# Accuracy of a point-of-care CoaguChek test versus standard laboratory coagulation monitoring in cardiac surgery involving cardiopulmonary bypass: randomized clinical trial

## TL;DR

A point-of-care CoaguChek test was found to be as accurate as standard lab tests for coagulation monitoring during heart surgery with cardiopulmonary bypass.

## Contribution

This study provides empirical evidence on the diagnostic accuracy of the CoaguChek XS device in cardiac surgery settings.

## Key findings

- CoaguChek XS showed good agreement with lab INR measurements pre- and post-cardiopulmonary bypass.
- Differences in INR readings were within a clinically irrelevant tolerance range.
- Secondary outcomes like prothrombin time and activity also aligned with standard lab results.

## Abstract

Intraoperative coagulopathies are common in complex surgeries, and timely coagulation monitoring is crucial. We assessed the accuracy of the point-of-care CoaguChek XS test against standard laboratory measurements in patients undergoing cardiac surgery with Cardiopulmonary Bypass (CPB).

We conducted a single-center, diagnostic accuracy study to assess the coagulation profile of 50 participants before and after CPB. The index test was the CoaguChek XS device and the reference test was the standard laboratory assay. The primary outcome was the accuracy of the CoaguChek device in measuring the International Normalized Ratio (INR). We pre-specified a tolerance range of ± 0.5 INR units. Secondary outcomes included accuracy in measuring prothrombin time and prothrombin activity.

We included 50 patients undergoing cardiac surgery with CPB between October 2023 and January 2024. The mean (standard deviation) age was 59.2 (12.3) years, and 32 participants (64%) were male. For INR values, Lin’s coefficient was 0.72 (95% CI: 0.60‒0.82) pre-CPB and 0.66 (95% CI: 0.50‒0.77) post-CPB, both indicating good agreement. In the pre-CPB period, on average, the index test readings exceeded reference readings by 0.045 INR units (95% CI: 0.030‒0.059, p < 0.001), while in post-CPB period, index readings were, on average, 0.064 INR units lower (95% CI: -0.09 to -0.04, p < 0.001). Although statistically significant differences were observed, they fell within predefined tolerance range and were considered clinically irrelevant. Analyses of secondary outcomes were consistent with the primary outcome findings.

In patients undergoing cardiac surgery with cardiopulmonary bypass, CoaguChek XS provided results comparable to standard laboratory coagulation monitoring, both pre-and post-cardiopulmonary bypass.

Plataforma Brasil CAAE 70266023.8.0000.5553.

(https://clinicaltrials.gov/study/NCT06037720) NCT06037720, 14/09/2023.