Susanne Hosbond

Classification of Myocardial Infarction: Frequency and Features of Type 2 Myocardial Infarction

BACKGROUND The classification of myocardial infarction into 5 types was introduced in 2007 as an important component of the universal definition. In contrast to the plaque rupture-related type 1 myocardial infarction, type 2 myocardial infarction is considered to be caused by an imbalance between demand and supply of oxygen in the myocardium. However, no specific criteria for type 2 myocardial infarction have been established. METHODS We prospectively studied unselected hospital patients who had cardiac troponin I measured on clinical indication. The diagnosis and classification of myocardial infarction were established, and the frequency and features of type 2 myocardial infarction were investigated by use of novel developed criteria. RESULTS From January 2010 to January 2011, a total of 7230 consecutive patients who had cardiac troponin I measured were evaluated, and 4499 patients qualified for inclusion. The diagnosis of myocardial infarction was established in 553 patients, of whom 386 (72%) had a type 1 myocardial infarction and 144 (26%) had a type 2 myocardial infarction. Patients in the group with type 2 myocardial infarction were older and more likely to be female, and had more comorbidities. The proportion of patients without significant coronary artery disease was higher in those with type 2 myocardial infarction (45%) than in those with type 1 myocardial infarction (12%) (P < .001). Tachyarrhythmias, anemia, and respiratory failure were the most prevalent mechanisms causing type 2 myocardial infarction. CONCLUSIONS In a cohort of patients with myocardial infarction who were admitted consecutively through 1 year, the category of type 2 myocardial infarction comprised one fourth when diagnosed by the use of newly developed criteria. Approximately half of patients with type 2 myocardial infarction had no significant coronary artery disease.

Mortality rate in type 2 myocardial infarction: Observations from an unselected hospital cohort

BACKGROUND The classification of myocardial infarction into 5 types was introduced in 2007. The prognostic impact of this universal definition, with particular focus on type 2 myocardial infarction, has not been studied prospectively in unselected hospital patients. METHODS During a 1-year period, all hospitalized patients having cardiac troponin I measured were considered. The diagnosis of a myocardial infarction was according to the universal definition, and specified criteria were used in the classification of type 2 myocardial infarction. Follow-up was at least 1 year, with mortality as the end point. RESULTS A total of 3762 consecutive patients were studied, of whom 488 (13%) had a myocardial infarction. In 119 patients a type 2 myocardial infarction was diagnosed. After a median of 2.1 years (interquartile range, 1.6-2.5 years), 150 patients had died, with a mortality rate of 49% (58/119) in those with type 2 myocardial infarction and 26% (92/360) in those with type 1 myocardial infarction (P < .0001). In a multivariable Cox regression analysis the following variables were independently associated with mortality: current or prior smoker, high age, prior myocardial infarction, type 2 myocardial infarction, hypercholesterolemia, high p-creatinine, and diabetes mellitus. The multivariable-adjusted hazard ratio for type 2 myocardial infarction was 2.0 (95% confidence interval, 1.3-3.0). With shock as the only exception, mortality was independent of the triggering conditions leading to type 2 myocardial infarction. CONCLUSIONS Mortality in patients with type 2 myocardial infarction is high, reaching approximately 50% after 2 years. Further descriptive and survival studies are needed to improve the scientific evidence on which treatment of type 2 myocardial infarction is based.

Clinical Characteristics and Outcomes of Patients with Myocardial Infarction, Myocardial Injury, and Nonelevated Troponins

BACKGROUND Cardiac troponins have emerged as the preferred biomarkers for detecting myocardial necrosis and diagnosing myocardial infarction. However, current cardiac troponin assays do not discriminate between ischemic and nonischemic causes of myocardial cell death. Thus, when an increased troponin value is encountered in the absence of obvious myocardial ischemia, a careful search for other clinical conditions is crucial. METHODS In 2010 to 2011, we prospectively studied hospitalized patients who had cardiac troponin I measured on clinical indication. An acute myocardial infarction was diagnosed in cases of a cardiac troponin I increase or decrease pattern with at least 1 value >30 ng/L (99th percentile) together with myocardial ischemia. Myocardial injury was defined as cardiac troponin I values >30 ng/L, but without signs or symptoms indicating overt cardiac ischemia. Patients with peak values ≤30 ng/L were classified as nonelevated cardiac troponin I. Follow-up was at least 3 years with all-cause mortality as the sole clinical end point. RESULTS A total of 3762 patients were included. Of these, 488 (13%) had acute myocardial infarction, 1089 (29%) had myocardial injury, and 2185 (58%) had nonelevated cardiac troponin I values. Patients with myocardial injury frequently presented with dyspnea, were older, and had more comorbidity than patients in the 2 other groups. During a median follow-up of 3.2 years, 1342 patients died. Mortality differed significantly between groups: 39% in those with myocardial infarction, 59% in those with myocardial injury, and 23% in those with nonelevated cardiac troponin I (log-rank test; P < .0001). No significant difference in mortality between patients with type 2 myocardial infarction and patients with myocardial injury was observed (63% and 59%, respectively). CONCLUSIONS Patients with myocardial injury are older and have more comorbidity than those with acute myocardial infarction. Both groups exhibit a poorer prognosis than patients with nonelevated cardiac troponin I values. Of note, a very high long-term mortality is observed in patients with type 2 myocardial infarction and patients with myocardial injury.

