European Heart Journal Advance Access originally published online on October 11, 2007
European Heart Journal 2007 28(24):2985-2991; doi:10.1093/eurheartj/ehm428
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The electrocardiographic window of opportunity to treat vs. the different evolving stages of ST-elevation myocardial infarction: correlation with therapeutic approach, coronary anatomy, and outcome in the DANAMI-2 trial
1 Department of Cardiology, Heart Center, Tampere University Hospital, Biokatu 6, PO Box 2000, 33520 Tampere, Finland
2 Department of Cardiology B, Heart Centre, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
3 Procardia Medical Center, Tel Aviv, Israel
4 Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
5 School of Public Health, University of Tampere, Tampere, Finland
Received 31 March 2007; revised 17 August 2007; accepted 31 August 2007; online publish-ahead-of-print 11 October 2007.
* Corresponding author. Tel: +358 3 311 66080; fax: +358 3 311 64157. E-mail address: markku.eskola{at}pshp.fi
See page 2957 for the editorial comment on this article (doi:10.1093/eurheartj/ehm512)
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Abstract |
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Aims: The aim of the study was to assess two distinct 12-lead electrocardiogram (ECG) patterns and their prognostic value with respect to reperfusion strategy.
Methods and results: In a DANAMI-2 substudy (n = 1522), we defined the pre-infarction syndrome (PIS) as ST-elevation accompanied by positive T waves and evolving myocardial infarction (EMI) as pathological Q waves and/or negative T wave. We used a composite of death, clinical re-infarction, or disabling stroke at median 2.7 year follow-up. A higher overall event rate was observed in the EMI group compared with the PIS group [11.4 (9.4–13.9) and 6.9 (6.0–8.0) per 100 person-years, respectively, ratio of the rate (RR) 1.6, P < 0.001]. The EMI pattern was independently predictive of adverse outcome in multivariable analysis (hazard ratio 1.52, confidence interval 1.01–2.30, P = 0.04). The PIS pattern (n = 952) was associated with lower overall event rate in patients treated with primary percutaneous coronary intervention (PCI) compared with fibrinolytic therapy (FT) [5.5 (4.4–6.9) and 8.5 (7.0–10.4) per 100 person-years, respectively, RR = 0.6, P = 0.004]. No significant difference in the outcome between treatment strategies was observed in the EMI group as a whole. However, in patients with anterior EMI without ECG signs of reperfusion, superiority of primary PCI was driven by a 51% reduction in the relative risk of composite endpoint (P = 0.008).
Conclusion: More detailed ECG analysis, involving also Q- and T-wave morphology, is useful for rapid identification of high-risk patients in whom every effort should be made to transfer for primary PCI, or vice versa, for identifying low-risk patients in whom FT might be an alternative option.
Key Words: Myocardial infarction • Electrocardiogram • Percutaneous coronary intervention • Fibrinolysis • Risk stratification • Prognosis
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Introduction |
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Final infarct size is a major prognostic determinant in acute ST-elevation myocardial infarction (STEMI).1 Duration of coronary occlusion and efficiency of epicardial and myocardial flow restoration are important determinants of myocardial damage.2,3 Primary percutaneous coronary intervention (PCI) has several advantages compared with fibrinolytic therapy (FT), such as superior efficacy in restoring coronary blood flow, making it the preferred strategy for STEMI reperfusion today.4 However, in a global perspective, most patients are treated in hospitals without 24 h/7 day cardiac catheterization facilities. Building up round-the-clock invasive systems is a big logistic and economic challenge. Hence, it would be crucially important to be able to define low-risk populations that could be treated alternatively with FT in the acute phase. The Thrombolysis in Myocardial Infarction (TIMI) risk score identifies a group of high-risk patients who have a reduced mortality with invasive strategy of primary angioplasty.5 Differences in treatment delay and in patient characteristics modulate the relative survival advantage for primary PCI over fibrinolysis.6 The acuteness score has been used as a tool to define the different stages of the evolving myocardial infarction (EMI) process.7 However, such scores may be unpractical in the setting of rapid decision-making about therapeutic strategies in the acute phase. Another alternative to define the stage of the infarct process, the use of distinct electrocardiogram (ECG) patterns, has been described by Sclarovsky.8 Sudden occlusion of a coronary artery or a major side-branch results within seconds in positive and tall T waves, followed by the elevation of the ST-segment (‘injury vector’) in the ECG. In patients with acute chest pain, this ‘pre-infarction syndrome’ (PIS) represents the window of opportunity to treat before irreversible myocardial damage develops. Successful reperfusion results in the normalization of the ST-segment, usually accompanied by T-wave inversion, a marker of an open infarct-related artery with restored myocardial blood flow. The pre-infarction stage may evolve towards MI with or without Q waves (EMI).
