Electrocardiographic predictors of culprit artery in acute inferior ST elevation myocardial infarction

Background

In acute inferior ST-segment elevation myocardial infarction (STEMI), multiple electrocardiographic algorithms have been proposed to predict the culprit artery. Our purpose is to review these and compare them to ST depression in lead aVR to predict culprit artery in inferior STEMI.

Methods

In 106 patients with acute inferior STEMI who underwent emergent coronary angiography, we correlated electrocardiographic and angiographic findings pertaining to the culprit artery. We then reviewed the algorithms proposed by Fiol et al and Tierala et al, and applied them and our own from Kanei et al using ST depression in aVR for predicting the left circumflex artery (LCx) as the culprit, to the population. Finally, we compared the sensitivities and specificities of the respective algorithms for predicting the culprit artery.

Results

The sensitivity and specificity of ST depression in lead aVR to predict LCx as the culprit were 53% and 86%, respectively, and 86% and 55%, respectively for predicting the right coronary artery (RCA) as the culprit. When their algorithms were applied to our population, the sensitivities and specificities of Fiol et al and Tierala et al were slightly higher.

Conclusion

Compared to other proposed algorithms, ST depression in aVR is a simple method with satisfactory sensitivity and specificity to predict the culprit artery in inferior STEMI.     

Predicting the culprit artery in acute ST-elevation myocardial infarction and introducing a new algorithm to predict infarct-related artery in inferior ST-elevation myocardial infarction: correlation with coronary anatomy in the HAAMU Trial

Aims

The objective of this study is to predict the culprit artery from the electrocardiogram (ECG) by predefined criteria and to compare a new algorithm with a previous one for predicting the culprit artery in inferior ST-elevation myocardial infarction (STEMI).

Methods and Results

In “all-comers” (n = 187) with acute STEMI, with ECG and angiography from the acute phase, the positive and negative predictive values for the prediction of the left anterior descending coronary artery, left circumflex coronary artery, or right coronary artery as the infarct-related artery were 96% and 96%, 65% and 95%, 92% and 97%, respectively. In inferior STEMI (n = 98), positive and negative predictive values to predict the right coronary artery or the left circumflex coronary artery as the culprit artery were 92% and 75% and 75% and 94%, respectively.

Conclusions

In “all-comers” with STEMI, the culprit artery could be predicted by ECG criteria with high predictive values. In inferior STEMI, a new algorithm for culprit artery prediction was successfully tested.     

Location of myocardium at risk in patients with first-time ST-elevation infarction: comparison among single photon emission computed tomography, magnetic resonance imaging, and electrocardiography

Background

The amount of myocardium at risk (MaR) during acute coronary occlusion and the duration of occlusion are important determinants of final infarct size. The main goal of early reperfusion therapy is to salvage ischemic myocardium, thereby preserving left ventricular function. The aims of the present study were to test the feasibility of developing polar plot representations of MaR, for perfusion single photon emission computed tomography (SPECT), regional wall thickening by magnetic resonance imaging (MRI), and distribution of ST-segment changes. A second aim was to test the hypothesis that these different modalities display similar localization of the MaR in patients with reperfused first-time myocardial infarction.

Methods

Eleven patients with first-time myocardial infarction with ST-elevation received ^99mTc tetrofosmin before primary percutaneous coronary intervention, SPECT imaging within 3 hours, and cardiac MRI of the left ventricle within 24 hours. The results for SPECT, MRI, and electrocardiogram (ECG) were developed into polar plots, and two expert observers designated the culprit coronary artery as assessed by angiography.

Results

The perfusion SPECT, MRI wall thickening, and ST changes are presented in side-by-side polar plots. In total, the culprit artery, based on the location of the MaR, was correctly designated in 91%, 82%, and 91% of cases by SPECT, MRI, and ECG, respectively.

Conclusions

Polar representation for localization of the MaR by SPECT perfusion, MRI wall thickening, and ECG ST-segment deviation is feasible. All 3 modalities have the potential to be used for indirect visual designation of the culprit artery in patients with first-time acute coronary occlusion.     

The clinical profile and outcomes associated with coronary collaterals in patients with coronary artery disease

Background

The clinical correlates of coronary collaterals and the effects of coronary collaterals on prognosis are incompletely understood.

