Extent of ST-segment deviation in a single electrocardiogram lead 90 min after thrombolysis as a predictor of medium-term mortality in acute myocardial infarction

Comparison of myocardial tissue reperfusion of inferior wall and a right ventricle among patients after primary angioplasty for an inferior myocardial infarction with right ventricular infarction

BACKGROUND

Impaired myocardial tissue reperfusion affects prognosis of patients with ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) and can be identified by ST-segment analysis. To date, evaluation of the myocardial tissue reperfusion of the right ventricle (RV) among the patients treated with PCI for inferior STEMI with right ventricular infarction (RVI) has not been made yet.

METHODS

Patients with inferior STEMI were screened for RVI. Tissue reperfusion was evaluated by maximal residual ST-segment deviation post PCI, independently for the RV and for inferior wall. Myocardial injury was assessed by the peak creatine kinase-mb (CK-MB) value.

RESULTS

Among 456 patients with inferior STEMI, concomitant RVI occurred in 153 (33.5%) subjects (59.86±10.35 years old, 71.9% females). Tissue reperfusion of LV was present in 75 (49%), whereas 55 (35.9%) had both successful LV and RV reperfusion. Among 97 (63.4%) with successful tissue reperfusion of RV, 55 (56.7%) had associated successful tissue reperfusion of inferior wall. Adequate LV reperfusion was accompanied by RV in over 73.3% of patients (P=0.006). Mean peak CK-MB was lower in the group with adequate versus impaired RV tissue-perfusion (197±143 vs. 305±199 U/L, P=0.021 respectively).

CONCLUSIONS

Impaired reperfusion of RV is observed in more than one third of inferior STEMIs with RVI and is not strictly associated with impaired reperfusion of inferior wall and clinical or angiographic variables, therefore ST-segment analysis for RV is mandatory.

ECG analysis in patients with acute coronary syndrome undergoing invasive management: rationale and design of the electrocardiography sub-study of the MATRIX trial

BACKGROUND

The twelve‑lead electrocardiogram (ECG) has become an essential tool for the diagnosis, risk stratification, and management of patients with acute coronary syndromes (ACS). However, several areas of residual controversies or gaps in evidence exist. Among them, P-wave abnormalities identifying atrial ischemia/infarction are largely neglected in clinical practice, and their diagnostic and prognostic implications remain elusive; the value of ECG to identify the culprit lesion has been investigated, but validated criteria indicating the presence of coronary occlusion in patients without ST-elevation are lacking; finally, which criteria among the multiple proposed, better define pathological Q-waves or success of revascularisation deserve further investigations.

METHODS

The Minimizing Adverse hemorrhagic events via TRansradial access site and systemic Implementation of AngioX (MATRIX) trial was designed to test the impact of bleeding avoidance strategies on ischemic and bleeding outcomes across the whole spectrum of patients with ACS receiving invasive management. The ECG-MATRIX is a pre-specified sub-study of the MATRIX programme which aims at analyzing the clinical value of ECG metrics in 4516 ACS patients (with and without ST-segment elevation in 2212 and 2304 cases, respectively) with matched pre and post-treatment ECGs.

CONCLUSIONS

This study represents a unique opportunity to further investigate the role of ECGs in the diagnosis and risk stratification of ACS patients with or without ST-segment deviation, as well as to assess whether the radial approach and bivalirudin may affect post-treatment ECG metrics and patterns in a large contemporary ACS population.

German contribution to development and innovations in the management of acute myocardial infarction and cardiogenic shock

Treatment of acute coronary syndromes has evolved over time leading to a significantly reduced mortality. Multiple major trials have been performed in Germany leading to new treatment strategies in acute coronary syndromes including cardiogenic shock. This review article will summarize major trials and their impact on guideline recommendations in acute myocardial infarction highlighting reperfusion strategies, antiplatelet regimens, prognosis assessment and also mechanical circulatory support in stable infarction patients and in cardiogenic shock.

The Prognostic Values of the Admission Electrocardiography, Myocardial Injury Markers and Physical Examination in Patients with Acute Myocardial Infarction

Introduction

Acute coronary syndromes (ACS) are leading life threatening causes of chest pain, which is one of the most common complaints in the emergency department (ED). The aim of the study was to demonstrate the usefulness of physical examination, ECG and cardiac markers to predict short term outcome of ACS patients.

Methods

A total of 1728 patients with chest pain were evaluated between 1st January 2003 and 31st December 2003 in the ED and 236 of the patients matched our study criteria.

Results

In the study group 184 patients were (78%) male and the mean age was 59.8±12.2 (range=4-92) years old. Age, Killip score, cardiac marker values, the time interval between the beginning of the chest pain and ED entry and the ECG changes were the studied variables. With the logistic regression analysis, Killip score and any rhythm other than normal sinus rhythm on the first ECG were found to be the only independent variables to predict early mortality (p=0.036 and p=0.033).

Conclusion

Simple measures in the ED such as ECG and serum markers of myocardial injury along with the thorough physical evaluation of the physician may predict early negative outcome.

Usefulness of Intra-aortic Balloon Pump Counterpulsation

Intra-aortic balloon pump (IABP) counterpulsation is the most widely used mechanical circulatory support device because of its ease of use, low complication rate, and fast manner of insertion. Its benefit is still subject of debate, and a considerable gap exists between guidelines and clinical practice. Retrospective nonrandomized studies and animal experiments show benefits of IABP therapy. However, recent large randomized trials do not show benefit of IABP therapy, which has led to a downgrading in the guidelines. In our view, this dichotomy between trials and practice might be the result of insufficient understanding of the prerequisites needed for effective IABP therapy, that is, exhausted autoregulation, and of not including the right patient population in trials. The population included in recent large randomized trials has been heterogeneous, also including patients in whom benefit of IABP could not be expected. The clinical condition in which most benefit is expected, that is persistent ischemia in acute ST-elevation myocardial infarction, is discussed in this review. In conclusion, this review aims to explain the physiological principles needed for effective IABP therapy, to reflect critically on the large randomized trials, and to solve some of the controversies in this field.

Endothelial dysfunction evaluated by peripheral arterial tonometry is related with peak TnI values in patients with ST elevation myocardial infarction treated with primary angioplasty

PURPOSE

The role of endothelial-dependent function in patients with acute ST elevation myocardial infarction (STEMI) is not clear. Endothelial dysfunction may contribute to the pathophysiological processes occurring after STEMI and influence the extension of myocardial necrosis. Endothelial-dependent dysfunction evaluated by peripheral arterial tonometry (PAT) has already showed to be correlated with microvascular coronary endothelial dysfunction. Our purpose was to evaluate the impact of endothelial dysfunction on peak Troponin I (TnI) values, as a surrogate for the extension of myocardial infarction, in patients with STEMI treated with primary angioplasty (P-PCI).

