Do different heparin brands influence activated clotting times?

Area of Science:

• Pharmacology
• Cardiovascular Surgery
• Biochemistry

Background:

• A change in heparin sodium suppliers occurred at our institution.
• Anecdotal reports suggested potential differences in potency between the two heparin products.
• Both heparin products are derived from porcine intestinal mucosa.

Purpose of the Study:

• To compare the clinical potency of two different brands of heparin sodium used for anticoagulation during cardiopulmonary bypass.
• To investigate if differences in heparin potency could be attributed to variations in pharmacopeial standards.

Main Methods:

• Retrospective review of perfusion records for patients undergoing cardiopulmonary bypass.
• Analysis of anticoagulation data, including initial loading dose, activated clotting time (ACT), and heparin units per kilogram per minute.
• Comparison between Heparin Leo (1000 IU/ml BP) and Hepalean (10,000 USP/ml).

Main Results:

• Heparin Leo was found to be less clinically potent than Hepalean.
• Patients receiving Heparin Leo required a 5% higher initial loading dose but had a 17% lower initial post-load ACT.
• Heparin units per kilogram per minute of bypass were 23% higher for Heparin Leo.
• A higher proportion of Heparin Leo patients failed to achieve the target ACT (>400 seconds).

Conclusions:

• Significant differences in clinical potency exist between Heparin Leo and Hepalean.
• The observed potency discrepancies are not adequately explained by differences between British Pharmacopeia and United States Pharmacopeia heparin reference standards.
• Further investigation into the manufacturing or formulation of heparin products is warranted.