Recurrence Risk in Posthemorrhage Anticoagulation
Recurrence Risk in Posthemorrhage Anticoagulation
Hello, and welcome to this Medscape stroke update. I am Dr. Mark Alberts, Professor and Vice Chair of Neurology at University of Texas Southwestern Medical Center in Dallas, Texas.
Today I want to share the results of a study published in the journal Neurology in March 2014. In this study, Poli and colleagues looked at 267 patients who were receiving vitamin K antagonist anticoagulants for a number of reasons(we will talk more about that in a minute), had an intracranial hemorrhage, and then, after they were treated and stabilized, were restarted on anticoagulation to see how well they did. This study included patients who were enrolled and followed at anticoagulation centers throughout Italy.
Why were the patients on the various anticoagulants to begin with? About 45% had atrial fibrillation and 30% had mechanical valves, both good reasons to be on anticoagulation. What types of intracranial hemorrhages did they have initially? In all, 50% had either acute or chronic subdural hematomas and about 33% had primary intracerebral hemorrhages. Typically, the patients were kept off anticoagulation for a mean or median of about 60 days, and then once the anticoagulation was restarted, they were followed for a mean or median of 1.3 years.
What did the investigators find after more than a year of follow-up? The rate of recurrent intracranial hemorrhage overall was 7.5%. Sixty percent of these were subdural hematomas and 40% were intracerebral hemorrhages. Of interest, the median INR at the time of the recurrent bleed was only 2.2. This is consistent with other studies that have shown that although the risk for bleeding goes up as the INR rises, most cases of intracranial hemorrhage occur in patients who have an INR within what is considered the therapeutic range of 2.0 to 3.0. Among those patients who had a recurrent intracranial hemorrhage, 25% of cases ended up being fatal.
What can we conclude from this study and other, similar studies in the literature? First, it is true that the majority of these patients can be restarted on anticoagulation without serious consequences, but that risk is not minimal. In this study, 7.5% of patients had a recurrent hemorrhage, and of those cases, one quarter were fatal.
One of my concerns about this study is the workup the patients underwent to ascertain the underlying etiology of the initial bleed. Did they all undergo CT angiograms, for example, or MRI to rule out cerebral amyloid angiopathy? It is very unclear what the extent of the workup was and how intensively the authors looked for the underlying etiology of the initial hemorrhage, which perhaps may have guided them in decisions about beginning or not beginning subsequent or recurrent anticoagulation.
The other big factor is the great hope that the newer novel oral anticoagulants overall tend to have a much lower risk for primary hemorrhage compared with warfarin and other vitamin K antagonists. Whether this will be true in real clinical practice remains to be seen, although some of the early data we are seeing, especially from the US Food and Drug Administration dabigatran long-term follow-up study, seem to indicate that, overall, the risk for hemorrhage appears to be rather low with some of novel oral anticoagulants, if not all of them.
Thank you for tuning in for this Medscape stroke update. Have a good day.
Hello, and welcome to this Medscape stroke update. I am Dr. Mark Alberts, Professor and Vice Chair of Neurology at University of Texas Southwestern Medical Center in Dallas, Texas.
Today I want to share the results of a study published in the journal Neurology in March 2014. In this study, Poli and colleagues looked at 267 patients who were receiving vitamin K antagonist anticoagulants for a number of reasons(we will talk more about that in a minute), had an intracranial hemorrhage, and then, after they were treated and stabilized, were restarted on anticoagulation to see how well they did. This study included patients who were enrolled and followed at anticoagulation centers throughout Italy.
Why were the patients on the various anticoagulants to begin with? About 45% had atrial fibrillation and 30% had mechanical valves, both good reasons to be on anticoagulation. What types of intracranial hemorrhages did they have initially? In all, 50% had either acute or chronic subdural hematomas and about 33% had primary intracerebral hemorrhages. Typically, the patients were kept off anticoagulation for a mean or median of about 60 days, and then once the anticoagulation was restarted, they were followed for a mean or median of 1.3 years.
What did the investigators find after more than a year of follow-up? The rate of recurrent intracranial hemorrhage overall was 7.5%. Sixty percent of these were subdural hematomas and 40% were intracerebral hemorrhages. Of interest, the median INR at the time of the recurrent bleed was only 2.2. This is consistent with other studies that have shown that although the risk for bleeding goes up as the INR rises, most cases of intracranial hemorrhage occur in patients who have an INR within what is considered the therapeutic range of 2.0 to 3.0. Among those patients who had a recurrent intracranial hemorrhage, 25% of cases ended up being fatal.
Conclusions and Concerns
What can we conclude from this study and other, similar studies in the literature? First, it is true that the majority of these patients can be restarted on anticoagulation without serious consequences, but that risk is not minimal. In this study, 7.5% of patients had a recurrent hemorrhage, and of those cases, one quarter were fatal.
One of my concerns about this study is the workup the patients underwent to ascertain the underlying etiology of the initial bleed. Did they all undergo CT angiograms, for example, or MRI to rule out cerebral amyloid angiopathy? It is very unclear what the extent of the workup was and how intensively the authors looked for the underlying etiology of the initial hemorrhage, which perhaps may have guided them in decisions about beginning or not beginning subsequent or recurrent anticoagulation.
The other big factor is the great hope that the newer novel oral anticoagulants overall tend to have a much lower risk for primary hemorrhage compared with warfarin and other vitamin K antagonists. Whether this will be true in real clinical practice remains to be seen, although some of the early data we are seeing, especially from the US Food and Drug Administration dabigatran long-term follow-up study, seem to indicate that, overall, the risk for hemorrhage appears to be rather low with some of novel oral anticoagulants, if not all of them.
Thank you for tuning in for this Medscape stroke update. Have a good day.
