Optimization of vitamin K antagonist treatment: Near patient monitoring versus standard of care a parallel group clinical trial in older patients with atrial fibrillation.

Purpose: Atrial fibrillation (AF) is common in the elderly population and is associated with a high risk of thromboembolic events. Although non-vitamin K oral anticoagulants (NOACs) are the preferred drugs in antithrombotic therapy for AF, Vitamin K Anticoagulant drug (VKA) treatment is still used in a considerable proportion of patients with AF. Moreover, recent findings revealed that switching VKA to NOAC is associated with more bleeding complications in frail older patients with AF. Standard of care (SOC) monitoring of VKA treatment consists of venous blood sampling and back office dosage advice with a chain of processes and involvement of several health care professionals. We have designed a new procedure for monitoring (Near Patient Therapeutic Monitoring / NPTM) in order to improve the quality and safety of VKA treatment. NPTM consists of INR measurement with a point-of-care (POC) device in the home setting of a patient, performed by one professional and with an instant dosage advice.

Methods: This is a cluster-randomised, parallel group, open label study to compare SOC with NPTM of VKA treatment in patients in a home setting. The follow-up period was one year. The primary outcome was time in therapeutic range (TTR), and secondary outcomes were adverse events (deaths, bleeding and thromboembolic events).

Results: 555 Patients were included in the study. After randomisation, 271 patients received SOC and 284 patients received NPTM. The TTR did not differ significantly: 63.71% versus 62.47% (p > 0.05) for SOC and NPTM, respectively. Significant differences were found for all-cause death (SOC n = 34 versus NPTM n = 16, p < 0.05, OR 0.47, 95% CI: 0.25-0.87), total number of minor bleedings (79 events in SOC vs 52 in NPTM, p < 0.05, OR 64 (95%CI: 0,37-0,81) and all non-major bleedings (100 events in SOC vs 67 in NPTM, p < 0.05, OR 0.62 (95% CI: 043-0.90).

Conclusions: NPTM of VKA treatment in AF-patients does not result in an improved TTR when compared to SOC. All-cause death, total number of minor bleedings and all non-major bleedings may be reduced in NPTM, although the study was not powered for these secondary outcomes. Future studies are needed to determine the cost-effectiveness of NTPM versus SOC.