Improved Time in Therapeutic Range With Patient Self-Testing of Their INR Compared to Usual Care

Prosthetic replacement of diseased heart valves is a routine procedure, and mechanical heart valves have excellent hemodynamic performance and durability. However, mechanical valves are thrombogenic, necessitating lifelong anticoagulation. Hazards of anticoagulation include bleeding when it is excessive or thromboembolism when the intensity of anticoagulation is below the recommended level. Monitoring the level of anticoagulation is accomplished by analyzing the International Normalized Ratio. Until recently, this was performed at medical laboratories or hospitals, but recent literature suggests that patient self-testing of oral anticoagulation improves patient compliance, medical outcomes, and quality of life.

The objective of this study is to evaluate the time in therapeutic range of patients who self-test their INR compared to patients receiving the usual care. Additionally, we will evaluate the educational components and corollaries of self-testing.

Two hundred consecutively enrolled adults, having undergone implantation of a mechanical heart valve, will be randomized to either self-testing or usual care. Those randomized to the self-testing group will undergo self-testing instruction prior to hospital dismissal. For three months after hospital discharge, subject will record their INR results obtained by self-testing or as prescribed by their primary physician. They will then submit the record of the INR results and complete a survey.

Inclusion criteria

• Patients that received a mechanical valve while in our hospital
• Age > 18 years

Exclusion criteria

• Pregnant or lactating women
• Patients that have genetic clotting disorders such as Factor 5
• Physical disabilities (for example, poor eyesight, tremor, or other neurological disability) that would prevent the patient from being able to perform finger stick blood sampling. (Patients may not be excluded for physical disabilities if a care giver is willing to learn and assist with performing patient self-testing.)