METHODS

58 patients with STEMI treated with P-PCI (mean age 59.0 ± 14.0 years, 46 males) were included. Endothelial function was assessed by reactive hyperaemia index (RHI) determined by PAT. Patients were divided in two groups according to the previously reported RHI threshold for high risk (1.67). The extension of myocardial necrosis was evaluated by peak TnI levels.

RESULTS

RHI median value was 1.78 (IQR0.74);25 patients had endothelial dysfunction (RHI b 1.67). The two groups had no significant differences in age, gender, main risk factors and pain-to-balloon time. Patients with an RHI b 1.67 had significant larger infarcts: TnI 73.5 ng/mL (IQR 114.42 ng/mL) versus TnI 33.2 ng/mL (IQR 65.2 ng/mL); p = 0.028. On multivariate analysis, the presence of an RHI b 1.67 kept significant impact on TnI peak values (p=0.02).

CONCLUSIONS

The presence of endothelial-dependent dysfunction, assessed by PAT, is related with higher peak TnI values in STEMI patients treated with P-PCI. These results strength the possibility that endothelial-dependent dysfunction may be a marker of poor prognosis and eventually a therapeutic target in patients with STEMI.

ST-segment resolution with bivalirudin versus heparin and routine glycoprotein IIb/IIIa inhibitors started in the ambulance in ST-segment elevation myocardial infarction patients transported for primary percutaneous coronary intervention: The EUROMAX ST-segment resolution substudy

BACKGROUND

Myocardial reperfusion after primary percutaneous coronary intervention (PCI) can be assessed by the extent of post-procedural ST-segment resolution. The European Ambulance Acute Coronary Syndrome Angiography (EUROMAX) trial compared pre-hospital bivalirudin and pre-hospital heparin or enoxaparin with or without GPIIb/IIIa inhibitors (GPIs) in primary PCI. This nested substudy was performed in centres routinely using pre-hospital GPI in order to compare the impact of randomized treatments on ST-resolution after primary PCI.

METHODS

Residual cumulative ST-segment deviation on the single one hour post-procedure electrocardiogram (ECG) was assessed by an independent core laboratory and was the primary endpoint. It was calculated that 762 evaluable patients were needed to show non-inferiority (85% power, alpha 2.5%) between randomized treatments.

RESULTS

A total of 871 participated with electrocardiographic data available in 824 patients (95%). Residual ST-segment deviation one hour after PCI was 3.8±4.9 mm versus 3.9±5.2 mm for bivalirudin and heparin+GPI, respectively ( p=0.0019 for non-inferiority). Overall, there were no differences between randomized treatments in any measures of ST-segment resolution either before or after the index procedure.

CONCLUSIONS

Pre-hospital treatment with bivalirudin is non-inferior to pre-hospital heparin + GPI with regard to residual ST-segment deviation or ST-segment resolution, reflecting comparable myocardial reperfusion with the two strategies.

A novel method to capture the onset of dynamic electrocardiographic ischemic changes and its implications to arrhythmia susceptibility

Background

This study investigates the hypothesis that morphologic analysis of intracardiac electrograms provides a sensitive approach to detect acute myocardial infarction or myocardial infarction‐induced arrhythmia susceptibility. Large proportions of irreversible myocardial injury and fatal ventricular tachyarrhythmias occur in the first hour after coronary occlusion; therefore, early detection of acute myocardial infarction may improve clinical outcomes.

Methods and Results

We developed a method that uses the wavelet transform to delineate electrocardiographic signals, and we have devised an index to quantify the ischemia‐induced changes in these signals. We recorded body‐surface and intracardiac electrograms at baseline and following myocardial infarction in 24 swine. Statistically significant ischemia‐induced changes after the initiation of occlusion compared with baseline were detectable within 30 seconds in intracardiac left ventricle (P<0.0016) and right ventricle–coronary sinus (P<0.0011) leads, 60 seconds in coronary sinus leads (P<0.0002), 90 seconds in right ventricle leads (P<0.0020), and 360 seconds in body‐surface electrocardiographic signals (P<0.0022). Intracardiac leads exhibited a higher probability of detecting ischemia‐induced changes than body‐surface leads (P<0.0381), and the right ventricle–coronary sinus configuration provided the highest sensitivity (96%). The 24‐hour ECG recordings showed that the ischemic index is statistically significantly increased compared with baseline in lead I, aVR, and all precordial leads (P<0.0388). Finally, we showed that the ischemic index in intracardiac electrograms is significantly increased preceding ventricular tachyarrhythmic events (P<0.0360).

Conclusions

We present a novel method that is capable of detecting ischemia‐induced changes in intracardiac electrograms as early as 30 seconds following myocardial infarction or as early as 12 minutes preceding tachyarrhythmic events.

Design and methods of European Ambulance Acute Coronary Syndrome Angiography Trial (EUROMAX): an international randomized open-label ambulance trial of bivalirudin versus standard-of-care anticoagulation in patients with acute ST-segment-elevation myocardial infarction transferred for primary percutaneous coronary intervention

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) triaged to primary percutaneous coronary intervention (PCI), anticoagulation often is initiated in the ambulance during transfer to a PCI site. In this prehospital setting, bivalirudin has not been compared with standard-of-care anticoagulation. In addition, it has not been tested in conjunction with the newer P2Y12 inhibitors prasugrel or ticagrelor.

DESIGN

EUROMAX is a randomized, international, prospective, open-label ambulance trial comparing bivalirudin with standard-of-care anticoagulation with or without glycoprotein IIb/IIIa inhibitors in 2200 patients with STEMI and intended for primary percutaneous coronary intervention (PCI), presenting either via ambulance or to centers where PCI is not performed. Patients will receive either bivalirudin given as a 0.75 mg/kg bolus followed immediately by a 1.75-mg/kg per hour infusion for ≥30 minutes prior to primary PCI and continued for ≥4 hours after the end of the procedure at the reduced dose of 0.25 mg/kg per hour, or heparins at guideline-recommended doses, with or without routine or bailout glycoprotein IIb/IIIa inhibitor treatment according to local practice. The primary end point is the composite incidence of death or non-coronary-artery-bypass-graft related protocol major bleeding at 30 days by intention to treat.

CONCLUSION

The EUROMAX trial will test whether bivalirudin started in the ambulance and continued for 4 hours after primary PCI improves clinical outcomes compared with guideline-recommended standard-of-care heparin-based regimens, and will also provide information on the combination of bivalirudin with prasugrel or ticagrelor.

