# The association between heparin sensitivity index and postoperative blood loss in Chinese patients undergoing elective off-pump coronary artery bypass grafting: a single center retrospective study

## TL;DR

This study found that the heparin sensitivity index does not affect postoperative blood loss in Chinese patients undergoing heart surgery, but high preoperative platelet counts are linked to lower heparin sensitivity.

## Contribution

The study provides new evidence on the relationship between heparin sensitivity and postoperative outcomes in Chinese OPCAB patients.

## Key findings

- Intraoperative heparin sensitivity index was not associated with postoperative blood loss.
- Preoperative high platelet count was an independent predictor of low heparin sensitivity index.
- No significant differences in transfusion requirements or complications were found between HSI groups.

## Abstract

The heparin sensitivity index (HSI) is closely associated with perioperative ischemic events and increased blood loss in cardiac surgery. Previous studies have produced conflicting results. Therefore, this study aimed to investigate the relationship between HSI and postoperative blood loss specifically in Chinese patients undergoing elective off-pump coronary artery bypass grafting (OPCAB).

Patients underwent OPCAB between March 2021 and July 2022 were retrospectively included. Enrolled patients were classified into Low-HSI (HSILOW; HSI < 1.3) and Normal-HSI (HSINORM; HSI ≥ 1.3) groups. HSI = [(activated clotting time (ACT) after heparin) – (baseline ACT)] / [loading dose of heparin (IU/kg)]. Primary outcome included postoperative blood loss at 24 h. Secondary outcomes were total postoperative blood loss, transfusion requirement of red blood cell (RBC), fresh frozen plasma (FFP), platelet concentrates (PC), and other complications.

We retrospectively analyzed 303 Chinese OPCAB patients. HSILOW group had higher preoperative platelet (PLT) count (221 × 109/L vs. 202 × 109/L; P = 0.041) and platelet crit (PCT) value (0.23% vs. 0.22%; P = 0.040) compared to HSINORM group. Two groups showed no significant differences in postoperative blood loss at 24 h (460 mL vs. 470 mL; P = 0.252), total blood loss (920 mL vs. 980 mL; P = 0.063), RBC transfusion requirement (3.4% vs. 3.1%; P = 1.000), FFP transfusion requirement (3.4% vs. 6.2%; P = 0.380), and other complications. Preoperative high PLT count was associated with low intraoperative HSI value (odds ratio: 1.006; 95% confidence interval: 1.002, 1.011; P = 0.008).

Intraoperative HSI value was not associated with postoperative blood loss in Chinese patients undergoing OPCAB. Preoperative high PLT count was an independent predictor of low intraoperative HSI value.