Prospective analysis of creatine kinase muscle-brain fraction and comparison with troponin T to predict cardiac risk and benefit of an invasive strategy in patients with non-ST-elevation acute coronary syndromes.

Abstract

OBJECTIVE:

We sought to determine whether elevation of plasma creatine kinase muscle-brain fraction (CK-MB) would be useful to triage patients with acute coronary syndromes (ACS) to early angiography/revascularization.

BACKGROUND:

It is unknown whether the measurement of CK-MB is effective for triage to an aggressive management strategy.

METHOD:

Patients in the Treat Angina With Aggrastat and Determine Cost of Therapy With an Invasive or Conservative Strategy (TACTICS-TIMI) 18 study received aspirin, heparin, and tirofiban for treatment of ACS, were randomized to an invasive or a conservative strategy (angiography/revascularization between 4 and 48 h), and were followed up for a composite end point of death, myocardial infarction, or rehospitalization for ACS. Of 2,220 patients, CK-MB was elevated in 826 (37%). Of the patients with negative CK-MB, troponin T was elevated in 361 (31.2%). Event rates at 30 and 180 days were twice as high in patients with elevated CK-MB than in patients without elevated CK-MB. Both groups had similar benefit from an invasive strategy; there was no evidence of interaction between CK-MB elevation and strategy on the composite end point at 30 or 180 days. When patients were stratified according to both CK-MB and troponin status, there was evidence of a benefit in the invasive strategy among patients who were CK-negative but troponin-positive (odds ratios [95% confidence interval]: 0.13 [0.04 to 0.39] at 30 days and 0.29 [0.16 to 0.52] at 180 days).

CONCLUSION:

Patients with minimal amounts of recent onset myonecrosis but elevated risk as indicated by CK-MB and troponin, respectively, benefit most from invasive management. Determination of troponin levels yielded significant information regarding triage to an invasive strategy, particularly in CK-MB-negative patients.

• Authors: Neal S Kleiman, Nasser Lakkis, Christopher P Cannon, Sabina A Murphy, Peter M DiBattiste, Laura A Demopoulos, William S Weintraub, Eugene Braunwald, TACTICS-TIMI 18 Investigators
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 40 Issue 6 Pg. 1044-50 (Sep 18 2002) ISSN: 0735-1097 [Print] United States
• PMID: 12354426 (Publication Type: Clinical Trial, Comparative Study, Journal Article, Randomized Controlled Trial)

Chemical References

• Isoenzymes
• Troponin T
• Creatine Kinase
• Creatine Kinase, MB Form

Topics

• Acute Disease
• Aged
• Coronary Angiography
• Coronary Disease (blood, diagnostic imaging, surgery)
• Creatine Kinase (blood)
• Creatine Kinase, MB Form
• Female
• Humans
• Isoenzymes (blood)
• Male
• Middle Aged
• Myocardial Revascularization (adverse effects)
• Outcome Assessment, Health Care
• Predictive Value of Tests
• Prospective Studies
• Risk Assessment
• Syndrome
• Time Factors
• Troponin T (blood)