New ST-depression: an under-recognized high-risk category of 'complete' ST-resolution after reperfusion therapy

AIM

It is not known if there is an association between resolution of ST-elevation to ST-depression following fibrinolysis and 30-day mortality.

METHODS

In an ECG substudy of HERO-2, which compared bivalirudin to unfractionated heparin following streptokinase in 12,556 patients with ST-elevation myocardial infarction ECGs were recorded at baseline and at 60 minutes after commencing fibrinolysis. The main outcome measure was 30-day mortality.

RESULTS

Using summed ST-segment elevation and five categories of changes in the infarct leads, further ST-elevation, 0-30% ST-resolution, >30-70% (partial) ST-resolution, >70% (complete) ST-resolution, and new ST-depression occurred in 21.7, 24.9, 36.8, 14.8, and 1.8% of patients, with 30-day mortality of 12.3, 11.7, 8.0, 4.2, and 8.1%, respectively. For the comparison of new ST-depression with complete ST-resolution and no ST-depression, p<0.01 with 24-hour mortality 4.5 vs. 1.3%, respectively (p=0.0003). Patients with new ST-depression had similar peak cardiac enzyme elevations as patients with complete ST-resolution without ST-depression. On multivariate analysis including summed ST-elevation at baseline, age, sex, and infarct location, new ST-depression was a significant predictor of 30-day mortality (OR 1.82, 95% CI 1.42-4.29).

CONCLUSIONS

In patients with complete ST-resolution following fibrinolysis, new ST-depression at 60 minutes developed in 10.8% of patients. These patients had higher mortality than patients with complete ST-resolution without ST-depression and represent a high-risk group which could benefit from rapid triage to early angiography and revascularization as appropriate.

Bimodal response to aspirin loading in acute ST-elevation myocardial infarction

Patients with stable coronary disease who exhibit platelet hypo-responsiveness to aspirin (ASA) have worse outcomes. Little data exist regarding platelet response to ASA in ST-elevation myocardial infarction (STEMI) patients. Our objective was to assess acute platelet response to ASA loading in STEMI patients undergoing primary percutaneous coronary intervention (PCI). The study comprised 102 consecutive patients with STEMI. All patients received a loading dose of 300 mg chewable ASA upon admission. Platelet reactivity was assessed immediately prior to primary PCI, at a median of 95(63 139) minutes after ASA loading. A bimodal response to arachidonic acid (AA) stimulation was observed, such that two distinct populations could be discerned: "good responders" had a mean AA-induced platelet aggregation of 36 ± 11% vs. 79 ± 9% for "poor responders." Despite equivalent demographic, clinical, and angiographic characteristics, good responders were significantly more likely to demonstrate early ST-segment resolution ≥70% after primary PCI (80% vs. 48%, p = 0.001), suggestive of better myocardial reperfusion. Early inhibition of AA-induced platelet aggregation post-ASA loading in the setting of STEMI is associated with better tissue reperfusion; however, a sizeable proportion of patients do not achieve significant inhibition of AA-induced platelet aggregation in response to ASA loading at the time of primary PCI.

Prehospital abciximab in ST-segment elevation myocardial infarction: results of the randomized, double-blind MISTRAL study

BACKGROUND

The value of prehospital initiation of glycoprotein IIb/IIIa inhibitors remains a controversial issue. We sought to investigate whether in-ambulance initiation of abciximab in patients with ST-segment elevation myocardial infarction (STEMI) improves ST-segment elevation resolution (STR) after primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

MISTRAL (Myocardial Infarction with ST-elevation Treated by Primary Percutaneous Intervention Facilitated by Early Reopro Administration in Alsace) is a prospective, randomized, double-blind study. Two hundred and fifty-six patients with acute STEMI were allocated to receive abciximab either in the ambulance (ambulance group, n=127) or in the catheterization laboratory (hospital group, n=129). The primary end point was complete (>70%) STR after PCI. Complete STR was not significantly different between the 2 groups (before PCI, 21.6% versus 15.5%, P=0.28; after PCI, 70.3% versus 65.8%, P=0.49). Thrombolysis In Myocardial Infarction (TIMI) 2 to 3 flow rates before PCI tended to be higher in the ambulance group (46.8% versus 35%, P=0.08) but not after PCI (70.3% versus 65.8%, P=0.49). Slow flow tended to be lower (5.6% versus 13.4%, P=0.07), and distal embolization occurred significantly less often in the ambulance group (8.1% versus 21.1%, P=0.008). One- and 6-month major adverse cardiac event rates were low and similar in both groups.

CONCLUSIONS

Early ambulance administration of abciximab in STEMI did not improve either STR or TIMI flow rate after PCI. However, it tended to improve TIMI flow pre-PCI and decreased distal embolization during procedure. Larger studies are needed to confirm these results.

Endogenous serum erythropoietin and no-reflow in patients with ST-elevation myocardial infarction

BACKGROUND

In models of acute ischaemia, erythropoietin (EPO) administration has been found to attenuate vascular injury largely through reduced apoptosis, suppressed inflammation and increased nitric oxide availability. We studied the association between circulating endogenous EPO and no-reflow in patients with first ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

METHODS

Blood sampling was performed before PPCI. Consecutive patients with (n = 24) or without (n = 24) evidence of angiographic no-reflow after PPCI were enrolled. Angiographic no-reflow was defined as Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 2 or as TIMI flow = 3 but with myocardial blush grade < 2. We also assessed electrocardiographic (ECG) no-reflow as ≤ 50% resolution of maximal ST elevation 60 min after PPCI.

RESULTS

Baseline characteristics did not correlate significantly with EPO concentrations. In contrast, both angiographic and ECG no-reflow correlated with lower EPO levels at univariate analysis [median (interquartile): 4·2 (0·6-9·5) vs. 12·2 (5·2-20·3) mIU mL(-1), P = 0·001, and 4·0 (0·6-7·1) vs. 9·3 (1·0-12·6) mIU mL(-1), P = 0·01, respectively]. At multivariable analysis, decreasing EPO tertiles and left anterior descending as the infarct-related artery were the only factors that predicted both angiographic and ECG no-reflow (P = 0·017 and P = 0·02 for EPO; P < 0·005 and P > 0·05 for left anterior descending artery, respectively).

CONCLUSIONS

We found an independent, graded, inverse relation between endogenous EPO levels and angiographic and ECG no-reflow following PPCI. In animal models of ischaemia, EPO has been found to be protective. In humans, endogenous EPO may contribute to offset the mechanisms responsible for no-reflow.

The impact of plaque characterization assessed by intravascular ultrasound on myocardial perfusion after primary angioplasty in patients With ST-segment elevation myocardial infarction

BACKGROUND

Previous studies described that inadequate tissue perfusion after primary angioplasty in ST-elevation myocardial infarction (STEMI) patients is associated with adverse cardiac events. This study evaluated whether plaque morphological intravascular ultrasound (IVUS) characteristics affects tissue perfusion after stent implantation in STEMI patients.

