CARDIOVASCULAR MEDICINE

Long term risk stratification of patients with acute coronary syndromes: characteristics of troponin T testing and continuous ST segment monitoring

B L Nørgaard¹, K Andersen², K Thygesen¹, J Ravkilde¹, P Abrahamsson², L Grip², M Dellborg²

¹ Department of Medicine and Cardiology A, Aarhus University Hospital, Aarhus, Denmark
² Department of Medicine and Cardiology, Sahlgrenska University Hospital, Göteborg, Sweden

Correspondence to:
Correspondence to:
Dr Bjarne L Nørgaard
Department of Cardiology B, Aarhus University Hospital, Skejby Hospital, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark; bnorgaard{at}dadlnet.dk

Objective: To examine the long term prognostic characteristics of troponin T testing and continuous multi-lead ST segment monitoring in combination with clinical and 12 lead ECG risk indicators in patients with acute coronary syndromes (ACS).

Patients and design: Patients with suspected ACS (n = 213) were studied. Troponin T was analysed in blood samples collected during the first 12 hours after admission. Continuous vectorcardiography ST segment monitoring was performed for 24 hours and the number of ST vector magnitude episodes was registered. Patients were followed up for a median of 28 months. The end point was a composite of cardiac death and acute myocardial infarction.

Results: Thirty eight (18%) patients reached the composite end point. The median (interquartile range) time from study inclusion to the time of the composite end point was longer for patients predicted to be at risk by troponin T testing (n = 27) than for those predicted to be at risk by ST segment monitoring (n = 20) (8.4 (0.2–15) months v 0.3 (0.1–4.3) months, p = 0.04). Significant univariate predictors of the composite end point were age 65 years, diabetes, previous myocardial infarction, congestive heart failure, use of ß blockers or diuretics at admission, 12 lead ECG ST segment depression at admission, troponin T concentration 0.10 µg/l, and 1 ST vector magnitude episodes. Age 65 years, previous myocardial infarction, and troponin T concentration 0.10 µg/l provided independent prognostic information after multivariate analysis of potential risk variables. The prognostic value of transient ischaemic episodes in ACS seems to be confined to the short term.

Conclusions: Both biochemical and continuous ECG markers reflect an increased risk for patients with ACS; however, the methods exhibit different temporal risk characteristics.

Abbreviations: ACS, acute coronary syndromes; AMI, acute myocardial infarction; CI, confidence interval; HR, hazard ratio; IQR, interquartile range; ST-VM, ST vector magnitude; TRIM, thrombin inhibition in myocardial ischemia

Keywords: prognosis; myocardial infarction; troponin; vectorcardiography; electrocardiography

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Sandau, K. E., Smith, M. (2009). Continuous ST-Segment Monitoring: Protocol for Practice. Crit Care Nurse 29: 39-49 [Full Text]  
• Body, R, Carley, S, McDowell, G, Ferguson, J, Mackway-Jones, K (2009). Can a modified thrombolysis in myocardial infarction risk score outperform the original for risk stratifying emergency department patients with chest pain?. Emerg. Med. J. 26: 95-99 [Abstract] [Full Text]  
• Shah, R., Selter, J., Wang, Y., Greenspan, M., Foody, J. M. (2007). Association of Troponin Status With Guideline-Based Management of Acute Myocardial Infarction in Older Persons. Arch Intern Med 167: 1621-1628 [Abstract] [Full Text]  
• Bugiardini, R (2004). Risk stratification in acute coronary syndrome: focus on unstable angina/non-ST segment elevation myocardial infarction. Heart 90: 729-731 [Abstract] [Full Text]