A retrospective validation of ROTEM algorithms for detecting hyperfibrinolysis demonstrates poor agreement for prediction of in-hospital mortality and transfusion requirement in a general, non-cardiac, surgical population.

INTRODUCTION: Hyperfibrinolysis diagnosed on Rotational Thromboelastography (ROTEM) is associated with increased transfusion requirements and mortality in trauma. The diagnosis and significance of hyperfibrinolysis in a mixed, non-cardiac, general surgical population has not been investigated. We aimed to measure agreement between four ROTEM algorithms for diagnosing hyperfibrinolysis and transfusion requirements and mortality in general surgical patients. These algorithms mostly incorporate measures of early or late clot amplitude reduction on the Extrinsic Clotting Pathway Test with Tissue Factor (EXTEM) channel. METHOD: Four hospital administrative data sets were linked from 2019 to 2022. Adults >18 years were included if a ROTEM was performed during their surgery (intraoperative period) or within 24-h of the surgery completion (postoperative period). The four hyperfibrinolysis criteria were applied to the ROTEM data and assessed for their agreement, intraoperative and postoperative transfusion requirements and in-patient mortality. RESULTS: We linked 933 ROTEMs to 558 patient-procedures. One algorithm identified hyperfibrinolysis on only three patients so was excluded. Agreement between the remaining three was slight (Cohens Kappa 0.18 (p < 0.001)) with hyperfibrinolysis diagnosed between 22 and 69 % of the procedures. The association between hyperfibrinolysis diagnosis and intraoperative or postoperative transfusion requirement was inconsistent between the criteria. However, an algorithm put forward by Goerling et al. was more often associated with transfusion requirement and inpatient mortality. DISCUSSION: The poor agreement between criteria suggests that some ROTEM criteria may not transfer directly to general surgical patients. Future research should focus on optimising hyperfibrinolysis cut-off values to update algorithms for bleeding general surgical patients.

Measurement of diffuse ventricular fibrosis with myocardial T1 in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is associated with cardiac fibrosis, which can now be measured noninvasively using T1-mapping with cardiac magnetic resonance imaging (CMRI). This study aimed to assess the impact of AF on ventricular T1 at the time of CMRI. METHODS: Subjects with AF scheduled for AF ablation underwent CMRI with standard electrocardiography gating and breath-hold protocols on a 1.5 T scanner with post-contrast ventricular T1 recorded from 6 regions of interest at the mid-ventricle. Baseline demographic, clinical, and imaging characteristics were examined using univariate and multivariable linear regression modeling for an association with myocardial T1. RESULTS: One hundred fifty-seven patients were studied (32% women; median age, 61 years [interquartile range {IQR}, 55-67], 50% persistent AF [episodes>7 days or requiring electrical or pharmacologic cardioversion], 30% in AF at the time of the CMRI). The median global T1 was 404 ms (IQR, 381-428). AF at the time of CMRI was associated with a 4.4% shorter T1 (p=0.000) compared to sinus rhythm when adjusted for age, sex, persistent AF, body mass index, congestive heart failure, and renal dysfunction (estimated glomerular filtration rate<60). A post-hoc multivariate model adjusted for heart rate suggested that heart rate elevation (p=0.009) contributes to the reduction in T1 observed in patients with AF at the time of CMRI. No association between ventricular T1 and AF recurrence after ablation was demonstrated. CONCLUSION: AF at the time of CMRI was associated with lower post-contrast ventricular T1 compared with sinus rhythm. This effect was at least partly due to elevated heart rate. T1 was not associated with the recurrence of AF after ablation.