METHODS AND RESULTS

A total of consecutive 306 STEMI patients who underwent primary angioplasty with IVUS were analyzed. Maximum ST-segment elevation before angioplasty was compared with ST-segment levels 60min after angioplasty. Percent ST-segment resolution (STR) was calculated and categorized as complete (>70%), partial (30-70%), and absent (<30%). Qualitative and quantitative IVUS analyses were performed using standard methods. Plaque with ultrasound attenuation was defined as IVUS finding with backward signal attenuation behind plaque >180° without dense calcium. One-hundred-fifty patients had complete, 101 had partial, and 55 had absent STR. The incidence of in-hospital death tended to be higher in absent STR than in partial and complete STR groups. Multivariate analysis indicated that remodeling index (P=0.004), the presence of ultrasound attenuation (P=0.02), percentage stent expansion (P=0.03), and the presence of deep calcium (P=0.049) were the independent predictors related to the occurrence of absent STR after angioplasty.

CONCLUSIONS

Positive vessel remodeling, plaque with ultrasound attenuation >180°, deep calcium, and stent overexpansion as assessed by IVUS are associated with the absence of STR after primary angioplasty in patients with STEMI.

Routine invasive management after fibrinolysis in patients with ST-elevation myocardial infarction: a systematic review of randomized clinical trials

Background

Patients with ST-elevation myocardial infarction (STEMI) treated with fibrinolysis are increasingly, and ever earlier, referred for routine coronary angiography and where feasible, undergo percutaneous coronary intervention (PCI). We sought to examine the randomized clinical trials (RCTs) on which this approach is based.

Methods

We systematically searched EMBASE, Medline, and references of relevant studies. All contemporary RCTs (published since 1995) that compared systematic invasive management of STEMI patients after fibrinolysis with standard care were included. Relevant study design and clinical outcome data were extracted.

Results

Nine RCTs that randomized a total of 3320 patients were identified. All suggested a benefit from routine early invasive management. They were individually reviewed but important design variations precluded a formal quantitative meta-analysis. Importantly, several trials did not compare a routine practice of invasive management after fibrinolysis with a more selective 'ischemia-guided' approach but rather compared an early versus later routine invasive strategy. In the other studies, recourse to subsequent invasive management in the usual care group varied widely. Comparison of the effectiveness of a routine invasive approach to usual care was also limited by asymmetric use of a second anti-platelet agent, differing enzyme definitions of reinfarction occurring spontaneously versus as a complication of PCI, a preponderance of the 'soft' outcome of recurrent ischemia in the combined primary endpoint, and an interpretative bias when invasive procedures on follow-up were tallied as an endpoint without considering initial invasive procedures performed in the routine invasive arm.

Conclusions

Due to important methodological limitations, definitive RCT evidence in favor of routine invasive management following fibrinolysis in patients with STEMI is presently lacking.

Does ST resolution achieved via different reperfusion strategies (fibrinolysis vs percutaneous coronary intervention) have different prognostic meaning in ST-elevation myocardial infarction? A systematic review

OBJECTIVE

We perform a systematic review to discern if ST resolution achieved via percutaneous coronary intervention (PCI) has a different meaning to that achieved via fibrinolysis.

BACKGROUND

Resolution of ST-segment elevation in acute myocardial infarction has been widely used as a surrogate for treatment success. A recent randomized study suggested that after primary PCI, the prognostic significance of ST resolution may have been overemphasized.

METHODS

Using the MEDLINE, COCHRANE, EMBASE, and PUBMED databases to search for the relevant papers, we analyze the data with a new ST-resolution score. ST-resolution groups of <30%, 30% to < 70%, and ≥ 70% are given scores of 1, 2, and 3 respectively, whereas ST-resolution groups reported as < 50% are scored as 1.5, and ≥ 50% scored as 2.5.

RESULTS

We identify 18 fibrinolysis cohorts (32,341 patients) and 5 PCI cohorts (1,913 patients). The mean ST-resolution score weighted for the number of patients in each cohort is 1.87 ± 0.15 for PCI and 1.66 ± 0.20 for fibrinolysis (P < .001). The raw combined 30-day mortality is 4.9% with fibrinolysis and 4.3% with PCI (P = .452 by Poisson regression). There is a linear relationship with lower 30-day mortality associated with higher ST-resolution score. The regression line for the PCI cohorts almost overlaps with that from the fibrinolysis cohorts. On multivariate regression, only ST-resolution score is significant in predicting 30-day mortality. When tested, the interaction term (treatment group × ST resolution score) is never a significant predictor (P > .25 in all models).

CONCLUSION

ST resolution after different reperfusion therapies has similar prognostic meaning.

Dynamic Changes in ST Segment Resolution After Myocardial Infarction and the Association with Microvascular Injury on Cardiac Magnetic Resonance Imaging

BACKGROUND

persistent ST elevation after reperfused ST elevation myocardial infarction (STEMI) is believed to be related to poor microvascular perfusion. Cardiac magnetic resonance imaging (CMR) can evaluate microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH) both of which represent severe microvascular damage, have independent prognostic value and are dynamic and evolving over the first 48hours after reperfusion. The aim of this study was to assess whether the development of MVO or IMH has an impact upon ST segment resolution.

METHODS

patients undergoing primary percutaneous coronary intervention (PCI) for STEMI had serial 12 lead electrocardiograms (ECG) from one hour after PCI until discharge. Persistent single lead maximal residual ST elevation (maxSTE) at each time point was calculated. ST segment deterioration (re-elevation) was calculated on each ECG until discharge compared with one hour post PCI ECG. CMR was performed within seven days post infarct utilising T2 weighted imaging to evaluate culprit artery area at risk (AAR) and IMH. Gadolinium delayed enhancement CMR quantified infarct size and MVO.

RESULTS

in the 41 patients studied 58% had MVO and 41% had IMH. ST segment deterioration was more common in those with MVO or IMH (p=0.03 and p=0.008 respectively). MaxSTE was higher at each time point after PCI in those with MVO but only became statistically significant after 24hours. The measurement of maxSTE at 48 or 72hours after revascularisation provided the best correlation with the combination of infarct size, AAR, MVO and intramyocardial haemorrhage.

CONCLUSION

microvascular injury as defined on CMR is associated with dynamic changes and persistence of ST segment elevation in the first 72hours after reperfusion.