The aim of the present study was to investigate the distribution of two distinct ECG patterns, PIS and EMI in the acute infarct process, and the impact of the ECG features on outcomes of patients treated with PCI or FT.
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Study patients
The Danish Trial in Acute Myocardial Infarction-2 (DANAMI-2) randomized 1572 patients, from December 1997 to October 2001, with ST-segment elevation acute MI to either primary PCI or FT with intravenous alteplase. A detailed description of inclusion and exclusion criteria for the DANAMI-2 trial has been reported previously.9 In this substudy, the primary endpoint was a composite of mortality, clinical infarction, and disabling stroke at 2.7 year [median, inter-quartile range (IQ) 1.9–3.6] follow-up. The patients were entered into the database immediately after randomization. Primary endpoint was at 30 days, and during this period, all endpoint data on the patients were entered continuously. After a minimum follow-up period of 2 years, the status on admissions (acute MI and stroke) and death was obtained from various registries. Follow-up information was available for all patients utilizing National Social Security number-based registries. The study complies with the Declaration of Helsinki, and the research protocol was approved by the National Ethics Committee of Denmark. All eligible patients provided written informed consent.
For this substudy, baseline ECGs were available and could be linked to the DANAMI-2 database from 1522 patients. Patients with ECG confounders such as left bundle branch block, left ventricular hypertrophy, pacemaker ECG, and right bundle branch block in association with left anterior hemiblock were excluded. Also, patients with ECG signs of lateral STEMI were not included owing to the small number of cases (n = 23). Finally, 1300 patients with anterior (n = 624) or inferior (n = 676) infarct locations were included in the statistical analyses of the substudy. The patients were divided into two subgroups on the basis of ECG findings: PIS (n = 952) and EMI (n = 348). In addition, the EMI group was graded according to ECG signs of reperfusion. The more specific flow charts in Figure 1 illustrate the ECG subgroups and treatment of the patients.
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Electrocardiogram analysis
Randomization ECGs were analysed by three investigators blinded to the clinical data and angiographic findings at the independent core laboratory at Tampere University Hospital. Any disagreement between the investigators was resolved by consensus. The ST-segment was measured manually at the J point with the TP-segment as the iso-electric line. The T wave was considered positive or negative if it was 0.5 mm or more above or below the iso-electric line, measured more than 120 ms after the J point. Pathological Q waves were defined by standard criteria.10 Anterior MI was defined as ST-elevation
2 mm, maximally in at least two contiguous chest leads V2–V4. Inferior MI was defined as 1 mm ST-elevation in two or more of the extremity leads II, III, and aVF. In case of concomitant ST-elevation in the precordial leads V1–V3, patients were included into the inferior MI group if the sum of ST-elevation was higher in leads V1–V2 than in leads V2–V3. Patients with ST-elevations (in two or more leads) in leads II, III, and aVF with concomitant ST-elevation in leads V4–V6 but not in leads V1–V3 were classified as inferior MI.
Definitions
The ‘pre-infarction syndrome’; was defined as ST-segment elevation fulfilling the aforementioned criteria for anterior or inferior MI, but without pathological Q waves or inverted T waves in the leads with ST-elevation (Figure 2A).
