Prevalence of coronary occlusion and outcome of an immediate invasive strategy in suspected acute myocardial infarction with and without ST-segment elevation

Beyond STEMI-NSTEMI Paradigm: Dante Pazzanese's Proposal for Occlusion Myocardial Infarction Diagnosis

Although the existing framework for classifying acute myocardial infarction (AMI) into STEMI and NSTEMI has been beneficial, it is now considered to be falling short in addressing the complexity of acute coronary syndromes. The study aims to scrutinize the current STEMI-NSTEMI paradigm and advocate for a more nuanced framework, termed as occlusion myocardial infarction (OMI) and non-occlusion myocardial infarction (NOMI), for a more accurate diagnosis and management of AMI. A comprehensive analysis of existing medical literature was conducted, with a focus on the limitations of the STEMI-NSTEMI model. The study also outlines a new diagnostic approach for patients presenting with chest pain in emergency settings. The traditional STEMI-NSTEMI model falls short in diagnostic precision and effective treatment, especially in identifying acute coronary artery occlusions. The OMI-NOMI framework offers a more anatomically and physiologically accurate model, backed by a wealth of clinical research and expert opinion. It underscores the need for quick ECG assessments and immediate reperfusion therapies for suspected OMI cases, aiming to improve patient outcomes. The OMI-NOMI framework offers a new avenue for future research and clinical application. It advocates for a more comprehensive understanding of the underlying mechanisms of acute coronary syndromes, leading to individualized treatment plans. This novel approach is expected to ignite further scholarly debate and research, particularly in the Brazilian cardiology sector, with the goal of enhancing diagnostic accuracy and treatment effectiveness in AMI patients.

The global prevalence of myocardial infarction: a systematic review and meta-analysis

BACKGROUND

Myocardial infarction (MI) is one of the life-threatening coronary-associated pathologies characterized by sudden cardiac death. The provision of complete insight into MI complications along with designing a preventive program against MI seems necessary.

METHODS

Various databases (PubMed, Web of Science, ScienceDirect, Scopus, Embase, and Google scholar search engine) were hired for comprehensive searching. The keywords of "Prevalence", "Outbreak", "Burden", "Myocardial Infarction", "Myocardial Infarct", and "Heart Attack" were hired with no time/language restrictions. Collected data were imported into the information management software (EndNote v.8x). Also, citations of all relevant articles were screened manually. The search was updated on 2022.9.13 prior to the publication.

RESULTS

Twenty-two eligible studies with a sample size of 2,982,6717 individuals (< 60 years) were included for data analysis. The global prevalence of MI in individuals < 60 years was found 3.8%. Also, following the assessment of 20 eligible investigations with a sample size of 5,071,185 individuals (> 60 years), this value was detected at 9.5%.

CONCLUSION

Due to the accelerated rate of MI prevalence in older ages, precise attention by patients regarding the complications of MI seems critical. Thus, determination of preventive planning along with the application of safe treatment methods is critical.

Beyond the ST-segment in Occlusion Myocardial Infarction (OMI): Diagnosing the OMI-nous

The ST-segment elevation (STE) myocardial infarction (MI)/non-STEMI (NSTEMI) paradigm has been the central dogma of emergency cardiology for the last 30 years. Although it was a major breakthrough when it was first introduced, it is now one of the most important obstacles to the further progression of modern MI care. In this article, we trace why a disease with an established underlying pathology (acute coronary occlusion [ACO]) was unintentionally labeled with a surrogate electrocardiographic sign (STEMI/NSTEMI) instead of pathologic substrate itself (ACO-MI/non-ACO-MI or occlusion MI [OMI]/non-OMI [NOMI] for short), how this fundamental mistake caused important clinical consequences, and why we should change this paradigm with a better one, namely OMI/NOMI paradigm.

Time for a new paradigm shift in myocardial infarction

The ST-elevation myocardial infarction (STEMI)/non-STEMI paradigm per the current guidelines has important limitations. It misses a substantial proportion of acute coronary occlusions (ACO) and results in a significant amount of unnecessary catheterization laboratory activations. It is not widely appreciated how poor is the evidence base for the STEMI criteria; the recommended STEMI cutoffs were not derived by comparing those with ACO with those without and not specifically designed for distinguishing patients who would benefit from emergency reperfusion. This review aimed to discuss the origins, evidence base, and limitations of STEMI/non-STEMI paradigm and to call for a new paradigm shift to the occlusion MI (OMI)/non-OMI.