Plasma osteoprotegerin is related to carotid and peripheral arterial disease, but not to myocardial ischemia in type 2 diabetes mellitus

BackgroundCardiovascular disease (CVD) is frequent in type 2 diabetes mellitus patients due to accelerated atherosclerosis. Plasma osteoprotegerin (OPG) has evolved as a biomarker for CVD. We examined the relationship between plasma OPG levels and different CVD manifestations in type 2 diabetes.MethodsType 2 diabetes patients without known CVD referred consecutively to a diabetes clinic for the first time (n = 305, aged: 58.6 ± 11.3 years, diabetes duration: 4.5 ± 5.3 years) were screened for carotid arterial disease, peripheral arterial disease, and myocardial ischemia by means of carotid artery ultrasonography, peripheral ankle and toe systolic blood pressure measurements, and myocardial perfusion scintigraphy (MPS). In addition, plasma OPG concentrations and other CVD-related markers were measured.ResultsThe prevalence of carotid arterial disease, peripheral arterial disease, and myocardial ischemia was 42%, 15%, and 30%, respectively. Plasma OPG was significantly increased in patients with carotid and peripheral arterial disease compared to patients without (p < 0.001, respectively), however, this was not the case for patients with myocardial ischemia versus those without (p = 0.71). When adjusted for age, HbA1c and U-albumin creatinine ratio in a multivariate logistic regression analysis, plasma OPG remained strongly associated with carotid arterial disease (adjusted OR: 2.12; 95% CI: 1.22-3.67; p = 0.008), but not with peripheral arterial disease or myocardial ischemia.ConclusionsIncreased plasma OPG concentration is associated with carotid and peripheral arterial disease in patients with type 2 diabetes, whereas no relation is observed with respect to myocardial ischemia on MPS. The reason for this discrepancy is unknown.Trial registration numberat http://www.clinicaltrial.gov: NCT00298844

Osteoprotegerin as a marker of atherosclerosis: A systematic update

Abstract Objective. Osteoprotegerin (OPG) may be involved in development of atherosclerosis. To evaluate plasma concentrations of OPG in individuals with stable coronary artery disease (CAD), acute coronary syndrome (ACS), peripheral artery disease (PAD), and cerebrovascular disease (CBVD) a systematic literature review was performed. Design and methods. Studies investigating OPG concentrations in stable CAD, ACS, PAD, and CBVD were extracted from PubMed and the Cochrane Library, retrieving 280 articles. Nonrelevant articles were excluded and after thorough evaluation, and only 14 studies with clearly defined cohorts qualified for this review. Results. In 11 studies, OPG concentrations were elevated. Severity of atherosclerosis was significantly associated with higher OPG concentrations compared to healthy controls. No association between PAD and OPG concentrations was observed. Conclusion. OPG concentrations are associated with the presence and severity of stable CAD, ACS, and CBVD. Larger studies are needed to reach conclusions concerning OPG concentrations in PAD. Studies addressing a putative role for OPG in suspected CAD and CBVD are warranted.

Capillary refill time: a study of interobserver reliability among nurses and nurse assistants.

Objectives The interobserver variability of capillary refill time (CRT) has been questioned. Earlier studies of interobserver variability of CRT have been on a large number of patients but with few observers. The objective of our study was to investigate how a large group of nurses and nurse assistants would grade CRT. Methods We recorded a video of the index finger of six medical patients and these were shown to nurses and nurse assistants. They were asked to record the CRT and whether they found this value to be normal. The data were analyzed using the Fleiss Kappa Coefficient Analysis and graded according to the Landis and Koch correlation. Correlation between the exact numbers was evaluated using interclass correlation. Results Nine nurse assistants and 37 nurses participated. The patients were aged between 44 and 87 years. All but one patient had a systolic blood pressure reading above 130 mmHg. All had arterial blood oxygen saturation above 92% and all but one had normal body temperature. The &kgr; value for normality was 0.56. The interclass correlation of measurement of CRT was 0.62. Conclusion This is the largest interobserver study of CRT when looking at the number of observers. We found an only moderate agreement for the exact value of CRT and a moderate agreement for normality. We believe that CRT should be used with caution in clinical practice.

