Definition Of Acute Myocardial Infarction Research Articles

Chest pain in patients with cancer: prevalence of myocardial infarction and diagnostic performance of high-sensitivity cardiac troponin T/I

Abstract Background Among patients with active or past cancer presenting with acute chest discomfort to the emergency department (ED), multiple uncertainties remain regarding the prevalence of acute myocardial infarction (AMI), outcomes, and the diagnostic utility of recommended diagnostic tools. Purpose We aimed to evaluate 1) the prevalence of AMI among consecutive patients with a history of cancer presenting with acute chest pain to the ED; 2) time to discharge from the ED and hospitalization rate; 3) the diagnostic accuracy of 34 predefined chest pain characteristics (CPCs) and ECG signatures; 4) the diagnostic accuracy of hs-cTnT and hs-cTnI concentrations; and 5) the performance of the European Society of Cardiology (ESC) 0/1h-hs-cTnT/I algorithms. Methods Patients presenting with chest pain to the ED were prospectively enrolled in an international multicenter diagnostic study. Cancer status was prospectively assessed. Final diagnosis was centrally adjudicated by two independent cardiologists, applying the 4th universal definition of AMI. Findings were externally validated in an independent, multicenter cohort. Results Among 8267 patients, 711 (8.6%) had cancer. Cancer patients had a higher burden of cardiovascular risk factors and preexisting cardiac disease, and more often a final diagnosis of AMI (184 [26%] patients with cancer vs 1562 [21%, P<0.001] without cancer). This difference was largely due to a significantly higher proportion of NSTEMIs in cancer patients (23% vs 17%; p<0.001). Total length of stay in the ED was significantly longer in patients with cancer versus those without (5.2h versus 4.3h, p<0.001). The hospitalization rate was higher in cancer patients (49.8%) than in non-cancer patients (34.3%, P<0.001), driven by non-AMI diagnoses (36.3% vs 21.3%, P<0.001). All-cause mortality at 5-years was 34.4% in patients with cancer versus 8.9% in patients without cancer (P<0.001). In cancer patients, high-sensitivity cardiac troponin (hs-cTn) T, but not hs-cTnI, concentrations had lower diagnostic accuracy for NSTEMI versus those without cancer (hs-cTnT area under the receiver-operating characteristics curve 0.89 [95%CI 0.86-0.92] vs 0.94 [95%CI 0.93-0.94], p<0.001). In cancer patients, the ESC 0/1h-hs-cTnT/I-algorithms maintained a very high safety but had lower efficacy with significantly more patients remaining in the observe zone (with hs-cTnT: 39.0% vs 20.0%, P<0.001). Similar findings were obtained in the external validation cohort. Conclusions Patients with current or past cancer have a substantially higher prevalence of AMI as the cause of acute chest pain. Time to discharge from the ED and the rate of hospitalization are increased, mainly due to non-AMI causes. The diagnostic performance of hs-cTnT/I and the efficacy of the ESC 0/1-h-hs-cTnT/I-algorithms is reduced.

Abstract 12920: Double Peak of Cardiac Troponin T in Non ST-Segment Elevation Myocardial Infarction

