Elsevier

The Annals of Thoracic Surgery

Volume 72, Issue 5, November 2001, Pages 1523-1527
The Annals of Thoracic Surgery

Original article: cardiovascular
Self-managed anticoagulation: results from a two-year prospective randomized trial with heart valve patients

https://doi.org/10.1016/S0003-4975(01)03049-1Get rights and content

Abstract

Background. This study was conducted to assess the ability of patients receiving heart valve replacements to practice self-managed anticoagulation using a portable coagulometer.

Methods. We carried out a prospective, randomized trial, comparing self-managed anticoagulation with conventional management. Patients practicing self-managed anticoagulation (51 patients) did so at home, measuring their international normalized ratio and then deciding on their dosage of warfarin, while conventionally controlled patients (n = 49) attended hospital clinics or were managed by their family physicians.

Results. We successfully trained 41 of 44 patients who agreed to self-manage their anticoagulant therapy; 34 of the 41 managed their own anticoagulation at home for 2 years. Their control, assessed by a number of tests in range (67.6% versus 58.0%) and time in therapeutic range (76.5% versus 63.8%), was significantly better than that for the group managed conventionally (p < 0.0001). There was no significant difference in mortality or morbidity between the two groups.

Conclusions. Self-managed anticoagulation is a reliable, easily learned method of controlling anticoagulation, and it is suitable for approximately two thirds of patients, with excellent results.

Section snippets

Material and methods

The Coaguchek is a portable coagulometer that uses a test strip containing a reaction chamber coated with iron oxide particles and thromboplastin derived from rabbit brain. A drop of capillary blood (10 to 25 μL) obtained from a finger prick is applied to the strip, which is in an electromagnetic field. As the blood clots, the iron oxide particles, previously agitated by the electromagnetic field, stop moving, and this lack of movement is detected by reflectance photometry. Each box of test

Results

Of the 51 patients who were randomized to group 1 (SMA group), 7 patients declined training. The reasons stated were distance from training center (n = 4), lack of confidence in ability to manage warfarin dosing (n = 2), and lack of confidence in ability to perform finger-prick sampling of blood (n = 1).

The remaining patients (n = 44) attended all the required training sessions. Of these patients, 3 were considered unsuitable for SMA as they either had difficulty with blood sampling or with

Comment

Most patients in our study were able to learn SMA, and we successfully trained 41 of 44 (93%) patients who attempted SMA. Of the 3 patients (6.8%) deemed unsuitable for SMA, 1 could not grasp the concept of self-dosing and the other 2 could not consistently measure their INR. It is interesting that one of the latter patients who had difficulty measuring her INR was a non–insulin-dependent diabetic who practiced home monitoring of her blood glucose levels. She had difficulty obtaining the 25 μL

Acknowledgements

We thank Roche Diagnostics (Lewes, Surrey, UK; formerly Boehringer Mannheim) for providing the Coaguchek coagulometers and test strips used in this study.

Copies of our training schedule and written tests for patients are available upon request.

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