Methods

We performed a study of 55,751 patients undergoing coronary angiography to evaluate the correlates of angiographically apparent coronary collaterals, and to evaluate their association with survival.

Results

The characteristic most strongly associated with the presence of collaterals was a coronary occlusion (odds ratio [OR], 28.9; 95% confidence interval [CI], 27.1-30.6). Collaterals were associated with improved adjusted survival overall (hazard ratio [HR] 0.89; 95% CI, 0.85-0.95), and in both acute coronary syndrome (ACS) (HR 0.90; 95% CI, 0.84-0.96) and non-ACS (HR 0.84; 95% CI, 0.77-0.92) patients. Collaterals were associated with improved survival in those receiving angioplasty (HR 0.78; 95% CI, 0.71-0.85) and those with low risk anatomy treated medically (HR 0.84; 95% CI, 0.72-0.98), but not for those treated with coronary bypass graft surgery or those with high-risk anatomy treated without revascularization.

Conclusions

The major correlate of coronary collaterals is the presence/extent of obstructive coronary artery disease. Collaterals are associated with better survival overall and in both ACS and non-ACS presentations, but not for those treated with coronary artery bypass graft (CABG) or those with high-risk anatomy who are not revascularized.     

Electrocardiographic determination of culprit lesion site in patients with acute coronary events

Purpose

The purpose of our study was to determine the ability of electrocardiographic (ECG) criteria derived from prior angiographic-ECG correlative studies to identify life-threatening coronary artery obstructive lesions.

Methods

We studied 128 consecutive patients referred from the emergency department for emergent coronary angiography for symptoms and ECG changes suggesting an acute coronary event. Using ECG criteria derived from prior studies, we attempted to predict not only the vessel housing the culprit lesion, but whether the lesion was located proximally in that vessel, and then determined the positive and negative predictive values (PPV and NPV) of the criteria used.

Results

Our criteria correctly identified 7 of 11 patients with left main disease, with a PPV of 100% and an NPV of 97%; 12 of 19 patients with proximal left anterior descending coronary artery disease, with a PPV of 67% and an NPV of 94%; and 25 of 28 patients with proximal right coronary artery disease, with a PPV of 64% and an NPV of 97%. The combined PPV and NPV for predicting patients with either left main coronary artery, proximal left anterior descending coronary artery, or proximal right coronary artery disease were 72% and 81%.

Conclusion

Our study indicates that the location of life-threatening coronary artery lesions in patients presenting with signs and symptoms of acute coronary syndromes can be predicted from the initial ECG with a high degree of accuracy. Recognizing the ECG criteria for such lesions has the potential for shortening door-to-reperfusion time and improving patient outcomes.     

Electrocardiographic characteristics in angiographically documented occlusion of the dominant left circumflex artery with acute inferior myocardial infarction: limitations of ST elevation III/II ratio and ST deviation in lateral limb leads

Background

The prognosis of dominant left circumflex artery (LCx) occlusion-related inferior acute myocardial infarction (AMI) patients is poor, but the electrocardiographic (ECG) characteristics of this AMI entity have not been described.

Methods

One hundred thirty-five patients with first dominant right coronary artery (RCA) or dominant LCx-related inferior AMI were included. The characteristics of ECG obtained on admission for 55 patients with culprit lesions proximal to the first major right ventricular (RV) branch of dominant RCA (group proximal dominant RCA), 62 patients with culprit lesions distal to the first major RV branch of dominant RCA (group distal dominant RCA), and 18 patients with culprit lesions in dominant LCx (group dominant LCx) were compared.

Results

There were no significant differences among the 3 groups in the prevalence regarding an S/R ratio greater than 1:3 in aVL, ST elevation in aVR (ST↑_aVR), ST depression in aVR (ST↓_aVR) of 1 mm or more, and atrioventricular block. Greater ST elevation in lead III than in II and greater ST depression in aVL than I showed specificity of 17% and 44% to identify dominant RCA as culprit lesion, respectively. All 3 groups could be distinguished on the basis of ST↑_V4R, ST↓_V4R, ST↓_V3/ST↑_III of 1.2 or less, and ST↓_V3/ST↑_III of more than 1.2.

Conclusions

Greater ST elevation in lead III than in II, greater ST depression in aVL than I, and an S/R ratio of greater than 1:3 in aVL were not useful to discriminate between dominant RCA and dominant LCx occlusion-related inferior AMI. ST-segment deviation in lead V₄R and the ratio of ST↓_V3/ST↑_III were useful in predicting the dominant artery occlusion-related inferior AMI.     

