Prevalence of acute cardiac disorders in patients with suspected ST-segment elevation myocardial infarction and non-significant coronary artery disease.

BACKGROUND AND PURPOSE: We aimed to study the prevalence of acute cardiac disorders in patients with suspected ST-segment elevation myocardial infarction (STEMI) and non-significant coronary artery disease (CAD). METHODS: From January to October 2012 we consecutively included patients admitted with suspected STEMI and non-significant CAD (coronary artery stenosis diameter <50%). Patients were diagnosed with acute cardiac disorder in the presence of elevated cardiac biomarkers (troponin T >50ng/l or creatine kinase MB >4µg/l) or dynamic ECG changes (ST-segment changes or T-wave inversion). RESULTS: Of the 871 patients admitted with suspected STEMI, 11% (n=95) had non-significant CAD. Of these, 67% (n=64) had elevated cardiac biomarkers or dynamic ECG changes and were accordingly diagnosed with acute cardiac disorders. In the remaining 33% (n=31) of patients, cardiac biomarkers were normal and ECG changes remained stationary. CONCLUSIONS: Acute cardiac disorders were diagnosed in two thirds of patients with suspected STEMI and non-significant CAD.

Left ventricular contractile function after distal protection in primary percutaneous coronary intervention: results from the Drug Elution and Distal Protection in ST-Elevation Myocardial Infarction trial.

BACKGROUND: Coronary intervention (PCI) may result in an increased infarct size. We evaluated the effect of distal protection during PCI for ST-segment elevation myocardial infarction (STEMI) on myocardial function. METHODS: Patients with STEMI were randomly referred within 12 h for PCI with (N = 312) or without distal protection (N = 314). Left ventricular (LV) contractile function was assessed with echocardiography 8 months after PCI. Global LV myocardial wall motion index (WMI) was calculated as the average wall motion score of all myocardial segments. The occurrence of death, nonfatal re-infarction, and stroke 8 months after PCI were also recorded. RESULTS: The occurrence of death, nonfatal re-infarction, and stroke 8 months after PCI was 7.1% after distal protection and 5.7% after conventional treatment (p = 0.17). WMI improved by 4.1% at 8 months in patients treated with distal protection compared to patients receiving conventional PCI (p < 0.01). In myocardium supplied by a culprit artery treated by distal protection regional LV function was 9-11% higher than myocardial regions treated conventionally ( p < 0.02). CONCLUSIONS: Routine use of distal protection during primary PCI is associated with a significant improvement in LV contractile function, with no detectable impact on intermediate term clinical outcome.

Influences of electrocardiographic ischaemia grades and symptom duration on outcomes in patients with acute myocardial infarction treated with thrombolysis versus primary percutaneous coronary intervention: results from the DANAMI-2 trial.

OBJECTIVE: To determine whether ischaemia grade (GI) on the presenting ECG and duration of symptoms can identify subgroups of patients who would derive more benefit than the general population of patients with ST segment elevation acute myocardium infarction (STEMI) from primary percutaneous coronary intervention (pPCI) over thrombolytic treatment (TT) in reducing mortality or reinfarction. METHODS: 1319 DANAMI-2 (Danish trial in Acute Myocardial Infarction-2) patients were classified as having grade 2 ischaemia (GI2; ST segment elevation without terminal QRS distortion) or grade 3 ischaemia (GI3; ST segment elevation with terminal QRS distortion in > or = 2 adjacent leads), and were divided into early and late groups split by the median time (3 h) from symptom onset to treatment. Outcomes were 30-day mortality and reinfarction. RESULTS: Mortality was significantly higher for GI3 than for GI2 (9.7% v 4.8%, p < 0.001) and doubled for patients presenting late (GI2: 6.0% v 3.3%, p = 0.01; GI3: 12.5% v 4.7%, p = 0.05). Overall mortality did not differ significantly between pPCI and TT; however, a 5.5% absolute mortality reduction was seen in GI3 treated early with pPCI (1.4% v 6.9%, p = 0.10). Reinfarction rate was particularly high among GI3 patients presenting late and treated with TT (12.2%). pPCI in such patients significantly reduced the rate of reinfarction (0%, p < 0.001). Logistic regression analysis showed that age (odds ratio (OR) 1.09, 95% confidence interval (CI) 1.06 to 1.12, p < 0.001), prior angina (OR 2.56, 95% CI 1.44 to 4.54, p = 0.001), heart rate (OR 1.03, 95% CI 1.01 to 1.04, p = 0.001) and GI3 (OR 1.91, 95% CI 1.06 to 3.44, p = 0.031) were independently associated with mortality, whereas the sum of ST segment elevation was not. CONCLUSIONS: GI3 is an independent predictor of mortality among patients with STEMI. Mortality increased significantly with symptom duration in both GI2 and GI3. pPCI may be especially beneficial for patients with GI3 presenting early, whereas patients with GI3 presenting late and treated with TT are at particular risk of reinfarction.

