Background: Elevated serum levels of growth differentiation factor-15 (GDF-15), is an established risk factor for a range of cardiovascular diseases. We aimed to evaluate the predictive value of plasma GDF-15 as a biomarker for secondary cardiovascular events (CVE) in patients with atherosclerosis undergoing carotid endarterectomy (CEA). Secondly, we determined whether plasma GDF-15 was associated with carotid plaque characteristics.

Methods: Circulating GDF-15 levels were determined by Luminex assay in a cohort of 1056 patients from the Athero-Express biobank. Composite endpoint was defined as major CVE, death and peripheral vascular interventions. Findings were validated in 473 patients from the independent Carotid Plaque Imaging Project biobank.

Results: GDF-15 levels did not associate with secondary CVE in the total cohort. However, following a significant interaction with sex, it was found to be strongly, independently predictive of secondary CVE in women but not men (quartile 4 vs. quartile 1: HR 3.04 [95% CI 1.35-6.86], p=0.007 in women vs. HR 0.96 [95% CI 0.66-1.40], p=0.845 in men). This was also observed in the validation cohort (women: HR 2.28 [95% CI 1.04-5.05], p=0.041), albeit dependent upon renal function. In addition, GDF-15 was associated with the presence of plaque smooth muscle cells and calcification.

Conclusion: High circulating GDF-15 levels are predictive of secondary CVE in women but not in men with carotid atherosclerotic disease undergoing CEA, suggesting a potential use for GDF-15 as a biomarker for secondary prevention in women. Sex differences in the role of GDF-15 in atherosclerotic disease deserve further interest.