Spontaneous coronary artery dissection: Current state of the science: A scientific statement from the American Heart Association

© 2018 American Heart Association, Inc. Spontaneous coronary artery dissection (SCAD) has emerged as an important cause of acute coronary syndrome, myocardial infarction, and sudden death, particularly among young women and individuals with few conventional atherosclerotic risk factors. Patient-initiated research has spurred increased awareness of SCAD, and improved diagnostic capabilities and findings from large case series have led to changes in approaches to initial and long-term management and increasing evidence that SCAD not only is more common than previously believed but also must be evaluated and treated differently from atherosclerotic myocardial infarction. High rates of recurrent SCAD; its association with female sex, pregnancy, and physical and emotional stress triggers; and concurrent systemic arteriopathies, particularly fibromuscular dysplasia, highlight the differences in clinical characteristics of SCAD compared with atherosclerotic disease. Recent insights into the causes of, clinical course of, treatment options for, outcomes of, and associated conditions of SCAD and the many persistent knowledge gaps are presented

Oxygen therapy for acute myocardial infarction

BACKGROUND: Oxygen (O2) is widely used in people with acute myocardial infarction (AMI). Previous systematic reviews concluded that there was insufficient evidence to know whether oxygen reduced, increased or had no effect on heart ischaemia or infarct size. Our first Cochrane review in 2010 also concluded there was insufficient evidence to know whether oxygen should be used. Since 2010, the lack of evidence to support this widely used intervention has attracted considerable attention, prompting further trials of oxygen therapy in myocardial infarction patients. It is thus important to update this Cochrane review. OBJECTIVES: To assess the effects of routine use of inhaled oxygen for acute myocardial infarction (AMI). SEARCH METHODS: We searched the following bibliographic databases on 6 June 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (OVID), Embase (OVID), CINAHL (EBSCO) and Web of Science (Thomson Reuters). LILACS (Latin American and Caribbean Health Sciences Literature) was last searched in September 2016. We also contacted experts to identify eligible studies. We applied no language restrictions. SELECTION CRITERIA: Randomised controlled trials in people with suspected or proven AMI (ST-segment elevation myocardial infarction (STEMI) or non-STEMI) within 24 hours after onset, in which the intervention was inhaled oxygen (at normal pressure) compared to air, regardless of co-therapies provided to participants in both arms of the trial. DATA COLLECTION AND ANALYSIS: Two authors independently reviewed the titles and abstracts of identified studies to see if they met the inclusion criteria and independently undertook the data extraction. We assessed the quality of studies and the risk of bias according to guidance in the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome was death. The measure of effect used was the risk ratio (RR) with a 95% confidence interval (CI). We used the GRADE approach to evaluate the quality of the evidence and the GRADE profiler (GRADEpro) to import data from Review Manager 5 and create 'Summary of findings' tables. MAIN RESULTS: The updated search yielded one new trial, for a total of five included studies involving 1173 participants, 32 of whom died. The pooled risk ratio (RR) of all-cause mortality in the intention-to-treat analysis was 0.99 (95% CI 0.50 to 1.95; 4 studies, N = 1123; I(2) = 46%; quality of evidence: very low) and 1.02 (95% CI 0.52 to 1.98; 4 studies, N = 871; I(2) = 49%; quality of evidence: very low) when only analysing participants with confirmed AMI. One trial measured pain directly, and two others measured it by opiate usage. The trial showed no effect, with a pooled RR of 0.97 for the use of opiates (95% CI 0.78 to 1.20; 2 studies, N = 250). The result on mortality and pain are inconclusive. There is no clear effect for oxygen on infarct size (the evidence is inconsistent and low quality). AUTHORS' CONCLUSIONS: There is no evidence from randomised controlled trials to support the routine use of inhaled oxygen in people with AMI, and we cannot rule out a harmful effect. Given the uncertainty surrounding the effect of oxygen therapy on all-cause mortality and on other outcomes critical for clinical decision, well-conducted, high quality randomised controlled trials are urgently required to inform guidelines in order to give definitive recommendations about the routine use of oxygen in AMI

