Grade 3 ischemia on the admission electrocardiogram predicts rapid progression of necrosis over time and less myocardial salvage by primary angioplasty

The prognostic significance of grade of ischemia in the ECG in patients with ST-elevation myocardial infarction: A substudy of the randomized trial of primary PCI with or without routine manual thrombectomy (TOTAL trial)

BACKGROUND

The importance of the grade of ischemia (GI) ECG classification in the risk assessment of patients with STEMI has been shown previously. Grade 3 ischemia (G3I) is defined as ST-elevation with distortion of the terminal portion of the QRS complex in two or more adjacent leads, while Grade 2 ischemia (G2I) is defined as ST-elevation without QRS distortion. Our aim was to evaluate the prognostic impact of the GI classification on the outcome in patients with STEMI.

METHODS

7,211 patients from the TOTAL trial were included in our study. The primary outcome was a composite of cardiovascular death, recurrent myocardial infarction (MI), cardiogenic shock, or New York Heart Association (NYHA) class IV heart failure within one year.

RESULTS

The primary outcome occurred in 153 of 1,563 patients (9.8%) in the G3I group vs. 364 of 5,648 patients (6.4%) in the G2I group (adjusted HR 1.27; 95% CI, 1.04 - 1.55; p=0.022). The rate of cardiovascular death (4.8% vs. 2.5%; adjusted HR 1.48; 95% CI 1.09 - 2.00; p=0.013) was also higher in patients with G3I.

CONCLUSIONS

G3I in the presenting ECG was associated with an increased rate of the composite of cardiovascular death, recurrent MI, cardiogenic shock, or NYHA class IV heart failure within one year compared to patients with G2I. Patients with G3I also had a higher cardiovascular death compared to patients with G2I.

Terminal QRS Distortion in ST Elevation Myocardial Infarction as a Prediction of Mortality: Systematic Review and Meta-Analysis

Background

Terminal QRS distortion reflects advanced stage and large myocardial infarction predisposing the heart to adverse outcomes. Recent studies suggest that terminal QRS distortion is associated with morbidity and mortality in ST elevation myocardial infarction (STEMI). However, a systematic review and meta-analysis of the literature have not been done.

Objective

We assessed the association between terminal QRS distortion in patients with STEMI and mortality by a systematic review of the literature and a meta-analysis.

Methods

We comprehensively searched the databases of MEDLINE and EMBASE from inception to September 2017. Included studies were published prospective or retrospective cohort studies that compared all-cause mortality in subjects with STEMI with QRS distortion versus those without QRS distortion. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate risk ratios and 95% confidence intervals.

Results

Fifteen studies from January 1993 to May 2015 were included in this meta-analysis involving 7,479 subjects with STEMI (2,906 QRS distortion and 4,573 non-QRS distortion). QRS distortion was associated with increased mortality (pooled risk ratio = 1.81, 95% confidence interval: 1.37-2.40, p < 0.000, I² = 41.6%). Considering the introduction of clopidogrel in 2004, we performed subgroup analyses before and after 2004, and the associated with higher mortality was still present (before 2004, RR 1.75, 95% CI 1.08-2.82, p = 0.022, I² = 66.1%; after 2004, RR 1.96, 95% CI 1.44-2.65, p < 0.001, I² = 0%).

Conclusions

Terminal QRS distortion increased all-cause mortality by 81%. Our study suggests that terminal QRS distortion is an important tool to assess the risk in patients with STEMI.

Automatic electrocardiographic algorithm for assessing severity of ischemia in ST-segment elevation myocardial infarction

BACKGROUND

Terminal QRS distortion on the electrocardiogram (ECG) is a sign of severe ischemia in patients with STEMI and can be quantified by the Sclarovsky-Birnbaum Severity of Ischemia. Due to score complexity, it has not been applied in clinical practice. Automatic scoring of digitally recorded ECGs could facilitate clinical application. We aimed to develop an automatic algorithm for the severity of ischemia.

METHODS

Development set: 50 STEMI ECGs were manually (Manual-score) and automatically (Auto-score) scored by our designed algorithm. The agreement between Manual- and Auto-score was assessed by kappa statistics. Test set: ECGs from 199 STEMI patients were assigned a severity grade (severe or non-severe ischemia) by the Auto-score. Infarct size estimated by median peak Troponin T (TnT) and Creatinine Kinase Myocardial Band (CKMB) was tested between the groups.

