Comparison of coagulation monitoring using ROTEM and Sonoclot devices in cardiac surgery: a single-center prospective observational study.

BACKGROUND: Viscoelastic tests (VETs) are recommended during cardiac surgery to monitor coagulation status and guide transfusion. We compared the results of two VETs, the Sonoclot Analyzer and the ROTEM Sigma. Agreement between viscoelastic tests' subdiagnoses and overall diagnosis severity was assessed. Correlations with conventional coagulation tests (CCT) and the discriminatory potential of numerical VET outputs for transfusion thresholds was determined. METHODS: Single-center, prospective observational study in a tertiary academic center. In fifty adult patients undergoing elective cardiac surgery, parallel Sonoclot, ROTEM and CCT analysis was performed before heparin, or after protamine or coagulation product administration. All patients completed the study, resulting in 139 data points. RESULTS: Agreement on the severity of coagulation disorders was acceptable (83%), but poor (27%) on the differentiation of the underlying causes. Correlations between ROTEM parameters and CCT were good (postprotamine: FIBTEM A5 (r2=0.90 vs. fibrinogen) and EXTEM-FIBTEM A5 difference (r2=0.81 vs. platelet count). Sonoclot correlated less (Clot Rate (r2=0.25 vs. fibrinogen) and Platelet Function (r2=0.43 vs. platelet count). This was reflected in the discriminatory potential of these parameters as found by linear mixed modelling. We suggest clinically useful grey zones for VET cutoff interpretation. CONCLUSIONS: ROTEM and Sonoclot accord well on the detection of severity of coagulation dysfunction, but not on the diagnosis of the underlying cause. ROTEM correlated more closely with CCT then Sonoclot. We propose a testing strategy that could lead to a cost-effective approach to the bleeding cardiac surgery patient.

Incongruous effect of phenylephrine on changes in cerebral blood volume measured by near-infrared spectroscopy (NIRS) indicating extracranial contamination.

We assessed extracranial contamination of the near-infrared spectroscopy (NIRS) signal during administration of phenylephrine. The study was performed with NIRO 200NX which employs both the Modified Beer-Lambert (MBL) method to measure total hemoglobin (tHb, expressed in µM), and Spatially Resolved Spectroscopy (SRS) to measure total hemoglobin content (nTHI, expressed in arbitrary units (a.u.)). SRS tends to not be affected by extracranial blood flow. As vasoconstriction with phenylephrine mainly occurs in the extracranial area, we hypothesized that if NIRS measurements are indeed prone to extracranial contamination, tHb will be more affected by the administration of phenylephrine than nTHI. After ethical committee approval, 20 consenting cardiac surgery patients were included. Phenylephrine was administered whenever clinically indicated and its effect on nTHI and tHb was evaluated. To adjust for the difference in raw scale units, Z-scores were calculated. Data were analyzed with Wilcoxon Signed Ranks Test and the Hodges-Lehmann method. A total of 191 data sets were obtained in 20 patients (10 male, 65 ± 15 years, 77 ± 16 kg, 166 ± 11 cm). The median difference before and after administration of phenylephrine was - 0.006 a.u. [95%CI - 0.010 to - 0.002] (p < 0.001) and - 0.415 µM [95%CI - 0.665 to - 0.205] (p < 0.001) for nTHI and tHb, respectively. The median difference between the Z-scores of nTHI and tHb was - 0.02 [95%CI - 0.04 to - 0.003] (p = 0.03), with a higher variability in the Z-scores of tHb. Phenylephrine induced significant larger changes in MBL values compared to SRS values, indicating that the MBL method might be more prone to extracranial contamination. Trial and clinical registry: Trial registration number: B670201939459, ethical committee number: 2019/0265, date of approval: March 19, 2019.

Repeat procedures after second-generation cryoballoon ablation as an index procedure for persistent atrial fibrillation: one-year follow-up.

PURPOSE: Data indicate that the second-generation cryoballoon (Arctic Front Advance, Medtronic, Minnesota, USA) could be effective for persistent atrial fibrillation. However, electrophysiological findings and the midterm clinical outcome of repeat procedures following second-generation cryoballoon ablation are lacking. METHODS: Consecutive patients with drug-resistant persistent atrial fibrillation who underwent a repeat ablation due to arrhythmia recurrence following an index procedure with second-generation cryoballoon were retrospectively included in our analysis. A total of 24 patients were included. Twenty underwent repeat procedures because of atrial fibrillation or left atrial arrhythmias and four because of typical atrial flutter. Mean time to recurrence of atrial tachyarrhythmias was 6.6 ± 3 months. Mean redo procedural time was 122 ± 23 min. RESULTS: At a mean follow-up of 11.8 ± 6.5 months, 15 patients (75 %) did not experience recurrence of atrial arrhythmias. Of the five patients (25 %) who had recurrence of atrial tachyarrhythmia, four presented with persistent atrial fibrillation and one with a mitral isthmus-dependent flutter. Of note is that the four patients with typical flutter were free from atrial tachycardia recurrence after the redo procedure. Two patients (9 %) underwent a third procedure. Mean time to recurrence of atrial arrhythmias from the repeat procedure was 9 ± 1 months. CONCLUSIONS: Our findings show that repeat ablation procedures following a second-generation cryoballoon ablation for persistent atrial fibrillation result in 75 % of freedom from any atrial tachycardia at 12 months follow-up. Of the recurrences, 63 % were due to new onset of atrial fibrillation and 37 % to organized tachycardias.