STEMI: A transitional fossil in MI classification?

An important task in emergency cardiology is distinguishing patients with acute coronary occlusion (ACO), who will benefit from emergent reperfusion therapy, from those without ongoing myocyte loss who can be managed with medical therapy and for whom potentially harmful invasive interventions can be deferred. The electrocardiogram is critical in this process. Although the ST-segment elevation myocardial infarction (STEMI)/non-STEMI paradigm is well-established, with "STEMI" representing ACO, its evidence base is poor, and this can have dire consequences. The universally recommended STEMI criteria do not accurately diagnose ACO; in fact, they miss more than one-fourth of the patients with ACO, and also result in a substantial burden of unnecessary catheterization laboratory activations. We here discuss why we believe it is time to change the current STEMI/non-STEMI paradigm.

DIagnostic accuracy oF electrocardiogram for acute coronary OCClUsion resuLTing in myocardial infarction (DIFOCCULT Study)

Background

Although ST-segment elevation (STE) has been used synonymously with acute coronary occlusion (ACO), current STE criteria miss nearly one-third of ACO and result in a substantial amount of false catheterization laboratory activations. As many other electrocardiographic (ECG) findings can reliably indicate ACO, we sought whether a new ACO/non-ACO myocardial infarction (MI) paradigm would result in better identification of the patients who need acute reperfusion therapy.

Methods

A total of 3000 patients were enrolled in STEMI, non-STEMI and control groups. All ECGs were reviewed by two cardiologists, blinded to any outcomes, for the current STEMI criteria and other subtle signs. A combined ACO endpoint was composed of peak troponin level, troponin rise within the first 24 h and angiographic appearance. The dead or alive status was checked from hospital records and from the electronic national database.

Results

In non-STEMI group, 28.2% of the patients were re-classified by the ECG reviewers as having ACO. This subgroup had a higher frequency of ACO, myocardial damage, and both in-hospital and long-term mortality compared to non-STEMI group. A prospective ACOMI/non-ACOMI approach to the ECG had superior diagnostic accuracy compared to the STE/non-STEMI approach in the prediction of ACO and long-term mortality. In Cox-regression analysis early intervention in patients with non-ACO-predicting ECGs was associated with a higher long-term mortality.

Conclusions

We believe that it is time for a new paradigm shift from the STEMI/non-STEMI to the ACOMI/non-ACOMI in the acute management of MI. (DIFOCCULT study; ClinicalTrials.gov number, NCT04022668.).

An initial exploration of subtraction electrocardiography to detect myocardial ischemia in the prehospital setting

BACKGROUND

In the prehospital triage of patients presenting with symptoms suggestive of acute myocardial ischemia, reliable myocardial ischemia detection in the electrocardiogram (ECG) is pivotal. Due to large interindividual variability and overlap between ischemic and nonischemic ECG-patterns, incorporation of a previous elective (reference) ECG may improve accuracy. The aim of the current study was to explore the potential value of serial ECG analysis using subtraction electrocardiography.

METHODS

SUBTRACT is a multicenter retrospective observational study, including patients who were prehospitally evaluated for acute myocardial ischemia. For each patient, an elective previously recorded reference ECG was subtracted from the ambulance ECG. Patients were classified as myocardial ischemia cases or controls, based on the in-hospital diagnosis. The diagnostic performance of subtraction electrocardiography was tested using logistic regression of 28 variables describing the differences between the reference and ambulance ECGs. The Uni-G ECG Analysis Program was used for state-of-the-art single-ECG interpretation of the ambulance ECG.

RESULTS

In 1,229 patients, the mean area-under-the-curve of subtraction electrocardiography was 0.80 (95%CI: 0.77-0.82). The performance of our new method was comparable to single-ECG analysis using the Uni-G algorithm: sensitivities were 66% versus 67% (p-value > .05), respectively; specificities were 80% versus 81% (p-value > .05), respectively.

CONCLUSIONS

In our initial exploration, the diagnostic performance of subtraction electrocardiography for the detection of acute myocardial ischemia proved equal to that of state-of-the-art automated single-ECG analysis by the Uni-G algorithm. Possibly, refinement of both algorithms, or even integration of the two, could surpass current electrocardiographic myocardial ischemia detection.

