Association of contemporary sensitive troponin I levels at baseline and change at 1 year with long-term coronary events following myocardial infarction or unstable …

HD White, A Tonkin, J Simes, R Stewart, K Mann… - Journal of the American …, 2014 - jacc.org
HD White, A Tonkin, J Simes, R Stewart, K Mann, P Thompson, D Colquhoun, M West…
Journal of the American College of Cardiology, 2014jacc.org
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 …
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.
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