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Evolving MI was defined by ECG signs of myocardial necrosis (pathological Q waves) and/or signs of reperfusion (negative or biphasic T waves). For convenience, we use the term ‘negative T wave’ also for patients with biphasic T waves with a
0.5 mm negative terminal portion. No reperfusion was defined as ST-elevation with a positive T wave (Figure 2B). Incomplete reperfusion was defined as ST-elevation with inversion of the T wave (Figure 2C). Complete reperfusion was defined as an iso-electric ST-segment with a completely inverted T wave (Figure 2D).8
Statistics
Categorical variables were expressed as numbers of patients or percentages and continuous variables as medians followed by IQ range. Confidence intervals (CIs) were calculated at the 95% significance level. Statistical significance (two-tailed P-value <0.05) was assessed by the 
2 test or Fisher’s exact test for categorical variables and the Mann–Whitney test for numerical variables. The event rates were presented per 100 person-years with CIs. The ratios of the rates (RRs) were analysed by Mantel–Haenszel method. Composite endpoint data between ECG subgroups were plotted as Kaplan–Meier curves. Comparison between groups was performed using log-rank statistic. Cox regression analysis was used to test the prognostic significance of baseline and ECG variables concerning composite endpoints at follow-up. Also, hazard ratios were presented. The multivariable analyses were performed by entering the following variables: age 75 years, Killip class on admission, heart rate > 100 b.p.m., anterior location of infarction, time to treatment > 4 h, weight < 67 kg, history of diabetes, history of hypertension, smoking status, gender, lipid-lowering medication, aspirin medication, ECG pattern, and treatment group. The effect of ECG pattern on composite endpoint was determined by evaluating the interaction term (ECG pattern-treatment group). Calculations were performed with the SPSS 12.5 statistical package and the Stata 8.2 for Windows.
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Of the 1522 patients, 624 (41%) had an anterior STEMI and 676 (44%) an inferior STEMI based on our ECG criteria (Figure 1A). The ECG pattern of PIS was more common than EMI in patients with acute anterior STEMI (59 vs. 41%, respectively). In inferior infarctions, the ECG pattern of EMI was rare (14%).
The baseline data of patients are presented in Table 1. The patients with PIS were younger and more often smokers compared with the patients with EMI. They also had shorter time to randomization and time to reperfusion therapy. The patients with EMI more often had diabetes and angiotensin-converting enzyme inhibitor medication. They also had faster heart rates, higher systolic blood pressure, and lower ejection fraction than patients with PIS. Only very few patients (4%) with anterior MI had other than the left anterior descending artery as the culprit artery according to angiographic findings. In inferior MI, most cases were caused either by right (74%) or left circumflex (17%) coronary artery occlusions.
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The event rate for the composite endpoint was higher in EMI than in the PIS group [11.4 (9.4–13.9) and 6.9 (6.0–8.0) per 100 person-years, respectively, RR 1.6, P < 0.001]. The difference was explained with the higher mortality in the EMI group than in the PIS group [8.3 (6.7–10.4) and 3.9 (3.2–4.7) per 100 person-years, respectively, RR 2.1, P < 0.001]. In multivariable analysis, the ECG finding of EMI predicted poor prognosis compared with the ECG finding of PIS. The other variables which provided independent prognostic information in multivariable analysis were age
75 years, aspirin treatment, lipid-lowering treatment, anterior MI, and weight < 67 kg (Table 2). The interaction term indicated that the ECG pattern was independently predictive (P for interaction 0.167).
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In the patients with PIS (n = 952), the event rate of primary composite endpoint was lower in patients treated with primary PCI compared with FT at follow-up [5.5 (4.4–6.9) and 8.5 (7.0–10.4) per 100 person-years, respectively, RR = 0.6, P = 0.004] (Figure 3A). The difference was explained with the lower re-infarction rate in the primary PCI group than in the FT group [3.0 (2.1–4.3) and 6.8 (5.2–8.7) per 100 person-years, respectively, RR 0.5, P < 0.001]. The number needed to treat with primary PCI to avoid one endpoint event during 2.7-year follow-up was 17 (CI 9–89). There was no statistically significant difference in mortality, clinical re-infarction, or disabling stroke at 2.7-year follow-up between the two treatment arms within patients with EMI (n = 348) (Figure 3B). In the anterior EMI group, however, the patients with no signs of reperfusion on the ECG (n = 139) treated with primary PCI had a better prognosis than the patients treated with FT (Table 3). In this group, the superiority of primary PCI over FT was driven by a 51% reduction in the relative risk of composite endpoint. The number needed to treat with primary PCI in order to avoid one death, clinical re-infarction, or disabling stroke in a 2.7-year period was 5 (CI 3–26). In inferior EMI without ECG signs of reperfusion, the probability of reaching an endpoint was higher with primary PCI than with FT.