Clinical evaluation of a matrix metalloproteinase-12 cleaved fragment of titin as a cardiovascular serological biomarker

BackgroundTitin is a muscle-specific protein found in cardiac and skeletal muscles which is responsible for restoring passive tension. Levels and functioning of titin have been shown to be affected by cardiac damage. Due to the inherent difficulty of measuring titin levels in vivo in a clinical setting, we aimed to develop an assay that could reliably measure fragments of degraded titin in serum and potentially be used in the assessment of cardiac muscle damage.MethodsA competitive ELISA was developed to specifically measure levels of the titin sequence 12670’ NVTVEARLIK 12679’, derived by the degradation of titin by matrix metalloproteinase (MMP)-12. Serum samples from 90 individuals were divided into 3 equally sized groups. One group had been diagnosed with acute myocardial infarction (AMI) while the remaining two were asymptomatic individuals either with CT-scan signs of coronary calcium (CT-plusCa) or without coronary calcium (CT-noCa).ResultsMean geometric levels of the titin fragment in the CT-noCa group were 506.5 ng/ml (±43.88). The CT-plusCa group showed 50.6% higher levels of the marker [763 ng/ml (±90.14)] (P < 0.05). AMI patients showed 56.3% higher levels [792 ng/ml (±149)] (P < 0.05).ConclusionsThe titin-12670 fragment is present in both individuals with undiagnosed and diagnosed CVD. The statistically significant increase in level of the marker in the AMI group is indicative that this neoepitope biomarker may be a useful serological marker in AMI.

Coronary computed tomography angiography – Tolerability of β-blockers and contrast media, and temporal changes in radiation dose

Abstract Objective. To determine the risk in administering β-blockers, contrast-induced nephropathy (CIN) and the trend in X-ray use, during coronary computed tomography angiography (CCTA). Methods. A total of 416 patients were referred for elective CCTA. To achieve a resting heart rate below 60 beats per minute, oral and/or intravenous β-blockers were administered. Using questionnaires, information on the adverse effects of β-blockers was collected from the patients. The levels of s-creatinine and estimated GFR (eGFR) were measured before and after contrast enhanced CCTA. Radiation exposure was compared with the exposure 3 years earlier. Results. There was no significant difference in the symptoms (dizziness, lipothymia and palpitations) between patients with and patients without β-blocker pretreatment. Compared to baseline values, the decrease in s-creatinine was not significant (75.2 vs. 74.6 μmol/L, p = 0.09), while the increase in eGFR was not significant (78 vs. 79 mL/min, p = 0.17). Also, subgroups of patients with hypertension, hypercholesterolemia, diabetes or pre-existing slight impairment in renal function did not develop CIN. The mean radiation exposure decreased from 17.5 to 6.7 mSv, p < 0.0001. Conclusions. In terms of the side effects of β-blockers and contrast media, there were no short term complications to CCTA. Furthermore, the radiation dose has been dramatically diminished over the last three years.

Comparison of Mortality in Patients With Acute Myocardial Infarction Accidentally Admitted to Non-cardiology Departments Versus That in Patients Admitted to Coronary Care Units

The aim of this study was to prospectively investigate the clinical characteristics including symptoms and long-term mortality in patients with acute myocardial infarction (AMI) accidentally admitted to non-cardiology departments (NCDs). For comparison, similar observations in patients admitted to the coronary care unit (CCU) were collected. During a 1-year period, consecutive patients having cardiac troponin I measured at the Odense University Hospital were considered. The hospital has 27 clinical departments. Patients were classified as having an AMI if the diagnostic criteria of the universal definition were met. Follow-up was at least 1 year with mortality as the clinical end point. Of 3,762 consecutive patients, an AMI was diagnosed in 479, of whom 114 patients (24%) were hospitalized in NCDs and 365 (76%) in the CCU. Chest pain or chest discomfort more frequently occurred in patients from the CCU (83%) than in patients from the NCDs (45%, p <0.0001). At median follow-up of 2.1 years, 150 patients had died: 73 (64%) of patients from the NCDs and 77 (21%) of the patients from the CCU. In the multivariable Cox regression analysis, the adjusted hazard ratio of mortality for patients from the NCDs versus CCU was 2.0 (95% confidence interval 1.3 to 3.2). In conclusion, chest pain/discomfort was absent in more than half of the patients with AMI admitted to NCDs, and admission to NCDs was an independent predictor of a 2 times higher long-term mortality in comparison with admission to the CCU.

Perception of time by professional health care workers during simulated cardiac arrest.

has been shown that the direction of ETT advancement from the guiding channel differs between the curved and straight ETTs [7]. The curved ETT advanced from the guiding channel tends to travel forward for a short distance almost in line and align with the glottis, whereas the straight ETT tends to move in a posterior direction and not toward the center of the target mark or the glottis. When a straight ETT is chosen, therefore, there may be a risk of failed intubation with the AWS despite standard positioning of the glottis and target mark on the monitor. Our experience suggests that a polyvinyl chloride ETT with the inherent anterior curve is best choice for tracheal intubation with the AWS. Fifth, the AWS has only one fixed-size Pblade. In some patients, it can be difficult to position the PBlade tip inferior to the epiglottis [8], because the distance from the mouth to the larynx of the patient is longer than the designed length of the PBlade. In this situation, the pendulous epiglottis may obstruct the view to the glottis and interfere with alignment of the ETTs tip with the glottis. A mannequin study revealed that when the AWS failed to reach the larynx, the use of a Parker Flex-Tip tube could be an alternative solution [9]. Also, a clinical study determined that nasotracheal intubation might improve the success rate when this problem occurred [10]. Finally, because the PBlade is relatively bulky (1.6 cm at thickest), the AWS is not useful when mouth opening is so severely limited as to preclude insertion of the PBlade.