Introduction: cardiac biomarkers are the cornerstone of the biological definition of acute myocardial infarction. In previous literature it was shown that hs-Troponin T blood assay follows a typical biphasic kinetic in patients (pts) affected by ST segment elevation myocardial infarction (STEMI), treated by primary percutaneous coronary intervention (PCI), while this does not appear to be the case for creatinphosphokinase (CPK) and hs-Troponin I assays. Hypothesis: According to these previous data, we studied hs-troponin T and CPK kinetics in pts suffering from non-ST segment elevation myocardial infarction (NSTEMI). Methods: we retrospectively analysed blood samples for cardiac biomarkers in NSTEMI pts consecutively admitted to the coronary care unit of our institution from January 2022 to May 2023. Results: A total of 83 pts were included. 89% of pts were treated by PCI; 98% of these pts received PCI within 24 hours from hospital admission. Among the 83 enrolled pts, only 11% was treated by surgical revascularization and/or anti-ischemic pharmacological therapy. A double peak of hs-troponin T was observed only in pts treated by PCI (p=0,0001). In these pts the mean time to first hs-troponin T peak was at 35,84 ± 4,4 hours while the mean time to second hs-troponin T peak was at 78,62 ± 8,7 hours. CPK value at hospital admission was 208,6 ± 34,8 U/L while first hs-troponin T peak was 560,1 ± 112,9 ng/L; the second hs-troponin T peak was 240,3 ± 33,7 ng/L, in absence of CPK double peak. Conclusions: similarly to previous studies in STEMI pts, our data confirm the presence of hs-troponin T double peak, in the absence of CPK second dispersion, also in NSTEMI pts. The hs-troponin T second peak is strongly related to PCI procedure while pts undergoing conservative treatment or surgical coronary revascularization do not show such a kinetic. Another interesting issue is the absence of CPK second dispersion. This could suggest a potential trivial meaning of hs-troponin T second peak. Therefore, the second peak could not be of any significance for prognostic evaluation and appropriate timing of pts discharge from acute cardiac care units.

Do Chest Pain Characteristics in Patients with Acute Myocardial Infarction Differ between Those with and without Obstructive Coronary Artery Disease?

The universal definition of acute myocardial infarction (MI) requires both evidence of myocardial injury and myocardial ischaemia. In MINOCA (MI with non-obstructive coronary arteries), patients must fulfil this MI criteria, but is their chest pain similar to those who have MI with obstructive CAD (MICAD)? This study compares prospectively collected chest pain features between patients with MINOCA and MICAD. Utilising the Coronary Angiogram Database of South Australia (CADOSA), consecutive MI patients were categorized as MINOCA or MICAD based on angiographic findings. Chest pain data were collected via direct patient interviews by trained staff members. Of 6811 consecutive patients fulfilling a clinical MI diagnosis, 411 (6.0%) were MINOCA, and 5948 MICAD. The MINOCA patients were younger, more often female and had less cardiovascular risk factors than those with MICAD. There were no significant differences in chest pain characteristics between the MINOCA and MICAD cohorts in relation to pain location, quality, associated symptoms, or duration. In conclusion, MINOCA patients have chest pain characteristics that are indistinguishable from MICAD patients, suggesting that their pain is ischaemic in nature. Thus, in the presence of positive myocardial injury markers, ischaemic chest pain fulfils the universal criteria for MI, despite the absence of obstructive coronary artery disease.

Perioperative Acute Myocardial Infarction and Ischemia After Noncardiac Surgery: Pathophysiology, Prevention, and Nursing Implications.

Perioperative acute myocardial infarction (AMI) after noncardiac surgery increases the mortality rate of patients who experience it. Depending on the definition of AMI used and the patient population studied, perioperative AMI occurs in 0.01% to 10% of patients. Most instances of perioperative AMI occur within the first two days after surgery, do not present with classic myocardial infarction symptoms, and are the result of myocardial oxygen supply versus oxygen demand mismatch. Older patients; those with preexisting cardiovascular conditions; those undergoing thoracic, upper abdominal, or major vascular procedures; and those who experience perioperative hemodynamic instability are at particular risk. This article provides a clinically based review of the pathophysiology, perioperative risks, treatment options, outcomes, and nursing implications of perioperative AMI and ischemia. It provides evidence to assist perioperative nurses with meeting the physiologic and safety needs of their patients and highlights the evolving scientific understanding and clinical guidelines to promote current practice.

Accuracy of the European Society of Cardiology 0/1-, 0/2-, and 0/3-hour algorithms for diagnosing acute myocardial infarction.

Accuracy of the European Society of Cardiology 0/1-, 0/2-, and 0/3-hour algorithms for diagnosing acute myocardial infarction.

