Conventional Weight-Based versus Low-Dose Regimen of Heparin Administration to Achieve Target Activated Clotting Time on Cardiopulmonary Bypass in Pakistani Population


  • Musfireh Siddiqeh Associate Professor RIC
  • Wajahat Javed Mirza
  • Javed Iqbal Associate Professor, Cardiac Surgery, Rawalpindi Institute of Cardiology, Rawalpindi
  • Imran Khan Associate Consultant Cardiac Surgeon Damam KSA
  • Ali R Mangi Senior Registrar NIVID, Karachi



Objective: A weight-based dose of heparin is calculated to achieve target ACT (Activated clotting time) for establishing CPB (cardiopulmonary bypass). Whether a target ACT can be achieved with lower dose of heparin in Pakistani population was the aim of this study.

Methodology: The cross-sectional comparative study was conducted at Rawalpindi Institute of Cardiology, Department of Cardiac Surgery from 1st January 2019 to 1st January 2020. Three hundred thirty-six (336) patients undergoing elective open-heart surgeries on CPB were included in this study. Patients receiving weight-based heparin dose were placed in Group-A, while those on low-dose heparin were placed in Group-B. ACT was considered to have reached the target value in range of 400-480 seconds, values between 481-1500 seconds were considered excessive, whereas ACT of >1500 was regarded as potentially high-risk for peri-operative bleeding .

Results: 14.1% (n= 28) of Group-A patients achieved target ACT, whereas 58.3% (n=116) exceeded the target of 480. In 25.1% (n=50), ACT values were beyond the measuring capacity of the assay machine i.e. >1500. Only 2.5% (n=5) required additional dosage of heparin. Target ACT in Group B was achieved in 19.7% (n= 27), 55.5% (n=76) had excessive ACT values, whereas in 16.8% (n= 23), it was >1500. 9.5% (n=13) required an additional dosage of Heparin.

Conclusion: In Pakistani population, a target ACT can be achieved with significantly lower dose than the conventional weight-based heparin dose. Larger studies, preferably randomized controlled trials are needed to determine the optimal heparin dose calculation for safe anti-coagulation during CPB.





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