Updated electrocardiographic classification of acute coronary syndromes

Early/Subtle Electrocardiography Features of Acute Coronary Syndrome and ST-Segment Elevation Myocardial Infarction

Chest pain is one of the most common presenting complaints in the emergency department. Interpreting a 12-lead electrocardiography (ECG) for evidence of ischemia is always challenging. Frank ECG changes such as ST-segment elevation and ST-segment depression can be easily identified by emergency physicians. However, identifying subtle or early features of ACS in the 12-lead ECG is essential in preventing significant mortality and morbidity from ACS. In the following case series, we describe five of the subtle/early ECG changes of ACS, namely (1) T-wave inversion in lead aVL; (2) terminal QRS distortion; (3) hyperacute T-waves; (4) negative U-waves in precordial leads; and (5) loss of precordial T-wave balance. In all these cases, the initial 12-lead ECG showed only subtle/early ECG changes which were followed up with serial ECGs which progressed to STEMI.

microRNA-3646 serves as a diagnostic marker and mediates the inflammatory response induced by acute coronary syndrome

Acute coronary syndrome (ACS) is one of the main syndromes of coronary artery disease with high mortality. The identification of biomarkers associated with disease occurrence and progression could improve early detection and risk prediction. This study was aimed to reveal the clinical significance and function of miR-3646 in ACS.

The expression of miR-3646 was evaluated in ACS patients, healthy volunteers, and non-ACS patients and estimated the clinical significance of miR-3646. The ACS modeling rats were also established in this study to explore the potential mechanism underlying the function of miR-3646. miR-3646 was upregulated in ACS patients compared with healthy volunteers and non-ACS patients. The expression of miR-3646 was positively correlated with the severity and progression of ACS patients and could discriminate ACS patients from healthy volunteers and non-ACS patients. The knockdown of miR-3646 could reverse the inflammatory response induced by ACS.miR-3646 serves as a diagnostic biomarker for ACS. The knockdown of miR-3646 could alleviate ACS by reversing inflammatory response. These results provide a potential therapeutic target of ACS.

Culprit lesion detection in patients presenting with non-ST elevation acute coronary syndrome and multivessel disease

BACKGROUND/PURPOSE

Identification of the culprit lesion in patients with non-ST elevation acute coronary syndrome (NSTE-ACS) allows appropriate coronary revascularization but may be unclear in patients with multivessel coronary disease (MVD). Therefore, we investigated the rate of culprit lesion identification during coronary angiography in NSTE-ACS and multivessel disease.

METHODS/MATERIALS

Consecutive patients presenting with NSTE-ACS and MVD, between January 2012 and December 2016 were evaluated. Coronary angiograms, intravascular imaging, and ECGs were analyzed for culprit lesion identification. Long-term clinical outcomes in terms of major adverse cardiac events (MACE) and mortality were reported in patients with or without culprit identification.

RESULTS

A total of 1107 patients with NSTE-ACS and MVD were included in the analysis, 310 (28.0%) with unstable angina and 797 (72.0%) with non-ST elevation myocardial infarction. The culprit lesion was angiographically identified in 952 (86.0%) patients, while no clear culprit lesion was found in 155 (14.0%) patients. ECG analysis allowed to predict the location of the culprit vessel with low sensitivity (range 28.4%-36.7%) and high specificity (range 90.6%-96.5%). Higher lesion complexity was associated with inability to identify the culprit. Intravascular imaging was applied in 55 patients and helped to identify the culprit lesion in 53 patients (96.4%). There was no difference in all-cause mortality (21.4% vs. 25.8%, p = 0.24) and MACE (39.2% vs. 47.6%, p = 0.07) between the cohorts with or without culprit lesion identification by angiography.

CONCLUSIONS

The culprit lesion appeared unclear by coronary angiography in >10% of patients with NSTE-ACS and MVD. Complementary invasive imaging substantially enhanced the diagnostic accuracy of culprit lesion detection.