Major adverse cardiovascular event definitions used in observational analysis of administrative databases: a systematic review

BackgroundMajor adverse cardiovascular events (MACE) are increasingly used as composite outcomes in randomized controlled trials (RCTs) and observational studies. However, it is unclear how observational studies most commonly define MACE in the literature when using administrative data.MethodsWe identified peer-reviewed articles published in MEDLINE and EMBASE between January 1, 2010 to October 9, 2020. Studies utilizing administrative data to assess the MACE composite outcome using International Classification of Diseases 9th or 10th Revision diagnosis codes were included. Reviews, abstracts, and studies not providing outcome code definitions were excluded. Data extracted included data source, timeframe, MACE components, code definitions, code positions, and outcome validation.ResultsA total of 920 articles were screened, 412 were retained for full-text review, and 58 were included. Only 8.6% (n = 5/58) matched the traditional three-point MACE RCT definition of acute myocardial infarction (AMI), stroke, or cardiovascular death. None matched four-point (+unstable angina) or five-point MACE (+unstable angina and heart failure). The most common MACE components were: AMI and stroke, 15.5% (n = 9/58); AMI, stroke, and all-cause death, 13.8% (n = 8/58); and AMI, stroke and cardiovascular death 8.6% (n = 5/58). Further, 67% (n = 39/58) did not validate outcomes or cite validation studies. Additionally, 70.7% (n = 41/58) did not report code positions of endpoints, 20.7% (n = 12/58) used the primary position, and 8.6% (n = 5/58) used any position.ConclusionsComponents of MACE endpoints and diagnostic codes used varied widely across observational studies. Variability in the MACE definitions used and information reported across observational studies prohibit the comparison, replication, and aggregation of findings. Studies should transparently report the administrative codes used and code positions, as well as utilize validated outcome definitions when possible.

WHAT IS STRESS HYPERGLYCEMIA? A SUGGESTION FOR AN IMPROVEMENT OF ITS DEFINITION.

Stress hyperglycemia has been studied in numerous critical illnesses for several decades. Despite the extensive accumulation of knowledge about this topic, the definition of stress hyperglycemia is not updated since 2007. We performed a narrative review about stress hyperglycemia in acute myocardial infarction (AMI), aiming to improve its current definition and to give evidence supporting this. The definition of stress hyperglycemia in 2021 we recommend is: "SH is a high ABGly in an AMI patient irrespective of DM status. It can be calculated as e.g., "stress hyperglycemia ratio" or "admission glucose delta"/"glycemic gap". This definition may serve to start a consensus document of the experts in the field. The evidence accumulates supporting the possibility to recognize stress hyperglycemia also in AMI patients with diabetes mellitus (DM) by calculating glycemia during the previous 2-3 months using glycated hemoglobin. Moreover, it is now obvious that 2007 definition of stress hyperglycemia did not take into account the necessity to separate cut-offs for the subgroups with vs. without DM. We demonstrated the insufficiency of the current 2007 definition of stress hyperglycemia, provided evidence-based recommendation for the improvement and suggested the need for a consensus of the experts on this topic. In order to optimize the treatment of stress hyperglycemia in numerous critical illnesses, we ought to have its universal definition (as we already have the universal definition of AMI).

Management of myocardial infarction with Nonobstructive Coronary Arteries (MINOCA): a subset of acute coronary syndrome patients.

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) represents a significant proportion (up to 15%) of acute myocardial infarction (AMI) population. MINOCA is diagnosed in patients who fullfilled the fourth universal definition of AMI in the absence of significant obstructive coronary artery disease on coronary angiography. MINOCA is a group of heterogeneous diseases with different pathophysiological mechanisms requiring multimodality imaging. Left ventriculography, cardiac magnetic resonance imaging and intra-coronary imaging (IVUS, OCT) are useful tools playing a pivotal role in the diagnostic work-up. There are no standard guidelines on the management of MINOCA patients and the therapeutic approach is personalized, thereby detecting the underlying aetiology is fundamental to initiate an early appropriate cause-targeted therapy.

Clinical presentation of patients with prior coronary artery bypass grafting and suspected acute myocardial infarction.

