Recommencing anticoagulation treatment in surgically managed patients with intracerebral haemorrhage and mechanical heart valves: An Aotearoa-New Zealand analysis.

Purpose: Intracerebral haemorrhage (ICH) is an absolute contraindication for therapeutic oral anticoagulation therapy (OAT). Re-bleeding carries significant risk of morbidity and mortality. Patients with prosthetic heart valves are at higher risk of thromboembolic complications when OAT is withheld. The aim of our study is to establish the safe time periods where OAT can recommence, and assess the complication rates of re-introduction and associated risk factors.

Methodology: New Zealand-wide, retrospective (2005-2021) and prospective (2021-2023) data was collected from patients with prosthetic heart valves, aged 18 years or older who underwent surgical management of ICH. The time to re-bleeding or thromboembolic event was recorded and the time period that balances the risks was examined. Primary outcomes included rate of re-bleeding and thromboembolic events. Associated medical, radiological, surgical and valve risk factors were examined.

Results: Thirty patients were identified and included in the analysis. Average time to therapeutic anticoagulation was 12.2 days post-op (95 % CI 6.9 - 17.5 days), 62.5 % recommenced OAT at or before day 14 (Range 3-13 days). Four patients (13.3 %) sustained a re-bleeding event after recommencing OAT. Three of the 4 re-bleeding events were observed in the group recommencing prior day 14, without reaching statistical significance. Of these, two patients died following the event. Group mortality was 30 %. One patient had a thromboembolic complication at day 14 post OAT, age of valve was 2 months. No thromboembolic complications were observed in patients recommencing after day 14. Maori and Pasifika patients were disproportionately represented and their condition was associated with a background of Rheumatic Heart Disease in 10 out of 11 cases.

Conclusion: Early re-commencing of OAT is effective in preventing thromboembolic complications associated to prosthetic heart valves. There is a tendency for re-bleeding to occur when OAT is recommenced prior to day 14 (not significant). These data suggest that in this New Zealand cohort, the thromboembolic risks of withholding OAT may be overestimated at the expense of early anticoagulation, with an increased risk of re-bleeding in this surgically managed cohort. Further prospective studies are warranted to definitively examine the risks of early therapeutic anticoagulation in this group.