Complete versus culprit vessel percutaneous coronary intervention in multivessel disease: a randomized comparison

Background

The purpose of this study was to compare the safety, efficacy, and costs of complete versus “culprit” vessel revascularization in multivessel coronary artery disease treated with percutaneous coronary interventions (PCI).

Methods

Patients with multivessel disease and an identified culprit vessel were randomly assigned to complete revascularization of vessels ≥50% stenoses (n = 108) versus revascularization limited to the culprit vessel (n = 111). The primary end point, major adverse cardiac events (MACE), were defined as cardiac or noncardiac death, myocardial infarction, need for coronary artery bypass graft surgery, and repeat PCI up to 1 year.

Results

Despite equal MACE at 24 hours (6.3% vs 7.4%), strategy success was higher in the culprit vessel than in the complete revascularization group (93.7% vs 81.5%, P = .007). MACE rates at 1 month (14.4% vs 9.3%), 1 year (32.4% vs 26.9%), and 4.6 ± 1.2 years (40.4% vs 34.6%) were similar in both groups. Repeat PCI was performed more often in the culprit vessel group (31.2% vs 21.2%, P = .06). A lower consumption of medical material was associated with lower procedural costs in the culprit vessel group (5784 vs 7315 Euros; P < .001). However, between 1 year and the end of follow-up, costs had equalized in both groups.

Conclusions

Complete versus culprit vessel revascularization in multivessel coronary disease treated with PCI was associated with a lower strategy success rate, similar MACE rates, and initially higher costs. However, over the long term, more repeat PCIs were conducted in patients treated by culprit revascularization only, mostly because of the need to treat lesions initially left untreated. As a consequence, incremental costs had equalized within 1 year. The decision of whether to perform culprit vessel or complete revascularization can be made on an individual basis.     

An algorithm for the differentiation of the infarct territory in difficult to discern electrocardiograms

Background

In a minority of the patients presenting with ST-segment elevation (STE) myocardial infarction (MI), electrocardiogram (ECG) may show a balanced STE in both anterior and inferior lead groups and may cause diagnostic confusion about involved myocardial territory. In this study, we sought ECG clues which may facilitate discriminating (1) MI location and then (2) culprit artery in patients with difficult-to-discern ECGs.

Maximal increase in sensitivity with minimal loss of specificity for diagnosis of acute coronary occlusion achieved by sequentially adding leads from the 24-lead electrocardiogram to the orderly sequenced 12-lead electrocardiogram

Objectives

This study investigates whether sequential addition of inverted (negative) leads from the 24-lead electrocardiogram (ECG) to the orderly sequenced 12-lead ECG would identify a number of leads with which the sensitivity for diagnosis of acute transmural ischemia is significantly increased with minimal loss of specificity.

Background

Acute transmural ischemia due to thrombotic coronary occlusion typically progresses to infarction. Its recognition is based on currently accepted ST-elevation myocardial infarction (STEMI) criteria with suboptimal sensitivity, which could be potentially increased by consideration of the principle that each of the 12 ECG leads can be inverted to provide an additional lead with the opposite (180°) orientation, generating a 24-lead ECG.

Methods

The study population included 162 patients who underwent prolonged coronary occlusion during elective percutaneous transluminal coronary angioplasty. Balloon occlusion was performed in the left anterior descending coronary artery (51 patients), in the right coronary artery (67 patients), or in the left circumflex coronary artery (44 patients). To be classified as indicative of the epicardial injury current of acute ischemia, the ECGs had to fulfill either the criteria of a consensus document from the American College of Cardiology or the European Society of Cardiology or thresholds for the inverted leads based on a population study from Scotland.

Results

The addition of −V1, −V2, −V3, −aVL, −I, aVR, and −III increased sensitivity from 61% to 78% (P ≤ .01) and decreased specificity from 96% to 93% (P = .06).

Conclusions

Addition of 7 leads from the 24-lead ECG, thus creating a 19-lead ECG, was found optimal for attaining high sensitivity while retaining high specificity when compared with the performance of the standard 12-lead ECG.     

