THE OUTCOMES OF USING FIXED-DOSE NOMOGRAM-GUIDED UNFRACTIONATED HEPARIN THERAPY IN ELDERLY PATIENTS IN COMPARISON WITH YOUNGER PATIENTS

Abstract

Introduction: In elderly patients, the dosing of unfractionated heparin is difficult because of changing metabolism, which affects the determination of a therapeutic level. The aim of this study was to evaluate the effects of unfractionated heparin therapy in an older population and to determine whether there was any difference from a younger population in terms of the activated partial thromboplastin time results and complication rates when using a standard nomogram.

Materials and Methods: A total of 120 patients aged <80 years (Group 1) and 120 patients aged >= 80 years (Group 2), all of whom had been given unfractionated heparin therapy for selected indications in the coronary care unit, were randomly selected and retrospectively enrolled in the study. Infusion time up to a maximum of 48 hours was included, and activated partial thromboplastin time results in that period were categorised as subtherapeutic, therapeutic, or supratherapeutic. The rates of the patients' subtherapeutic, therapeutic, and supratherapeutic results were compared between groups.

Results: The peak activated partial thromboplastin time level was higher in patients aged >= 80 years (58.85 [51.28] vs 76.50 [57.45], p<0.001). The supratherapeutic activated partial thromboplastin time percentage (0 [0.25] vs 0.20 [0.43], p<0.001) and numbers of first activated partial thromboplastin time in the supratherapeutic range (10% vs 24.2%, p=0.004) were significantly higher in the older group.

Conclusion: Over-anticoagulation may be a problem in the elderly population when using standard nomograms. It was concluded that improvements should be made for a nomogram specific to an older population.