Analytical Management of Patients Undergoing Oral Anticoagulant Therapy Could Have a Strong Impact on Clinical Outcomes: A Follow-up Study

Introduction: Oral anticoagulant therapy, such as vitamin K antagonists (VKAs), is prominent for the prevention of cerebral ischemic stroke or systemic embolism and all-cause mortality in patients with atrial fibrillation, venous thromboembolism, and mechanical or biological valve. VKA treatment requires monitoring of the international normalized ratio (INR) in order to maintain it in a therapeutic range, avoiding side effects, the main and most significant of which is bleeding. The aim of the present study was to evaluate the event rates of several clinical composite outcomes, such as bleeding, thromboembolic events, and all-cause death.

Methods: We compared three organizational models distinguished by a total (from 1 January to 31 December 2015 in which PT/INR analysis with the relative internal and external quality controls was performed by the surveillance center) or partial (from 15 January to 15 July 2016 and from 15 August to 15 November 2016, in which the surveillance center had the ability to view only the PT/INR results or all patients analyses, including blood count, creatinine, liver enzymes, etc., respectively) analytical patient management. The present longitudinal follow-up study included 1225 patients, recruited from 1 January 2015 to 15 November 2016 at a surveillance center for the prevention of cerebral ischemic stroke and systemic embolism in Chieti (Italy).

Results: The results show a significant rise of the incidence rate ratio in patients undergoing VKA treatment during the period 15 January to 15 July 2016 compared to the previous one regarding total bleeding, especially for minor bleeding and digestive bleeding; thromboembolic events; and all-death cause.

Conclusions: These findings show that analytical and clinical data and information should be under the direct supervision and responsibility of the surveillance center. In fact, this approach seems to highlight the best results in terms of safety and therapeutic effectiveness.