MedicalResearch: What are the main findings of the study?
Dr. Poon: At present, we know that the incidence and one-month case fatality of intracerebral haemorrhage (ICH) have remained static for the past two decades. However, any trend in long-term survival after ICH is less clear. Survivors face the risks of recurrent ICH as well as ischaemic events in the future. The balance between these risks has particular clinical implication on the decision about restarting antiplatelet/anticoagulant therapy after ICH. To address these questions, we undertook a systematic review and meta-analysis to determine whether long-term survival after intracerebral haemorrhage has changed over time, and to re-assess the balance between the risks of recurrent ICH and ischaemic events in studies quantifying both of these risks in the same population.
The survival rates after ICH at 1 year and 5 years do not appear to have changed over time – 1 year survival was 46% and 5 year survival was 29%. The risk of recurrent ICH may be influenced by the ICH location, with lobar ICH having a higher rate of recurrence. In contrast to the previous systematic review, we found the risk of ischaemic stroke to be at least as high as the risk of recurrent ICH over 3 years after ICH. This reinforces the difficulty that clinicians and patients have in deciding about antithrombotic treatment after ICH.
MedicalResearch: Were any of the findings unexpected?
Dr. Poon: Part of our original aim was to compare the risk of recurrent intracerebral haemorrhage to the risk of ischaemic events. However, there were no data on ischaemic heart disease, and the only data available was on ischaemic stroke. This may mean that the risk of ischaemic events could be higher than that of recurrent ICH.
MedicalResearch: What should clinicians and patients take away from your report?
Dr. Poon: ICH remains a serious condition associated with high mortalities in the short- and long-term that do not appear to have changed over time. The risk of recurrent ICH may be influenced by the initial ICH location. At present, the existing evidence on the risk of ischaemic events after ICH is incomplete. The balance between the risk of recurrent intracerebral haemorrhage and the risk of ischaemic events remains an uncertainty.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr. Poon: The proportion of ICH patients who are on antithrombotic medications at the time of their ICH is increasing over time. If these drugs are restarted after ICH, they may increase the risk of recurrent ICH, worsen its severity, or decrease the risk of ischaemic events following the haemorrhage. Long-term estimates of the rates of these events after ICH might help resolve this dilemma, which is best addressed in a randomised controlled trial such as our ongoing RESTART trial.
The RESTART trial is testing whether a policy of starting antiplatelet drugs results in a beneficial net reduction of all serious vascular events over two years compared with a policy of avoiding antiplatelet drugs. It has recently started recruiting patients and is open to hospitals in the UK.
Further population-based epidemiological studies quantifying the risk of all ischaemic events after ICH would help inform our decision-making regarding antithrombotic medications.