The stability of the ST segment estimation of myocardial area at risk between the prehospital and hospital electrocardiograms in patients with ST elevation myocardial infarction

Purpose

Several ST segment deviation scores have been developed to estimate the myocardial area at risk (AAR) during acute myocardial infarction (AMI), which can be used to measure the effectiveness of reperfusion therapy. The purpose of this study was to assess whether one of these ST segment deviation scores (the Aldrich score) is sufficiently stable between the electrocardiogram (ECG) recorded in the ambulance (ECG 1) and the ECG recorded at the time of admission to the hospital (ECG 2) to be used as a baseline estimation of the AAR.

Methods

The Aldrich scores were compared between ECG 1 and ECG 2 in 77 patients who met the criteria for ST elevation myocardial infarction. The ECGs had a time interval of at least 5 minutes and were recorded before reperfusion therapy. Sufficiently stable was defined as 95% of the patients did not show a temporal change of the Aldrich score of more than 4.5%.

Results

The mean time interval between ECG 1 and ECG 2 was 20 ± 9 minutes. Forty-three percent of the total study population showed an “unstable Aldrich score” between ECG 1 and ECG 2. Fifty-seven percent showed a “stable Aldrich score”, which means that the 95% standard for sufficiently stable was not fulfilled. By dividing the population based on infarct location, the group with inferior AMI (n = 43) showed more stability (67%) than the group with anterior AMI (n = 34) (44%) (P < .05). However, this remains less than the 95% stability standard.

Conclusion

For both inferior and anterior AMI locations, the Aldrich score was not sufficiently stable to be used as a reliable baseline estimation of the AAR in AMI.     

P-wave amplitude and pulmonary artery pressure in scleroderma

Background and Purpose

Scleroderma is an immune-mediated disease characterized by excess deposition of collagen leading to microvascular occlusion. Morbidity and mortality are often secondary to pulmonary hypertension from injury to pulmonary microvasculature and interstitial lung disease. This study correlated P-wave findings on the 12-lead electrocardiogram (ECG) with mean pulmonary artery pressure (mPAP) measured by right heart catheterization in patients with scleroderma.

Methods

A retrospective review of 12-lead ECGs in 23 patients referred to a rheumatology clinic with the diagnosis of scleroderma was performed. Right heart catheterization was performed within 1 month of the resting ECG.

Results

Linear regression related P-wave amplitude in lead II with mPAP (r = 0.52, P = .011) This model was 73% sensitive and 67% specific for the presence or absence of elevated mPAP.

Conclusions

P-wave amplitude analysis on the ECG may be helpful in the assessment of pulmonary hypertension in patients with scleroderma.     

Determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction with ST-segment elevation

Background

This study aimed to clarify the determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction (AAMI).

Methods

We analyzed ST-segment levels in all 12 leads on admission and emergency coronary angiographic findings in 261 patients with a first AAMI with ST-segment elevation. The length of the left anterior descending coronary artery (LAD) was classified as follows: short = not reaching the apex; medium = perfusing less than 25% of the inferior wall; long = perfusing 25% or more of the inferior wall.

Results

The ST-segment level in lead aVR correlated significantly with the ST-segment levels in leads I, II, III, aVF, V₁, and V_3-6, especially with those in leads II and V₆ (r = −0.63, P < .001; r = −0.61, P < .001; respectively). Patients with a proximal LAD occlusion had a greater ST-segment level in lead aVR than those with a distal LAD occlusion (P < .001). Patients with a long LAD had a lower ST-segment level than those with a short or medium LAD (P < .05).

Conclusions

The ST-segment levels, especially in leads II and V₆, the site of the LAD occlusion, and the length of the LAD affect the ST-segment level in lead aVR in ST-segment elevation AAMI.     

Optimization of the precordial leads of the 12-lead electrocardiogram may improve detection of ST-segment elevation myocardial infarction

Background

For the assessment of patients with chest pain, the 12-lead electrocardiogram (ECG) is the initial investigation. Major management decisions are based on the ECG findings, both for attempted coronary artery revascularization and risk stratification. The aim of this study was to determine if the current 6 precordial leads (V₁-V₆) are optimally located for the detection of ST-segment elevation in ST-segment elevation myocardial infarction (STEMI).

