfusion therapy will be required to determine if such evolution to electrocardiogram documented acute myocardial infarction can be prevented in patient with marked ST depression acute coronary syndromes.

Comparison of continuous vectorcardiography and continuous 12-lead electrocardiography of patients with unstable coronary artery disease: do they identify the same population?

BACKGROUND

Continuous vectorcardiography (cVCG) and continuous 12-lead electrocardiography (c12ECG) are important tools for assessing patients with unstable coronary artery disease.

OBJECTIVE

To compare the incidences of ischemia detected by the two methods, and examine whether the patients identified belonged to the same population, with respect to various clinical variables.

METHODS

Within a randomized prospective trial (FRISC II) including patients with unstable coronary artery disease, ST-segment monitoring was performed either by cVCG or by c12ECG for 24 h after admission for 1016 patients.

RESULTS

cVCG and c12ECG were performed for 730 and 286 patients, respectively. Transient ischemic episodes in 253 (34.7%) patients were detected by cVCG and such episodes were detected in 91 (31.8%) patients by c12EGG. When patients in whom transient ischemic episodes had been detected by cVCG and c12ECG were compared, the groups were similar with respect to baseline characteristics, signs of myocardial damage (67.5 versus 70.5%), occurrence of exercise-induced ischemia (59.0 versus 60.0%), and presence of severe coronary lesions (57.0 versus 51.3%).

CONCLUSIONS

Results of this study suggest that these two methods identify the same high-risk population, and that these patients can be considered one group when results obtained using either system are analyzed in multicenter studies. This also implies that results concerning the occurrence of episodes of resting ischemia obtained using one system may also be applicable for the other.

Unstable angina pectoris and non-Q-wave myocardial infarction

Unstable angina pectoris and non-Q-wave myocardial infarction are clinical syndromes that share many pathophysiologic and clinical features. In the spectrum of coronary artery disease, these syndromes lie between chronic stable angina and Q-wave myocardial infarction. Although both conditions are associated with significant morbidity and mortality, patients presenting with these syndromes can be further risk stratified into higher and lower risk based on a number of readily available clinical features and biochemical parameters. Such risk stratification can allow for more tailored treatment and better resource allocation. Although routine early coronary angiography and revascularization has not been shown to be superior to conservative management, certain high-risk patients may benefit from a more aggressive strategy. Medical therapy with the use of antiplatelet, anticoagulant, and antiischemic agents remains the cornerstone of emergent treatment for patients presenting with these syndromes. The recent demonstration of a reduction in both morbidity and mortality with the glycoprotein IIb/IIIa antagonists has further expanded the armamentarium of available agents. Following initial stabilization, risk stratification with stress testing can help identify patients with a large residual ischemic burden who may benefit from coronary angiography with revascularization if feasible.

Unstable angina: the first 48 hours and later in-hospital management

Unstable angina is a common cardiovascular condition associated with major adverse clinical events. Over the last 15 years, therapeutic advances have dramatically reduced the complication and mortality rates of this serious condition. The standard of therapy in patients with unstable angina now incorporates the combined use of potent antithrombotic (aspirin, clopidogrel, heparin and glycoprotein IIb/IIIa receptor antagonists) and anti-anginal (beta-blockade and intravenous nitrates) regimens complemented by the selective and judicious application of coronary revascularisation strategies. Increasingly, these invasive and non-invasive therapeutic interventions are being guided not only by the clinical risk profile but also by the determination of serum cardiac and inflammatory markers. Moreover, rapid and intensive management of associated risk factors, such as hypercholesterolaemia, would appear to have potentially substantial benefits even within the acute in-hospital phase of unstable angina.

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

BACKGROUND

In patients with unstable coronary artery disease, there is a relation between the short-term risk of death and blood levels of troponin T (a marker of myocardial damage) and C-reactive protein and fibrinogen (markers of inflammation). Using information obtained during an extension of the follow-up period in the Fragmin during Instability in Coronary Artery Disease trial, we evaluated the usefulness of troponin T, C-reactive protein, and fibrinogen levels and other indicators of risk as predictors of the long-term risk of death from cardiac causes.