Effect of essential oil of Syringa pinnatifolia Hemsl. var. alashanensis on ischemia of myocardium, hypoxia and platelet aggregation

AIM OF THE STUDY

To investigate the cardioprotective potential of Syringa pinnatifolia Hems1. var. alashanensis essential oil (SPEO) against experimental acute myocardial ischemia (AMI), hydrogen peroxide (H(2)O(2))-induced myocyte injury and activities against hypoxia and platelet aggregation.

MATERIALS AND METHODS

Wistar rats, Kunming mice and primary cultured rat neonatal myocytes were used in this study. AMI in rats was induced by ligation of the left anterior descending (LAD) coronary artery, and deviation of ST-segment, as well as changes of myocardial enzyme activities were observed. Hypoxia test in Kunming mice was performed to evaluate the effect of SPEO against hypoxia. The protective effect of SPEO on H(2)O(2)-induced cell injury was evaluated in terms of cell viability assay. The in vitro effect of SPEO against platelet aggregation was studied using adenosine 5'-diphosphate (ADP) as agonist.

RESULTS

Administration of SPEO reduced deviation of ST-segment, decreased the levels of lactate dehydrogenase (LDH), creatine kinase (CK) and Troponin T (TnT) while increased the activities of superoxide dismutase (SOD). The protective role of SPEO was further confirmed by histopathological examination. In the hypoxia test, both 8 and 32 mg/kg of SPEO could prolong survival time of mice under hypoxia condition. At the meantime SPEO showed remarkable protective effect on cultured rat myocyte death induced by H(2)O(2). SPEO also inhibited ADP-induced rat platelet aggregation by 47.4%, 37.0% and 32.9% at the dose of 5, 2.5 and 1.25 microg/mL, respectively.

CONCLUSIONS

These results suggest that SPEO possessing activities against hypoxia, oxidative stress and platelet aggregation has a significant protective effect against experimental myocardial ischemia.

Early versus late ST-segment resolution and clinical outcomes after percutaneous coronary intervention for acute myocardial infarction

Background. Absence of complete ST-segment resolution (STR) after percutaneous coronary intervention (PCI) for ST-segment-elevation myocardial infarction (STEMI) is a determinant of mortality. Traditionally, STR is determined on the coronary care unit (CCU) 60 to 90 minutes after the initiation of reperfusion therapy. We studied the prognostic value of STR immediately after PCI. Methods. We analysed 223 consecutive patients with STEMI and successful PCI. Continuous ECG data were collected during PCI and at 30 minutes after arrival on the CCU (mean time 81±17 minutes after reflow of the culprit artery). Patients were divided into three groups: patients with complete STR immediately after PCI ('early'), patients with complete and persistent STR at 30 minutes on the CCU, but not immediately after PCI ('late') and patients without STR. One-year follow-up was obtained for death and rehospitalisation for major adverse cardiac events. Cox proportional hazards regression was used to evaluate the association between STR and outcome. Results. Early STR occurred in 115 (52%) and late STR in 43 (19%) patients. Patients with early or late STR had a lower incidence of one-year cardiac death than those without STR (1.9 vs. 9.2%; p=0.02). In contrast, rehospitalisation occurred more frequently in patients with early or late STR (20.3 vs. 6.2%; p=0.009). As compared with patients without STR, early and late STR had a similar prognostic value (hazard ratios [95% confidence interval] for cardiac death 0.40 [0.08-2.03] and 0.25 [0.03-2.08]).Conclusions. We found no (major) change in prognostic value of STR during the 0 to 90 minutes time window after PCI. (Neth Heart J 2010;18:416-22.).

Prognostic value of lead V1 ST elevation during acute inferior myocardial infarction

BACKGROUND

Lead V(1) directly faces the right ventricle and may exhibit ST elevation during an acute inferior myocardial infarction when the right ventricle is also involved. Leads V(1) and V(3) indirectly face the posterolateral left ventricle, and ST depression ("mirror-image" ST elevation) in V(1) through V(3) may reflect concomitant posterolateral infarction. The prognostic significance of V(1) ST elevation during an acute inferior myocardial infarction may therefore be dependent on V(3) ST changes.

METHODS AND RESULTS

In 7967 patients with acute inferior myocardial infarction in the Hirulog and Early Reperfusion or Occlusion-2 (HERO-2) trial, V(1) ST levels were analyzed with adjustment for lead V(3) ST level for predicting 30-day mortality. V(1) ST elevation at baseline, analyzed as a continuous variable, was associated with higher mortality. Unadjusted, each 0.5-mm-step increase in ST level above the isoelectric level was associated with approximately 25% increase in 30-day mortality; this was true whether V(3) ST depression was present or not. The odds ratio for mortality was 1.21 (95% confidence interval, 1.07 to 1.37) after adjustment for inferolateral ST elevation and clinical factors and 1.24 (95% confidence interval, 1.09 to 1.40) if also adjusted for V(3) ST level. In contrast, lead V(1) ST depression was not associated with mortality after adjustment for V(3) ST level. V(1) ST elevation >or=1 mm, analyzed dichotomously in all patients, was associated with higher mortality. The odds ratio was 1.28 (95% confidence interval, 1.01 to 1.61) unadjusted, 1.51 (95% confidence interval, 1.19 to 1.92) adjusted for V(3) ST level, and 1.35 (95% confidence interval, 1.04 to 1.76) adjusted for ECG and clinical factors. Persistence of V(1) ST elevation >or=1 mm 60 minutes after fibrinolysis was associated with higher mortality (10.8% versus 5.5%, P=0.001).

CONCLUSIONS

V(1) ST elevation identifies patients with acute inferior myocardial infarction who are at higher risk.

Comparison by meta-analysis of eptifibatide and tirofiban to abciximab in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention

Adjunctive therapy with abciximab during primary percutaneous coronary intervention (PPCI) in patients with ST-elevation myocardial infarction (STEMI) determines a better short-term outcome compared to placebo. Tirofiban and eptifibatide represent a valid option with lower cost, but these have been less studied. The aim of the present study was to combine all randomized trials and registries to demonstrate the noninferiority of tirofiban and eptifibatide compared to abciximab in patients with STEMI treated with PPCI. We identified 6 randomized trials and 4 registries. Overall, 4,653 received small molecules and 2,696 abciximab, and the rate of combined death and nonfatal reinfarction did not differ (4.6% vs 4.5%, odds ratio 0.99, 95% confidence interval [CI] 0.78 to 1.27, p = 0.95) up to 30 days of follow-up, with an absolute difference of 0.1% (95% CI -1.06 to 0.8). Because the noninferiority limit was set at +1.5%, and because the upper point estimate (0.8%) of the 95% CI did not cross the prespecified limit, the noninferiority of the small molecules was documented. In-hospital major bleeding was also similar (8.8% vs 6.1%, odds ratio 0.92, 95% CI 0.75 to 1.13, p = 0.43). Sensitivity analysis comparing randomized trials to registries and tirofiban or eptifibatide to abciximab did not show any significant differences. In conclusion, our results documented noninferiority of "small molecules" compared to abciximab and, therefore, support their alternative use as adjunctive therapy during PPCI for patients with STEMI.

aVR ST elevation: an important but neglected sign in ST elevation acute myocardial infarction

AIM

This study evaluated the prognostic implications of aVR ST elevation during ST elevation acute myocardial infarction (AMI).