Pharmacological modulation of the ATP sensitive potassium channels during repeated coronary occlusions: no effect on myocardial ischaemia or function.

BACKGROUND: Repeated episodes of myocardial ischaemia may lead to ischaemic preconditioning. This is believed to be mediated by the ATP sensitive potassium channels. OBJECTIVE: To examine the effect of pharmacological modulation of the ATP sensitive potassium channels during repeated coronary occlusions. DESIGN: Double blind, double dummy study. METHODS: 38 patients with a proximal stenosis of the left anterior descending coronary artery and no visible coronary collateral vessels underwent three identical 90 second balloon occlusions, each followed by five minutes of reperfusion. The patients were randomised to pinacidil 25 mg, glibenclamide 10.5 mg, or matching placebo 90 minutes before the start of the procedure. Myocardial ischaemia was measured by continuous monitoring of ECG ST segment changes. Changes in left ventricular function were recorded with a miniature radionuclide detector, and angina was scored on the Borg scale. RESULTS: In all patients the first balloon occlusion led to significant ST segment elevation, a clear decrease in left ventricular ejection fraction, and angina pectoris. This response was not attenuated at the second or third balloon occlusion, either in the placebo group or in the patients pretreated with pinacidil or glibenclamide. CONCLUSIONS: Under the given experimental conditions, this randomised and double blind study did not support the view that the human myocardium has an intrinsic protective mechanism that is activated by short lasting episodes of ischaemia.

Platelet serotonin transporter in stroke patients.

OBJECTIVES: Post-stroke depression can be treated with serotonin transport inhibitors suggesting a role for the serotonin system in these patients. The number of platelet serotonin transporters in stroke patients and in control subjects have been measured in this study. MATERIAL AND METHODS: Newly admitted stroke patients who did develop or who did not develop a post-stroke depression, non-acute patients who previously had had a stroke and control subjects were compared. The number of platelet serotonin transporters was analysed by ligand binding methodology. RESULTS: The number of platelet serotonin transporters was low shortly after a stroke compared with normal subjects; no difference was found between the stroke patients who developed a post-stroke depression and those who did not. CONCLUSION: A low number of platelet serotonin transporters may be a non-specific state marker for a condition as acute stroke.

Clinical significance of abnormal T waves in patients with non-ST-segment elevation acute coronary syndromes.

