Very elderly patients can benefit from well-managed vitamin K antagonist thromboprophylaxis, study suggests

Adequate management of vitamin K antagonist (VKA) therapy in trained centers allowed very old and frail patients to benefit from VKA thromboprophylaxis, an Italian study concluded.

To evaluate the quality of anticoagulation and the incidence of bleeding, Italian researchers performed a prospective observational study that enrolled from 27 centers 4,093 patients 80 years of age or older who were naive to VKA for thromboprophylaxis of atrial fibrillation (AF) or after venous thromboembolism (VTE).

Major end points of the study were:

• first major bleeding, defined as fatal, intracranial (documented by imaging), ocular causing blindness, articular, or retroperitoneal bleeding;
• when surgery or another invasive procedure was needed to stop bleeding;
• when transfusion of more than 2 units of blood was required; or
• when hemoglobin was reduced by more than 2 g/dL.

Follow-up was stopped after the first major bleed occurred, after the cessation of oral anticoagulation, or when a patient was no longer monitored by the participating center. Results were published online Aug. 1 by Circulation.

The follow-up was 9,603 patient-years; median age at the beginning of follow-up was 84 years (range, 80 to 102 years). During follow-up, 385 patients died (total mortality rate, 4.0 per 100 patient years). Of these, 26 (6.8%) died of hemorrhagic complications, 112 (29.1%) of cardiovascular disease, 34 (8.8%) of sudden death, 12 (3.1%) of stroke, 56 (14.5%) of cancer, and 145 (37.7%) of another disease unrelated to VKA treatment.

There were 179 major bleedings (rate, 1.87 per 100 patient-years), of which 53 (rate, 0.55 per 100 patient-years) were intracranial and 26 were fatal (rate, 0.27 per 100 patient-years). The rate of bleeding was higher in men than in women (relative risk [RR], 1.4; 95% CI, 1.12 to 1.72; P=0.002) and among patients 85 years of age or older compared with younger patients (RR, 1.3; 95% CI, 1.0 to 1.65; P=0.048).

The first three months of treatment were associated with a high risk of bleeding (RR, 2.4), as were renal failure, history of previous bleeding events, history of falling (a fivefold higher risk), and active cancer. Patients with prior gastroenterological bleedings were especially prone to recurrence (hazard ratio, 6.2).

The distribution of bleeding events in relation to indication for VKA treatment was higher among patients on VKA for VTE compared with patients on VKA for AF (RR, 1.4; 95% CI, 1.1 to 1.8; P=0.03).

The authors wrote, “In this large study on very old patients on VKA treatment, the rate of bleeding complications was low, suggesting that age in itself should not be considered a contraindication to treatment. Adequate management of VKA therapy through careful monitoring of patients in specifically trained centers allows very old and frail patients to benefit from VKA thromboprophylaxis.”