RESULTS

The agreement between Manual- and Auto-score was 0.83 ((95% CI 0.55-1.00), p < 0.0001), sensitivity 75% and specificity 100%, PPV 100% and NPV 94.6%. In the test set 152 (76%) patients were male, mean age 61 ± 12 years. The Auto-score designated severe ischemia in 42 (21%) and non-severe ischemia in 157 (79%) patients. Patients with ECG signs of severe vs. non-severe ischemia had significantly higher levels of biomarkers of infarct size. In multiple linear regression, ECG sign of severe ischemia was an independent predictor for higher TnT and CKMB levels.

CONCLUSION

The automatic ECG algorithm for severity of ischemia in STEMI performs adequately for clinical use. Severe ischemia obtained by the Auto-score was associated with biomarker estimated larger infarct size.

Electrocardiographic scores of severity and acuteness of myocardial ischemia predict myocardial salvage in patients with anterior ST-segment elevation myocardial infarction

BACKGROUND

Terminal "QRS distortion" on the electrocardiogram (ECG) (based on Sclarovsky-Birnbaum's Grades of Ischemia Score) is a sign of severe ischemia, associated with adverse cardiovascular outcome in ST-segment elevation myocardial infarction (STEMI). In addition, ECG indices of the acuteness of ischemia (based on Anderson-Wilkins Acuteness Score) indicate myocardial salvage potential. We assessed whether severe ischemia with or without acute ischemia is predictive of infarct size (IS), myocardial salvage index (MSI) and left ventricular ejection fraction (LVEF) in anterior versus inferior infarct locations.

METHODS

In STEMI patients, the severity and acuteness scores were obtained from the admission ECG. Based on the ECG patients were assigned with severe or non-severe ischemia and acute or non-acute ischemia. Cardiac magnetic resonance (CMR) was performed 2-6days after primary percutaneous coronary intervention (pPCI). LVEF was measured by echocardiography 30days after pPCI.

RESULTS

ECG analysis of 85 patients with available CMR resulted in 20 (23%) cases with severe and non-acute ischemia, 43 (51%) with non-severe and non-acute ischemia, 17 (20%) with non-severe and acute ischemia, and 5 (6%) patients with severe and acute ischemia. In patients with anterior STEMI (n=35), ECG measures of severity and acuteness of ischemia identified significant and stepwise differences in myocardial damage and function. Patients with severe and non-acute ischemia had the largest IS, smallest MSI and lowest LVEF. In contrast, no difference was observed in patients with inferior STEMI (n=50).

CONCLUSIONS

The applicability of ECG indices of severity and acuteness of myocardial ischemia to estimate myocardial damage and salvage potential in STEMI patients treated with pPCI, is confined to anterior myocardial infarction.

Pre-hospital electrocardiographic severity and acuteness scores predict left ventricular function in patients with ST elevation myocardial infarction

OBJECTIVES

System delay (time from first medical contact to primary percutaneous coronary intervention) is associated with heart failure and mortality in patients with ST segment elevation myocardial infarction (STEMI). We evaluated the impact of system delay on left ventricular function (LVF) according to the combination of ischemia severity (Sclarovsky-Birnbaum grades) and acuteness (Anderson-Wilkins scores) in the pre-hospital electrocardiogram (ECG).

METHODS

In a predefined secondary analysis of a prospective study, the severity and acuteness scores were performed on the pre-hospital ECG. Patients were assessed with respect to 4 classifications which were not mutually exclusive: severe ischemia (+SI) or non-severe ischemia (-SI) and acute ischemia (+AI) or non-acute ischemia (-AI). LVF was assessed by global longitudinal strain (GLS) within 48hours of admission. Adjusted linear regression investigated the association of system delay with GLS in each group.

RESULTS

In total 262 patients were eligible for analysis of the ECG, which resulted in 42 (16%) with (+SI, -AI), 110 (42%) with (-SI, -AI), 90 (34%) with (-SI, +AI), and 20 (8%) patients with (+SI, +AI). Although system delay did not differ between groups, patients with severe and non-acute ischemia had the most impaired LVF. System delay correlated weakly with GLS in the entire population (r=0.133, p=0.031), and well with GLS in the (+SI, +AI) group (r=0.456, p=0.04), while there was no correlation in the other groups. By adjusted analysis, system delay predicted impaired GLS only in the (+SI, +AI) group (β=0.578, p=0.002).

