ECG signs of acute myocardial ischemia in the prehospital setting of a suspected acute coronary syndrome and its association with outcomes.

AIMS: The aims of this study were (a) to determine the prehospital prevalence of electrocardiographic (ECG) signs of acute myocardial ischemia in patients with suspected acute coronary syndrome and (b) to describe the relationships between the various ECG patterns and the diagnosis of acute myocardial infarction (AMI) and outcomes. METHODS: Prospective cohort study using data from an interventional trial in acute chest pain patients transported by the emergency medical services. These patients were classified into 3 groups: patients with ECG showing signs of acute myocardial ischemia, patients with ECG showing other abnormal changes (bundle-branch block, pacemaker rhythm, Q-wave or T-wave inversion) and patients without significant pathologic findings. All P values are age-adjusted. RESULTS: Among 1546 patients, 312 (20%) had ECG signs of acute myocardial ischemia. Of them, 57% had a final diagnosis of AMI versus 26% of those with other abnormal ECGs and 12% of those with ECG without significant pathologic findings (P<.0001). In all, 53% of all AMI cases involved patients without ECG signs of acute myocardial ischemia. Although ECG signs of acute myocardial ischemia predicted heart failure and ventricular tachyarrhythmias both prior to and after hospital admission, there was no significant difference in 30-day mortality between the 3 patient groups (4.3%, 3.7%, and 1.2%, respectively, P=.11). CONCLUSION: Among patients with a clinical suspicion of AMI in the prehospital setting, the prevalence of ECG signs suggesting AMI was low, as was the ability to identify AMI patients using ECG findings only. We therefore need better instruments in the prehospital triage of patients with acute chest pain.

Characteristics of and outcome for patients with chest pain in relation to transport by the emergency medical services in a 20-year perspective.

AIM: The aims of this study were to describe the characteristics of and outcome of patients with chest pain in relation to transport by the emergency medical services (EMS) and to describe possible changes in this relationship in a 20-year perspective. METHODS: In the 2 periods, 1986 to 1987 and 2008, all patients with chest pain admitted to hospitals in Gothenburg, Sweden, were retrospectively evaluated in terms of previous history, final diagnosis, and mortality. P values were age adjusted. RESULTS: In 1986 to 1987 and 2008, 34% of 4270 patients with chest pain and 39% of 2286 patients, respectively, were transported to the hospital by the EMS (P = .0001). In both periods, patients who used EMS were older and had a higher prevalence of previous cardiovascular diseases and more often had a final diagnosis of acute myocardial infarction (AMI) than those who did not use EMS. The EMS users were more frequently hospitalized in 1986 to 1987 than in 2008 (P < .0001). Emergency medical service use was related to a significantly higher age-adjusted 1-year mortality in both periods for all patients with chest pain as well as for those hospitalized. Among hospitalized patients with myocardial ischemia and among patients with a final diagnosis of AMI, EMS use was associated with a higher 30-day mortality in 1986 to 1987. Regardless of the use of EMS, there was a decrease in the proportion of patients developing AMI as well as the rate of death at 30 days and 1 year in 2008 as compared with 1986 to 1987. CONCLUSIONS: For 20 years, the proportion of patients with chest pain using the EMS increased. EMS users were more frequently hospitalized in 1986 to 1987 than in 2008. In overall terms, mortality was higher among EMS users than among nonusers in both periods. Among hospitalized patients with myocardial ischemia and among patients with a final diagnosis of AMI, EMS use was associated with a higher 30-day mortality only in 1986 to 1987.

Characteristics of and outcomes for elderly patients with acute myocardial infarction: differences between females and males.

