Format

Send to:

Choose Destination
See comment in PubMed Commons below
Am J Clin Pathol. 2003 Dec;120(6):944-7.

A comparison between six- and four-week intervals in surveillance of oral anticoagulant treatment.

Author information

  • 1Clinical Cardiology, Thrombosis Center, University of Padova School of Medicine, Ex Busonera Hospital, via Gattamelata 64, I-35128 Padova, Italy.

Abstract

We determined whether international normalized ratio (INR) monitoring at 6 weeks rather than 4 weeks would benefit patients and reduce costs. Patients receiving stable oral anticoagulation treatment (target INR, 3.0) with a prosthetic mechanical heart valve for more than 6 months were randomized for a maximum interval between INR determinations of 6 weeks (group 1, n = 59) or 4 weeks (group 2 [control], n = 65). Patients were followed up for 2 years. The primary end point of the study was the biologic risk of overanticoagulation or underanticoagulation, estimated as the rate of values at risk (INR, < 1.5 and > 5). The rates of INR values at risk for hemorrhagic (INR, > 5) or thromboembolic (INR, < 1.5) complications were 3.27% in group 1 and 3.09% in group 2 (P = .81). The INRs of patients in group 1 trended toward higher values, but no difference between groups was observed in time spent at various INR ranges by using the method of linear change. The mean time between INR determinations was 24.9 +/- 18.1 days (1.20 per month) in group 1 and 22.5 +/- 9.5 days (1.33 per month) in group 2 (P < .0003). For patients in stable condition with a prosthetic heart valve who are monitored at an anticoagulation clinic, a 6-week interval between INR determinations does not increase the biologic risk of thromboembolic or hemorrhagic events.

PMID:
14671984
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk