Enoxaparin is a cost-effective adjunct to fibrinolytic therapy for ST-elevation myocardial infarction in contemporary practice.

INTRODUCTION

In patients receiving fibrinolytic therapy for ST-elevation myocardial infarction (STEMI), adjunct treatment with enoxaparin has been shown to provide superior net clinical benefit compared with unfractionated heparin (UFH) in the Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment - Thrombolysis in Myocardial Infarction (ExTRACT-TIMI) 25 study. The objective of this study was to compare the cost effectiveness of enoxaparin and UFH strategies.

METHODS

A cost-utility analysis was conducted using a two-stage model: (1) A 30-day decision tree analytical model for the acute treatment phase, and (2) a lifetime Markov model (from 30 days post-STEMI until death) populated using patient survival data.

RESULTS

Assuming treatment continuation for 7 days, the mean day 1-30 incremental cost associated with enoxaparin was pound 49 per patient, and mean lifetime incremental cost was pound 592 per patient ( pound 91,091 vs. pound 90,499, respectively). Given an additional 0.048 life years gained per patient with enoxaparin, the cost per life year saved was pound 12,353, and given an additional 0.038 quality-adjusted life years (QALY) per patient with enoxaparin, the cost per QALY was pound 15,413. In an alternative scenario, reflecting contemporary practice assuming early treatment discontinuation at 48 hours, for example following urgent revascularization, the incremental cost per QALY was pound 13,556.

CONCLUSION

The use of an enoxaparin versus UFH strategy in patients receiving fibrinolytic therapy for STEMI, whether continued for 7 days or discontinued early, for example following urgent revascularization, is cost effective at a pound 20,000 willingness-to-pay threshold.