Low diagnostic yield of ST elevation myocardial infarction amplitude criteria in chest pain patients at the emergency department

OBJECTIVES

To evaluate the diagnostic yield of the ECG criteria for ST-elevation myocardial infarction in a large cohort of emergency department chest pain patients, and to determine whether extended ECG criteria or reciprocal ST depression can improve accuracy. Design: Observational, register-based diagnostic study on the accuracy of ECG criteria for ST-elevation myocardial infarction. Between Jan 2010 and Dec 2014 all patients aged ≥30 years with chest pain who had an ECG recorded within 4 h at two emergency departments in Sweden were included. Exclusion criteria were: ECG with poor technical quality; QRS duration ≥120 ms; ECG signs of left ventricular hypertrophy; or previous coronary artery bypass surgery. Conventional and extended ECG criteria were applied to all patients. The main outcome was acute myocardial infarction (AMI) and an occluded/near-occluded coronary artery at angiography. Results: Finally, 19932 patients were included. Conventional ECG criteria for ST elevation myocardial infarction were fulfilled in 502 patients, and extended criteria in 1249 patients. Sensitivity for conventional ECG criteria in diagnosing AMI with coronary occlusion/near-occlusion was 17%, specificity 98% and positive predictive value 12%. Corresponding data for extended ECG criteria were 30%, 94% and 8%. When reciprocal ST depression was added to the criteria, the positive predictive value rose to 24% for the conventional and 23% for the extended criteria. Conclusions: In unselected chest pain patients at the emergency department, the diagnostic yield of both conventional and extended ECG criteria for ST-elevation myocardial infarction is low. The PPV can be increased by also considering reciprocal ST depression.

Impact of admission serum acid uric levels on in-hospital outcomes in patients with acute coronary syndrome

BACKGROUND

To assess the association between admission serum uric acid (SUA) levels and in-hospital outcomes in a real-world patients population with acute coronary syndrome (ACS) and to investigate the potential incremental prognostic value of SUA added to GRACE score (GRACE-SUA score).

METHODS

The data of consecutive ACS patients admitted to Coronary Care Unit of San Paolo and Niguarda hospitals in Milan (Italy) were retrospectively analyzed.

RESULTS

1088 patients (24% female) were enrolled. Mean age was 68 years (IQR 60-78). STEMI and NSTE-ACS patients were 504 (46%) and 584 (54%) respectively. SUA (OR 1.72 95%CI 1.33-2.22, p < 0.0001) and GRACE score (OR 1.04 95%CI 1.02-1.06, p < 0.0001) were significantly associated with an increased risk of in-hospital death at the multivariate analysis. Admission values of SUA were stratified in four quartiles. Rates of acute kidney injury, implantation of intra-aortic balloon pump and non-invasive ventilation use were significantly higher in the last quartile compared to Q1, Q2 and Q3 (p < 0.01). The areas under the ROC curve (AUC) for GRACE score and for SUA were 0.91 (95% CI 0.89-0.93, p < 0.0001) and 0.79 (95% CI 0.76-0.81, p < 0.0001) respectively. The AUC was larger for predicting in-hospital mortality with the GRACE-SUA score (0.94; 95% CI 0.93-0.95).

CONCLUSIONS

High admission levels of SUA are independently associated with in-hospital adverse outcomes and mortality in a contemporary population of ACS patients. The inclusion of SUA to GRACE risk score seems to lead to a more accurate prediction of in-hospital mortality in this study population.

Electrocardiographic identification of the culprit coronary artery in acute non-ST-elevation myocardial infarction: predictive value of N-wave and T-wave precordial instability

BACKGROUND

Recently, novel ischemic electrocardiographic changes have been described, which may be clinically significant in the identification of the culprit coronary vessel in patients with non-ST-elevation myocardial infarction (NSTEMI). We sought to determine the predictive value of N-wave, T-wave precordial instability, de-Winter ST/T-wave complex, and inferolateral myocardial infarction in the identification of the culprit artery in patients with NSTEMI referred for early invasive (<24 h) treatment.

METHODS

A total of 148 patients with NSTEMI, aged 40-91 years, were enrolled from a cohort of 510 consecutive NSTEMI subjects, hospitalized in our center in 2015-2017.

RESULTS

Of the evaluated ischemic ECG changes, the most common finding in patients with culprit left circumflex (LCx)/obtuse marginal artery or right coronary artery was T-wave precordial instability (28.3 and 13.5%, respectively), whereas in individuals with culprit left anterior descending/diagonal artery, T-wave precordial instability and N-wave in leads II, III or aVF occurred equally often (16.0%). A significant relationship was found between the occurrence of N-wave in inferolateral leads and culprit LCx/obtuse marginal. In multivariable analysis, N-wave in lead aVL [odds ratio (OR) 2.10; 95% confidence interval (CI), 1.15-3.81], and T-wave precordial instability (OR 1.56; 95% CI, 1.02-2.41) were independent predictors of culprit LCx/obtuse marginal. The accuracy of N-wave in lead aVL in predicting the culprit LCx/obtuse marginal was 73.9% and was higher than the accuracy of T-wave precordial instability, which was 69.1%.