CONCLUSION

Pre-hospital risk stratification by ECG identifies patients with acute and severe ischemia who are at increased risk for reduced ventricular function (assessed by GLS) after STEMI. Optimizing reperfusion delays in these patients can therefore be of particular benefit in improving clinical outcome after STEMI.

QRS distortion in pre-reperfusion electrocardiogram is a bedside predictor of large myocardium at risk and infarct size (a METOCARD-CNIC trial substudy)

BACKGROUND

QRS distortion is an electrocardiographic (ECG) sign of severe ongoing ischemia in the setting of ST-segment elevation acute myocardial infarction (STEMI). We sought to evaluate the association between the degree of QRS distortion and myocardium at risk and final infarct size, measured by cardiac magnetic resonance (CMR).

METHODS

A total of 174 patients with a first anterior STEMI reperfused by primary angioplasty were prospectively recruited. Pre-reperfusion ECG was used to divide the study population into three groups according to the absence of QRS distortion (D0) or its presence in a single lead (D1) or in 2 or more contiguous leads (D2+). Myocardium at risk and infarct size were determined by CMR one week after STEMI. Multiple regression analysis was used to study the association of QRS distortion with myocardium at risk and infarct size, with adjustment for relevant clinical and ECG variables.

RESULTS

101 patients (58%) were in group D0, 30 (17%) in group D1, and 43 (25%) in group D2+. Compared with group D0, presence of QRS distortion (groups D2+ and D1) was associated with a significantly adjusted larger extent of myocardium at risk (group D2+: absolute increase 10.4%, 95% CI 6.1-14.8%, p<0.001; group D1: absolute increase 3.3%, 95% CI 1.3-7.9%, p=0.157) and larger infarct size (group D2+: absolute increase 10.1%, 95% CI 5.5-14.7%, p<0.001; group D1: absolute increase 4.9%, 95% CI 0.08-9.8%, p=0.046).

CONCLUSIONS

Distortion in the terminal portion of the QRS complex on pre-reperfusion ECG in two or more leads is independently associated with larger myocardium at risk and infarct size in the setting of primary angioplasty-reperfused anterior STEMI. QRS distortion in only one lead is independently associated with larger infarct size in this setting. Our findings suggest that QRS distortion analysis could be included in risk-stratification of patients presenting with anterior STEMI.

QRS complex distortion (Grade 3 ischaemia) as a predictor of myocardial damage assessed by cardiac magnetic resonance imaging and clinical prognosis in patients with ST-elevation myocardial infarction

AIMS

Distortion of the terminal portion of the QRS complex (so-called Grade 3 ischaemia, G3I) has been associated with adverse outcomes in ST-elevation myocardial infarction (STEMI) populations. However, the correlation of G3I with infarct size and microvascular injury as defined by cardiac magnetic resonance (CMR) is not well defined. Aim of this study was to assess the relation of G3I with myocardial damage as assessed by CMR and clinical outcomes in STEMI patients.

METHODS AND RESULTS

We analysed the ECGs of 572 consecutive STEMI patients regarding the presence or absence of G3I. CMR was performed within 1 week after infarction for comprehensive assessment of myocardial damage using a standardized protocol. The primary clinical endpoint was major adverse cardiac events (MACE) within 12 months after infarction. G3I was present in 186 (32%) patients. The presence of G3I was associated with larger infarct size (P = 0.01), the presence of late microvascular obstruction (P = 0.05), the presence of intramyocardial haemorrhage (P = 0.04), and impaired myocardial salvage (P = 0.01). G3I was associated with a higher incidence of MACE (P = 0.01) and was identified as an independent predictor of MACE in Cox regression analysis (HR 2.19; 95% CI 1.10 to 4.38, P = 0.03).

CONCLUSION

This largest study to date correlating G3I on the admission ECG with CMR markers of myocardial damage demonstrates that G3I is significantly associated with infarct size, impaired myocardial salvage, and reperfusion injury in a reperfused STEMI population. Moreover, G3I was independently associated with MACE. CLINICALTRIALS.GOV: NCT00712101.

The relationship between grade of ischemia, success of reperfusion, and type of thrombolytic regimen

BACKGROUND

This study was aimed to determine whether the grade of ischemia can predict the success of reperfusion in patients treated with thrombolytic therapy (TT) for ST elevation myocardial infarction (STEMI).

