Growth Differentiation Factor-8 (GDF8)/Myostatin Is a Predictor of Troponin I Peak and a Marker of Clinical Severity after Acute Myocardial Infarction

Objective: Growth differentiation factor-8 (GDF8), also known as myostatin, is a member of the transforming growth factor-beta superfamily that inhibits skeletal muscle growth. We aimed to investigate the association between GDF8 and peak troponin I levels after acute myocardial infarction (AMI). Methods: All consecutive patients admitted from June 2016 to February 2018 for type 1 AMI in the Coronary Care Unit of University Hospital of Dijon Bourgogne (France) were included in our prospective study. Blood samples were harvested on admission, and serum levels of GDF8 were measured using a commercially available enzyme-linked immunosorbent assay kit. Results: Among the 296 patients with type 1 AMI, median age was 68 years and 27% were women. GDF8 levels (median (IQR) = 2375 ng/L) were negatively correlated with age, sex and diabetes (p < 0.001 for all). GDF8 levels were higher in patients with in-hospital ventricular tachycardia or fibrillation (VT/VF) than those without in-hospital VT/VF. GDF8 was positively correlated with troponin I peak (r = 0.247; p < 0.001). In multivariate linear regression analysis, log GDF8 (OR: 21.59; 95% CI 34.08-119.05; p < 0.001) was an independent predictor of troponin I peak. Conclusions: These results suggest that GDF8 levels could reflect the extent of myocardial damage during AMI, similar to peak troponin I, which is currently used to estimate infarct size. Further studies are needed to elucidate the underlying mechanisms linking the GDF8 cytokine with troponin I levels.