Diagnosis of acute myocardial infarction (AMI) can be challenging in patients with prior coronary artery bypass grafting (CABG). Final diagnoses were adjudicated by two independent cardiologists using the universal definition of AMI among patients presenting to the emergency department (ED) with suspected AMI. Diagnostic accuracy of 34 chest pain characteristics (CPCs) and four electrocardiogram (ECG) signatures stratified according to the presence or absence of prior CABG were prospectively quantified. Among 4015 patients (no prior CABG: n = 3686; prior CABG: n = 329), prevalence of AMI and unstable angina were higher in patients with prior CABG (35% vs. 18%; 26% vs. 8%; both P < 0.001). Three CPCs (9%) and two electrocardiographic findings (50%) showed a different diagnostic performance (interaction P < 0.05) with loss of diagnostic value in patients with prior CABG. The diagnostic accuracy as quantified by the area under the curve (AUC) of the integrated clinical judgement was moderate to good in patients with prior CABG, and significantly lower compared to patients without prior CABG [AUC 0.80 (95% confidence interval (CI) 0.75-0.84) vs. AUC 0.87 (95% CI 0.86-0.89); P = 0.004]. Time to discharge from the ED was significantly longer in patients with prior CABG [359 (215-525) min vs. 300 (192-435) min; P < 0.001]. Key findings were confirmed in a large independent external validation cohort (n = 13653). Patients with prior CABG presenting with suspected AMI have a high prevalence of AMI and unstable angina and lower diagnostic accuracy of CPCs and the ECG, possibly justifying liberal use of early coronary angiography in these vulnerable patients. Number NCT00470587.

Baseline High Sensitivity Cardiac Troponin I Level Below Limit of Quantitation Rules Out Acute Myocardial Infarction in the Emergency Department.

The objective of our study was to determine the utility of a baseline high sensitivity cardiac troponin (hs-cTnI) value below the limit of quantitation to rule-out acute myocardial infarction (AMI) in patients presenting to the emergency department (ED) with any suspicious symptoms of a cardiac etiology. We enrolled subjects presenting to the ED with symptoms suspicious for AMI. Blood specimens were collected within 1 hour after a triage electrocardiogram. Cardiac troponin I was measured using the Beckman Coulter Access hs-cTnI assay. The diagnosis of AMI was adjudicated by 2 cardiologists using the Third Universal Definition of AMI and Roche Diagnostics Troponin T Generation 5 assay with all available clinical data at 30 days after presentation. A total of 567 subjects had all data required for data analyses. AMI was diagnosed in 46 (8.1%) patients. Two hundred thirty-two (40.9%) individuals had presentation hs-cTnI results <4.0 ng/L. None of the patients with baseline hs-cTnI <4.0 ng/L had an AMI, yielding a negative predictive value of 100.0% and a sensitivity of 100%, and a good prognosis (no AMIs or cardiac-related deaths at 30 days). In this single-center ED study, a baseline presenting novel hs-cTnI value of <4.0 ng/L effectively ruled out AMI in 40.9% of all patients presenting to the ED and having any symptoms suspicious for AMI. Importantly all patients, not only those with chest pain, and those having symptoms for any duration or those with end-stage renal disease requiring dialysis were included.

P4147Declining risk of heart failure hospitalisation following first acute myocardial infarction in Scotland between 1990 and 2015