MATERIAL AND METHODS

We enrolled 229 consecutive patients with diagnosis of STEMI and receiving TT. Patients were divided into 2 groups--grade 2 ischemia (GI2) and grade 3 ischemia (GI3)--according to initial electrocardiogram (ECG). As TT, fibrin-specific (tissue plasminogen activator (t-PA)) or non-fibrin-specific (streptokinase (SKZ)) regimens were used. Successful reperfusion was defined as >50% resolution of the maximal ST segment on 90-min ECG. We tried to evaluate whether the grade of ischemia could predict the success of reperfusion and if there were any differences in terms of successful reperfusion between different thrombolytic regimens.

RESULTS

The successful reperfusion rate was significantly higher in GI2 than GI3 (82.4% vs. 64.4% respectively, p=0.002). The success rate was lowest at anterior GI3 (55.8%). Although there was no significant difference between thrombolytic regimens in all groups (p=0.77), t-Pa was superior to SKZ in anterior GI3 (63,6% vs. 30%, p=0.061). In addition, in multivariate analysis, GI and infarct localization were found as independent predictors for successful reperfusion with TT (p=0.006 and p=0.042, respectively).

CONCLUSIONS

In the current study, we found that GI2 is an independent predictor for successful reperfusion in STEMI treated with TT. Fibrin specific regime should be preferred in anterior GI3.

Relationship between neutrophil-to-lymphocyte ratio and electrocardiographic ischemia grade in STEMI

Background

Neutrophil-to-lymphocyte ratio (NLR) has been found to be a good predictor of future adverse cardiovascular outcomes in patients with ST-segment elevation myocardial infarction (STEMI). Changes in the QRS terminal portion have also been associated with adverse outcomes following STEMI.

Objective

To investigate the relationship between ECG ischemia grade and NLR in patients presenting with STEMI, in order to determine additional conventional risk factors for early risk stratification.

Methods

Patients with STEMI were investigated. The grade of ischemia was analyzed from the ECG performed on admission. White blood cells and subtypes were measured as part of the automated complete blood count (CBC) analysis. Patients were classified into two groups according to the ischemia grade presented on the admission ECG, as grade 2 ischemia (G2I) and grade 3 ischemia (G3I).

Results

Patients with G3I had significantly lower mean left ventricular ejection fraction than those in G2I (44.58 ± 7.23 vs. 48.44 ± 7.61, p = 0.001). As expected, in-hospital mortality rate increased proportionally with the increase in ischemia grade (p = 0.036). There were significant differences in percentage of lymphocytes (p = 0.010) and percentage of neutrophils (p = 0.004), and therefore, NLR was significantly different between G2I and G3I patients (p < 0.001). Multivariate logistic regression analysis revealed that only NLR was the independent variable with a significant effect on ECG ischemia grade (odds ratio = 1.254, 95% confidence interval 1.120–1.403, p < 0.001).

Conclusion

We found an association between G3I and elevated NLR in patients with STEMI. We believe that such an association might provide an additional prognostic value for risk stratification in patients with STEMI when combined with standardized risk scores.

Twenty years of ECG grading of the severity of ischemia

Shortly following an occlusion of an epicardial coronary artery, changes in the surface electrocardiogram (ECG) can be detected. Initially, T waves in leads with their positive poles facing the ischemic zone become positive, tall and symmetrical. Later, ST segment elevation (STE) becomes apparent. If ischemia continues, changes in the terminal portion of the QRS may also be detected. The changes in the terminal portion of the QRS are believed to be caused by prolongation of the electrical conduction in the ischemic zone and reflect severe ischemia due to lack of protection by preconditioning or collateral circulation. Several groups have shown that patients with the QRS changes of grade 3 ischemia have higher mortality, higher incidence of reinfarction and heart failure than patients presenting with only the T and ST changes of grade 2 ischemia, despite equal success in recanalizing the epicardial coronary artery by either thrombolytic therapy or primary percutaneous coronary intervention. Grade 3 ischemia is associated with more rapid progression of necrosis and larger final infarct size. Further studies are needed to better understand the underlying mechanisms that determine the severity of ischemia and how we should use this method based on the standard 12 lead ECG to implement clinical therapeutic decisions.