T-wave abnormalities are common electrocardiographic occurrences in patients with non-ST-segment elevation acute coronary syndromes. Although these abnormalities are considered relatively benign, physicians use them to guide therapies. The study objective was to examine the prognostic predictive information of T-wave abnormalities in the setting of unstable coronary artery disease. The T-wave abnormality criterion was based on a new set of normal T-wave amplitude limits differentiated by gender, age, electrocardiographic lead, and QRS axis. Four hundred sixty-eight patients suspected of an acute ischemic incident and considered ineligible for reperfusion therapy were included. Thirteen categories of T-wave abnormalities were tested prospectively. The primary 30-day end point was the combination of refractory angina, myocardial infarction, or death. Quantitative T-wave analysis in an electrocardiographic core laboratory revealed 6 of 13 prespecified categories of T-wave abnormalities that were significantly associated with an adverse outcome. T-wave abnormalities had no prognostic value when ST-segment depression was also present, but this occurred in only 7.9% of patients. T-wave abnormalities as the sole manifestation of ischemia were common (74.4%). Patients with abnormal T waves in > or =1 of 6 selected abnormality categories (70.3%) had a significantly higher risk of death, acute myocardial infarction, and refractory angina (11% vs 3%; p = 0.018). Thus, T-wave abnormalities in patients presenting with non-ST-segment elevation acute coronary syndromes are common and should not automatically be regarded as benign phenomena. Quantitative T- wave analysis provides optimal risk stratification.

Comparison of primary coronary angioplasty versus thrombolysis in patients with ST-segment elevation acute myocardial infarction and grade II and grade III myocardial ischemia on the enrollment electrocardiogram.

We investigated the impact of primary angioplasty compared with thrombolysis in 894 patients with ST elevation acute myocardial infarction and electrocardiographic grades II and III ischemia on enrollment. Patients were divided into 2 groups based on the enrollment electrocardiogram-grade III: (1) absence of an S wave below the isoelectric baseline in leads that usually have a terminal S configuration (leads V(1) to V(3)), or (2) ST J-point amplitude > or =50% of the R-wave amplitude in all other leads. To be included in the grade III group, grade III criteria in > or =2 adjacent leads were required. Patients with ST elevation but without grade III criteria were classified as having grade II. In-hospital mortality was 3.2% and 6.8% in the grade II (n = 616) and grade III (n = 278) groups, respectively (p = 0.016). In the grade II group, in-hospital mortality was similar in the thrombolysis and angioplasty subgroups (3.2% and 3.3%, p = 0.941). In patients with grade III, in-hospital mortality was 6.4% and 7.3%, respectively (p = 0.762). The odds ratio for the grade III group for death with thrombolysis was 2.06 (95% confidence intervals [CI] 0.82 to 5.19; p = 0.125); the odds ratio for primary angioplasty was 2.30 (95% CI 0.93 to 5.66; p = 0.07). In the thrombolysis group, reinfarction occurred in 3.3% and 6.5% of the grade II and grade III subgroups (p = 0.137). In the angioplasty group, reinfarction occurred in 1.3% and 4.4%, respectively (p = 0.239). Grade III ischemia on admission was associated with higher in-hospital and 30-day mortality and a higher rate of reinfarction. There was no difference in mortality between primary angioplasty and thrombolysis in the grade II and grade III ischemia patients.

Standards for the function of an academic 12-lead electrocardiographic core laboratory.

An academic 12-lead electrocardiogram (ECG) core laboratory aims to provide the highest possible quality ECG recording, measurement, and storage to aid clinicians in research into important cardiovascular outcomes and to maximize the credibility of scientific results based solely, or in part, on ECG data. This position paper presents a guide for the structure and function of an academic ECG core laboratory. The key functional aspects are: 1) Data collection, 2) Staff composition, 3) Diagnostic measurement and definition standards, 4) Data management, 5) Academic considerations, 6) Economic consideration, and 7) Accreditation. An ECG Core Laboratory has the responsibility for rapid and accurate analysis and responsible management of the electrocardiographic data in multicenter clinical trials. Academic Laboratories, in addition, provide leadership in research protocol generation and production of research manuscripts for submission to the appropriate peer-review journals.

Early reperfusion assessment and repeated thrombolysis in acute myocardial infarction estimated by repeated standard electrocardiography. A randomised, double-blind, placebo-controlled pilot study.