Abstract Background Mortality from acute myocardial infarction (AMI) has declined, increasing the pool of survivors at risk of later development of heart failure (HF). However, coronary reperfusion limits infarct size and secondary prevention therapy has improved. In light of these competing influences on risk of HF, we have examined long-term trends in incident HF hospitalisation (HFH) after AMI in a long-term, nationwide study with a single healthcare provider. Purpose To describe temporal trends in the risk of HFH following first AMI occurring in Scotland over a 26 year period. Methods All patients in Scotland discharged alive after a first AMI between 1990 and 2015 were followed until a first HFH or death until the end of 2016 (minimum follow-up 1 year, maximum 27 years). The cumulative incidence of HF was estimated at 1, 5 and 10 years following MI, accounting for the competing risk of death, with adjustment for comorbidities, age, sex and socioeconomic deprivation. In a sensitivity analysis, rates of HFH by AMI type (ST elevation MI [STEMI], non-STEMI and unknown ST type) were calculated for the period 2012 to 2015. Results A total of 184,826 people with no prior history of HF were discharged alive after a first AMI during the period of study. 23,414 (12.7%) had a first HFH during a median follow-up time of 6.8 years. Accounting for the competing risk of death, the cumulative incidence of first HFH, at 1 year, fell between 1990 and 2015 from 5.0% to 2.9%; the 5 year risk fell from 10.4% to 5.8%; 10 year risk from 14.8% to 9.0% (Figure). The adjusted risk of HFH at 1 year after discharge fell by 55% (95% CI 49–60%). The adjusted 5 year risk of HFH fell by 57% (95% CI 53–60%) and 10 year risk fell by 53% (95% CI 50–57%). The adjusted risk of death after first MI fell at 1 year (44%; 95% CI 39–48%), 5 years (37%; 34–39%) and 10 years (34%; 31–36%). The 10 year risk of HF following AMI was higher in older individuals (&lt;55 years vs. ≥85 years HR 3.31; 95% CI 3.08–3.55), if there was HF complicating the index admission (HR 2.14; 95% CI 2.07–2.22), in patients with diabetes (HR 1.77; 95% CI 1.70–1.84), renal disease (HR 1.40; 95% CI 1.32–1.49), atrial fibrillation (HR 1.37; 95% CI 1.31–1.43), and in those not undergoing coronary revascularisation within 30 days of AMI (HR 1.36; 95% CI 1.29–1.43). Similar results were seen at 1 and 5 years. In the sensitivity analysis 2012–2015, the overall rate of HF following STEMI, non-STEMI, and unknown MI type was similar (4.0%, 6.5% and 6.7% respectively). Figure 1 Conclusion Despite an increasing pool of survivors of AMI at risk of HF, the incidence of HF hospitalisation following AMI in Scotland has consistently decreased since 1990. This is despite changes in the treatment and definition of AMI. These trends suggest that better treatment of MI and secondary prevention are having an impact on the risk of HF at a population level. Acknowledgement/Funding This study was funded by an NHS Greater Glasgow and Clyde endowment fund award (GN17CA406)

Contemporary Diagnosis and Management of Patients With Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease: A Scientific Statement From the American Heart Association.

Myocardial infarction in the absence of obstructive coronary artery disease is found in ≈5% to 6% of all patients with acute infarction who are referred for coronary angiography. There are a variety of causes that can result in this clinical condition. As such, it is important that patients are appropriately diagnosed and an evaluation to uncover the correct cause is performed so that, when possible, specific therapies to treat the underlying cause can be prescribed. This statement provides a formal and updated definition for the broadly labelled term MINOCA (incorporating the definition of acute myocardial infarction from the newly released "Fourth Universal Definition of Myocardial Infarction") and provides a clinically useful framework and algorithms for the diagnostic evaluation and management of patients with myocardial infarction in the absence of obstructive coronary artery disease.

A New Definition of Acute Myocardial Infarction – Changing Perspectives in Acute Cardiac Care

A New Definition of Acute Myocardial Infarction – Changing Perspectives in Acute Cardiac Care

“It Was the Best of Times, It Was the Worst of Times”: Cardiovascular Disease and Troponins

<h3>ABSTRACT</h3> There have been significant changes in the diagnosis and definition of acute myocardial infarction over the years. From its first description and definition over 150 years ago to the high-sensitivity cardiac troponin assays of today, we have come a long way in the diagnosis, management, and treatment of those with cardiovascular disease. With the recent United States Food and Drug Administration’s clearance of the fifth-generation high-sensitivity cardiac troponin assays, a new history in diagnosing, treating, and managing those with heart disease is just beginning. The three articles associated with this FOCUS series described advances in diagnosis and definition of acute myocardial infarction (AMI), with the first article presenting an in-depth description into the structure and function of troponin in health and disease, a second article presenting a description of AMI and how its diagnosis and definition has changed over the years culminating with a description of the highly sensitive troponin assays, and a third article presenting clinical implications of the new high-sensitivity troponin assays.

