Quartiles of peak troponin are associated with long-term risk of death in type 1 and STEMI, but not in type 2 or NSTEMI patients.
BACKGROUND
The prognostic value of peak cardiac troponin (cTn) in different types of acute myocardial infarction (AMI) under the universal clinical classification is unknown.


OBJECTIVE
We tested the hypothesis that the prognostic value of cTn varies with its peak level and type of AMI.


METHODS
We studied 345 consecutive patients with AMI with mean follow-up of 30.6 months according to quartiles of peak cTn level (QPTL) and the type of AMI. The study outcomes were the major adverse cardiovascular events (MACE; composite of all causes of mortality and recurrent AMI) and the individual components of MACE.


RESULTS
The study included patients with AMI Type 1 (n = 276), type 2 (n = 54), ST-segment elevation myocardial infarction (STEMI; n = 159), and non-ST-segment elevation myocardial infarction (NSTEMI; n = 186). Overall, peak cTn level was an independent predictor of MACE (hazard ratio [HR]: 1.001, 95% confidence interval [CI]: 1.000-1.003, P = 0.01) and death (HR: 1.002, 95% CI: 1.001-1.004, P = 0.003), but not of recurrent AMI. The highest risk of MACE and death was in the highest QPTL (61.6%, P = .016 and 66.3%, P = 0.021, respectively) while the highest risk of recurrent AMI was in the lowest QPTL (83.7%, P = 0.04). Quartiles of peak cTn level were significantly associated with increased risk of MACE and death in patients with Type 1 (all P = 0.01) and STEMI (P = 0.01 and P = 0.02, respectively), but no association existed in type 2 or NSTEMI patients.


CONCLUSIONS
Overall, peak cTn predicts the risk of MACE and death but not the risk of AMI. While in Type 1 and STEMI patients, QPTL are associated with risk of MACE and death, no association exists in type 2 or NSTEMI patients.
Gonzalez
Manuel A
MA
East Carolina Heart Institute at East Carolina University, Greenville, North Carolina 27834, USA. gonzalezm@ecu.edu
Porterfield
Christopher P
CP
Eilen
Dana J
DJ
Marzouq
Rana A
RA
Patel
Hiren R
HR
Patel
Amit A
AA
Nasir
Summiyah
S
Lim
Heang M
HM
Babb
Joseph D
JD
Rose
John D
JD
Cascio
Wayne E
WE
D000368:Aged; D015415:Biomarkers / Q000097:blood; D052279:Creatine Kinase, MB Form / Q000097:blood; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D013997:Time Factors; D014336:Troponin / Q000097:blood*
D015415:Biomarkers; D014336:Troponin; D052279:Creatine Kinase, MB Form