The predictive value of an ECG-estimated Acute Ischemia Index for prognosis of myocardial salvage and infarct healing 3months following inferior ST-elevated myocardial infarction

BACKGROUND AND PURPOSE

Identification of prognostic markers can be used to stratify patients in the acute phase of ST-elevated myocardial infarction (STEMI) according to their potential to retain viable myocardium after reperfusion. The percentage of the myocardial area at risk (MaR) that is ischemic at admission, defined as the Acute Ischemia Index, is potentially salvageable. The percentage of the MaR viable at 3months post-reperfusion, by salvage and healing, was defined as the Chronic Salvage Index. A positive relationship between the Acute Ischemia Index and the Chronic Salvage Index was hypothesized.

METHODS

Both indices were assessed by using the ECG indices Aldrich ST and Selvester QRS scores estimating the ischemic and infarcted myocardium. The study population comprised inferior STEMI patients. (N=59).

RESULTS

A correlation of 0.253 (P=0.053) was found.

CONCLUSIONS

These results are relevant and suggest evidence of a trend in the association between these indices.

The impact of preinfarction angina on electrocardiographic ischemia grades in patients with acute myocardial infarction treated with primary percutaneous coronary intervention

OBJECTIVE

Grade 3 ischemia (G3I) is defined as ST elevation with distortion of the terminal portion of the QRS (emergence of the J point > 50% of the R wave in leads with qR configuration, or disappearance of the S wave in leads with an Rs configuration). Patients with G3I on the presenting electrocardiogram (ECG) had worse prognosis than the patients with lesser (grade 2-G2I) ischemia. The aim of this study is to examine the effects of preinfarct angina (PIA) on electrocardiographic ischemia grades.

METHODS

One hundred forty-eight consecutive patients with ST-segment myocardial infarction (STEMI) were included in this study. All patients underwent primary percutaneous coronary intervention. The admission ECGs was analyzed retrospectively for electrocardiographic ischemia grades and compared with the presence of PIA.

RESULTS

Study population consisted of 110 patients with G2I (88 men, mean age = 63 +/- 6 years) and 38 patients with G3I (32 men, mean age = 61 +/- 8 years). Baseline characteristics of the groups were the same except for patients with G3I had significantly longer pain to balloon time and higher admission creatine kinase MB isoenzyme (CK-MB) levels. Tissue myocardial perfusion grade (TMPG) was better in patients with G2I. While 18 patients (47%) with G3I had PIA, 81 patients (70%) with G2I had PIA (P = 0.005). Although pain to balloon time and admission CK-MB were independent predictor of worse electrocardiographic ischemia grade (OR 1.69, 95% CI 1.09-2.62; P = 0.01; OR 1.01, 1.00-1.02, P = 0.04), PIA and left ventricular ejection time (LVEF) were independent predictors of better electrocardiographic ischemia grade (OR 0.4, 95% CI 0.17-0.90; P = 0.02, OR 0.92, 95% CI 0.85-0.99; P = 0.03, respectively) in multivariate logistic regression analysis.

CONCLUSION

PIA is one of the most important clinical predictors of better ischemia grades especially when combined with the pain to balloon time, LVEF, and admission CK-MB levels in patients with STEMI. This study provided another evidence for the protective effects of PIA.

Grade 3 ischemia on admission electrocardiogram and chest pain duration predict failure of ST-segment resolution after primary percutaneous coronary intervention for acute myocardial infarction

OBJECTIVES

ST resolution (STR) is a surrogate marker of myocardial tissue reperfusion and a predictor of outcome after primary percutaneous coronary intervention (pPCI) for ST-elevation myocardial infarction (STEMI). Terminal QRS distortion (grade 3 ischemia) has been shown to predict failure of STR after thrombolysis for STEMI, but the ability of grade 3 ischemia to predict STR with pPCI is unclear.

METHODS

We retrospectively analyzed 155 patients who underwent pPCI and compared grade 2 ischemia (ST elevation without terminal QRS distortion; n = 89) to grade 3 ischemia (n = 66) on admission for baseline characteristics, in-hospital course, and STR immediately after pPCI and at 18 to 24 hours.

