Copeptin assessment to predict vasoplegia after cardiopulmonary by-pass. An observational cohort study.

Abstract Background Post-cardiotomy vasoplegic syndrome is a vasodilatory shock characterized by a decrease of vascular tone with a normal or increased cardiac output. A relative deficit in vasopressin secretion in the postoperative was hypothesized. Copeptin is secreted in equimolar ratio with vasopressin but it is more stable and easier to measure. The aim of the present study was to investigate whether perioperative copeptin was associated with post-cardiotomy vasoplegic syndrome. Methods All patients scheduled for cardiac surgery were evaluated. Exclusion criteria were age < 18 years old, corticosteroids therapy, heart transplantation, extra-circulatory life support, sepsis, preoperative use of vasoactive drugs, off-pump surgery, chronic hepatic and renal failure, paraneoplastic syndrome, lack of informed consent. Post-cardiotomy vasoplegic syndrome was defined as a mean arterial pressure < 60 mmHg, a reduction of systemic vascular resistances < 1200 dyn*s/cm 5 *m 2 and/or the need of nor-epinephrine ³ 0.1 µg/kg/min. All patients underwent a preoperative evaluation of the corticotropin stimulation test; then, before surgery (T0), on day one after surgery (T1) and after 7 days (T2) copeptin and NT-proBNP concentration were measured. Results Among 55 enrolled patients, 9 (16.3%) developed post-cardiac surgery vasoplegia. Patients with vasoplegia had higher preoperative level of copeptin (19.2 pmol/L, IQR 17.89 – 21.29 vs 11.39 pmol/L, IQR 6.33 - 14.78; p < 0.001) and NT-proBNP (1435 pg/ml, IQR 721.75 – 1836.25 vs 365.5 pg/ml, IQR 141 - 977); p = 0.006) compared to the control group. At the multivariable analysis, preoperative copeptin resulted a significant predictor of vasoplegia (OR 1.56, 95% CI 1.002-1.33) and the ROC analysis showed an accurate copeptin cut off able to identify vasoplegic patients (> 16.9 pmol/L, AUC = 0.86, 95% CI 0.73-0.94). Otherwise, a lack of response to the low dose corticotropin test was not a predictor of PCVS; no patient presented a pathological response to the standard dose test. ConclusionsIncreased preoperative copeptin and NT-proBNP levels might be associated with an increased risk to develop post-cardiotomy vasoplegic syndrome. Our results suggest that patients with a decompensated neuroendocrine control of cardiovascular function are more prone to develop postoperative vasoplegia.