Abstract 2060: Persisting Troponin I Elevations Predict Adverse Outcome in Stabilized Patients After an Episode of Acute Coronary Syndrome.
Introduction: In patients with acute coronary syndrome (ACS), any troponin elevation is associated with an increased risk for cardiovascular events. However, the prevalence and prognostic importance of persisting troponin elevations in stabilized patients after an episode of ACS is not known. We therefore measured troponin I (TnI) in stabilized patients participating in the FRISC II trial, in which patients with nonSTE-ACS were randomized to an invasive vs. a non-invasive strategy and to long-term treatment with dalteparin vs. placebo.
Method: TnI was measured in blood samples obtained 3 months after inclusion in 1017 patients without a myocardial infarction (MI) or coronary procedure within the last 14 days. TnI was analyzed using the Access AccuTnI assay (Beckman-Coulter). The 99th percentile of healthy subjects below 60 years of age, 0.02 μg/L, was chosen as prognostic cut-off. The 10% CV level of the assay was found to be at 0.012 μg/L. All patients were followed for at least 5 years.
Results: TnI at 3 months was elevated > 0.02 μg/L in 17.1% of the patients. TnI > 0.02 μg/L predicted 5-year cardiac mortality (11.5% vs 3.4%; p < 0.001) and MI (25.0% vs 14.8%; p= 0.003). The TnI-level was predictive both in patients randomized to an invasive and non-invasive strategy. Even after adjustment for gender, age, calculated creatinine-clearance and randomized strategy, TnI > 0.02 μg/L was an independent predictor of long-term cardiac mortality (OR 2.8; 95% CI 1.5–5.3; p=0.001) and, to a lesser extent, of MI (OR 1.5; 95% CI 1.0 –2.4; p=0.049).
Conclusion: Persisting TnI elevations can frequently be detected in patients with stabilized ACS with the use of a sensitive assay. TnI >0.02 μg/L in patients with stabilized ACS predicts adverse cardiac events during long-term follow-up. Our results emphasize the importance of further troponin testing in ACS patients after discharge. The occurrence of minor TnI elevations in a large proportion of patients with stabilized ACS also cast doubts on using a very low troponin level as a criterion for the diagnosis of acute MI.