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In the EMI group as a whole (n = 348), there was no difference in composite endpoints according to the presence (76%) or absence of Q waves (24%) on the ECG.
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Discussion |
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This study adds new interesting data to our knowledge about prognostic and therapeutic differences between STEMI patient groups. It represents the first study to evaluate the clinical significance of two distinct ECG patterns, ST-segment elevation without (PIS) or with (EMI) pathological Q waves or negative T waves, in a large patient cohort. We found that patients with PIS had better long-term outcome with primary PCI than with FT. Also, patients with anterior evolving STEMI without T-wave inversion, an ECG sign of reperfusion, had better outcome with invasive therapy than with pharmacological reperfusion. Maximal effort should be put to provide immediate invasive treatment for these patient groups. Data from the National Registry of Myocardial Infarction indicate that benefits and limitations of the reperfusion strategy, patient characteristics, and system delays should be considered when a reperfusion strategy for STEMI is selected. Patient age, duration of symptoms, and infarct location significantly modulated how rapidly the survival advantage of primary PCI compared with FT therapy was lost.6 Our study adds to these findings by showing differences in treatment response to reperfusion therapy with different ECG presentations. When ECG signs of reperfusion were present, FT resulted in a similar long-term outcome as primary PCI both in anterior and inferior STEMI. Our prediction was based solely on the ECG presentations in the acute phase without knowledge of clinical parameters.
When using only traditional ECG parameters, typically ST-segment elevation, patient outcome in the DANAMI-2 trial in different subgroups has favoured primary angioplasty. Regardless of infarct localization, invasive therapy was superior to non-invasive.11 Also when comparing the prognostic value of the sum of ST-segment elevations within quartiles, the relative benefit of primary PCI was similar.12 However, Sejersten et al.13 recently showed that defining grades of ischaemia on the presenting ECG in the DANAMI-2 study enabled the identification of high-risk patient populations with adverse outcome. This together with the results of our study indicates that extension of ECG interpretation beyond traditional ST-segment analysis is important.
In the present study, patients with EMI had about 1 h longer median time delay from symptom onset to randomization and to reperfusion therapy compared with patients with PIS, indicating a later stage of the evolutionary MI process. We found that time to treatment >4 h was not an independent predictor for outcome when ECG pattern indicating the stage of the infarct process was included into the model. Interestingly, neither PCI treatment was independently predictive. Because of the limitations with patient-reported timing of symptom onset, ECG phasing and acuteness scores were developed, and later modified, by Anderson and Wilkins et al. to estimate the extent to which a patient has progressed through the MI process by the time of clinical presentation.7,14 The clinical importance of the Anderson–Wilkins (AW) score has been validated, but for the acuteness score to be clinically useful, it should be an integral component of a commercial automated ECG analysis program.15 So far, such programs are not universally available. Our results support an alternative approach using simple ECG patterns to divide STEMI patients into clinically relevant categories. Actually, these patterns are distinguished by the same ECG parameters, the Q and T waves, used in the AW scoring system.
