Increased plasma levels of five proteins yielded significant associations with all-cause mortality in patients with co-existing AF; TIMP-4 (HR 1.33; CI95% 1.07–1.66; p = 0.010), GDF-15 (HR 1.30; CI95% 1.05–1.62; p = 0.017), GAL-3 (HR 1.29; CI95% 1.03–1.61; p = 0.029), ST-2 (HR 1.48; CI95% 1.18–1.85; p < 0.001), and MMP-3 (HR 1.33; CI95% 1.09–1.63; p = 0.006). Here, LGALS3 is linked to atrial fibrillation.