Patients on warfarin may now have a glimmer of hope after a study published online Dec. 1 in The Lancet found that self-monitoring warfarin therapy cut patients' risk of thromboembolic events (i.e., deep vein thrombosis, stroke and myocardial infarction) in half compared with those who receive conventional care.
“Introduction of reliable and analytically accurate point-of-care devices allows self-testing by the patient in the home setting,” according to background information of the article. “Patients can have their test result managed by their healthcare provider (self-testing) or they can interpret their INR result, and adjust their own dose of anticoagulant accordingly (self-management).”
However, despite evidence of its success, self-testing and self-management of warfarin have not taken off, wrote Carl Heneghan, MD, of Oxford University in Oxford, U.K., and colleagues.
To better understand the self-monitoring of oral anticoagulation, Heneghan et al conducted a meta-analysis of individual patient data addressing gaps in evidence including estimate of the effect on time to death, first major hemorrhage and thromboembolism using the Ovid versions of Embase and Medline databases.
The researchers included data from 11 trials that included 6,417 patients and 12,800 person-years of follow-up, and the authors reported a reduction in thromboembolic events in the self-monitoring group but not hemorrhagic events or death.
Data showed that patients under 55 years had a large reduction in thrombotic events, as did participants with mechanical heart valves. Additionally, the authors found that patients over the age of 85 had no adverse effects from the intervention.
The authors also reported that a larger of number of men with mechanical heart valves who were self-monitoring saw a reduction in thromboembolic events; however, women did not see the same reduction. These men also saw significant reductions in major hemorrhagic events.
Within the first seven days, atrial fibrillation (AF) patients who had a mechanical heart valve and were self-monitoring spent more time within the therapeutic range compared with those who did not self-monitor. However, the authors noted that self-monitoring also led to an increase in the number of tests taken.
While thromboembolic events were reduced in the self-monitoring group, the effects for major hemorrhaging or morality were not statistically different.
“Patients who self-tested and adjusted their doses had significantly lower rates of thromboembolic events, which suggests that patients should be given the opportunity, and provided with training, to undertake self-management,” the authors wrote.
“However, self-management does not mean that patients are left to fend for themselves: for instance, in one trial participants had 24-hour backup available, and good quality control measures are needed.”
While the potential to incorporate self-monitoring into practice looks promising, the authors noted that adoption will depend on the results of economic analyses, which in the past have had conflicting results. For example, while a U.K. analysis found self-management to be more cost-effective than anticoagulation clinics, a Canadian study showed that self-management is a cost-effective strategy for patients receiving long-term anticoagulation therapy for AF or a mechanical heart valve.
“We believe the results of our review will lead to a systematic change in practice, in terms of the significant reduction in thromboembolic events in patients with a mechanical heart valve requiring long-term anticoagulation,” the authors summed. “Such patients should be offered the option to self-manage their disease with suitable healthcare support as backup.”