Exercise dynamics of cardiac biomarkers and hemoconcentration in patients with chronic systolic heart failure.

BACKGROUND Mid-regional pro-atrial natriuretic peptide (MR-proANP), mid-regional pro-adrenomedullin (MR-proADM), copeptin, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin measured by ultrasensitive assays (single-molecule troponin I, sm-TnI) provide prognostic information in patients with chronic systolic heart failure (HF). Exercise dynamics of these biomarkers and their post-exercise prognostic impact remain largely unknown. METHODS AND RESULTS A total of 108 patients with HF and 25 controls underwent exercise stress testing. Biomarker levels and total protein concentration were measured before and immediately after exercise. During a follow-up of 1050±664 days, sixty patients experienced an adverse outcome defined as death, urgent heart transplantation or mechanical circulatory support implantation. Exercise induced significant hemoconcentration assessed as total protein (TP) increase that was comparable in control subjects and patients with HF after the correction for achieved workload (0.006 ± 0.002 g.dL-1.watt-1 for controls and 0.008 ± 0.005 g.dL-1.watt-1 for patients with HF, p=0.11). After correction for TP, exercise-induced increase in sm-cTnI was caused by hemoconcentration alone. In contrast, MR-proANP, NT-proBNP, copeptin and MR-proADM showed significant exercise-induced dynamics independent of hemoconcentration. Both baseline and post-exercise levels of NT-proBNP, MR-proANP, MR-proADM and copeptin were associated with adverse outcomes. Predictive value of baseline and post-exercise levels did not differ. CONCLUSION MR-proANP, NT-proBNP, MR-proADM and copeptin showed significant hemoconcentration-independent dynamics upon exercise. Biomarkers measured immediately after exercise provided similar prognostic information as their baseline levels.