METHODS

Levels of C-reactive protein and fibrinogen at enrollment and the maximal level of troponin T during the first 24 hours after enrollment were analyzed in 917 patients included in a clinical trial of low-molecular-weight heparin in unstable coronary artery disease. The patients were followed for a mean of 37.0 months (range, 1.6 to 50.6).

RESULTS

During follow-up, 1.2 percent of the 173 patients with maximal blood troponin T levels of less than 0.06 microg per liter died of cardiac causes, as compared with 8.7 percent of the 367 patients with levels of 0.06 to 0.59 microg per liter and 15.4 percent of the 377 patients with levels of at least 0.60 microg per liter (P=0.007 and P=0.001, respectively). The rates of death from cardiac causes were 5.7 percent among the 314 patients with blood C-reactive protein levels of less than 2 mg per liter, 7.8 percent among the 294 with levels of 2 to 10 mg per liter, and 16.5 percent among the 309 with levels of more than 10 mg per liter (P=0.29 and P=0.001, respectively). The rates of death from cardiac causes were 5.4 percent among the 314 patients with blood fibrinogen levels of less than 3.4 g per liter, 12.0 percent among the 300 with levels of 3.4 to 3.9 g per liter, and 12.9 percent among the 303 with levels of at least 4.0 g per liter (P=0.004 and P=0.69, respectively). In a multivariate analysis, levels of troponin T and C-reactive protein were independent predictors of the risk of death from cardiac causes.

CONCLUSIONS

In unstable coronary artery disease, elevated levels of troponin T and C-reactive protein are strongly related to the long-term risk of death from cardiac causes. These markers are independent risk factors, and their effects are additive with respect to each other and other clinical indicators of risk.

Prognostic significance of ST segment depression in lateral leads I, aVL, V5 and V6 on the admission electrocardiogram in patients with a first acute myocardial infarction without ST segment elevation

OBJECTIVES

We sought to investigate the short-term prognostic value of the admission electrocardiogram (ECG) in patients with a first acute myocardial infarction (MI) without ST segment elevation.

BACKGROUND

ST segment depression on hospital admission predicts a worse outcome in patients with a first acute MI, but the prognostic information provided by the location of ST segment depression remains unclear.

METHODS

In 432 patients with a first acute MI without Q waves or > or = 0.1 mV of ST segment elevation, we evaluated the ability of the initial ECG to predict in-hospital death.

RESULTS

The presence, magnitude and extent of ST segment depression were associated with an increased mortality, but the only electrocardiographic variable that was significant in predicting death after adjusting for baseline predictors was ST segment depression in two or more lateral (I, aVL, V5, or V6) leads (odds ratio 3.5, 95% confidence interval 1.2 to 10.6). Patients with lateral ST segment depression (n = 91, 21%) had higher rates of death (14.3% vs. 2.6%, p < 0.001), severe heart failure (14.3% vs. 4.1%, p < 0.001) and angina with electrocardiographic changes (20.0% vs. 11.6%, p = 0.04) than did the remaining patients, even though they had similar peak creatine kinase, MB fraction levels (129 +/- 96 vs. 122 +/- 92 IU/liter, p = NS). In contrast, ST segment depression not involving the lateral leads did not predict a poor outcome. Among patients who were catheterized, those with lateral ST segment depression had a lower left ventricular ejection fraction (57 +/- 12% vs. 66 +/- 13%, p = 0.001) and more frequent left main coronary artery or three-vessel disease than did the remaining patients (60% vs. 22%, p < 0.001).

CONCLUSIONS

In patients with a first non-ST segment elevation acute MI, ST segment depression in the lateral leads on hospital admission predicts a poor in-hospital outcome.

Evaluation of the emergency department chest pain patient

Patients presenting to the emergency department with chest pain are a common and perplexing problem. Because of the limitations of the initial evaluation, most patients are admitted, although many are found to have noncardiac causes of their symptoms. Recognition of these limitations has driven the investigation of newer evaluation techniques and protocols in an attempt to improve diagnostic sensitivity without increasing overall costs. These have included modifications of the standard electrocardiogram and use of newer myocardial markers of necrosis, such as mass assays for CK-MB as well as troponin T and troponin I. Use of acute rest myocardial perfusion imaging also has been shown to be a highly valuable technique for risk stratification of the intermediate- to low-risk chest pain patient.