Factors other than body weight predicting heparin loading to acquire optimal activated clotting time in endovascular neurointerventions

Abstract

Objectives: The aim of this study was to investigate the relationship between the activated clotting time (ACT) and heparin loading based on body weight (BW), and factors other than BW that may contribute to the ACT after heparin loading to establish a more accurate regimen for achieving ACT targets during endovascular neurointerventions.

Patients and methods: Japanese patients who underwent endovascular coiling of unruptured intracranial aneurysms or carotid artery stenting in our institution between January 2014 and November 2017 were enrolled. The ACT was measured before (pre-ACT) and 3 min after heparinization (post-ACT). The correlation between ACT and heparin loading based on BW and factors that may contribute to the ACT after heparin loading were analyzed retrospectively.

Results: A total of 199 cases (109 males, age: 66 ± 12 years) were analyzed. There were positive correlations between the heparin loading per kg of BW and post-ACT, post-ACT - pre-ACT (ΔACT) (Spearman's r = 0.2946, 0.2633, P: <0.0001, 0.0002, respectively). Heparin loading per kg of BW, gender, hematocrit (Ht), estimate glomerular filtration rate (eGFR) were significant confounding factors to ΔACT. The calculated predicted ΔACT based on these significant factors was found to be highly correlated with ΔACT compared with the heparin loading per kg of BW. (Spearman's r = 0.5820, P = <0.0001).

Conclusion: Initial BW-based heparin loading is a simple way in endovascular neurointerventions. ACT after heparin loading based on BW has individual differences greatly, it is possible to estimate more accurately the heparin loading for acquiring the optimal ACT considering not only BW but also gender, Ht and eGFR.

Keywords: Activated clotting time; Bodyweight; Endovascular neurointerventions; Estimate glomerular filtration rate; Gender; Hematcrit; Heparin loading.