Novel ECG changes in acute coronary syndromes. Would improvement in the recognition of 'STEMI-equivalents' affect time until reperfusion?

Current guidelines recommend that patients with non-ST elevation myocardial infarction (NSTEMI) are treated with medical management alone, or in combination with coronary angiography within 24 h. Recent research suggests that NSTEMIs show angiographic evidence of complete occlusion at rates comparable to STEMIs, suggesting a subgroup of NSTEMI patients who require urgent angiography. Novel ECG changes, termed 'STEMI-equivalents', have been described as a way of identifying this subgroup. The aim of this study was to determine whether patients with STEMI-equivalent ECG changes experience similar degrees of myocardial damage, and would thus benefit from urgent PCI. Cardiac catheterisation databases at The Wollongong Hospital were searched for STEMI, and NSTEMI patients with complete occlusion of the culprit vessel, between January 2011 and December 2013. A total of 1429 patients underwent angiography during this time period. Of these, 220 were eligible for ECG analysis. We found 10-25% of NSTEMIs with 'STEMI equivalent' ECG changes correlated with complete vessel occlusion on angiography. These patients demonstrated equivalent initial troponin readings. Recognition of STEMI-equivalents represent a chance for earlier intervention with prompt coronary angiography, as these findings are often associated with complete occlusion of the culprit vessel. These findings provide further evidence supporting the potential inclusion of STEMI-equivalents in future ACS guidelines.

Prevalence and outcome of patients with non-ST segment elevation myocardial infarction with occluded "culprit" artery - a systemic review and meta-analysis

BACKGROUND

The aim was to determine the prevalence and impact of an occluded "culprit" artery (OCA) in patients with non-ST segment elevation myocardial infarction (NSTEMI).

METHODS

We searched PubMed, EMBASE, and Web of Science, with no language restrictions, up to 1 Jul. 2016. Observational cohorts or clinical trials of adult NSTEMI were eligible for inclusion to determine the prevalence if the proportion of OCA on coronary angiography was reported. Studies were further eligible for inclusion to determine the outcome if the association between OCA and clinical endpoints was reported.

RESULTS

Among the 60,898 patients with NSTEMI enrolled in 25 studies, 17,212 were found to have OCA. The average proportion of OCA in NSTEMI was 34% (95% CI 30-37%). Patients with OCA were more likely to have left circumflex artery as their culprit artery (odds ratio (OR) 1.65, 95% CI 1.15-2.37, p = 0.007), and this was associated with lower left ventricular ejection fraction (standard mean difference -0.29, 95% CI -0.34 to -0.34, p < 0.001), higher peak enzyme level (standard mean difference 0.43, 95% CI 0.27-0.58, p < 0.001), and higher risk for cardiogenic shock (OR 1.66, 95% CI 1.35-2.04, p < 0.001), compared with patients with a non-occlusive culprit artery. Death rate (OR 1.72, 95% CI 1.49-1.98, p < 0.001) and recurrent myocardial infarction (OR 1.7, 95% CI 1.06-2.75, p = 0.029) were also higher in patients with OCA, compared with patients with a non-occlusive culprit artery.

CONCLUSIONS

Patients with OCA comprised a substantial portion of the NSTEMI population. These patients present with more severe symptoms and worse clinical outcome. Whether these patients should be treated with more aggressive strategy warrants further study.

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.

Prehospital diagnosis of patients with acute myocardial infarction

Primary percutaneous intervention (PPCI) is the preferred treatment in patients with ST elevation myocardial infarction (STEMI) if this can be performed in a timely manner. The

Role of 2D speckle tracking echocardiography in predicting acute coronary occlusion in patients with non ST-segment elevation myocardial infarction

Background

A substantial fraction of patients with non ST-elevation acute coronary syndrome have an occluded culprit vessel on coronary angiography. Acute coronary occlusion often results in myocardial infarction and loss of systolic function. Identification of these patients may have considerable impact on treatment and prognosis.

Aim

The study aims at investigating role of 2D speckle tracking echocardiography as a non-invasive predictor of acute coronary artery occlusion in patients with non ST-segment elevation myocardial infarction.

