l

The content of this website is intended for healthcare professionals only

Oral anticoagulants after hospital discharge reduce non-fatal blood clots

Study suggests that oral anticoagulants should be continued after discharge to prevent blood clots

Ingrid Torjesen

Tuesday, 28 August 2018

Medically ill patients who use oral anticoagulants for 45 days following their discharge from the hospital have a lower rate of non-fatal symptomatic blood clots although the treatment has no impact on fatal blood clots, according to results from the MARINER trial* at ESC Congress 2018 and published in The New England Journal of Medicine.

A significant proportion of patients hospitalised for heart attack, pneumonia, flu, bronchitis, asthma, or broken bones are at risk of venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism, while in hospital and up to six weeks afterwards. In fact, around 70% of hospital-acquired fatal pulmonary embolism occurs in medically ill patients.

While anticoagulants delivered by intravenous drip or injection are recommended to prevent blood clots in medically ill patients while in hospital, guidelines do not recommend any use of anticoagulants post-discharge. However, after leaving the hospital the rate of symptomatic VTE more than doubles over the first 21 days and is associated with a five-fold increased risk of fatal pulmonary embolism within 30 days post-discharge.

The MARINER trial investigated whether continuing thromboprophylaxis with an oral anticoagulant after discharge could reduce the risk of symptomatic VTE and VTE-related death in medically ill patients at risk for VTE. The trial enrolled 12,024 patients from 671 centres in 36 countries. Patients were 40 years of age or older, had been hospitalised for an acute medical illness, and had other risk factors for VTE as defined by a VTE risk score that included immobilisation for one day or longer, being in intensive care, age over 60 years, limb paralysis, previous VTE, thrombophilia or a D-dimer level more than two times the upper limit of normal. Four in ten patients had been admitted to hospital for heart failure, 27% for respiratory insufficiency, 17% for infectious disease, 14% for ischaemic stroke, and 2% for inflammatory disease.

Patients were randomly allocated to a 45-day course of either once daily oral rivaroxaban 10 mg (7.5 mg in patients with reduced kidney function) or placebo at the time of hospital discharge. The final analysis included 12,019 patients, of whom 11,962 (99.5%) had taken at least one dose of study drug.

During the 45-days post-discharge, 50 (0.83%) patients taking rivaroxaban had symptomatic VTE or died from VTE-related causes compared to 66 (1.1%) taking placebo (p=0.136). When examining symptomatic VTE only, which included lower extremity DVT and non-fatal pulmonary embolism, there were fewer events with rivaroxaban (0.18%) compared to placebo (0.42%; hazard ratio 0.44, 95% confidence interval 0.22-0.89, p=0.023).

The researchers also examined symptomatic VTE and all-cause mortality and found that 1.3% of patients taking rivaroxaban experienced an event compared to 1.78% of patients in the placebo group (HR 0.73, 95% CI 0.54-0.97, p=0.033). Major bleeding occurred in 17 (0.28%) patients in the rivaroxaban group compared to nine (0.15%) taking placebo (p=0.124), with very few critical and fatal bleeds and no significant difference between groups.

Researcher Professor Alex Spyropoulos, of the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, New York, US, said: "Anticoagulants help prevent blood clots in medically ill patients while they are under our supervision at the hospital. However, the risk of blood clots extends well beyond this period. Our results suggest we may be able to offer further protection to patients at risk from non-fatal blood clots, with no increase in major bleeding, by prescribing an oral anticoagulant for use after discharge. This study has potential to reduce the public healthcare burden of non-fatal blood clots in a large proportion of medically ill patients."


*Spyropoulos AC, Ageno W, Albers GW, et al. Rivaroxaban for Thromboprophylaxis after Hospitalization for Medical Illness. NJEM, August 26, 2018. DOI: 10.1056/NEJMoa1805090

Registered in England and Wales. Reg No. 2530185. c/o Wilmington plc, 5th Floor, 10 Whitechapel High Street, London E1 8QS. Reg No. 30158470