CONCLUSIONS

In patients with NSTEMI referred for early invasive treatment, the presence of N-wave or T-wave precordial instability may be of greater clinical importance in the prediction of culprit LCx/obtuse marginal than classic ischemic changes.

Optimal measuring point for ST deviation in chest pain patients with possible acute coronary syndrome

INTRODUCTION

In the ECG, significant ST elevation or depression according to specific amplitude criteria can be indicative of acute coronary syndrome (ACS). Guidelines state that the ST amplitude should be measured at the J point, but data to support that this is the optimal measuring point for ACS detection is lacking. We evaluated the impact of different measuring points for ST deviation on the diagnostic accuracy for ACS in unselected emergency department (ED) chest pain patients.

MATERIAL AND METHODS

We included 14,148 adult patients with acute chest pain and an ECG recorded at a Swedish ED between 2010 and 2014. ST deviation was measured at the J point (STJ) and at 20, 40, 60 and 80 ms after the J point. A discharge diagnosis of ACS or not at the index visit was noted in all patients.

RESULTS

In total, 1489 (10.5%) patients had ACS. ST amplitude criteria at STJ had a sensitivity of 28% and a specificity of 92% for ACS. With these criteria, the highest positive and negative predictive values for ACS were obtained near the J point, but the optimal point varied with ST deviation, age group and sex. The overall best measuring points were STJ and ST20.

CONCLUSIONS

This study indicates that the diagnostic accuracy of the ECG criteria for ACS is very low in ED chest pain patients, and that the optimal measuring point for the ST amplitude in the detection of ACS differs between ST elevation and depression, and between patient subgroups.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Correlation of anteroseptal ST elevation with myocardial infarction territories through cardiovascular magnetic resonance imaging

BACKGROUND

Anteroseptal ST elevation myocardial infarction (STEMI) is traditionally defined on the electrocardiogram (ECG) by ST elevation (STE) in leads V1-V3, with or without involvement of lead V4. It is commonly taught that such infarcts affect the basal anteroseptal myocardial segment. While there are suggestions in the literature that Q waves limited to V1-V4 represent predominantly apical infarction, none have evaluated anteroseptal ST elevation territories. We compared the distribution of the myocardium at risk (MaR) in STEMI patients presenting with STE limited to V1-V4 and those with more extensive STE (V1-V6).

METHODS

We identified patients in the MITOCARE study presenting with a first acute STEMI and new STE in at least two contiguous anterior leads from V1 to V6. Patients underwent cardiac magnetic resonance (CMR) imaging three to five days after acute infarction.

RESULTS

Thirty-two patients met inclusion criteria. In patients with STE in V1-V4 (n = 20), myocardium at risk (MaR) > 50% was seen in 0%, 85%, 75%, 100%, and 90% in the basal anteroseptal, mid anteroseptal, apical anterior, apical septal segments, and apex, respectively. The group with STE in V1-V6 (n = 12), MaR > 50% was seen in 8%, 83%, 83%, 92%, and 83% of the same segments.

CONCLUSIONS

Patients with acute STEMI and STE in leads V1-V4, exhibit MaR in predominantly apical territories and rarely in the basal anteroseptum. We found no evidence to support existence of isolated basal anteroseptal or septal STEMI. "Anteroapical" infarction is a more precise description than "anteroseptal" infarction for acute STEMI patients exhibiting STE in V1-V4.