Patients

This study was carried on 60 patients with first attack non ST segment elevation myocardial infarction who were admitted to coronary care unit of Ain Shams University Hospitals. All patients underwent thorough history taking, full clinical examination, 12 leads surface ECG, full 2D, M-mode and Doppler echocardiographic study, two-dimensional speckle tracking strain study and coronary angiography.

Results

2D derived peak global longitudinal strain had a highly significant relationship in prediction of the presence of total occlusion, and also number of segments with reduced strain (functional risk area by strain) had a highly significant relationship in prediction of the presence of total occlusion. In this study, 2D derived peak longitudinal strain sensitivity and specificity were 68.9% and 77.7% respectively at a cutoff value of -15.5 while number of segments with reduced longitudinal strain sensitivity and specificity were 63.6% and 77.7% respectively at a cutoff value of 5 segments.

Conclusion

Both global and regional peak longitudinal systolic strain can offer accurate, feasible, and non-invasive predictor for acute coronary artery occlusion in patients with non ST elevation myocardial infarction who may benefit from early revascularization.

Incidence and impact of totally occluded culprit coronary arteries in patients presenting with non-ST-segment elevation myocardial infarction

The accuracy of the 12-lead electrocardiogram in detecting coronary artery occlusion is limited. We sought to determine the incidence, distribution, and outcomes of patients who have total occlusion of the culprit artery but present with non-ST-segment elevation myocardial infarction (NSTEMI). The randomized Acute Catheterization and Urgent Intervention Triage Strategy trial enrolled 13,819 patients presenting with non-ST-segment elevation acute coronary syndromes who underwent an early invasive strategy. The present study includes 1,319 patients with baseline biomarker elevation (NSTEMI) and no history of coronary artery bypass graft who underwent percutaneous coronary intervention of a single culprit vessel. We compared the baseline characteristics and outcomes according to whether the culprit vessel was occluded (baseline Thrombolysis In Myocardial Infarction [TIMI] 0 to 1) or patent (TIMI 2 to 3 flow) by angiographic core laboratory assessment. TIMI 0 to 1 flow in the culprit artery was present in 262 of 1,319 (19.9%) patients. The incidence of coronary occlusion was 28.4%, 19.3%, and 12.6% in patients with NSTEMI because of right coronary, left circumflex, and left anterior descending artery disease, respectively. Patients with an occluded culprit artery were more commonly men and had ST-segment deviation ≥1 mm. One-year outcomes, including death (3.5% vs 3.0%, p = 0.68) and myocardial infarction (8.4% vs 9.6%, p = 0.47), did not differ significantly between patients with versus without occluded culprit arteries, respectively. In conclusion, the present study demonstrates that the culprit artery is totally occluded in approximately 1 in 5 patients presenting with NSTEMI and single-vessel disease; however, the presence of total occlusion in NSTEMI was not associated with an incremental hazard of death or reinfarction at 1 year.

Role of the ECG in initial acute coronary syndrome triage: primary PCI regardless presence of ST elevation or of non-ST elevation

The major initial triaging decision in acute coronary syndrome (ACS) is whether or not percutaneous coronary intervention (PCI) is the primary treatment. Current guidelines recommend primary PCI in ST-elevation ACS (STEACS) and initial antithrombotic therapy in non-ST-elevation ACS (NSTEACS). This review probes the question whether this decision can indeed be based on the ECG. Genesis of STE/NSTE ECGs depends on the coronary anatomy, collateral circulation and site of the culprit lesion. Other causes than ischaemia may also result in ST-segment changes. It has been demonstrated that the area at risk cannot reliably be estimated by the magnitude of the ST change, that complete as well as incomplete occlusions can cause STE as well as NSTE ECGs, and that STE and NSTE patterns cannot differentiate between transmural and non-transmural ischaemia. Furthermore, unstable angina can occur with STE and NSTE ECGs. We conclude that the ECG can be used to assist in detecting ischaemia, but that electrocardiographic STE and NSTE patterns are not uniquely related to distinctly different pathophysiological mechanisms. Hence, in ACS, primary PCI might be considered regardless of the nature of the ST deviation, and it should be done with the shortest possible delay, because ‘time is muscle’.