The Case for Takotsubo Cardiomyopathy (Syndrome) as a Variant of Acute Myocardial Infarction

The Case for Takotsubo Cardiomyopathy (Syndrome) as a Variant of Acute Myocardial Infarction

P103: Performance characteristics of the modified Sgarbossa criteria for diagnosis of acute coronary occlusion in emergency department patients with ventricular paced rhythm and symptoms of acute coronary syndrome

Introduction: The ECG diagnosis of acute coronary occlusion (ACO) in the setting of ventricular paced rhythm (VPR) is purported to be impossible. However, VPR has a similar ECG morphology to LBBB. The validated Smith-modified Sgarbossa criteria (MSC) have high sensitivity (Sens) and specificity (Spec) for ACO in LBBB. MSC consist of 1 of the following in 1 lead: concordant ST Elevation (STE) 1 mm, concordant ST depression 1 mm in V1-V3, or ST/S ratio &lt;−0.25 (in leads with 1 mm STE). We hypothesized that the MSC will have higher Sens for diagnosis of ACO in VPR when compared to the original Sgarbossa criteria. We report preliminary findings of the Paced Electrocardiogram Requiring Fast Emergency Coronary Therapy (PERFECT) study Methods: The PERFECT study is a retrospective, multicenter, international investigation of ED patients from 1/2008 - 12/2016 with VPR on the ECG and symptoms suggestive of acute coronary syndrome (e.g. chest pain or shortness of breath). Data from four sites are presented. Acute myocardial infarction (AMI) was defined by the Third Universal Definition of AMI. A blinded cardiologist adjudicated ACO, defined as thrombolysis in myocardial infarction score 0 or 1 on coronary angiography; a pre-defined subgroup of ACO patients with peak cardiac troponin (cTn) &gt;100 times the 99% upper reference limit (URL) of the cTn assay was also analyzed. Another blinded physician measured all ECGs. Statistics were by Mann Whitney U, Chi-square, and McNemars test. Results: The ACO and No-AMI groups consisted of 15 and 79 encounters, respectively. For the ACO and No-AMI groups, median age was 78 [IQR 72-82] vs. 70 [61-75] and 13 (86%) vs. 48 (61%) patients were male. The median peak cTn ratio (cTn/URL) was 260 [33-663] and 0.5 [0-1.3] for ACO vs. no-AMI. The Sens and Spec for the MSC and the original Sgarbossa criteria were 67% (95%CI 39-87) vs. 46% (22-72; p=0.25) and 99% (92-100) vs. 99% (92-100; p=0.5). In pre-defined subgroup analysis of ACO patients with peak cTn &gt;100 times the URL (n=10), the Sens was 90% (54-100) for the MSC vs. 60% (27- 86) for original Sgarbossa criteria (p=0.25). Conclusion: ACO in VPR is an uncommon condition. The MSC showed good Sens for diagnosis of ACO in the presence of VPR, especially among patients with high peak cTn, and Spec was excellent. These methods and results are consistent with studies that have used the MSC to diagnose ACO in LBBB.

The classification of acute myocardial infarction types and the preconditions for its development. Type II myocardial infarction

The article presents the concept of myocardial infarction of the second type in the context of the universal definition of acute myocardial infarction. The problem of differential diagnosis for heart attacks first vs. the second types is discussed.

Non-gated high-pitch computed tomography aortic angiography: Myocardial perfusion defects in patients with suspected aortic dissection

ObjectivesTo investigate the diagnostic value of first-pass myocardial perfusion defects visualised in non-gated high-pitch computed tomography angiography (CTA) in patients admitted to the emergency department (ED) for suspected aortic dissection. MethodsWe recruited 174 ED patients who underwent high-pitch CTA of the aorta because of suspected aortic dissection. We divided these patients into two groups (diseased and control groups) based on whether their clinical data fulfilled the third universal definition of acute myocardial infarction (AMI), specifically an increase in cardiac troponin (cTn) with at least one of the following: (a) symptoms of ischemia; (b) new ST-segment-T wave (ST-T) changes or new left bundle branch block (LBBB); (c) development of pathological Q wave; (d) new loss of viable myocardium or new regional wall motion abnormality; or (e) identification of an intracoronary thrombus by angiography or autopsy. Twenty-two patients with a clinical diagnosis of AMI were placed in the diseased group. Myocardial perfusion defects were evaluated qualitatively and quantitatively on the late arterial phase obtained 50 s post-threshold. ResultsOf the 22 patients with a final diagnosis of AMI, visually identifiable perfusion defects were observed in 12 patients. The sensitivity, specificity, negative predictive value, and positive predictive value of any perfusion defect for predicting AMI were 54.6%, 94.7%, 93.5%, and 60.0%, respectively. Quantitative analysis indicated that CT attenuation was significantly lower within perfusion defects than within the normal myocardium (67.6 ± 29.5 HU vs. 92.2 ± 19.7 HU; p < 0.001). ConclusionsIn patients with acute chest pain, the presence of myocardial perfusion defect observed on nongated high-pitch CTA of the aorta can be used to identify individuals with AMI with high specificity, but low sensitivity.