Methods

We analyzed 528 (38% anterior [200], 44% inferior [233], and 18% lateral [95]) patients with STEMI with both a 12-lead ECG and an 80-lead body surface map (BSM) ECG (Prime ECG, Heartscape Technologies, Bangor, Northern Ireland). Body surface map was recorded within 15 minutes of the 12-lead ECG during the acute event and before revascularization. ST-segment elevation of each lead on the BSM was compared with the corresponding 12-lead precordial leads (V₁-V₆) for anterior STEMI. In addition, for lateral STEMI, leads I and aVL of the BSM were also compared; and limb leads II, III, aVF of the BSM were compared with inferior unipolar BSM leads for inferior STEMI. Leads with the greatest mean ST-segment elevation were selected, and significance was determined by analysis of variance of the mean ST segment.

Results

For anterior STEMI, leads V₁, V₂, 32, 42, 51, and 57 had the greatest mean ST elevation. These leads are located in the same horizontal plane as that of V₁ and V₂. Lead 32 had a significantly greater mean ST elevation than the corresponding precordial lead V₃ (P = .012); and leads 42, 51, and 57 were also significantly greater than corresponding leads V₄, V₅, V₆, respectively (P < .001). Similar findings were also found for lateral STEMI. For inferior STEMI, the limb leads of the BSM (II, III, and aVF) had the greatest mean ST-segment elevation; and lead III was significantly superior to the inferior unipolar leads (7, 17, 27, 37, 47, 55, and 61) of the BSM (P < .001).

Conclusion

Leads placed on a horizontal strip, in line with leads V₁ and V₂, provided the optimal placement for the diagnosis of anterior and lateral STEMI and appear superior to leads V₃, V₄, V₅, and V₆. This is of significant clinical interest, not only for ease and replication of lead placement but also may lead to increased recruitment of patients eligible for revascularization with none or borderline ST-segment elevation on the initial 12-lead ECG.     

C-reactive protein is released in the coronary circulation and causes endothelial dysfunction in patients with acute coronary syndromes

Background

C-reactive protein (CRP) plasma levels correlate with cardiovascular events. Although a direct role for CRP in atherothrombosis has been suggested, at the moment little is known about its involvement in the pathophysiology of acute coronary syndromes (ACS). Thus, the aim of this study was to determine whether CRP is produced in the culprit lesion and released within the coronary circulation of patients with ACS and whether it may affect coronary endothelial function.

Methods

Blood samples were simultaneously obtained from the aorta (Ao) and the coronary sinus (CS) of patients with normal coronary artery (n = 16), stable angina (n = 30), and ACS (n = 29) for later measurement of plasma CRP levels. Endothelium-dependent and -independent coronary vasodilation were evaluated by means of a Doppler Flow Wire in response to the increasing intracoronary doses of acetylcholine and adenosine, respectively.

Results

CRP plasma levels were significantly higher across the coronary circulation only in ACS patients with the culprit lesion located in the left coronary artery, while no differences between CS and Ao CRP plasma levels were observed in all other groups. Transcardiac CRP levels were correlated with impairment in coronary endothelium-dependent vasodilation. In six additional patients (SA = 3 and ACS = 3), subjected to coronary atherectomy, real-time quantitative PCR revealed presence of CRP mRNA only in unstable plaques.

Conclusions

Thus, CRP is produced and released within the coronary circulation of patients with ACS; this is associated with impairment of endothelial function, suggesting a new pathophysiological link between CRP and ACS.     

Clinical and angiographic characteristics of patients with combined anterior and inferior ST-segment elevation on the initial electrocardiogram during acute myocardial infarction

Objective

We evaluated the significance of combined anterior and inferior ST-segment elevation on the initial electrocardiogram (EKG) in patients with acute myocardial infarction (AMI) and correlated it with AMI size and left ventricular (LV) function.

Methods

We analyzed admission EKGs of 2996 patients with AMI from the GUSTO-I angiographic substudy and the GUSTO-IIb angioplasty substudy who underwent immediate angiography. In all, we identified 1046 patients with anterior ST elevation (ST-segment elevation in ≥2 of leads V₁-V₄) and divided them into 3 groups: Group 1, anterior + inferior ST elevation (ST elevation in ≥2 of leads II, III, aVF, n =179); Group 2, anterior ST elevation only (<2 of leads II, III, aVF with ST elevation or depression, n = 447); Group 3, anterior ST elevation + superior ST elevation (ST depression in ≥2 of leads II, III, aVF, n = 420).

