Pattern and Management of ISTH Major Bleeding Complications with Direct Oral Anticoagulants - Results of the Prospective Dresden Noac Registry (NCT01588119)

Background: The most common side effects of oral anticoagulants are bleeding complications. In large trials, direct oral anticoagulants (DOAC) have been shown to reduce the risk of major bleeding compared to warfarin. However, little is known about the management and outcome of survivors of major DOAC bleeding.

Patients and methods: Using data from the prospective, non-interventional Dresden NOAC registry, we evaluated the management and outcome of survivors of major DOAC bleeding. All DOAC bleeding complications were centrally adjudicated and classified according to ISTH definition. For this analysis, every ISTH major bleeding was identified in the database and for each case, the first major bleeding was evaluated. Restart of oral anticoagulation (OAC) 30 days after major DOAC bleeding was assessed and the impact of restart on the composite endpoint of (recurrent major bleeding, stroke, TIA, systemic embolism, venous thromboembolism) or survival was evaluated using Kaplan-Meier time-to-first event estimation.

Results: Until January 31th 2015, 2771 patients were enrolled into the registry (1898 treated with rivaroxaban, 525 apixaban and 348 dabigatran).

During follow-up (mean follow-up duration 23.6 months) 127 patients developed 170 ISTH major bleeding  events during DOAC exposure (drop of hemoglobin ≥2g/l in 106 (62.4%) cases, transfusion of ≥2 units of red blood cells in 105 (61.8%) cases, critical site bleeding in 43 (25.3%) cases and/or fatal outcome in 9 cases (5.3%)).

Of the 127 patients with major bleeding (mean age 77±11 years; range 37-94), 53.5% were male the median HAS-BLED score was 2 (25^th/75^th percentile 1/2, range 0-5).

The majority major bleeding events occurred spontaneously (64.6%). In contrast, 14.2% major bleeding events occurred after trauma and 21.3% occurred after surgical or interventional procedures that were performed during treatment or within 3 days after last DOAC intake.

Most common sites of bleeding were gastrointestinal tract (37%), diffuse bleeding during or after surgery (15.7%), intracranial (11%), skin/mucosal (9.4%), intraocular (8.7%), genitourinary (7.9%), intraarticular bleeding (6.3%) and bleeding in other sites (4%). 

85 cases lead on to a hospitalization (mean duration 9±7d) and 11 cases were managed as outpatient. The remaining 31 bleeding events occurred during a hospital stay. The majority of cases were managed with surgical or interventional treatment (55.9%; mainly endoscopic treatment for gastrointestinal bleeding. In 75 (57.1%) cases red blood cell transfusion was given and 11 (8.7%) of cases received fresh frozen plasma. Furthermore, 15 (11.8%) of cases received PCC and 4 (3.1%) fibrinogen.

The restart of OAC (DOAC or vitamin K antagonists; VKA) was assessed at day 30 after major bleeding. While OAC was restarted in 80 patients (63%) it was not restarted 30 days after bleeding in the remaining 47 (37%). Patients who restarted OAC had a similar mean age (76 vs. 78y, p=0.309) and a similar mean HAS-BLED score (1.8 vs. 2.1, p=0.115) compared to patients who did not restart OAC.

During follow up after bleeding (mean follow-up duration 15.2 months), the rate of combined endpoint of recurrent major bleed and thromboembolism was significantly lower in patients that restarted OAC compared to those who did not restart (14.7/100 patient years; 95%-CI 8.0-24.7 vs. 38.6/100 patient years; 21.1-64.7; p=0.0342).

All-cause mortality was found to be 23.9/100 patient years (95% CI 16.9-32.8). Mortality was significantly lower in patients that restarted OAC compared to those who did not restart (16.4/100 patient years [9.7-25.9] vs. 40.6/100 patient years [24.8-62.7]; p=0.0099). Most common cause of death was fatal cardiovascular event (12/38, 31.6%) and fatal bleeding (9/38, 23.7%) followed by terminal malignant disease (6/38, 15.8%), infection/sepsis (6/38, 15.8%) and age related death (5/38, 13.2%).

Conclusion: Even in cases with major DOAC bleeding, acute mortality is low with a case-fatality rate of 5.3%. Furthermore, OAC is restarted within 30 days after major bleeding in only 63%. Patients who restarted OAC had significantly lower rates of the combined endpoint of thromboembolism or recurrent major bleeding and had a significantly better survival. Therefore, benefits of OAC continuation may outweigh the risks even in patients with major DOAC-related bleeding.