Elevated copeptin is a prognostic factor for mortality even in patients with renal dysfunction

Abstract

BackgroundCopeptin has turned out to give valuable prognostic information for future cardiovascular events. However, since its plasma concentration directly depends on renal function, the value of copeptin as a predictor for outcome also in patients with chronic kidney disease (CKD) is unknown. MethodsIn this single-center substudy of the German Coronary Artery Disease–REnal Failure (CAD-REF) registry, 301 patients with an angiographically diagnosed stenosis ≥50% in at least one major coronary vessel were included. Estimated glomerular filtration rate (eGFR) was determined using the MDRD formula and patients were classified according to their CKD stage. Copeptin concentrations were measured before initial angiography. Follow-up was performed at 180days, study endpoint was all-cause mortality. ResultsOf the 301 included patients, 35 (11.6%) patients had no CKD, 113 (37.5%) had CKD stage 1 or 2, 117 (38.9%) had CKD stage 3, and 36 (12.0%) had CKD stage 4 or 5. Copeptin was elevated (≥14pmol/L) in 81 (26.9%) patients and normal (<14pmol/L) in 220 (73.1%) patients. Copeptin values significantly increased with decreasing eGFR (p<0.001) and were strongly correlated with creatinine values (r=0.567, p<0.001). During 180days of follow-up, 15 patients (5.0%) died, 10 of them with elevated copeptin values. Multivariate Cox regression analysis showed that copeptin was the sole predictor for mortality (HRR 5.317 (95% CI 1.653–17.098), p=0.005), independent of serum creatinine. ConclusionElevated copeptin can be used as a valuable prognostic factor for intermediate-term mortality in patients with both coronary artery and renal disease.