Heparin management test versus activated coagulation time during cardiovascular surgery: correlation with anti-Xa activity.

OBJECTIVE

To compare the abilities of the heparin management test (HMT) and the activated coagulation time (ACT) to provide a measurement of heparin effect in patients undergoing cardiac or peripheral vascular surgery. These measurements of heparin effect were also compared with measurements of heparin concentrations tested by anti-Xa activity. A secondary objective was to compare the performance of the noncitrated HMT with that of the citrated HMT.

DESIGN

A prospective study.

SETTING

A single-center study conducted in a university hospital.

PARTICIPANTS

After human investigation committee approval and informed consent were obtained, adult patients undergoing cardiac or peripheral vascular surgery were included in this study.

INTERVENTIONS

In both surgical groups, blood was sampled for ACT, HMT, and anti-Xa activity. Each HMT was performed on both noncitrated and citrated samples.

MEASUREMENTS AND MAIN RESULTS

As an indicator of heparin effect, the HMT had a strong correlation with the ACT (r = 0.899; p < 0.01). In addition, the HMT had a significantly stronger correlation with anti-Xa activity than the ACT (p < 0.01). The correlation obtained from the noncitrated samples was identical with that obtained from the citrated samples (r = 0.819; p < 0.001 for both groups).

CONCLUSION

The ability of the HMT and the ACT to measure heparin effect was similar. The HMT performed better than the ACT when using anti-Xa activity as a measure of heparin concentration. Noncitrated HMT results were similar to citrated HMT results, thus supporting the use of fresh whole blood for testing purposes.