Thrombolytic therapy with streptokinase (SK) in acute myocardial infarction (AMI) does not result in early reperfusion in approximately 25% of patients. We hypothesized that early repeated thrombolysis with rt-PA in patients with early failed reperfusion would result in myocardial reperfusion. Fifty-nine AMI patients with a symptom delay of <6 h, treated with SK were included. ECG was taken on admission and after 90 and 180 min. An ST recovery of > or =25% at 90 min was interpreted as successful reperfusion. Sixteen patients had failed reperfusion at 90 min and were randomized to repeated thrombolysis with rt-PA or placebo. At 180 min from SK start, ST recovery was higher in the placebo group than in the rt-PA group (71 vs. 40%, p = 0.05). No serious bleeding complications were observed. Due to the limited sample size it was not possible to draw prominent conclusions.

[Clinical studies on glycoprotein IIb/IIIa receptor antagonist]. / Kliniske studier med glycoprotein IIb/IIIa-receptorantagonist.

Platelet activation plays a major role in the pathophysiology of acute coronary syndromes (ACS), and inhibition of platelet function is the basic pharmacological treatment of ACS. Platelet membrane glycoprotein IIb/IIIa inhibitors, a new class of potent antiplatelet agents, have been used in the treatment of ACS, as well as in the prevention of complications after percutaneous coronary interventions. The aim of this article is to describe the potential possibilities of platelet inhibition and to review the pharmacology of glycoprotein IIb/IIIa inhibitors, the results of the clinical trials with these agents, and their current use in the pharmacological treatment of ACS and in relation to percutaneous coronary intervention.

Very early diagnosis and risk stratification of patients admitted with suspected acute myocardial infarction by the combined evaluation of a single serum value of cardiac troponin-T, myoglobin, and creatine kinase MB(mass)

AIMS: The diagnostic and prognostic capacity of biochemical markers of acute myocardial infarction in the emergency department were evaluated in consecutive patients (n=155) with suspected acute myocardial infarction. METHODS AND RESULTS: Serum myoglobin >/=110 microg. l(-1)and creatine kinase MB(mass)>/=5 microg. l(-1)had a high accuracy (0.77-0.85) (ns) for acute myocardial infarction diagnosis in patients presenting >2 h after symptom onset. Troponin-T (>/=0.10 microg. l(-1)) had a lower accuracy (0.53-0.70) for acute myocardial infarction diagnosis, but was the most important 1-year prognostic marker (cardiac death or non-fatal acute myocardial infarction). In patients without ST elevation, combined analysis of two biochemical tests would accurately identify an additional 20% of acute myocardial infarction patients (predictive value of a positive test=0.82) and also identify those without acute myocardial infarction (predictive value of a negative test=0.80). One-year event-free survival was excellent (96%) for patients with two negative biochemical tests, intermediate (74%) for those with discordant tests, and only 53% for patients with two positive biochemical tests. CONCLUSIONS: Analysis of biochemical tests in the emergency department prior to hospital admission could accurately identify approximately 20% additional acute myocardial infarction patients. The prognosis of these patients is poor, and they may be a target for primary PTCA or new early initiated aggressive medical therapies.

Moving toward a new definition of acute myocardial infarction for the 21st century: status of the ESC/ACC consensus conference. European Society of Cardiology and American College of Cardiology.

The European Society of Cardiology and American College of Cardiology established their initial Joint Consensus Conference in July 1999 to develop a new definition of Acute Myocardial Infarction. This action was deemed necessary because of the development of new sensitive biochemical markers of myocardial necroses: Troponins T and I. There were 5 working groups, including one in Electrocardiography. The Conference adopted a definition that required only a history of "ischemic symptoms" and "a typical rise and fall" of at least one of the biochemical markers. The ECG Working Group strongly advised that a term distinctive from "myocardial infarction" such as "myocardial necrosette" be adopted as the diagnosis for an acute coronary event during which the peak biochemical marker level is below that which occurs when serial evolutionary ECG changes are observed. A pilot substudy from the GUSTO IIa Clinical Trial has identified the low end of the "ECG Change Range" to be: >2x the upper limit of normal for CK-MB, > 11 x for Troponin T, and >6 x for Troponin I.