Directionality and proportionality of the ST and ventricular gradient difference vectors during acute ischemia

BACKGROUND

The ECG is important in diagnosis and triage in the initial phase of the acute coronary syndrome (ACS). The primary goal of making an ECG at first medical contact should be the reliable detection of cardiac ischemia, thus facilitating a correct triage by corroborating the diagnosis of ACS. Ischemia detection by ST amplitude analysis is limited to situations in which there is an identifiable J point. The ventricular gradient (VG) is independent of conduction and might be an alternative ECG-based variable for ischemia detection.

METHODS

We studied vectorcardiograms (VCGs) synthesized of the ECGs of 67 patients who underwent elective PTCA with prolonged balloon occlusions (mean±SD occlusion duration 214±77s), and computed, during occlusions, the changes of the ST and VG vectors with respect to baseline, ΔST and ΔVG, and the angle between these vectors, ∠(ΔST, ΔVG). We then analyzed directionality and proportionality of ΔST and ΔVG by performing linear regressions of ∠(ΔST, ΔVG) on time after occlusion, and of ΔVG on ΔST, respectively.

RESULTS

Linear regression of ∠(ΔST, ΔVG) on time after occlusion yielded a slope of 1.55*10(-3) °/s and an intercept of 11.96°; r(2)<0.001 (NS). Linear regression of ΔVG on ΔST on all data yielded a slope of 253mV and an intercept of 14.4mV•ms; r(2)=0.75 (P<0.001). Broken stick linear regression (breakpoint ΔST=0.255mV) yielded slopes of 330mV and 160mV, intercepts of 5.6mV•ms and 47.2mV•ms, and r(2) values of 0.66 (P<0.001) and 0.63 (P<0.001) for the smaller and larger ΔST values, respectively.

CONCLUSION

Our study suggests that, because of the directionality and proportionality between ΔST and ΔVG, the change in the ventricular gradient, ΔVG, between a reference ECG and an ischemic ECG is a meaningful measure of ischemia.

Are the guidelines for treatment of myocardial infarction complied with?

BACKGROUND

New guidelines recommend early invasive evaluation and treatment for most patients with acute myocardial infarction--including patients with myocardial infarction without ST elevation in the ECG. This study examines compliance with the new guidelines at Sørlandet Hospital Arendal.

MATERIAL AND METHOD

All patients admitted to Sørlandet Hospital Arendal with acute myocardial infarction in 2012 were registered in the Norwegian Myocardial Infarction Register. Data from the register were used to analyse the time that passed from symptom onset to coronary angiography and revascularisation.

RESULTS

In 2012, 788 patients were admitted to Sørlandet Hospital Arendal with acute myocardial infarction. Of these, 269 (34.1%) had ST elevation mycardial infarction (STEMI) and 519 (65.9%) had non-ST elevation myocardial infarction (NSTEMI). Most patients with ST elevation infarction (220 (81.8%)) were admitted directly to Sørlandet Hospital Arendal, and the median time from admission to revascularisation was 31 minutes. 347 (66.9%) of the patients with non-ST elevation infarction were first admitted to a local hospital before being transferred to Sørlandet Hospital Arendal. Only four (1.2%) of them underwent angiography within two hours of admission to the first hospital. 13 (9.0%) of the patients with non-ST elevation infarction who were admitted directly and underwent angiography (n = 144) had an angiogram within two hours of admission. Angiography was performed within 24 hours in 119 (34.3%) of those transferred (n = 347) and in 82 (56.9%) of the directly admitted patients who underwent angiography (n = 144).

INTERPRETATION

Many patients with non-ST elevation infarction did not receive revascularisation with percutaneous coronary intervention (PCI) within the recommended time frame. Where there is a strong clinical suspicion of acute myocardial infarction, more patients should be admitted directly to hospitals with PCI preparedness.

Left bundle branch block without concordant ST changes is rarely associated with acute coronary occlusion

BACKGROUND

The Sgarbossa score has been used to identify acute myocardial infarction on ECG in the presence of LBBB but has relied on elevated CK-MB for validation rather than angiographic evidence of vessel occlusion.

METHODS

We determined (a) the presence or absence of Sgarbossa criteria with concordant (S-con) or discordant (S-dis) ST changes, (b) the presence of acute coronary occlusion or likely recent occlusion on angiography and (c) the biochemical evidence of myocardial infarction (Troponin T >0.10 μg/L, Troponin I >1.0 μg/L) in patients field-triaged with suspected AMI and LBBB.