OBJECTIVES: This study analyzed age-adjusted sex differences among acute myocardial infarction (AMI) patients aged 75 years and above with regard to 7-year mortality (primary end point) and the frequency of angiograms and admission to the coronary care unit (CCU) as well as 1-year mortality (secondary end points). METHODS: A retrospective cohort study comprised 1,414 AMI patients (748 females and 666 males) aged at least 75 years, who were admitted to Sahlgrenska University Hospital in Gothenburg, Sweden, during two periods (2001/2002 and 2007). All comparisons between female and male patients were age adjusted. RESULTS: Females were older and their previous history included fewer AMIs, coronary artery bypass grafting procedures, and renal diseases, but more frequent incidence of hypertension. On the contrary, males had higher age-adjusted 7-year mortality in relation to females (hazard ratio [HR] 1.16 with corresponding 95% confidence interval [95% CI 1.03, 1.31], P=0.02). Admission to the CCU was more frequent among males than females (odds ratio [OR] 1.38 [95% CI 1.11, 1.72], P=0.004). There was a nonsignificant trend toward more coronary angiographies performed among males (OR 1.34 [95% CI 1.00, 1.79], P=0.05), as well as a nonsignificant trend toward higher 1-year mortality (HR 1.18 [95% CI 0.99, 1.39], P=0.06). CONCLUSION: In an AMI population aged 75 years and above, males had higher age-adjusted 7-year mortality and higher rate of admission to the CCU than females. One-year mortality did not differ significantly between the sexes, nor did the frequency of performed coronary angiograms.

Pre-hospital prediction of death or cardiovascular complications during hospitalisation and death within one year in suspected acute coronary syndrome patients.

OBJECTIVES: To identify pre-hospital predictors of a) death or the development of cardiovascular complications during hospitalisation (primary objective) and b) all-cause death during one year of follow-up (secondary objective), in chest pain patients with suspected acute coronary syndrome (ACS). METHODS: A prospective study that comprised patients in western Sweden, who were transported to hospital by the emergency medical service (EMS) due to chest pain and suspected ACS. Multiple logistic regression was used to identify independent predictors of adverse outcomes. RESULTS: Among all 1600 eligible patients, 21% died or had a cardiovascular complication during hospitalisation and 10% died during one year of follow-up. Nine factors were identified pre-hospitalisation as independent predictors of death or cardiovascular complications during hospitalisation. They were increasing age, a history of congestive heart failure, nausea and/or vomiting, rapid breathing rate, low oxygen saturation, high heart rate, together with ST-segment elevation, ST-segment depression and right bundle branch block on the pre-hospital electrocardiogram (ECG). For the secondary objective of death during one year of follow-up, the following five factors were identified as independent predictors: increasing age, a history of congestive heart failure, dyspnea, low oxygen saturation and left bundle branch block on the pre-hospital ECG. CONCLUSIONS: In the pre-hospital setting of chest pain and suspected ACS, we identified nine predictors of the primary adverse outcome. They were factors representing previous history, symptoms and ECG findings. This information may contribute to the development of a decision support system for the EMS, which then needs to be clinically tested.

Patients admitted to hospital with chest pain--changes in a 20-year perspective.

OBJECTIVES: To describe the differences in characteristics and outcome between two consecutive series of patients admitted to hospital with chest pain in a 20-year perspective. Particular emphasis is placed on changes in outcome in relation to the initial electrocardiogram (ECG). SUBJECTS: In the two periods, 1986-1987 and 2008, all patients with chest pain admitted to the study hospitals in Gothenburg, Sweden, were included. RESULTS: Five thousand and sixteen patients were registered in a period of 21 months in 1986-1987 and 2287 patients were registered during 3 months in 2008. In a comparison of the two time periods, the age of chest pain patients was not significantly different (mean age 60.1 ± 17.8 years in 1986-1987 and 59.8 ± 19.1 years in 2008, p=0.50). There was a lower prevalence of previous angina pectoris, congestive heart failure and current smoking in the second period, whereas a history of acute myocardial infarction, hypertension and diabetes mellitus had become more prevalent. The use of cardio-protective drugs increased and ECG changes indicating acute myocardial ischemia on admission to hospital decreased. Length of hospitalisation was reduced from a median of 5 days to 3 days (p<0.0001). A significant decrease in 30-day and 1-year mortality was found (3.8% in 1986-1987 vs 2.0% in 2008 and 9.9% vs 6.3% respectively, p<0.0001 for both comparisons). CONCLUSIONS: During a period of 20 years, the characteristics and outcome of patients admitted to hospital with chest pain changed. The most important changes were a lower prevalence of ECG signs indicating acute myocardial ischemia on admission, shorter hospitalisation time and a lower 30-day and 1-year mortality.