Minor elevations in troponin I are associated with mortality and adverse cardiac events in patients with atrial fibrillation.
OBJECTIVE
In patients with atrial fibrillation, minor troponin I elevation is regularly detected; however, the prognostic significance of this finding is unknown. We therefore sought to examine the prognostic value of elevated troponin I in patients with atrial fibrillation.


RESULTS
A prospective study was conducted analysing all consecutive patients admitted with atrial fibrillation in a 2-year period. Patients with an ST-elevation myocardial infarction (MI) were excluded. Minor troponin elevation was defined as a troponin I level between 0.15 and 0.65 ng/mL, which is still below the 99th percentile of the upper reference limit. A positive troponin I was defined as ≥ 0.65 ng/mL. Study outcomes were all-cause mortality (death), death and myocardial infarction (death/MI), or all major adverse cardiac events (MACE: death, MI, or revascularization). A total of 407 patients were eligible for inclusion. The median duration of follow-up was 688 days. A minor elevation occurred in 81 (20%) patients and 77 (19%) had a positive troponin I. In a multivariate model, minor troponin I elevation and a positive troponin I were independently associated with death [hazard ratio (HR): 2.36, 95% confidence interval (CI): 1.17-4.73 for minor elevation and HR: 3.77, 95% CI: 1.42-10.02 for positive troponin I]. Also, there was an independent correlation between the combined endpoints of death/MI and MACE and both a minor elevation and a positive troponin I.


CONCLUSIONS
Minor elevations in troponin I on hospital admission are associated with mortality and cardiac events in patients with atrial fibrillation and might be useful for risk stratification.
Cardiology Department, Albert Schweitzer Hospital, Dordrecht, The Netherlands. e.j.vanden.bos@asz.com
Ewout J
EJ
van den Bos
Alina A
AA
Constantinescu
Ron T
RT
van Domburg
Sakir
S
Akin
Luc J
LJ
Jordaens
Marcel J M
MJ
Kofflard
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000378:metabolism / Q000401:mortality*; D015415:Biomarkers / Q000378:metabolism; D002423:Cause of Death; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality; D017202:Myocardial Ischemia / Q000401:mortality; D009204:Myocardial Revascularization / Q000401:mortality; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D019210:Troponin I / Q000378:metabolism*
D015415:Biomarkers; D019210:Troponin I