RESULTS

Between April 2004 and March 2009, 102 patients had field ECGs transmitted by paramedics for triage--8 with S-con, 26 with S-dis and 68 with LBBB alone. Acute coronary occlusion was present in 8/8 with S-con but none of the S-dis or LBBB alone patients, and in all 8 S-con patients reperfusion resulted in resolution of S-con changes. Likely culprit lesions with TIMI 3 flow were found in 3 S-dis patients but stenting did not result in resolution of S-dis. LBBB did not resolve in any patient. Troponin was elevated in 26 patients--11 with occlusion or likely culprit lesions, 15 with non-ischaemic causes.

CONCLUSIONS

In the absence of S-con, LBBB is not associated with acute coronary occlusion and should not be used as criteria for reperfusion therapy in myocardial infarction.

Mitral annular displacement by Doppler tissue imaging may identify coronary occlusion and predict mortality in patients with non-ST-elevation myocardial infarction

BACKGROUND

Mitral annular displacement (MAD) is a simple marker of left ventricular (LV) systolic function. The aim of this study was to test the hypothesis that MAD can distinguish patients with non-ST-segment elevation myocardial infarctions (NSTEMIs) from those with significant coronary artery disease without infarctions, identify coronary occlusion, and predict mortality in patients with NSTEMIs. MAD was compared with established indices of LV function.

METHODS

In this retrospective study, 167 patients with confirmed NSTEMIs were included at two Scandinavian centers. Forty patients with significant coronary artery disease but without myocardial infarctions were included as controls. Doppler tissue imaging was performed at the mitral level of the left ventricle in the three apical planes, and velocities were integrated over time to acquire MAD. LV ejection fraction, global longitudinal strain (GLS), and wall motion score index were assessed according to guidelines.

RESULTS

MAD and GLS could accurately distinguish patients with NSTEMIs from controls. During 48.6 ± 12.1 months of follow-up, 22 of 167 died (13%). MAD, LV ejection fraction, and GLS were reduced and wall motion score index was increased among those who died compared with those who survived (P < .001, P < .001, P < .001, and P = .02, respectively). Multivariate Cox proportional-hazards analyses revealed that MAD was an independent predictor of death (hazard ratio, 1.36; 95% confidence interval, 1.07-1.73; P = .01). MAD and GLS were reduced and wall motion score index was increased in patients with coronary artery occlusion compared with those without occlusion (P = .006, P = .001, and P = .02), while LV ejection fraction did not differ (P = .20).

CONCLUSIONS

MAD accurately identified patients with NSTEMIs, predicted mortality, and identified coronary occlusion in patients with NSTEMIs.

High incidence of acute coronary occlusion in patients without protocol positive ST segment elevation referred to an open access primary angioplasty programme

BACKGROUND

Primary percutaneous coronary intervention (PPCI) programmes vary in admission criteria from open referral to acceptance of electrocardiogram (ECG) protocol positive patients only. Rigid criteria may result in some patients with acutely occluded coronary arteries not receiving timely reperfusion therapy.

OBJECTIVE

To compare the prevalence of acute coronary occlusion and, in these cases, single time point biomarker estimates of myocardial infarct size between patients presenting with protocol positive ECG changes and those presenting with less diagnostic changes in the primary angioplasty cohort of an open access PPCI programme.

METHODS

We retrospectively performed a single centre cross sectional analysis of consecutive patients receiving PPCI between January and August 2008. Cases were categorised according to presenting ECG-group A: protocol positive (ST segment elevation/left bundle branch block/posterior ST elevation myocardial infarction), group B: ST segment depression or T-wave inversion, or group C: minor ECG changes. Clinical characteristics, coronary flow grades and 12 h postprocedure troponin-I levels were reviewed.

RESULTS

During the study period there were 513 activations of the PPCI service, of which 390 underwent immediate angiography and 308 underwent PPCI. Of those undergoing PPCI, 221 (72%) were in group A, 41 (13%) in group B and 46 (15%) in group C. Prevalence of coronary occlusion was 75% in group A compared with 73% in group B and 63% in group C. Median 12 h postintervention troponin-I (25th-75th percentile) for those with coronary occlusion was significantly higher in group A patients; 28.9 μg/l (13.2-58.5) versus 18.1 μg/l (6.7-32.4) for group B (p=0.03); and 15.5 μg/l (3.8-22.0) for group C (p<0.001), suggesting greater infarct size in group A.