Randomized studies of acute STEMI use cut-off points for the amount of ST-elevation for patient inclusion.16 Changes in the Q and T waves are not considered. According to our results, clinically important information about the pathophysiology and the timing of the ischaemic process may be contained in these ECG parameters. The predictive value of a negative T wave as a marker of reperfusion has no general agreement. However, it has previously been shown that patients with acute anterior MI, in whom ST-segment elevation and positive T waves persist at discharge from the coronary care unit, have higher probability of a non-patent left anterior descending coronary artery compared with patients with an iso-electric ST-segment with negative T waves.17 Early inversion of the T wave in the leads with ST-elevation has been associated with improved outcome related to an open infarct-related artery, restored myocardial blood flow, re-appearance of the R wave, and better left ventricular function.18–21 Although our patients with EMI had 
4 h median time delay to reperfusion therapy, those with inverted T waves showed no significant difference in outcome between mechanical and pharmacological therapy. This may seem contradictory, as the effect of FT is significantly reduced after 3 h delay from symptom onset to treatment.22 Also in randomized trials such as PRAGUE-2 and CAPTIM, the superiority of primary PCI relative to fibrinolysis was most evident after 2–3 h delay from symptom onset.23,24 Appreciating negative T waves in this context as markers of restored epicardial and myocardial blood flow could explain this finding. Studies have shown that the occurrence of reperfusion before PCI is associated with more favourable clinical outcome.25 Therapeutic advantages of primary PCI might be less obvious in cases with an open infarct-related artery. High-risk patients, such as those with large thrombus burden and increased risk for distal embolization with no re-flow, may outweigh some of the benefits from PCI.26,27 Especially when access to primary PCI is limited, FT could be a reasonable alternative in patients presenting with negative T waves associated with ST-elevation.
The role of Q waves in the acute phase of STEMI is less well established than that of the T wave. Classically, the appearance of Q waves has been associated with irreversible myocardial necrosis. In animal studies, early appearance of Q waves may indicate reperfusion in the ischaemic myocardium. A study by Blumenthal et al.28 indicated that delayed appearance of Q waves was largely due to a lack of circulation in the infarcted area rather than to prolonged survival time. Severe myocardial ischaemia can produce early QRS changes by inducing intramyocardial conduction delays. Raitt et al.29 found abnormal Q waves in more than half of patients eligible for thrombolytic therapy with symptom duration less than 1 h to the initial ECG recording. The appearance of abnormal Q waves early in the course of acute MI did not lessen the benefit of reduced infarct size after thrombolytic therapy. On the other hand, the presence of Q waves in the initial ECG was an independent predictor of higher 30-day mortality in patients treated with FT in a recent HERO-2 substudy.30 In our study, EMI (Q waves present in three-fourth) was associated with worse prognosis compared with PIS. In the anterior EMI group without ECG signs of reperfusion, primary PCI resulted in a dramatic 51% reduction in the relative risk of composite endpoint. According to this, patients with anterior STEMI with Q waves, ST-elevation, and positive T waves should have high priority for invasive therapy. The result is in accordance with the ‘pathophysiological message’ from the ECG—a high probability of an occluded infarct-related artery (ST-elevation with positive T waves), with an extensive area of jeopardized myocardium (anterior localization).
Our study showed a difference in relative distribution of PIS and EMI between anterior and inferior STEMI. EMI was present in only 14% of inferior STEMI patients, compared with 41% in anterior STEMI. This may be related to differences in the electro/pathophysiological process or to differences in the definition of pathological Q waves. Other investigators have found differences in the proportion of initial Q waves in anterior and inferior STEMI.30 Interestingly, also the AW score faired differently in anterior and inferior STEMI.14 In our study, patients with inferior EMI without ECG signs of reperfusion had worse outcome with PCI than with fibrinolysis. This may be only a trend because of the small number of patients in this subgroup (n = 21). We cannot, however, rule out harm caused by invasive therapy in relatively low-risk patients.
Study limitations
This study has some limitations. It was not originally planned as part of the DANAMI-2 study. As the ECG investigators were totally blinded to angiographic findings and clinical data of the patients and the number of patients was large, the post hoc nature of the study should not have significant impact on the results. Data on TIMI perfusion grade would have improved the strength of the comparison between ECG changes and possible pathophysiological mechanisms. Our definition of Q waves did not differ between reperfusion- and necrosis-related Q waves.