Results

Cardiac risk factors, prior AMI, prior percutaneous transluminal coronary angioplasty or coronary artery bypass graft, Killip class, and thrombolytic therapy assignment did not differ among the 3 groups. Group 1 patients had greater number of leads with ST elevation compared to Groups 2 and 3 (ST elevation in ≥6 leads 83% vs 22% vs 49%, P = .001). Despite greater ST-segment elevation, Group 1 patients had a lower peak CK level (median baseline peak CK 1370 vs 1670 vs 2381 IU, P = .0001) and less LV dysfunction (median ejection fraction 0.53 vs 0.49 vs 0.45, P = .0001; median number of abnormal chords 21 vs 32 vs 40, P = .0001). Angiographically, Group 1 had 2 distinct subsets of patients with either right coronary artery (RCA) (59%) or left anterior descending coronary artery (LAD) (36%) occlusion. In contrast, the infarct-related artery (IRA) was almost entirely the LAD in Groups 2 and 3 (97%). Further, the site of IRA occlusion in Group 1 was mostly proximal RCA (67%) in the RCA subgroup and mid or distal LAD (70%) in the LAD subgroup. ST-segment elevation in lead V₁ ≥ V₃ and absence of progression of ST elevation from lead V₁ to V₃ on the EKG differentiated IRA-RCA from IRA-LAD in patients with combined anterior and inferior ST elevation.

Conclusions

The AMI size and LV dysfunction in patients with anterior ST elevation is directly related to the direction of ST segment deviation in the leads II, III, aVF; least with inferior ST elevation, intermediate with no ST deviation, and maximal with superior ST elevation (inferior ST depression). Despite greater ST-segment elevation, patients with combined anterior and inferior ST elevation have limited AMI size and preserved LV function. Angiographically, they comprise 2 distinct subsets with either proximal RCA or mid to distal LAD occlusion. A predominant right ventricular and limited inferior LV AMI from a proximal RCA occlusion, or a smaller anterior AMI from a more distal occlusion of LAD may explain their limited AMI size despite greater ST elevation.     

Ischemia-induced repolarization response in relation to the size and location of the ischemic myocardium during short-lasting coronary occlusion in humans

Background

The ventricular repolarization (VR) response to short-lasting coronary occlusion has been characterized by 3-dimensional vectorcardiography (VCG) in humans; the T vector loop becomes distorted and more circular. The purpose of this study was to relate these changes to the size of the myocardium at risk (MAR) and its location.

Methods

Continuous VCG was applied during transient coronary occlusion in 35 elective angioplasty patients, and the size of the MAR was estimated by single-photon emission computed tomography. Three VR aspects were assessed at baseline vs maximum ischemia: the ST segment, the T vector angles, and the T vector loop morphology.

Results

The T loop morphology changes were significantly associated with MAR size, but also dependent of its location. In contrast, the early phase of VR reflected by the ST segment responded to acute ischemia in relation to the MAR size independent of location.

Conclusion

The VR changes were related both to the size and the location of the MAR and most pronounced during occlusion of the left anterior descending artery.     

Peroxisome proliferator-activated receptor-γ agonist rosiglitazone reduces circulating platelet activity in patients without diabetes mellitus who have coronary artery disease

Background

Rosiglitazone, a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, is used in the treatment of type 2 diabetes mellitus, and in vitro data has shown that it may have anti-platelet effects independent of its hypoglycemic effects. The aim of this study was to assess the effect of rosiglitazone on circulating platelet activity in patients without diabetes mellitus who had coronary artery disease.

Methods

Ninety-two patients with stable, documented coronary artery disease without diabetes mellitus were studied. Patients were randomized (double-blind) to receive placebo or rosiglitazone for 12 weeks. Circulating platelet activity was measured at baseline and after 12 weeks of therapy with whole blood flow cytometry to quantify platelet P-selectin expression.

Results

The percentage of P-selectin positive platelets was significantly reduced by rosiglitazone treatment compared with placebo (P = .04). In the rosiglitazone group, the percentage of P-selectin positive platelets (median with interquartile range) decreased from 0.1 % (0.05-0.24) to 0.05 % (0.01-0.15). Rosiglitazone treatment significantly reduced the insulin resistance index (HOMA-R) compared with placebo (P = .02). No significant correlation was observed between change in platelet activity and change in HOMA-R.

