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
White, HD; West, M; Tonkin, A; Sullivan, D; Thompson, P; Colquhoun, D; Keech, AC; Hunt, D; Stewart, R; Mann, K; for the LIPID study investigators; Blankenberg, S; Nestel, P; Simes, J
Abstract
OBJECTIVES:
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.
Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
| Journal | J AM COLL CARDIOL |
| ISSN | 0735-1097 |
| Published | 04 Feb 2014 |
| Volume | 63 |
| Issue | 4 |
| Pages | 345-54 |
| DOI | 10.1016/j.jacc.2013.08.1643 |
| Type | Journal Article |
| Sponsorship |
NHMRC: 512657, 490968; Other
|