Background: Plasma metabolites could be suitable as predictive biomarkers for cardiovascular pathologies or death, thereby improving the prediction of protein biomarkers. The release of acylcarnitines may be altered after coronary artery disease (CAD) in subjects with recurrent clinical outcomes, and this could be used as a prognosis tool. Methods: Patients with stable coronary artery disease (SCAD) who had suffered an acute coronary syndrome 6–9 months before were followed for up to 4.3 years for adverse events. Soluble pro-inflammatory/fibrotic proteins, and a panel of 13 amino acids and 13 acylcarnitines, were evaluated by ELISA and metabolomics analyses as potential predictors of a primary outcome [heart failure (HF) or death]. Results: Among 139 patients (67.0 years old, BMI = 28.6 kg/m2, and 71.2% male), 25 developed the primary outcome after a mean follow-up of 2.2 years. These patients showed increased plasma levels of NT-proBNP (1300 vs. 250 pg/mL; p 2 pg/mL; p = 0.043), Gal-3 (12.7 vs. 7.9 ng/mL; p 2 ng/mL; p p = 0.007, and 3.22 vs. 6.49 × 10−2 µM, p p < 0.001). Conclusions: Patients with SCAD led to recurrent HF or all-cause death. Interestingly, increased levels of plasma NGAL and Gal-3, and a reduction in propionylcarnitine, could predict the occurrence of these events.