The correlation between presenting ST-segment depression and the final size of acute myocardial infarcts in patients with acute coronary syndromes.

The use of reperfusion therapy in patients with ST elevation acute coronary syndromes had been established. However, reperfusion therapy is usually considered contra-indicated in those with ST depression, despite the knowledge that regional posterior infarction is typically indicated by ST depression maximal in leads V1 to V3 and nonregional subendocardial infarction is typically indicated by marked ST depression maximal in other leads. This study of patients with non-ST-elevation acute coronary syndromes investigates the quantitative relationship between presenting ST depression and final QRS changes in both of these subgroups. The final QRS score was significantly higher (2.44 points) than that of a control group with not ST depression, (1.55 points) in the group with maximal ST depression in V1 to V3 (P = 0.04). However, in the entire population, there was a highly significant correlation (P = .003) between the sum of the presenting ST depression and the final QRS score. Trials of reperfusion therapy will be required to determine if such evolution to electrocardiogram documented acute myocardial infarction can be prevented in patient with marked ST depression acute coronary syndromes.

Relative contributions of a single-admission 12-lead electrocardiogram and early 24-hour continuous electrocardiographic monitoring for early risk stratification in patients with unstable coronary artery disease.

Patients with unstable coronary syndromes are a heterogeneous group with varying degrees of ischemia and prognosis. The present study compares the prognostic value of a standard electrocardiogram (ECG) obtained at admission to the hospital with the information from 24-hour continuous electrocardiographic monitoring obtained immediately after admission. The admission ECGs and 24 hours of vectorcardiographic (VCG) monitoring from 308 patients admitted with unstable coronary artery disease were analyzed centrally regarding standard electrocardiographic ST-T changes, ST-vector magnitude (ST-VM), and ST change vector magnitude episodes. End points were death, acute myocardial infarction, and refractory angina pectoris within a 30-day follow-up period. ST-VM episodes (> or = 50 microV for > or = 1 minute) during VCG monitoring was the only independent predictor of death or acute myocardial infarction by multivariate analysis. ST-VM episodes during vectorcardiography was associated with a relative risk of 12.7 for having a cardiac event, hypertension was associated with a relative risk of 1.7, and ST depression on the admission ECG was associated with a relative risk of 5.7. Patients with ST depression at admission had an event rate (death or acute myocardial infarction) of 17% at 30-day follow-up. Patients without ST depression could further be risk stratified by 24 hours of VCG monitoring into a subgroup with ST-VM episodes at similar (8%) risk and a subgroup without ST-VM episodes at low (1%) risk (p = 0.00005). Continuous VCG monitoring provides important information for evaluating patients with unstable coronary artery disease. It is recommended that patients not initially estimated at high risk based on the admission ECG are referred for 24 hours of VCG monitoring for further risk stratification.

Effects of revascularization after first acute myocardial infarction on the evolution of QRS complex changes (the DANAMI trial). DANish Trial in Acute Myocardial Infarction.

