Factors influencing physician risk estimates for acute cardiac events in emergency patients with suspected acute coronary syndrome.

BACKGROUND: Emergency physicians frequently assess risk of acute cardiac events (ACEs) in patients with undifferentiated chest pain. Such estimates have been shown to have moderate to high sensitivity for ACE but are conservative. Little is known about the factors implicitly used by physicians to determine the pretest probability of risk. This study sought to identify the accuracy of physician risk estimates for ACE in patients presenting to the ED with chest pain and to identify the demographic and clinical information emergency physicians use in their determination of patient risk. METHODS: This study used data from two prospective studies of consenting adult patients presenting to the ED with symptoms of possible acute coronary syndrome. ED physicians estimated the pretest probability of ACE. Multiple linear regression analysis was used to identify predictors of physician risk estimates. Logistic regression was used to determine whether there was a correlation between physicians' estimated risk and ACE. RESULTS: Increasing age, male sex, abnormal ECG features, heavy/crushing chest pain and risk factors were correlated with physician risk estimates. Physician risk estimates were consistently found to be higher than the expected proportion of ACE from the sampled population. CONCLUSION: Physicians systematically overestimate ACE risk. A range of factors are associated with physician risk estimates. These include factors strongly predictive of ACE, such as age and ECG characteristics. They also include other factors that have been shown to be unreliable predictors of ACE in an ED setting, such as typicality of pain and risk factors.

Triggering of acute myocardial infarction by respiratory infection.

BACKGROUND: Respiratory infection has been associated with an increased short-term risk of myocardial infarction (MI). However, previous studies have predominantly been conducted without angiographic confirmation of MI. The possibility can therefore not be excluded that raised troponin levels or electrocardiogram abnormalities that may be seen with respiratory infections are due to non-ischaemic causes. AIMS: To investigate the association between respiratory infection and angiographically confirmed MI. METHODS: Interviews were conducted within 4 days of hospitalisation in 578 patients with angiographically confirmed MI, to assess for recent exposure to respiratory infection symptoms and the usual annual frequency of these symptoms. Using case-crossover methodology, exposure to respiratory infection prior to the onset of MI was compared against the usual frequency of exposure in the past year. RESULTS: Symptoms of respiratory infection were reported by 100 (17%) and 123 (21%) within 7 and 35 days, respectively, prior to MI. The relative risk (RR) for MI occurring within 1-7 days after respiratory infection symptoms was 17.0 (95% confidence interval (CI) 13.2-21.8), and declined with subsequent time periods. In a subgroup analysis, the RR tended to be lower in groups taking regular cardiac medications. For those who reported milder, upper respiratory tract infection symptoms, the RR for the 1-7-day time period was 13.5 (95% CI 10.2-17.7). CONCLUSION: These findings confirm that respiratory infection can trigger MI. Further study is indicated to identify treatment strategies to decrease this risk, particularly in individuals who may have increased susceptibility.

Differences in Presentation, Management and Outcomes in Women and Men Presenting to an Emergency Department With Possible Cardiac Chest Pain.

BACKGROUND: Research suggests that female patients with acute coronary syndrome (ACS) experience delays in emergency department (ED) management and are less likely to receive guideline-based treatments and referrals for follow-up testing. Women are often found to have poorer clinical outcomes in comparison to men. This study aimed to assess current sex differences in the presentation, management and outcomes of patients with undifferentiated chest pain presenting to a tertiary ED. METHODS: Data were analysed from two prospective studies conducted at a single Australian site between 2007 and 2014. Eligible patients were those of 18 years of age or older presenting with at least 5 minutes of chest pain or other symptoms for which the treating physician planned to investigate for possible ACS. Presenting symptoms, ED time measures, follow-up testing and outcomes, including 30-day ACS and mortality, were measured and compared between male and female patients. RESULTS: Of 2349 (60% men) patients presenting with chest pain, 153 men and 51 women were diagnosed with ACS within 30days . Presenting symptoms were similar in men and women with confirmed ACS. Time from symptom onset to ED presentation, time spent in the ED and total time in hospital were similar between the sexes. Male and female patients had similar rates of follow-up provocative testing. After adjustment for clinical factors, the odds of undergoing angiography were 1.8 (95% CI: 1.36-2.40) times higher for men than women. Of those undergoing coronary angiography within 30 days, a smaller proportion of women, compared to men, received revascularisation. Within 30 days, three (0.2%) male and one (0.1%) female patient died. CONCLUSION: Minimal sex differences were observed in the contemporary emergency management of patients presenting with suspected ACS. Thirty-day outcomes were similarly low in men and women despite lower rates of coronary angiography and revascularisation in women. Further research is required to replicate these results in different hospital systems and cultural settings.

The Association of Electrocardiographic Abnormalities and Acute Coronary Syndrome in Emergency Patients With Chest Pain.

OBJECTIVES: The electrocardiograph (ECG) is an essential tool in initial management and risk stratification of patients with suspected acute coronary syndrome (ACS). A six-point reporting criterion has been proposed to facilitate standardized clinical assessment of patients presenting to the emergency department (ED) with suspected ACS. We set out to evaluate the efficacy of these criteria in identifying patients with major adverse cardiac events (MACE), Type 1 myocardial infarction (T1MI), Type 2 myocardial infarction (T2MI), and 1-year mortality in a cohort of emergency patients with chest pain. METHODS: This was an analysis of data from 2,349 patients who presented to the ED with chest pain between 2008 and 2013. Data were collected as part of two prospective trials. ECGs were recorded at presentation and categorized according to the six-point criteria by local cardiologists blinded to all clinical information. The primary outcome was 30-day MACE, including T1MI, T2MI, unstable angina pectoris, revascularization, and 30-day mortality. The outcome was adjudicated by cardiologists on the basis of all clinical information and test results. Likelihood ratios and odds ratios for 30-day MACE were reported for each ECG category. RESULTS: Major adverse cardiac events were diagnosed in 264 (11.3%) patients. Increasing ischemic abnormalities in ECGs, as categorized by the standardized reporting criteria, were associated with increasing rates of MACE. Within 30 days, T1MI occurred in 148 (6.3%) patients and T2MI occurred in 59 (2.5%) patients. Risk for T1MI increased with higher classification of ECG abnormalities. T2MI rates were highest in patients with ECGs of nonspecific changes. CONCLUSIONS: The rates of MACE, T1MI, and 1-year death can be stratified according to standardized ECG criteria in patients presenting to the ED with chest pain. The ECG findings in patients with T2MI are variable, and the ECG is less helpful in defining risk in this group.