Growth differentiation factor-15 (GDF-15) has appeared as a promising biomarker with strong predictive abilities in acute coronary syndrome (ACS). However, studies are solely based on single measurements in the acute phase of an ACS event. The way GDF-15 patterns in post-ACS patients behave on the long term is largely unknown. We conducted a nested case-control study within our multicenter, prospective, observational biomarker study (BIOMArCS) of 844 ACS patients. Following an index ACS event, high-frequency blood sampling was performed during 1-year of follow-up. GDF-15 was determined batchwise by electrochemiluminescence immunoassays in 37 cases with a recurrent event during 1-year follow-up, and in 74 event-free controls. Cases and controls had a mean ± standard deviation age of 66.9 ± 11.3 years and 81% were men. From 30 days onwards, patients showed stable levels, which were on average 333 (95% confidence interval 68 to 647) pg/mL higher in cases than controls (1704 vs 1371 pg/mL; p value 0.013). Additionally, in the post 30-day period, GDF-15 showed low within-individual variability in both cases and controls. In conclusion, post-ACS patients experiencing a recurrent event had stable and systematically higher GDF-15 levels during 30-day to 1-year follow-up than their event-free counterparts with otherwise similar clinical characteristics. Thus, postdischarge blood sampling might be used throughout the course of 1 year to improve prognostication, whereas, in view of the low within-individual variation, the number of repeated sampling moments might be limited.