METHODS AND RESULTS

The Hirulog and Early Reperfusion/Occlusion-2 study randomized 17 073 patients with acute ST elevation AMI within 6 h of symptom onset to receive either bivalirudin or heparin, in addition to streptokinase and aspirin. The treatments had no effect on the primary endpoint of 30-day mortality. Electrocardiographic recordings were performed at randomization and at 60 min after commencing streptokinase. aVR ST elevation > or =1 mm was associated with higher 30-day mortality in 15 315 patients with normal intraventricular conduction regardless of AMI location (14.7% vs. 11.2% for anterior AMI, P = 0.0045 and 16.0% vs. 6.4% for inferior AMI, P < 0.0001). After adjusting for summed ST elevation and ST depression in other leads, associations with higher mortality were found with aVR ST elevation of > or =1.5 mm for anterior [odds ratio 1.69 (95% CI 1.16 to 2.45)] and of > or =1 mm for inferior AMI [odds ratio 2.41 (95% CI 1.76 to 3.30)]. There was a significant interaction between aVR ST elevation and infarct location. Thirty-day mortality was similar with anterior and inferior AMI when aVR ST elevation was present (11.5% vs. 13.2%, respectively, P = 0.51 with 1 mm and 23.5% vs. 22.5% respectively, P = 0.84 with > or = 1.5 mm ST elevation). After fibrinolytic therapy, resolution of ST elevation in aVR to <1 mm was associated with lower mortality, while new ST elevation > or =1 mm was associated with higher mortality.

CONCLUSION

aVR ST elevation is an important adverse prognostic sign in AMI.

Predictive value of ST resolution analysis performed immediately versus at ninety minutes after primary percutaneous coronary intervention

ST segment resolution (STR) predicts epicardial and microvascular reperfusion after primary percutaneous coronary intervention (PPCI) or thrombolysis for ST-elevation myocardial infarction. Immediate restoration of epicardial coronary flow, with improved microvascular perfusion, is much more likely with PPCI. However, the predictive value of immediate STR compared to 90 minutes after PPCI remains unknown. In 622 consecutive patients with ST-elevation myocardial infarction (mean age 59 +/- 13 years), 217 had complete STR immediately after PPCI (group A), 188 had complete STR only at 90 minutes (group B), and 217 had incomplete STR at either point (group C). The primary end point was mortality and adverse cardiovascular events ([MACE] death, nonfatal repeat myocardial infarction, and heart failure). Group A had a greater left ventricular ejection fraction (53%, 47%, and 46%, p <0.001) and lower all-cause mortality (1.8%, 3.2%, and 6%, p = 0.07), lower heart failure (1.8%, 4.3%, and 7.8%, p <0.001), and MACE (5.1%, 9.6%, and 16.1%, p = 0.001) at 30 days compared to groups B and C, respectively. The rate of MACE at 1 year was 7.6%, 17.1%, and 20.2% in groups A, B, and C, respectively (p <0.001). Immediate STR independently predicted MACE (adjusted hazard ratio 0.36, 95% confidence interval 0.21 to 0.61, p = 0.001, group A vs C), and STR at 90 minutes did not. In conclusion, STR analysis performed immediately after PPCI provided superior differentiation for adverse cardiovascular events compared to STR at 90 minutes. Immediate STR should be the contemporary goal of reperfusion with PPCI.

Extent of ST-segment resolution after fibrinolysis adds improved risk stratification to clinical risk score for ST-segment elevation myocardial infarction

BACKGROUND

The TIMI risk score (TRS) for ST-segment elevation myocardial infarction (STEMI) is a convenient validated clinical risk score for predicting mortality. Although not part of the risk score, ST-segment resolution (STRes) may provide a simple method of risk stratification based on the response to reperfusion. We sought to determine whether STRes provides incremental risk stratification to the TIMI risk score.

METHODS

The Clopidogrel as Adjunctive Reperfusion Therapy--Thrombolysis in Myocardial Infraction (CLARITY-TIMI 28) trial randomized STEMI patients receiving fibrinolysis to clopidogrel or placebo. A total of 2,340 patients had electrocardiograms (ECGs) valid to calculate STRes at 90 minutes, which was defined as complete (>70%), partial (30%-70%), or no resolution (30%). TRS was defined as low (0-2), medium (3-4), and high (> or =5). Clinical follow-up was through 30 days. Results were validated in 2,743 patients from the ExTRACT-TIMI 25 study.

RESULTS

The degree of STRes at 90 minutes after fibrinolysis correlated in a stepwise fashion with death or heart failure (5.1% complete STRes, 8.9% partial STRes, 13.4% no STRes, P < .001). Furthermore, the degree of STRes provided a consistent and significant gradient of risk across all risk score categories (low, medium, or high) and significantly improved the discriminatory ability of TIMI risk score to predict death or heart failure (c-statistic 0.69 for TIMI risk score alone and 0.74 with STRes added to the model, P < .001). With the inclusion of STRes to the TIMI risk score, 913 patients (39%) were reclassified to higher or lower risk groups, and the net reclassification improvement (NRI) was highly significant (P < .001). In the ExTRACT-TIMI 25 trial, addition of the STRes improved also the c-statistic (P = .012) and NRI (P < .001).

CONCLUSIONS

The extent of STRes based on routinely obtained ECGs is an independent predictor of death and heart failure when used together with the TIMI risk score and significantly improves the ability to risk stratify patients after fibrinolysis.

Clinical impact of thrombectomy in acute ST-elevation myocardial infarction: an individual patient-data pooled analysis of 11 trials

AIMS

Thrombectomy in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) is associated to better myocardial reperfusion. However, no single trial was adequately powered to asses the impact of thrombectomy on long-term clinical outcome and to identify patients at higher benefit. Thus, we sought to assess these issues in a collaborative individual patient-data pooled analysis of randomized studies (study acronym: ATTEMPT, number of registration: NCT00766740).