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Conclusions |
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We re-evaluated the prognostic significance of two distinct ECG patterns in the modern era of acute STEMI treatment by including changes in the Q and T waves. We found that patients with acute anterior or inferior STEMI without Q waves and with positive T waves and those with anterior MI with Q waves, ST-elevation, and positive T waves had better long-term outcome with primary PCI than with FT. If T-wave inversion was present, FT resulted in similar long-term outcome as primary PCI both in anterior and inferior STEMI. Because of the post hoc nature of this study, the results should be assessed with caution. However, this finding merits prospective testing.
Conflict of interest: none declared.
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This study was supported financially by The Pirkanmaa Regional Fund of the Finnish Cultural Foundation, Tampere, Finland and by an unrestricted grant from Cordis, a Johnson & Johnson Co., Scandinavia.
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- White HD, Norris RM, Brown MA, Brandt PW, Whitlock RM, Wild CJ. Left ventricular end-systolic volume as the major determinant of survival after recovery from myocardial infarction. Circulation (1987) 76:44–51.
[Abstract/Free Full Text] - Christian TF, Schwartz RS, Gibbons RJ. Determinants of infarct size in reperfusion therapy for acute myocardial infarction. Circulation (1992) 86:81–90.
[Abstract/Free Full Text] - Zeymer U, Schroder R, Neuhaus KL. Patency, perfusion and prognosis in acute myocardial infarct. Herz (1999) 24:421–429.[Web of Science][Medline]
- Van de Werf F, Ardissino D, Betriu A, Cokkinos DV, Falk E, Fox KA, Julian D, Lengyel M, Neumann FJ, Ruzyllo W, Thygesen C, Underwood SR, Vahanian A, Verheugt FW, Wijns W, Task Force on the Management of Acute Myocardial Infarction of the European Society of Cardiology. Management of acute myocardial infarction in patients presenting with ST-segment elevation. The Task Force on the Management of Acute Myocardial Infarction of the European Society of Cardiology. Eur Heart J (2003) 24:28–66.
[Free Full Text] - Thune JJ, Hoefsten DE, Lindholm MG, Mortensen LS, Andersen HR, Nielsen TT, Kober L, Kelbaek H, for the Danish Multicenter Randomized Study of Fibrinolytic Therapy versus Acute Coronary Angioplasty in Acute Myocardial Infarction (DANAMI)-2 Investigators. Simple risk stratification at admission to identify patients with reduced mortality from primary angioplasty. Circulation (2005) 112:2017–2021.
[Abstract/Free Full Text] - Pinto DS, Kirtane AJ, Nallamothu BK, Murphy SA, Cohen DJ, Laham RJ, Cutlip DE, Bates ER, Frederick PD, Miller DP, Carrozza JP Jr, Antman EM, Cannon CP, Gibson CM. Hospital delays in reperfusion for ST-elevation myocardial infarction: implications when selecting a reperfusion strategy. Circulation (2006) 114:2019–2025.
[Abstract/Free Full Text] - Wilkins ML, Pryor AD, Maynard C, Wagner NB, Elias WJ, Litwin PE, Pahlm O, Selvester RH, Weaver WD, Wagner GS. An electrocardiographic acuteness score for quantifying the timing of a myocardial infarction to guide decisions regarding reperfusion therapy. Am J Cardiol (1995) 75:617–620.[CrossRef][Web of Science][Medline]
- Sclarovsky S. The evolving acute myocardial infarction. In: Electrocardiography of Acute Myocardial Ischaemic Syndromes—Sclarovsky S, ed. (1999) 1st ed. London: Martin Dunitz Ltd. p99–122.