Conclusions

Rosiglitazone significantly reduces circulating platelet activity in patients without diabetes mellitus who have coronary artery disease. This effect appears to be independent of any insulin-sensitising effect.     

Vectorcardiogram synthesized from the 12-lead electrocardiogram to image ischemia

Background

Knowledge of the location and size of ischemic myocardium at risk for infarction could impact prehospital patient triage and reperfusion therapy. The 12-lead electrocardiogram (ECG) can roughly estimate ischemia size; however, individual precordial ECG leads are at different distances from the left ventricle (LV) and certain LV walls have greater effects on the ECG. Vectorcardiographic corrected orthogonal lead systems can display the magnitude and direction of the ST-segment “injury current” vector in 3-dimensional space. We assessed whether the vectorcardiographic ST-vector direction and magnitude derived from the ECG by the inverse-Dower method can estimate the location and size of ischemia.

Methods and Results

Thirty-two patients underwent elective coronary angioplasty with control and 5-minute balloon-occlusion ECG and sestamibi injection followed by single photon emission computed tomography (SPECT). The ST-vector direction derived from the inverse-Dower method was projected to an LV model with normal coronary artery anatomy. The graphical display of ST-vector location could discriminate among occlusions of the different coronaries. The ST-vector located ischemia within the SPECT defect in 75% (24/32) of all patients and 96% (24/25) of patients with ischemia in more than 12% of the LV. ST-vector magnitude had a Spearman correlation of r = 0.68 (P < .0001) with SPECT ischemia size.

Conclusions

The 3-dimensional ST vector derived from the ECG can be graphically projected onto an LV model to localize ischemia, and ST-vector magnitude correlates with ischemia size. Further study is warranted to assess the ability of vectorcardiographic imaging to risk-stratify and provide decision-support for patients with acute myocardial infarction.     

In search of the best method to predict acute coronary syndrome using only the electrocardiogram from the emergency department

Introduction

The aim of this study was to compare different methods to predict acute coronary syndrome (ACS) using only data from a single electrocardiogram (ECG) in the emergency department (ED).

Method

We compared the ACS prediction abilities of classical ECG criteria, human expert ECG interpretation, a logistic regression model and an artificial neural network ensemble (ANN). The ED ECG and discharge diagnoses were retrieved for 861 patient visits to the ED for chest pain. Cross-validation was used to estimate the generalization performance of the logistic regression and the ANN model.

Results

The logistic regression model had the overall best performance in predicting ACS with an area under the receiver operating characteristic curve of 0.88. The sensitivities of logistic regression, ANN, expert physicians, and classical ECG criteria were 95%, 95%, 82%, and 75%, respectively, and the specificities were 54%, 44%, 63%, and 69%.

Conclusion

Our logistic regression model was the best overall method to predict ACS, followed by our ANN. Decision support models have the potential to improve even experienced ECG readers' ability to predict ACS in the ED.     

Infarctus par occlusion aiguë du tronc commun non protégé : à propos de six cas traités par angioplastie

Aim

Acute main left coronary artery occlusion is rarely observed during primary angioplasty in myocardial infarction. This retrospective study reports the results of six patients treated by angioplasty in a hospital without cardiac surgery department.

Patients and methods

From 2002 to 2009, 746 patients were treated by primary angioplasty for acute coronary syndromes with ST elevation. Among those patients, six (0,7%) had acute non protected main left coronary occlusion. We report clinical, angiographical data and follow-up.

Results

The population was composed of six patients (five males) with an average age of 64 ± 7 years. Five patients were admitted with cardiogenic shock and four were mechanically ventilated. Distal occlusion of main left coronary artery and dominant right coronary artery were noted in all cases. Sub-occluded lesion of right coronary artery was noted in one case. Successful procedure with bare metal stent was achieved in five cases. Mortality rate was 66% (n = 4): three patients died in hospital and another 1 or 2 months later of congestive heart failure. Coronary artery bypass grafting was performed at 4 and 12 months later for two patients. They are alive after 12 and 72 months of follow-up.

Conclusion

We demonstrate the feasibility of percutaneous coronary intervention of acute main left coronary occlusion. Inspite successful procedure, intrahospital mortality rate is still high and prognosis is related to cardiogenic shock.