The changes in QRS complex morphology associated with acute myocardial infarction (AMI) can resolve spontaneously over time. Whether complete revascularization of the infarct-related myocardial territory after AMI affects this QRS resolution has not been studied adequately. The present study compares the evolution of the changes in the QRS complex associated with AMI during 1-year follow-up in patients treated with or without revascularization after their first thrombolyzed AMI. The study is a substudy of the DANish Trial in Acute Myocardial Infarction (DANAMI) (n = 1,008) that randomized patients with inducible ischemia after their first AMI, treated with intravenous thrombolytic therapy, to conservative treatment or coronary angiography followed by the appropriate revascularization strategy. A total of 817 patients had complete sets of evaluable electrocardiograms. Electrocardiograms were obtained at randomization, and at 3, 6, and 12 months of follow-up and subjected to blinded core-laboratory evaluation according to the Selvester QRS scoring method. This score considers Q-, R-, and S-wave duration and ratios to provide a semiquantitative estimate of AMI size. The median electrocardiographic estimated infarct size in the entire population was 15% of the left ventricle at randomization. At the end of the follow-up period this estimate had decreased to 12% (p < 0.00001). There was no difference in the rate of QRS resolution whether the patients were subgrouped according to randomization or subgrouped according to actual treatment with or without revascularization. The present study confirms the findings from previous studies conducted in the prethrombolytic era, that considerable normalization of the QRS complex also occurs after AMI treated with thrombolytic therapy. This QRS normalization seems unaffected by an aggressive treatment strategy with revascularization via balloon angioplasty or bypass surgery.

Admission standard electrocardiogram for early risk stratification in patients with unstable coronary artery disease not eligible for acute revascularization therapy: a TRIM substudy. ThRombin Inhibition in Myocardial Infarction.

OBJECTIVES: The purpose of this study was to determine the prognostic capacity of a single electrocardiogram (ECG) obtained early after admission to the hospital in patients suspected of non-Q-wave myocardial infarction and unstable angina pectoris. METHODS: Six hundred twenty-nine patients from the TRIM study were included. The patients were divided into subgroups on the basis of ST-segment changes in the inclusion ECG. Death, acute myocardial infarction, or refractory angina (despite treatment) were registered during a follow-up period of 30 days. RESULTS: Patients with ST depression had a significantly higher event rate compared with patients with other ECG changes or with normal ECG results. The difference in event rates between patients with ST depression and patients without ST depression regarding the composite of death and acute myocardial infarction was highly significant (P =.0008). A significant association between the magnitude of the ST-segment depression (in millimeters) and the risk of cardiac events was also demonstrated. Multivariate analysis proved ST depression early after admission to be an independent predictor of high risk. CONCLUSION: In patients with unstable coronary artery disease, ST-segment depression at admission is a strong predictor of early (30 days) cardiac events and the extent of ST depression carries important prognostic information as well.

Very early risk stratification using combined ECG and biochemical assessment in patients with unstable coronary artery disease (A thrombin inhibition in myocardial ischemia [TRIM] substudy). The TRIM Study Group.

BACKGROUND: The diagnostic capability of troponin T (TnT), troponin I (TnI), myoglobin, and creatine kinase (CK)-MB mass for detection of myocardial injury seems evident. Newer studies have found these sensitive markers to carry independent prognostic information in patients with unstable coronary artery disease as well. ST-segment depression in the admission ECG is known to be an important indicator of poor outcome in these patients. The present study investigates the prognostic capacities of the ECG in combination with biochemical admission measurements in 516 patients admitted to hospital with unstable coronary artery disease. METHODS AND RESULTS: Baseline ECG recordings and blood samples were collected for central analysis. The patients were followed up for 30 days, and predefined end points, ie, death, myocardial infarction, and refractory angina, were registered as end points. By univariate analysis, ST-segment depression, inverted T waves in >/=5 leads, TnT >/=0.1 microg/L, TnI >/=0.5 microg/L, myoglobin >/=40 microg/L, female sex, and age >/=65 years were predictors of death and myocardial infarction at 30 days. By multivariate analysis, female sex, ST-segment depression at randomization, or inverted T-waves in >/=5 leads were the only independent predictors of death or myocardial infarction. On the basis of baseline ECG ST-T changes and CK-MB mass/TnT/TnI/myoglobin levels, the patients were divided into 3 subgroups at high (14% event rate), intermediate (6%), and low (3%) risk of early death/myocardial infarction. CONCLUSIONS: The present study found the combination of baseline values of TnT, TnI, CK-MB mass, and ST-T changes in the ECG to be effective for early risk stratification in patients with unstable coronary artery disease.