Lowering the bar of high-sensitivity cardiac troponin: more than limbo dancing?

To discharge or not to discharge remains one of the most common and contentious questions emergency department (ED) physicians are confronted with in patients presenting with acute chest pain. The success story of contemporary high-sensitivity cardiac troponin (hs-cTn) assays is remarkable and had great impact on this question: Biomarkers for the diagnosis of acute myocardial infarction (AMI) were first introduced in the 1960s with the use of aspartate transaminase (AST) which was also incorporated into the World Health organization (WHO) definition of AMI (1,2).

Abstract 129: Chest Pain Characteristics of Myocardial Infarction With Non-Obstructive Coronary Arteries (MINOCA) in Comparison to Myocardial Infarction With Coronary Artery Disease (MI-CAD)

Background: Myocardial infarction with non-obstructive coronary arteries (MINOCA) is being increasingly recognized with the frequent use of angiography following Acute Myocardial Infarction (AMI); yet there is little evaluation of these patients in the literature. The current study is a prospective, contemporary analysis of clinical features and chest pain characteristics between patients with MINOCA and Myocardial Infarction with coronary artery disease (MI-CAD). Methods: All consecutive patients undergoing coronary angiography for AMI (as per the Third Universal AMI Definition) in South Australian public hospitals from January 2012 - December 2013 were included. Data was captured by Coronary Angiogram Database of South Australia (CADOSA), a comprehensive registry compatible with the NCDR ® CathPCI ® Registry. The AMI patients were classified as MI-CAD or MINOCA on the basis of the presence or absence of a significant stenosis (≥50%) on angiography. Results: From 3,431 angiography procedures undertaken for AMI, 359 (11%) were classified as MINOCA. MINOCA patients were younger (59 ± 15 vs. 64 ± 13, p &lt;0.01) and more likely to be female (60% vs. 26%, p&lt;0.01), with age adjusted analysis revealing less cardiovascular risk factors in MINOCA compared to MICAD: current smoker (21% vs. 35%, p&lt; 0.01), hypertension (56% vs. 65%, p&lt;0.01), dyslipidaemia (46% vs. 61%, p&lt;0.01), and diabetes (20% vs. 32%, p&lt;0.01). Analysis of presenting chest pain characteristics showed no significant differences between MICAD and MINOCA for the presence of retrosternal pain (81% vs. 82%, p&gt;0.05,) or shoulder pain (27% vs. 26%, p&gt;0.05) respectively, however MINOCA patients were less likely to experience arm pain (33% vs. 40%, p&lt;0.01). In regards to precipitating factors, emotional stress was more common (14% vs. 5%, p&lt;0.001) and exertion related chest pain was less common (27% vs. 40%, p&lt;0.001) in MINOCA patients. Quality of pain for MINOCA and MICAD was similar with the most frequent descriptors being burning (11% vs. 9%, p&gt;0.05), sharp 21% vs. 23%, p&gt;0.05) and tightness (41% vs. 44%, p&gt;0.05). In addition, there were no significant differences observed between groups in relieving factors and duration of chest pain Conclusions: In contemporary cardiology practice, MINOCA presentation is more common than previously appreciated, with younger women frequently implicated. Delineating a MINOCA patient from MICAD on the basis of chest pain characteristics is not feasible.