METHODS AND RESULTS

Individual data of 2686 patients enrolled in 11 trials entered the pooled analysis. Primary endpoint of the study was all-cause mortality. Major adverse cardiac events (MACE) were considered as the occurrence of all-cause death and/or target lesion/vessel revascularization and/or myocardial infarction (MI). Subgroups analysis was planned according to type of thrombectomy device (manual or non-manual), diabetic status, IIb/IIIa-inhibitor therapy, ischaemic time, infarct-related artery, pre-PCI TIMI flow. Clinical follow-up was available in 2674 (99.6%) patients at a median of 365 days. Kaplan-Meier analysis showed that allocation to thrombectomy was associated with significantly lower all-cause mortality (P = 0.049). Thrombectomy was also associated with significantly reduced MACE (P = 0.011) and death + MI rate during the follow-up (P = 0.015). Subgroups analysis showed that thrombectomy is associated to improved survival in patients treated with IIb/IIIa-inhibitors (P = 0.045) and that the survival benefit is confined to patients treated in manual thrombectomy trials (P = 0.011).

CONCLUSION

The present large pooled analysis of randomized trials suggests that thrombectomy (in particular manual thrombectomy) significantly improves the clinical outcome in patients with STEMI undergoing mechanical reperfusion and that its effect may be additional to that of IIb/IIIa-inhibitors.

Obstructive sleep apnea in patients admitted for acute myocardial infarction. Prevalence, predictors, and effect on microvascular perfusion

BACKGROUND

We investigated the prevalence and predictors of obstructive sleep apnea (OSA) in patients admitted to the hospital for acute myocardial infarction and whether OSA has any association with microvascular perfusion after primary percutaneous coronary intervention (PCI).

METHODS

Recruited patients were scheduled to undergo an overnight sleep study between 2 and 5 days after primary PCI. An apnea-hypopnea index (AHI) of > or = 15 was considered diagnostic of OSA. Impaired microvascular perfusion after primary PCI was defined as an ST-segment resolution of < or = 70%, myocardial blush grade 0 or 1, or a corrected Thrombolysis in Myocardial Infarction (TIMI) [antegrade flow scale] frame count > 28.

RESULTS

Sleep study was performed in 120 patients and completed in 105 patients (study cohort, mean age 53 +/- 10 years, male 98%) with uncomplicated myocardial infarction. An AHI was > or = 15 in 69 patients (OSA-positive), giving a prevalence of 65.7%. Diabetes mellitus was found to be a significant risk factor for OSA (odds ratio, 2.86; 95% confidence interval, 1.06 to 8.24; p = 0.033). There were no differences between OSA-positive and OSA-negative groups with regard to the percentage of patients with < or = 70% ST-segment resolution (73% vs 64%, respectively; p = 0.411), myocardial blush grade 0 or 1 (39.1% vs 38.9%, respectively; p = 1.000), or corrected TIMI frame count > 28 (21.7% vs 25.0%, respectively; p = 0.807).

CONCLUSIONS

We found a high prevalence of previously undiagnosed OSA in patients admitted with acute myocardial infarction. Diabetes mellitus was independently associated with OSA. No evidence indicated that OSA is associated with impaired microvascular perfusion after primary PCI.

Individual patient-data meta-analysis comparing clinical outcome in patients with ST-elevation myocardial infarction treated with percutaneous coronary intervention with or without prior thrombectomy. ATTEMPT study: a pooled Analysis of Trials on ThrombEctomy in acute Myocardial infarction based on individual PatienT data

Background:

Available data from randomized trials on thrombectomy in patients with ST-elevation myocardial infarction (STEMI) have shown favorable trends in myocardial reperfusion. However, few data are available on the effect of thrombectomy on clinical outcome. Thus we have designed a collaborative individual patient-data meta-analysis which aimed to assess the long-term clinical outcome in STEMI patients randomized to percutaneous coronary intervention (PCI) with or without thrombectomy.

Method:

After a thorough database search, the principal investigators of randomized trials comparing thrombectomy with standard PCI in patients with STEMI were contacted. Principal investigators as authors of 11 randomized studies agreed to participate and were asked to complete a structured database by providing a series of key pre-PCI clinical and angiographic data as well as the longest available clinical outcome of the patients enrolled in the corresponding trial. The primary end-point of this pooled analysis is the comparison of overall survival rates between patients randomized to PCI with thrombectomy or PCI without thrombectomy. The secondary end-points are survival free from myocardial infarction (MI), target lesion revascularization (TLR), major adverse coronary events (MACE: death + MI + TLR) and death + MI between patients randomized to PCI with thrombectomy or PCI without thrombectomy. A pre-defined subgroup analysis is planned considering the following variables: type of thrombectomy device used, diabetes, rescue PCI, IIb/IIIa-inhibitors use, time-to-reperfusion, infarct-related artery, and pre-PCI TIMI flow.

Implications:

This study will provide useful data on the effect of the reported improved myocardial perfusion associated with thrombectomy on the long-term clinical outcome in patients with STEMI.

[Comparative effect of streptokinase and alteplase on electrocardiogram and angiogram signs of myocardial reperfusion in ST segment elevation acute myocardial infarction]

INTRODUCTION

Modern pharmacological reperfusion in ST segment elevation acute myocardial infarction means the application of fibrin specific thrombolytics combined with modern antiplatelets therapy--dual antiplateles therapy, acetylsalicylic acid and clopidogrel, and enoxaparin. The contribution of each agent has been widely examined in large clinical studies, but not sufficiently has been known about the effects of a combined approach, where the early angiography and percutaneous coronary intervention is added during hospitalization, if necessary.

OBJECTIVE

The aim of the paper is to compare the effects of streptokinase and alteplase, together with the standard modern adjuvant antiplatelets and anticoagulation therapy (aspirin, clopidogrel, enoxaparin) in patients with ST segment elevation acute myocardial infarction, on electrocardiographic and angiographic signs of the achieved myocardial reperfusion.

METHOD

The prospective study included 127 patients with the first ST segment elevation acute myocardial infarction who were treated with a fibrinolytic agent in the first 6 hours from the chest pain onset. The examined group included 40 patients on the alteplase reperfusion therapy, while the control 87 patients were on the streptokinase therapy. All the patients received the same adjuvant therapy and all were examined by coronary angiography on the 3rd to 10th day of hospitalization. Reperfusion effects were estimated on the basis of the following: ST segment resolution at 60, 90 and 120 minutes, the appearance of reperfusion arrhythmias at the electrocardiogram, percentage of residual stenosis at the "culprit" artery, TIMI coronary flow at the "culprit" artery and the appearance of new major adverse coronary events in the 6-month-follow-up period.

