Troponin T and quantitative ST-segment depression offer complementary prognostic information in the risk stratification of acute coronary syndrome patients.

Abstract

OBJECTIVES:

Our primary objective was to examine the prognostic relationship between baseline quantitative ST-segment depression (ST) and cardiac troponin T (cTnT) elevation. The secondary objectives were to: 1) examine whether ST provided additional insight into therapeutic efficacy of glycoprotein IIb/IIIa therapy similar to that demonstrated by cTnT; and 2) explore whether the time to evaluation impacted on each marker's relative prognostic utility.

BACKGROUND:

The relationship between the baseline electrocardiogram (ECG) and cTnT measurements in risk-stratifying patients presenting with acute coronary syndromes (ACS) has not been evaluated comprehensively.

METHODS:

The study population consisted of 959 patients enrolled in the cTnT substudy of the Platelet IIb/IIIa Antagonism for the Reduction of Acute coronary syndrome events in a Global Organization Network (PARAGON)-B trial. Patients were classified as having no ST (n = 387), 1 mm ST (n = 433), and ST > or =2 mm (n = 139). Forty-percent (n = 381) were classified as cTnT-positive based on a definition of > or =0.1 ng/ml.

RESULTS:

Six-month death/(re)myocardial infarction rates were 8.4% among cTnT-negative patients with no ST and 26.8% among cTnT-positive patients with ST > or =2 mm. On ECGs done after 6 h of symptom onset, ST > or =2 mm was associated with higher risk compared to its presence on ECGs done earlier (odds ratio [OR] 7.3 vs. 2.1). In contrast, the presence of elevated cTnT within 6 h of symptom was associated with a higher risk of adverse events compared with elevations after 6 h (OR 2.4 vs. 1.5).

CONCLUSIONS:

Quantitative ST and cTnT status are complementary in assessing risk among ACS patients and both should be employed to determine prognosis and assist in medical decision making.

• Authors: Padma Kaul, L Kristin Newby, Yuling Fu, Vic Hasselblad, Kenneth W Mahaffey, Robert H Christenson, Robert A Harrington, E Magnus Ohman, Eric J Topol, Robert M Califf, Frans Van de Werf, Paul W Armstrong, PARAGON-B Investigators
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 41 Issue 3 Pg. 371-80 (Feb 05 2003) ISSN: 0735-1097 [Print] United States
• PMID: 12575962 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Acetates
• Platelet Aggregation Inhibitors
• Platelet Glycoprotein GPIIb-IIIa Complex
• Troponin T
• Tyrosine
• lamifiban

Topics

• Acetates (therapeutic use)
• Acute Disease
• Aged
• Coronary Disease (blood, drug therapy, physiopathology)
• Electrocardiography (drug effects)
• Female
• Humans
• Male
• Middle Aged
• Platelet Aggregation Inhibitors (therapeutic use)
• Platelet Glycoprotein GPIIb-IIIa Complex (antagonists & inhibitors, therapeutic use)
• Prognosis
• Risk Assessment
• Syndrome
• Time Factors
• Troponin T (blood, drug effects)
• Tyrosine (analogs & derivatives, therapeutic use)