Growth-differentiation factor 15 for long-term prognostication in patients with non-ST-elevation acute coronary syndrome: an Invasive versus Conservative Treatment in Unstable coronary Syndromes (ICTUS) substudy.

BACKGROUND: No five-year long-term follow-up data is available regarding the prognostic value of GDF-15. Our aim is to evaluate the long-term prognostic value of admission growth-differentiation factor 15 (GDF-15) regarding death or myocardial infarction (MI) in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS).

METHODS: This is a subanalysis from the ICTUS (Invasive versus Conservative Treatment in Unstable coronary Syndromes) trial, including troponin positive NSTE-ACS patients. The main outcome for the current analysis was 5-year death or spontaneous MI. GDF-15 samples were available in 1151 patients. The prognostic value of GDF-15, categorized into <1200 ng/L, 1200-1800 ng/L and >1800 ng/L, was assessed in unadjusted and adjusted Cox regression models. Adjustments were made for identified univariable risk factors. The additional discriminative and reclassification value of GDF-15 beyond the independent risk factors was assessed by the category-free net reclassification improvement (1/2 NRI(>0)) and the integrated discrimination improvement (IDI) RESULTS: Compared to GDF-15<1200 ng/L, a GDF-15>1800 ng/L was associated with an increased hazard ratio for death or spontaneous MI, mainly driven by mortality. GDF-15 levels were predictive after adjustments for other identified predictors. Additional discriminative value was shown with the IDI, not with the NRI.

CONCLUSION: In patients presenting with NSTE-ACS and elevated troponin T, GDF-15 provides prognostic information in addition to identified predictors for mortality and spontaneous MI and can be used to identify patients at high risk during long-term follow-up.