RESULTS

Patients with grade 3 ischemia were older (60 +/- 12 vs 56 +/- 11 years; P = .018), had more anterior STEMI (42% vs 17%; P = .0004), and were less often smokers (41% vs 90%; P = .004). The grade 3 ischemic group had significantly less complete STR (35% vs 75% [P < .00001] immediately after pPCI and 33% vs 79% [P < .00001] 18-24 hours after pPCI), a longer hospital stay (6.4 +/- 4.1 vs 4.9 +/- 1.9 days; P = .008), and higher peak CKMB (292 +/- 231 vs 195 +/- 176 ng/mL; P = .0005). Duration of symptoms before pPCI (odds ratio [OR], 0.838; 95% confidence interval [CI], 0.724-0.969; P = .017) and grade 3 ischemia (OR, 0.181; 95% CI, 0.068-0.480; P < .001) were negative predictors of complete STR, whereas nonanterior STEMI (OR, 5.95; 95% CI, 2.154-16.436; P < .001) and initial sum of ST elevation (OR, 3.132; 95% CI, 1.140-8.605; P = .027) were positive predictors.

CONCLUSION

Grade 3 ischemia on presentation of STEMI and duration of chest pain are strong independent predictors of failure to achieve complete STR after pPCI.

Electrocardiogram dynamics for risk stratification in ST-segment elevation myocardial infarction—immediate and serially updated information on outcome

Early and serially updated predictions of final infarct-size and clinical outcome--before, during and after reperfusion treatment of ST-elevation myocardial infarction might allow a more individualized treatment: High-risk patients with a predicted major loss of viable myocardium can be identified immediately or during therapy, at a stage when treatment may still be modified; and low-risk patients with predictions of small infarcts and good outcome already after standard primary reperfusion therapy can be identified and thereby avoid a possibly harmful intensified treatment. The necessary information for such predictions seem to be available from the standard 12-lead ECG and from ST-segment monitoring. Today this information, however, is not readily available in clinical practice. Automated algorithms need to be engineered for a broader use and for possibilities of a refined triage and thus for a more individualized strategy of reperfusion therapy.

Electrocardiographic Diagnosis of ST-elevation Myocardial Infarction

The ECG is an essential part of the initial evaluation of patients who have chest pain, especially in the immediate decision-making process in patients who have ST-elevation myocardial infarction. This article reviews and summarizes the current information that can be obtained from the admission ECG in patients who have ST-elevation acute myocardial infarction, with an emphasis on: (1) prediction of final infarct size, (2) estimation of prognosis, and (3) the correlations between various ECG patterns and the localization of the infarct and the underlying coronary anatomy.

Influences of electrocardiographic ischaemia 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

OBJECTIVE

To determine whether ischaemia grade (GI) on the presenting ECG and duration of symptoms can identify subgroups of patients who would derive more benefit than the general population of patients with ST segment elevation acute myocardium infarction (STEMI) from primary percutaneous coronary intervention (pPCI) over thrombolytic treatment (TT) in reducing mortality or reinfarction.

METHODS

1319 DANAMI-2 (Danish trial in Acute Myocardial Infarction-2) patients were classified as having grade 2 ischaemia (GI2; ST segment elevation without terminal QRS distortion) or grade 3 ischaemia (GI3; ST segment elevation with terminal QRS distortion in > or = 2 adjacent leads), and were divided into early and late groups split by the median time (3 h) from symptom onset to treatment. Outcomes were 30-day mortality and reinfarction.

RESULTS

Mortality was significantly higher for GI3 than for GI2 (9.7% v 4.8%, p < 0.001) and doubled for patients presenting late (GI2: 6.0% v 3.3%, p = 0.01; GI3: 12.5% v 4.7%, p = 0.05). Overall mortality did not differ significantly between pPCI and TT; however, a 5.5% absolute mortality reduction was seen in GI3 treated early with pPCI (1.4% v 6.9%, p = 0.10). Reinfarction rate was particularly high among GI3 patients presenting late and treated with TT (12.2%). pPCI in such patients significantly reduced the rate of reinfarction (0%, p < 0.001). Logistic regression analysis showed that age (odds ratio (OR) 1.09, 95% confidence interval (CI) 1.06 to 1.12, p < 0.001), prior angina (OR 2.56, 95% CI 1.44 to 4.54, p = 0.001), heart rate (OR 1.03, 95% CI 1.01 to 1.04, p = 0.001) and GI3 (OR 1.91, 95% CI 1.06 to 3.44, p = 0.031) were independently associated with mortality, whereas the sum of ST segment elevation was not.

CONCLUSIONS

GI3 is an independent predictor of mortality among patients with STEMI. Mortality increased significantly with symptom duration in both GI2 and GI3. pPCI may be especially beneficial for patients with GI3 presenting early, whereas patients with GI3 presenting late and treated with TT are at particular risk of reinfarction.