CONCLUSIONS

A number of patients referred to an open access PPCI programme have protocol negative ECGs but myocardial infarction and acute coronary artery occlusion amenable to angioplasty.

Correlation between acute coronary syndrome classification and multi-detector CT characterization of plaque

OBJECTIVE

To determine if multi-detector CT (MDCT) characterization of plaque is correlated with the classification of acute coronary syndrome (ACS).

METHODS

Altogether 1900 patients were examined by MDCT from December 2007 to May 2009, of whom 95 patients fulfilled the criteria of ACS. Those patients were divided into the discrete plaque group ( n=61) and diffuse plaque group ( n=34) based on the findings in MDCT. The clinical diagnosis of ACS and CT results were analyzed, including segment stenosis score, segment involvement score, 3-vessel plaque score, left main score, calcification score, and remodeling index. The incidences of major adverse cardiac events in follow-up period were also recorded.

RESULTS

The patients of the diffuse plaque group were older than those of the discrete plaque group ( Pü0.0001). The diffuse plaque group presented more cases of hypertension, peripheral artery disease, diabetes, and heart failure than discrete plaque group (all P<0.05). All the 5 patients with ST-segment elevation myocardial infarction were found in discrete plaque group. The segment stenosis score of the discrete plaque group was lower than that of the diffuse plaque group(5.15±3.55 vs. 14.91±5.37, Pü0.001). The other four scores demonstrated significant inter-group difference as well (all P<0.05). The remodeling index of thediscrete plaque group was higher (1.12±0.16 vs.0.97±0.20, Pü0.05). Follow-up data showed that major adverse cardiac events occurred more frequently in diffuse plaque group than in discrete group (29.41% vs. 11.48%, P=0.0288).

CONCLUSIONS

Characteristics of discrete and diffuse plaques may be significantly different among different classes of ACS. The diffuse plaque may present higher risk, correlated to higher mortality. The diagnosis of discrete and diffuse plaques by MDCT would provide a new insight into the prognosis and treatment of ACS.

Comparison of angiographic and other findings and mortality in non-ST-segment elevation versus ST-segment elevation myocardial infarction in patients undergoing early invasive intervention

We sought to compare the angiographic findings and mortality in patients with non-ST-segment elevation (NSTEMI) versus ST-segment elevation myocardial infarction (STEMI) undergoing early invasive intervention. Of 11,872 patients enrolled in the Korean Acute Myocardial Infarction Registry from November 2005 to January 2008, we studied patients with NSTEMI undergoing early invasive intervention (n = 1,486) and those with STEMI undergoing primary percutaneous coronary intervention (n = 4,392). Multivessel coronary disease, baseline Thrombolysis In Myocardial Infarction (TIMI) flow grade 3, and the left circumflex artery as a culprit lesion occurred more frequently in patients with NSTEMI than in those with STEMI. Those with NSTEMI had a significantly lower mortality rate than those with STEMI during a median follow-up of about 12 months (3.8% vs 6.7%, p <0.001). In the patients with NSTEMI, the independent predictors of mortality included postprocedural TIMI flow grade 0 to 2 (hazard ratio [HR] 3.07, 95% confidence interval [CI] 1.01 to 9.29, p = 0.047) and multivessel coronary disease (HR 3.83, 95% CI 1.36 to 10.81, p = 0.010) but not baseline TIMI flow or infarct location. However, baseline TIMI flow grade 0 to 2 (HR 1.56, 95% CI 1.03 to 2.36, p = 0.035), anterior infarction (HR 1.69, 95% CI 1.28 to 2.23, p <0.001), multivessel coronary disease (HR 1.45, 95% CI 1.10 to 1.91, p = 0.008), and postprocedural TIMI flow grade 0 to 2 (HR 2.00, 95% CI 1.42 to 2.82, p <0.001) were all independent predictors of mortality in the patients with STEMI. In conclusion, the angiographic findings in patients from NSTEMI differ from those in patients with STEMI. Postprocedural TIMI flow and multivessel coronary disease were independent predictors of mortality in patients with NSTEMI undergoing early invasive intervention.