High-sensitivity troponin I for risk assessment in patients with atrial fibrillation: insights from the Apixaban for Reduction in Stroke and other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial.

Abstract

BACKGROUND:

High-sensitivity troponin-I (hs-TnI) measurement improves risk assessment for cardiovascular events in many clinical settings, but the added value in atrial fibrillation patients has not been described.

METHODS AND RESULTS:

At randomization, hs-TnI was analyzed in 14 821 atrial fibrillation patients in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial comparing apixaban with warfarin. The associations between hs-TnI concentrations and clinical outcomes were evaluated by using adjusted Cox analysis. The hs-TnI assay detected troponin (≥1.3 ng/L) in 98.5% patients, 50% had levels >5.4, 25% had levels >10.1, and 9.2% had levels ≥23 ng/L (the 99th percentile in healthy individuals). During a median of 1.9 years follow-up, annual rates of stroke or systemic embolism ranged from 0.76% in the lowest hs-TnI quartile to 2.26% in the highest quartile (>10.1 ng/L). In multivariable analysis, hs-TnI was significantly associated with stroke or systemic embolism, adjusted hazard ratio 1.98 (1.42-2.78), P=0.0007. hs-TnI was also significantly associated with cardiac death; annual rates ranged from 0.40% to 4.24%, hazard ratio 4.52 (3.05-6.70), P<0.0001, in the corresponding groups, and for major bleeding hazard ratio 1.44 (1.11-1.86), P=0.0250. Adding hs-TnI levels to the CHA2DS2VASc score improved c-statistics from 0.629 to 0.653 for stroke or systemic embolism, and from 0.591 to 0.731 for cardiac death. There were no significant interactions with study treatment.

CONCLUSIONS:

Troponin-I is detected in 98.5% and elevated in 9.2% of atrial fibrillation patients. The hs-TnI level is independently associated with a raised risk of stroke, cardiac death, and major bleeding and improves risk stratification beyond the CHA2DS2VASc score. The benefits of apixaban in comparison with warfarin are consistent regardless of hs-TnI levels.

CLINICAL TRIAL REGISTRATION URL:

http://www.clinicaltrials.gov. Unique identifier: NCT00412984.

• Authors: Ziad Hijazi, Agneta Siegbahn, Ulrika Andersson, Christopher B Granger, John H Alexander, Dan Atar, Bernard J Gersh, Puneet Mohan, Veli-Pekka Harjola, John Horowitz, Steen Husted, Elaine M Hylek, Renato D Lopes, John J V McMurray, Lars Wallentin, ARISTOTLE Investigators
• Journal: Circulation (Circulation) Vol. 129 Issue 6 Pg. 625-34 (Feb 11 2014) ISSN: 1524-4539 [Electronic] United States
• PMID: 24226808 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Anticoagulants
• Fibrinolytic Agents
• Pyrazoles
• Pyridones
• Troponin I
• apixaban
• Warfarin

Topics

• Aged
• Anticoagulants (administration & dosage, adverse effects)
• Atrial Fibrillation (diagnosis, drug therapy, metabolism, mortality)
• Death
• Double-Blind Method
• Female
• Fibrinolytic Agents (administration & dosage, adverse effects)
• Hemorrhage (chemically induced, mortality)
• Humans
• Incidence
• Male
• Middle Aged
• Pyrazoles (administration & dosage, adverse effects)
• Pyridones (administration & dosage, adverse effects)
• Risk Assessment (methods)
• Risk Factors
• Sensitivity and Specificity
• Stroke (mortality, prevention & control)
• Thromboembolism (mortality, prevention & control)
• Treatment Outcome
• Troponin I (blood)
• Warfarin (administration & dosage, adverse effects)