Bottles of warfarin

Photo courtesy of NIGMS

Allowing patients to self-manage anticoagulant therapy after heart valve surgery may lower the risk of death, according to a study published in the Annals of Thoracic Surgery.

Some of the patients studied were required to complete an educational program before they could manage their own treatment with a vitamin K antagonist (VKA).

For the remaining patients, VKA treatment was managed by a healthcare provider.

At 5 years, patients who managed their own treatment had a lower risk of death than patients on standard management.

“Oral anticoagulation therapy is usually monitored by laboratory analysis of the patient’s blood, which healthcare providers use to determine the appropriate dosage of medication,” said study author Thomas Decker Christensen, MD, PhD, of Aarhus University Hospital in Denmark.

“We believe that allowing patients to have more control over their own treatment can improve the standard of care in this patient group.”

Dr Christensen and his colleagues evaluated patients treated at 2 hospitals in Denmark between 1996 and 2012. There were 615 patients with mechanical heart valves who self-managed VKA treatment and 3075 control patients (a 1:5 ratio) who received standard VKA management following valve surgery.

Patients were required to attend an educational program consisting of a minimum of 3 lessons to be eligible for self-management. Over a period of 27 weeks following the educational training, patients gradually became self-managed.

“Once patients were approved for self-management, they were allowed to continue as such but could contact the treatment center with questions or concerns,” Dr Christensen noted.

“Patients were provided with a portable coagulometer, which they used to analyze medication levels and monitor dosage. Blood levels were measured and tracked weekly.”

Patients compared their own measurements against the International Normalized Ratio and adjusted their dosage levels according to what they had been taught in the educational training.

Bleeding and VTE

Over 5 years of follow-up, the risk of venous thromboembolism (VTE) and major bleeding was similar between self-managed patients and patients on standard management.

The rate of thromboembolic events requiring hospitalization was 1.6 events per 100 patient-years in the self-management group and 2.0 per 100 patient-years in the standard group. At 1 year of follow-up, the rates were 2.0 and 2.1, respectively.

When the researchers adjusted for potential confounders, there was a statistically nonsignificant higher risk of VTE among self-managed patients after 1 year (hazard ratio [HR]=1.29) and a statistically nonsignificant lower risk after 5 years (HR=0.91).

The rate of major bleeding was about 1.0 per 100 patient-years in the self-management group at both 1 year and 5 years. The corresponding rates in the standard management group were 1.9 at 1 year and 1.4 at 5 years.

When the researchers adjusted for potential confounders, there was a statistically nonsignificant lower risk of major bleeding in the self-management group at 1 year (HR=0.54) and at 5 years (HR=0.83).

Mortality

After 5 years, the rate of all-cause mortality was 1.1 per 100 patient-years in the self-management group and 2.5 in the standard management group. The adjusted HR was 0.49 in favor of the self-management group.

A landmark analysis restricting the survival analysis to patients alive 1 year after study inclusion resulted in an adjusted HR of 0.57.

“There are several reasons that patients who self-manage treatment have better outcomes than those who follow standard management,” Dr Christensen explained.

“Self-management patients receive more detailed information about oral anticoagulation therapy. They also learn more about the influence that diet, infectious diseases, alcohol, and other drug interactions can have on their treatment than do patients receiving standard management.”

He added that he hopes this study will have an impact on the management and care of heart valve patients.

“We believe that the majority of patients who have a mechanical heart valve inserted during surgery should be able to manage their oral anticoagulant therapy and recommend this as the standard treatment approach for these patients,” he concluded.

Patients may benefit from managing own VKA treatment