RESULTS

By analysing the resolution of the sum of ST segment elevation in infarction leading 60 minutes after the beginning of the medication application, we received a statistically significantly higher resolution of ST segment in the group of patients who received alteplase (p < 0.05). 60 minutes after the application of thrombolytics, 64% of patients at streptokinase showed the absence of ST segment resolution (<30%), and 32% of patients at alteplase (p < 0.0001). Reperfusion arrhythmias as the sign of successful myocardial reperfusion were present in 62.5% of patients at alteplase and in 57.4% of patients at streptokinase, but the difference is not statistically significant.There was no statistically significant difference in the degree of residual stenosis at the,culprit" artery in the compared groups of patients. TIMI 3 flow was achieved in 75% of patients at alteplase and in 38% of patients at streptokinase (p < 0.0001). There was no statistically significant difference in the frequency of major adverse coronary events in the 6-month-follow-up period after acute myocardial infarction.

CONCLUSION

Alteplase with modern adjuvant therapy of ST segment elevation acute myocardial infarction shows the earlier achievement of coronary perfusion as well as better coronary flow compared to streptokinase. There is no statistically significant difference in the frequency of reperfusion arrhythmias, degree of residual stenosis at the"culprit"artery and the frequency of new coronary events in the 6-month-follow-up period after acute myocardial infarction.

Spontaneous reperfusion in ST-elevation myocardial infarction: comparison of angiographic and electrocardiographic assessments

INTRODUCTION

Spontaneous reperfusion (SR) in ST-elevation myocardial infarction has traditionally been assessed by coronary angiography. The frequency of SR varies widely in prior studies, and the clinical implications in the modern reperfusion era are unclear. Accordingly, using data from the ASSENT 4 PCI (ASsessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention) study, we undertook a systematic assessment of SR using both electrocardiographic (ECG) and angiographic techniques.

METHODS AND RESULTS

Five hundred eighty-five patients randomized to the primary percutaneous coronary intervention (PCI) arm of ASSENT 4 PCI were studied: all had ECG and thrombolysis in myocardial infarction flow data available approximately 60 minutes after randomization and before PCI. Electrocardiographic SR (>/=70% ST-segment resolution) occurred in 14.9% (87/585) and angiographic SR (thrombolysis in myocardial infarction grade 3) in 14.7% (86/585) of patients. Thirty-day clinical outcomes of patients with ECG SR versus no ECG SR tended to have lower mortality (0% vs 3.4%, P = .091), a lower composite of death/shock/congestive heart failure (6.9% vs 12.2%, P = .148), and significant reductions in death/reinfarction (0% vs 5.6%, P = .014). By contrast, no such differences were evident in patients with angiographic SR versus no SR for death (2.3% vs 3.0%, P = 1.00), death/shock/congestive heart failure (9.3% vs 11.8%, P = .498), or death/reinfarction (2.3% vs 5.2%, P = .409).

CONCLUSIONS

Whereas the frequency of SR was comparable using either ECG or angiographic criteria, clinical outcomes were best aligned with ECG SR. These data support the role of the ECG in assessing reperfusion and likely reflect the overall impact of myocardial perfusion versus infarct-related artery epicardial patency alone.

Prognostic value of ST-segment resolution after rescue percutaneous coronary intervention. Data from the RICO survey

OBJECTIVES

The goal of the present study was to test the impact of ST segment resolution (STR) after rescue percutaneous coronary intervention (PCI) on the short-term prognosis.

BACKGROUND

The prognostic value of STR after rescue PCI for acute ST elevation myocardial infarction (STEMI) remains undetermined.

METHODS

From the French regional database, we analyzed 168 consecutive patients with STEMI and failed lysis, defined by <50 percent STR, who underwent rescue PCI. Patients were classified into two groups according to the degree of STR from the maximal ST-elevation measured on the single worst ECG lead before lysis and after rescue PCI: the without STR group (<50% STR) vs. the with STR group (> or =50%).

RESULTS

After rescue PCI, 26 (15%) patients did not have STR and 142 (85%) patients did. No difference was observed between the two groups regarding baseline characteristics, risk factors, and median time delay either from symptom onset to thrombolysis or from failed lysis to rescue PCI. We observed a lower proportion of patients with TIMI 2/3 flow post PCI in the without STR group (respectively 61% vs. 97%, P < 0.001) but an increased use of intra-aortic balloon counterpulsation (34% vs. 8%, P < 0.001) in this group. Thirty-day mortality was markedly higher in the without STR group than in the with STR group (27% vs. 9% respectively, P = 0.025). Moreover, multivariate analysis showed that absence of STR (OR: 5.65; 95% CI: 1.24-25.67), was an independent prognostic factor for mortality.

CONCLUSIONS

We showed for the first time that analysis of ST-segment resolution may be a simple reliable tool to identify patients at high risk after rescue PCI, and may provide useful information for the elaboration of therapeutic strategies.

Relationship between collateral circulation and successful myocardial reperfusion in acute myocardial infarction: a subanalysis of the PREMIAR trial

The aim of this study was to determine whether the presence of collateral circulation had a beneficial effect following primary angioplasty. In all, 114 patients who underwent primary angioplasty were included. Patients with collateral circulation had lower basal ST-segment deviation (P = .004), white cell count ( P = .001), peak creatine kinase (P = .001), and regional wall motion score values (P = .03) than patients without collateral circulation. After the procedure, the group with collaterals was associated with higher rates of normal myocardial blush, complete ST resolution, and shorter time to stable ST-recovery. Multivariable logistic analysis identified the presence of collateral circulation as independent predictor of normal myocardial blush (adjusted odds ratio = 3.98, 95% confidence interval, 1.12-14.09; P = .033) and rapid reperfusion (time to stable ST-segment recovery <7 minutes, adjusted odds ratio = 4.0, 95% confidence interval, 1.57-10.20; P = .004). The presence of collateral circulation has a protective effect on infarct size, resulting in faster reperfusion.

Reperfusion strategies in ST-elevation myocardial infarction--current status and perspectives for early and pre-hospital treatment

The latest guidelines on the emergency care of acute ST-elevation myocardial infarction were published by the European Resuscitation Council at the end of 2005. Since then, numerous studies have been presented, which have led to important conclusions. Among pharmacological interventions, the opinion on adjuncts to anticoagulant treatment in the area of thrombolysis as well as in primary coronary intervention seems to be moving away from unfractionated heparin towards low molecular weight heparin, and possibly even factor Xa-specific pentasaccharide or the direct antithrombin bivalirudin. Clopidogrel has developed to become an accepted standard alongside aspirin in thrombolytic therapy of ST-elevation myocardial infarction, even if some questions still remain open. The promising idea of "facilitated percutaneous coronary intervention" has shown itself to at least be problematic if performed immediately and routinely after thrombolysis; "rescue" intervention in the event of ineffective thrombolysis is, on the other hand, useful and effective. Apparently, a more individualistic approach is required, which combines new therapeutic options and patients' conditions on the one side with regional resources on the other, to produce an optimal and timely strategy, remembering that one size does not fit all.