- Andersen HR, Nielsen TT, Vesterlund T, Grande P, Abildgaard U, Thayssen P, Pedersen F, Mortensen LS, DANAMI-2 Investigators. Danish multicenter randomized study on fibrinolytic therapy versus acute coronary angioplasty in acute myocardial infarction: rationale and design of the DANish trial in Acute Myocardial Infarction-2 (DANAMI-2). Am Heart J (2003) 146:234–241.[CrossRef][Web of Science][Medline]
- Cannon CP, Battler A, Brindis RG, Cox JL, Ellis SG, Every NR, Flaherty JT, Harrington RA, Krumholz HM, Simoons ML, Van De Werf FJ, Weintraub WS, Mitchell KR, Morrisson SL, Brindis RG, Anderson HV, Cannom DS, Chitwood WR, Cigarroa JE, Collins-Nakai RL, Ellis SG, Gibbons RJ, Grover FL, Heidenreich PA, Khandheria BK, Knoebel SB, Krumholz HL, Malenka DJ, Mark DB, Mckay CR, Passamani ER, Radford MJ, Riner RN, Schwartz JB, Shaw RE, Shemin RJ, Van Fossen DB, Verrier ED, Watkins MW, Phoubandith DR, Furnelli T. American College of Cardiology key data elements and definitions for measuring the clinical management and outcomes of patients with acute coronary syndromes. A report of the American College of Cardiology Task Force on Clinical Data Standards (Acute Coronary Syndromes Writing Committee). J Am Coll Cardiol (2001) 38:2114–2130.
[Free Full Text] - Andersen HR, Nielsen TT, Rasmussen K, Thuesen L, Kelbaek H, Thayssen P, Abildgaard U, Pedersen F, Madsen JK, Grande P, Villadsen AB, Krusell LR, Haghfelt T, Lomholt P, Husted SE, Vigholt E, Kjaergard HK, Mortensen LS, DANAMI-2 Investigators. A comparison of coronary angioplasty with fibrinolytic therapy in acute myocardial infarction. N Engl J Med (2003) 349:733–742.
[Abstract/Free Full Text] - Sejersten M, Ripa RS, Maynard C, Wagner GS, Andersen HR, Grande P, Mortensen LS, Clemmensen P. Usefulness of quantitative baseline ST-segment elevation for predicting outcomes after primary coronary angioplasty or fibrinolysis (results from the DANAMI-2 trial). Am J Cardiol (2006) 97:611–616.[CrossRef][Web of Science][Medline]
- Sejersten M, Birnbaum Y, Ripa RS, Maynard C, Wagner GS, Clemmensen P. Influences of electrocardiographic ischemia grades and symptom duration on outcomes in patients with acute myocardial infarction treated with thrombolysis versus primary percutaneous coronary intervention (results from the DANAMI-2 trial). Heart (2006) 92:1577–1582.
[Abstract/Free Full Text] - Corey KE, Maynard C, Pahlm O, Wilkins ML, Anderson ST, Cerqueira MD, Pryor AD, Raitt MH, Startt Selvester RH, Turner J, Weaver WD, Wagner GS. Combined historical and electrocardiographic timing of acute anterior and inferior myocardial infarcts for prediction of reperfusion achievable size limitation. Am J Cardiol (1999) 83:826–831.[CrossRef][Web of Science][Medline]
- Ripa RS, Persson E, Heden B, Maynard C, Christian TF, Hammill S, Pahlm O, Wagner GS. Comparison between human and automated electrocardiographic waveform measurements for calculating the Anderson–Wilkins acuteness score in patients with acute myocardial infarction. J Electrocardiol (2005) 38:96–99.[Web of Science][Medline]
- Keeley EC, Boura JA, Grines CL. Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review of 23 randomised trials. Lancet (2003) 361:13–20.[CrossRef][Web of Science][Medline]
- Atak R, Ileri M, Senen K, Turhan H, Erbay AR, Basar N, Yetkin E, Demirkan D. Correlation between infarct-related coronary artery patency and predischarge electrocardiographic patterns in patients with first anterior myocardial infarction who received thrombolytic therapy. Heart Vessels (2004) 19:63–67.[CrossRef][Web of Science][Medline]
- Agetsuma H, Hirai M, Hirayama H, Suzuki A, Takanaka C, Yabe S, Inagaki H, Takatsu F, Hayashi H, Saito H. Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function. Heart (1996) 75:229–234.
