Prognostic value of biochemical markers, 12-lead ECG and patient characteristics amongst patients calling for an ambulance due to a suspected acute coronary syndrome.
OBJECTIVE
To evaluate whether a 12-lead ECG, together with a multi-marker strategy that used point-of-care measurements of myoglobin, creatine kinase (CK-MB) and troponin I, was able to predict patients at short- and long-term risk of death, when simultaneously considering age, gender, previous history, symptoms and clinical findings on arrival of the ambulance.


METHODS
Prospective observational study.


METHODS
Consecutive patients (n=511) in ambulances in Stockholm and Göteborg in Sweden who called for an ambulance due to chest pain or other symptoms raising a suspicion of acute coronary syndrome.


METHODS
In almost all patients, a diagnostic ECG, patient baseline characteristics and measurements of CK-MB, troponin I and myoglobin were recorded.


RESULTS
In univariate analysis, the highest 30-day mortality (17%) was found amongst patients with the combination of ECG signs of myocardial ischaemia and the elevation of any biochemical marker. The highest 1-year mortality (20%) was found amongst patients with ECG signs of myocardial ischaemia and the elevation of any biochemical marker. Increasing age (RR 1.07; 95 CI 1.02-1.13) lack of symptoms of chest pain and a previous history of hypertension (3.02; 1.08-8.79) were independent predictors of 30-day mortality. Myoglobin was the only biochemical marker independently associated with 30-day mortality (6.66; 1.83-22.3). Increasing age (1.11; 1.06-1.16), previous history of diabetes (3.42; 1.41-8.25) heart failure (2.64; 1.26-5.52) and other symptoms than chest pain and dyspnoea (5.23; 2.14-12.76) were independent predictors of 1-year mortality. In many of the variables the confidence limits were wide.


CONCLUSIONS
Amongst patients with a clinical suspicion of acute coronary syndrome, those with the combination of ECG signs of myocardial ischaemia and the elevation of any biochemical marker on arrival of the ambulance form a group with a particularly high risk of death. However, age as well as aspects of clinical history and type of symptoms independently contribute to prognostic information.
Svensson
L
L
Division of Cardiology, South Hospital, Stockholm, Sweden. leif.svensson@sos.sll.se
Axelsson
C
C
Nordlander
R
R
Herlitz
J
J
D000208:Acute Disease; D000367:Age Factors; D000368:Aged; D000552:Ambulances; D015415:Biomarkers / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D004562:Electrocardiography / Q000379:methods*; D004630:Emergencies; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis / Q000401:mortality; D017202:Myocardial Ischemia / Q000097:blood / Q000175:diagnosis / Q000401:mortality*; D009211:Myoglobin / Q000097:blood; D010342:Patient Acceptance of Health Care; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D019210:Troponin I / Q000097:blood
D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D019210:Troponin I; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form