Hot Line 5: HI-PRO
31 Aug 2025
Hot Line ESC Congress 2025 Extended apixaban reduces recurrence in at-risk patients with provoked VTE
Explaining the rationale of the HI-PRO trial, Doctor Gregory Piazza (Brigham and Women's Hospital, Boston, USA) said: “Patients with acute venous thromboembolism (VTE) with transient provoking factors, such as surgery, trauma or immobility, typically receive short-term anticoagulation. However, the risk of VTE recurrence may remain high in patients with enduring risk factors, including those with obesity, chronic lung disease or autoimmune disorders. In such patients, the optimal duration of anticoagulation is uncertain. We assessed the efficacy and safety of extended-duration apixaban 2.5 mg twice daily, compared with placebo, for the prevention of recurrence in patients with provoked VTE and at least one enduring risk factor.”
The double-blind HI-PRO trial, conducted at Brigham and Women’s Hospital, included patients with deep vein thrombosis or pulmonary embolism following a major provoking factor who had standard-dose anticoagulation for ≥3 months and ≥1 enduring risk factor. Patients were randomised to apixaban 2.5 mg twice daily or placebo for 12 months. The primary efficacy outcome was symptomatic recurrent VTE at 12 months. The principal safety outcome was major bleeding (ISTH definition).
Across the 600 patients randomised, the most common provoking factors were surgery (33.5%), immobility (31.3%), trauma (19.2%) and acute medical illness (18.3%). The most common enduring risk factors were chronic inflammatory disorder (52.2%), BMI ≥30 kg/m2 (48.2%), atherosclerotic cardiovascular disease (29.3%) and chronic lung disease (22.3%).
Symptomatic recurrent VTE occurred in 1.3% of patients with apixaban vs. 10.0% with placebo at 12 months, representing a significant 87% decrease (hazard ratio [HR] 0.13; 95% CI 0.04 to 0.36; p<0.001).
Major bleeding occurred in 1 patient (0.3%) who received apixaban and none who received placebo. Clinically relevant non-major bleeding was observed in 4.8% of patients with apixaban and 1.7% with placebo (HR 2.68; 95% CI 0.96 to 7.43; p=0.059).
Dr. Piazza concluded: “Low-intensity apixaban for 12 months effectively reduced symptomatic VTE recurrence with a low risk of major bleeding in patients with provoked VTE and enduring risk factors. Additional research is needed to identify which subgroups benefit most from extended anticoagulation.”