[Abstract/Free Full Text] - Porter A, Mazur A, Solodky A, Birnbaum Y, Sulkes J, Imbar S, Strasberg B. Correlation of predischarge electrocardiographic patterns with left ventricular function in patients with anterior wall myocardial infarction. Cardiology (2000) 93:163–167.[CrossRef][Web of Science][Medline]
- Doevendans PA, Gorgels AP, van der Zee R, Partouns J, Bar FW, Wellens HJ. Electrocardiographic diagnosis of reperfusion during thrombolytic therapy in acute myocardial infarction. Am J Cardiol (1995) 75:1206–1210.[CrossRef][Web of Science][Medline]
- Sgarbossa EB, Meyer PM, Pinski SL, Pavlovic-Surjancev B, Barbagelata A, Goodman SG, Lum AS, Underwood DA, Gates KB, Califf RM, Topol EJ, Wagner GS. Negative T waves shortly after ST-elevation acute myocardial infarction are a powerful marker for improved survival rate. Am Heart J (2000) 140:385–394.[CrossRef][Web of Science][Medline]
- Fibrinolytic Therapy Trialists’ (FTT) Collaborative Group. Indications for fibrinolytic therapy in suspected acute myocardial infarction: collaborative overview of early mortality major morbidity results from all randomised trials of more than 1000 patients. Lancet (1994) 343:311–322.[CrossRef][Web of Science][Medline]
- Widimsky P, Budesinsky T, Vorac D, Groch L, Zelizko M, Aschermann M, Branny M, St’asek J, Formanek P, ‘PRAGUE’ Study Group Investigators. Long distance transport for primary angioplasty vs. immediate thrombolysis in acute myocardial infarction. Final results of the randomized national multicentre trial—PRAGUE-2. Eur Heart J (2003) 24:94–104.
[Abstract/Free Full Text] - Steg PG, Bonnefoy E, Chabaud S, Lapostolle F, Dubien PY, Cristofini P, Leizorovicz A, Touboul P, Comparison of Angioplasty Prehospital Thrombolysis In acute Myocardial infarction (CAPTIM) Investigators. Impact of time to treatment on mortality after prehospital fibrinolysis or primary angioplasty: data from the CAPTIM randomized clinical trial. Circulation (2003) 108:2851–2856.
[Abstract/Free Full Text] - Brodie BR, Stuckey TD, Hansen C, Muncy D. Benefit of coronary reperfusion before intervention on outcomes after primary angioplasty for acute myocardial infarction. Am J Cardiol (2000) 85:13–18.[Web of Science][Medline]
- Singh M, Reeder GS, Ohman EM, Mathew V, Hillegass WB, Anderson RD, Gallup DS, Garratt KN, Holmes DR Jr. Does the presence of thrombus seen on a coronary angiogram affect the outcome after percutaneous coronary angioplasty? An angiographic trials pool data experience. J Am Coll Cardiol (2001) 38:624–630.
[Abstract/Free Full Text] - Cafri C, Svirsky R, Zelingher J, Slutky O, Kobal S, Weinstein JM, Ilia R, Gilutz H. Improved procedural results in coronary thrombosis are obtained with delayed percutaneous coronary interventions. J Invasive Cardiol (2004) 16:69–71.[Medline]
- Blumenthal MR, Wang HH, Pang LM. Experimental coronary arterial occlusion and release. Effects on enzymes, electrocardiograms, myocardial contractility and reactive hyperemia. Am J Cardiol (1975) 36:225–233.[CrossRef][Web of Science][Medline]
- Raitt MH, Maynard C, Wagner GS, Cerqueira MD, Selvester RH, Weaver WD. Appearance of abnormal Q waves early in the course of acute myocardial infarction: implications for efficacy of thrombolytic therapy. J Am Coll Cardiol (1995) 25:1084–1088.[Abstract]
- Wong CK, Gao W, Raffel OC, French JK, Stewart RA, White HD, HERO-2 Investigators. Initial Q waves accompanying ST-segment elevation at presentation of acute myocardial infarction and 30-day mortality in patients given streptokinase therapy: an analysis from HERO-2. Lancet (2006) 367:2061–2067.[CrossRef][Web of Science][Medline]
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