title: Association of contemporary sensitive troponin I levels at baseline and change at 1 year with long-term coronary events following myocardial infarction or unstable angina: results from the LIPID Study (Long-Term Intervention With Pravastatin in Ischaemic Disease).
abstract: OBJECTIVE
  This study sought to assess whether baseline and change in contemporary sensitive troponin I (TnI) levels predicts coronary heart disease (CHD) death and myocardial infarction (MI), and to determine the effects of pravastatin on TnI levels.
  
  
  BACKGROUND
  The role of troponins in predicting long-term outcomes in patients with stable CHD is not clearly defined.
  
  
  METHODS
  The LIPID (Long-Term Intervention With Pravastatin in Ischaemic Disease) study randomized patients with cholesterol levels of 155 to 271 mg/dl 3 to 36 months after MI or unstable angina to placebo or pravastatin 40 mg per day. TnI levels were measured at baseline and after 1 year in 7,863 patients. Median follow-up was 6 years. Change in TnI was defined as moving up or down 1 tertile or ≥50% change.
  
  
  RESULTS
  Baseline TnI tertiles were <0.006 ng/ml, 0.006 to <0.018 ng/ml, and ≥0.018 ng/ml. TnI levels were related to CHD death and MI after adjustment for 23 risk factors and treatment (≥0.018 ng/ml vs. <0.006 ng/ml hazard ratio [HR]: 1.64; 95% CI: 1.41 to 1.90; p < 0.001). TnI levels increased in 23.0%, were unchanged in 51.3%, and decreased in 25.7% of patients. Pravastatin decreased TnI levels by 0.003 ng/ml versus placebo (p = 0.002). In landmark analyses, increases in TnI levels were associated with increased numbers of CHD death and MI (HR: 1.31; 95% CI: 1.06 to 1.62) and decreases with decreased risk (HR: 0.90; 95% CI: 0.74 to 1.09; overall p = 0.01). Data were similar with 50% change criteria. Net reclassification improvement by adding TnI to the baseline model for CHD death and MI was 4.8% (p = 0.01).
  
  
  CONCLUSIONS
  Baseline TnI levels and change at 1 year are independent predictors of CHD death and MI. TnI levels are strong predictors of risk, and change modifies risk.
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital and Auckland University, Auckland, New Zealand. Electronic address: harveyw@adhb.govt.nz.
authors.forename: Harvey D
authors.initials: HD
authors.lastname: White
authors.affiliation: Monash University, Melbourne, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Tonkin
authors.affiliation: NHMRC Clinical Trials Centre, University of Sydney, Sydney, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Simes
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital and Auckland University, Auckland, New Zealand.
authors.forename: Ralph
authors.initials: R
authors.lastname: Stewart
authors.affiliation: NHMRC Clinical Trials Centre, University of Sydney, Sydney, Australia.
authors.forename: Kristy
authors.initials: K
authors.lastname: Mann
authors.affiliation: University of Western Australia, Perth, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Thompson
authors.affiliation: University of Queensland, Brisbane, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Colquhoun
authors.affiliation: University of Queensland, Brisbane, Australia.
authors.forename: Malcolm
authors.initials: M
authors.lastname: West
authors.affiliation: Baker IDI Heart & Diabetes Institute, Melbourne, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Nestel
authors.affiliation: Royal Prince Alfred Hospital, Camperdown, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Sullivan
authors.affiliation: NHMRC Clinical Trials Centre, University of Sydney, Sydney, Australia.
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Keech
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital and University of Melbourne, Melbourne, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Hunt
authors.affiliation: University Heart Centre Hamburg, Hamburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Blankenberg
mesh_terms: D000328:Adult; D000368:Aged; D000789:Angina, Unstable / Q000097:blood* / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D003327:Coronary Disease / Q000097:blood / Q000401:mortality; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000453:epidemiology; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000097:blood* / Q000453:epidemiology; D020097:Natriuretic Peptide, Brain / Q000097:blood; D017035:Pravastatin / Q000627:therapeutic use*; D018570:Risk Assessment; D020521:Stroke / Q000097:blood / Q000453:epidemiology; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D019210:Troponin I; D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein; D017035:Pravastatin
keywords: B-type natriuretic peptide; BNP; CHD; CVD; LIPID; MI; TnI; cardiovascular disease; coronary heart disease; high-sensitivity C-reactive protein; high-sensitivity troponinT; hsCRP; hsTnT; mortality; myocardial infarction; troponin I