Role of high sensitivity cardiac troponin assays in the assessment and experience of patients presenting to the Emergency Department with suspected acute coronary syndrome

The improved precision of high-sensitivity cardiac troponin (hs-cTnI) assays has enabled two advances in the assessment of patients with suspected acute coronary syndrome; 1) the use of sex-specific criteria for the diagnosis of myocardial infarction, and 2) the development of pathways to identify low risk patients in the Emergency Department setting, who may be suitable for immediate discharge. This thesis had two overarching aims: to explore the gendered dimensions of the new assessment process and to examine how patient experience of chest pain may be shaped by the implementation of an early rule-out pathway for myocardial infarction. In order to achieve these, the study had two components: a quantitative analysis of the presenting characteristics of men and women diagnosed with myocardial infarction using sex-specific criteria, and a qualitative interview study with patients who experienced assessment either before or after implementation of an early rule-out pathway. In the quantitative element of this thesis, I aimed to determine the frequency and predictive value of presenting characteristics in patients with myocardial infarction by evaluating patient reported symptoms in 1,941 patients (39% women) with suspected acute coronary syndrome. Typical symptoms were more common in women than men with myocardial infarction (77% [69/90] versus 59% [109/184], P=0.007), and were similar in those women and men who were reclassified with myocardial infarction due to the use of sex-specific criteria (74% [20/27] versus 44% [4/9], P=0.22). In women, the combination of three or more typical features was associated with a significantly positive likelihood ratio for a diagnosis of myocardial infarction (LR+1.18, 95% CI 1.03 to 1.31), but this relationship was not observed in men (LR+ 1.09, 95% CI 0.96 to 1.24). The improved precision of the hs-cTnI assay has enabled the diagnosis of myocardial infarction to be excluded in the Emergency Department without requiring hospital admission. Understanding the patient experience of earlier clinical decisions will ensure these new diagnostic pathways benefit both the healthcare system and patients themselves. The qualitative element was designed to explore how patient experience of chest pain may be shaped by the implementation of an early rule-out pathway. Patients attending the Emergency Department who had myocardial infarction ruled out were eligible for inclusion. Purposive sampling was used to ensure representation across age and sex categories. 23 participants were interviewed before, and 26 participants were interviewed after implementation of the early rule-out pathway one week following discharge. The content of participant accounts did not appear to be dictated by whether they were assessed before or after implementation of the early rule-out pathway with many common themes arising from both pathways. Patient experience of chest pain extended both before and after the in-hospital period revealing a phased illness episode. Participants described how they appraised their symptoms involving a complex process of interpretation and evaluation of the appropriate action. Patient accounts also revealed the differing priorities of the clinical pathway (the rule-out of myocardial infarction) to the holistic patient view desired by participants themselves. The confirmation of the absence of disease did not provide all patients with the reassurance that they desired. Providing pre-test information regarding the troponin test, in addition to active listening and the building of a trustful clinician-patient relationship appeared to relate to positive expressions of reassurance within participant accounts. Following discharge, participants had to continue to make sense of their chest pain experience. The way in which some participants made use of their acute chest pain presentation to hospital as an opportunity to consider their future heart health emerged as an unelicited theme. Participants assessed using the early rule-out pathway appeared to have a lesser orientation to use the episode of chest pain as a cue to action to appraise their future health status. The findings of this thesis suggest that high-sensitivity cardiac troponin assays will aid the assessment of patients with suspected acute coronary syndrome in two important ways. Firstly, the clinical significance of typical symptom clusters and their correlation to myocardial infarction in women is highlighted. Secondly, the successful implementation of early rule-out pathways into the Emergency Department will be aided by the addition of simple communication interventions during the chest pain assessment process. Extending the focus of assessment beyond the rule-out of myocardial infarction may enhance the care experience of patients. This thesis has also demonstrated how qualitative research has provided a mechanism through which to explore how the biochemical evidence of the early rule-out pathway may be applied in a clinical environment, enabling the application of trial data into a real-life clinical context that responds to patients’ needs

Primary Angioplasty

Medicine; Cardiolog

Primary Angioplasty

Medicine; Cardiolog