New Insights Into the Use of the 12-Lead Electrocardiogram for Diagnosing Acute Myocardial Infarction in the Emergency Department

The 12-lead electrocardiogram (ECG) remains the most immediately accessible and widely used initial diagnostic tool for guiding management in patients with suspected myocardial infarction (MI). Although the development of high-sensitivity cardiac troponin assays has improved the rule-in and rule-out and risk stratification of acute MI without ST elevation, the immediate management of the subset of acute MI with acute coronary occlusion depends on integrating clinical presentation and ECG findings. Careful interpretation of the ECG might yield subtle features suggestive of ischemia that might facilitate more rapid triage of patients with subtle acute coronary occlusion or, conversely, in identification of ST-elevation MI mimics (pseudo ST-elevation MI patterns). Our goal in this review article is to consider recent advances in the use of the ECG to diagnose coronary occlusion MIs, including the application of rules that allow MI to be diagnosed on the basis of atypical ECG manifestations. Such rules include the modified Sgarbossa criteria allowing identification of acute MI in left bundle branch block or ventricular pacing, the 3- and 4-variable formula to differentiate normal ST elevation (formerly called early repolarization) from subtle ECG signs of left anterior descending coronary artery occlusion, the differentiation of ST elevation of left ventricular aneurysm from that of acute anterior MI, and the use of lead aVL in the recognition of inferior MI. Improved use of the ECG is essential to improving the diagnosis and appropriate early management of acute coronary occlusion MIs, which will lead to improved outcomes for patients who present with acute coronary syndrome.

Appropriateness of anteroseptal myocardial infarction nomenclature evaluated by late gadolinium enhancement cardiovascular magnetic resonance imaging

BACKGROUND

In traditional literature, it appears that "anteroseptal" MIs with Q waves in V1-V3 involve basal anteroseptal segments although studies have questioned this belief.

METHODS

We studied patients with first acute anterior Q-wave (>30ms) MI. All underwent late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (MRI).

RESULTS

Those with Q waves in V1-V2 (n=7) evidenced LGE >50% in 0%, 43%, 43%, 57%, and 29% of the basal anteroseptal, mid anteroseptal, apical anterior, apical septal segments, and apex, respectively. Patients with Q waves in V1-V3 (n=14), evidenced involvement was 14%, 43%, 43%, 50%, and 7% of the same respective segments. In those with extensive anterior Q waves (n=7), involvement was 0%, 71%, 57%, 86%, and 86%.

CONCLUSIONS

Q-wave MI in V1-V2/V3 primarily involves mid- and apical anterior and anteroseptal segments rather than basal segments. Data do not support existence of isolated basal anteroseptal or septal infarction. "Anteroapical infarction" is a more appropriate term than "anteroseptal infarction."

A patient with non-ST-segment elevation acute coronary syndrome: Is it possible to predict the culprit coronary artery?

In acute coronary syndromes without ST-segment elevation (NSTE-ACS), identification of the culprit artery is, most often, not possible. In this case report, we elaborate on the likelihood of different culprit arteries in a patient with NSTE-ACS. While her symptoms were progressing, typical ECG findings of ischemia in the left coronary territories were diminishing. Instead, dynamic T-wave changes in the inferior leads were present and were most likely postischemic and "reischemic." Although the culprit artery could not be identified with certainty by means of these subtle changes, they correlated well with the findings on angiography and the ECG recorded afterward. This case report demonstrates the importance of analyzing ECG and its temporal changes in conjunction with evolving symptoms.

Emerging risk biomarkers in cardiovascular diseases and disorders

Present review article highlights various cardiovascular risk prediction biomarkers by incorporating both traditional risk factors to be used as diagnostic markers and recent technologically generated diagnostic and therapeutic markers. This paper explains traditional biomarkers such as lipid profile, glucose, and hormone level and physiological biomarkers based on measurement of levels of important biomolecules such as serum ferritin, triglyceride to HDLp (high density lipoproteins) ratio, lipophorin-cholesterol ratio, lipid-lipophorin ratio, LDL cholesterol level, HDLp and apolipoprotein levels, lipophorins and LTPs ratio, sphingolipids, Omega-3 Index, and ST2 level. In addition, immunohistochemical, oxidative stress, inflammatory, anatomical, imaging, genetic, and therapeutic biomarkers have been explained in detail with their investigational specifications. Many of these biomarkers, alone or in combination, can play important role in prediction of risks, its types, and status of morbidity. As emerging risks are found to be affiliated with minor and microlevel factors and its diagnosis at an earlier stage could find CVD, hence, there is an urgent need of new more authentic, appropriate, and reliable diagnostic and therapeutic markers to confirm disease well in time to start the clinical aid to the patients. Present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of CVDs, HF (heart failures), and various lipid abnormalities and disorders in the future.