Validation of an algorithm to predict decline in INR following warfarin cessation in patients undergoing invasive procedures

Acute-to-chronic subdural hematoma: radiographic and clinical progression from acute subdural hematoma

INTRODUCTION

The pathogenesis of chronic subdural hematoma (CSDH) has not been completely understood. However, different mechanisms can result in space-occupying subdural fluid collections, one pathway can be the transformation of an original trauma-induced acute subdural hematoma (ASDH) into a CSDH.

MATERIALS AND METHODS

All patients with unilateral CSDH, requiring burr hole trephination between 2018 and 2023 were included. The population was distributed into an acute-to-chronic group (group A, n = 41) and into a conventional group (group B, n = 282). Clinical and radiographic parameters were analyzed. In analysis A, changes of parameters after trauma within group A are compared. In analysis B, parameters between the two groups before surgery were correlated.

RESULTS

In group A, volume and midline shift increased significantly during the progression from acute-to-chronic (p < 0.001, resp.). Clinical performance (modified Rankin scale, Glasgow Coma Scale) dropped significantly (p = 0.035, p < 0.001, resp.). Median time between trauma with ASDH and surgery for CSDH was 12 days. Patients treated up to the 12th day presented with larger volume of ASDH (p = 0.012). Before burr hole trephination, patients in group A presented with disturbance of consciousness (DOC) more often (p = 0.002), however less commonly with a new motor deficit (p = 0.014). Despite similar midline shift between the groups (p = 0.8), the maximal hematoma width was greater in group B (p < 0.001).

CONCLUSION

If ASDH transforms to CSDH, treatment may become mandatory early due to increase in volume and midline shift. Close monitoring of these patients is crucial since DOC and rapid deterioration is common in this type of SDH.

Cost-Benefit Analysis of Genotype-Guided Interruption Days in Warfarin Pre-Procedural Management

BACKGROUND

Warfarin is commonly used in thromboembolic conditions. Warfarin interruption represents a significant challenge in pre-operative warfarin management as it is associated with major consequences. Genetics polymorphism demonstrated to be a significant predictor of the required days of warfarin interruption. This study sought to assess the economic benefit of implementing a pharmacogenetic-guided approach in the preprocedural warfarin management.

METHODS

From the hospital's perspective, a cost-benefit analysis was conducted based on a one-year decision-analytic follow-up model of the economic implications of using a pharmacogenetic algorithm versus standard of care in pre-operative warfarin management in the Hamad Medical Corporation, Qatar. The benefit of the interventional algorithm was based on estimated reduction in the probabilities of clinical events and their cost, added to the avoided cost because of canceled procedures. The cost of the algorithm was the cost of the genotyping assay. The model event probability inputs were extracted from major literature clinical trials, and the setting-specifc and cost inputs were locally obtained. The model was based on a multivariate analysis at its base case.

RESULTS

As per 10.3% prevalence of genetic variants, 82% bridging, and a calculated 20% optimization in the preparative period of warfarin management, the benefit to cost ratio was 4.0 in favor genotype-guided approach. This positive benefit to cost ratio was maintained in 100% of the simulated study cases. Sensitivity analyses confirmed the robustness and generalizability of the study conclusion.

CONCLUSION

A pharmacogenetic- guided pre-operative warfarin interruption management is a cost-beneficial approach in the Qatari practice.