A deeper look at the data from a randomized trial of
unruptured brain arteriovenous malformations (AVMs), known as ARUBA, shows that
outcomes (death or stroke) among those treated with interventional therapy
compared with medical therapy were worse than previously known. Data from the
new five year-analysis were presented here on Saturday at the AAN Annual
Meeting.
The investigators examined functional impairment as defined
by a modified Rankin Scale score (mRS) of 2 or greater at the time of death or
stroke. They also compared the frequency of functional impairment and its
association with both the score on the Spetzler-Martin Grading Scale and
primary outcome events in both the medical therapy and interventional groups.
The Spetzler-Martin Grading Scale assesses features of intracranial AVMs to
determine operability of AVMs on a scale of 1 to 6; a grade of 6 describes
inoperable lesions.
They found that after a median follow-up of 42 months the
risk of functional impairment after a primary outcome event was significantly
lower (HR 0.26, 95%CI 0.12-0.57) for patients randomized to medical management
compared with interventional treatment, which included neurosurgery,
embolization, or stereotactic radiotherapy, or a combination of those
interventions chosen by the participating center. The Spetzler-Martin Grade and
primary outcome events were not associated in the medical arm (p=0.80), but
were associated with increasing grades in the interventional arm (p=0.0002).
"Enough details exist now to show that the adverse
events in the interventional arm occurred for the most part very early — often
the day of initiation — while those in the medical arm occurred later, some of
them much later, and not clustered in time," said J.P. Mohr, MD, FAAN, the
Daniel Sciarra professor of neurology at Columbia University and the trial's
co-principal investigator. "More important, the few outcomes in the
medical arm were clinically mild compared with the more serious ones from
intervention."
"At five years follow-up, the trial looks like it
justifies watchful waiting, hoping that either no spontaneous hemorrhage will
occur in this lifetime condition or that if it does the effect will be
clinically mild," at which time intervention can be tried to eliminate the
AVM, Dr. Mohr said.
Commenting on the study, Dileep Yavagal, MD, FAAN, director
of interventional neurology at the University of Miami, said the findings
dovetail with his own experience. He agreed that "watchful waiting is the
better management strategy" for these AVMs.
The "one clear exception" to watchful waiting, he
said, would be cases with "feeding-artery" aneurysms that are more
than 4-5 mm in size associated with the AVMs. In those cases, interventional
treatment may be indicated to treat the aneurysms even if we do watchful
waiting for the AVMs."
Issam Awad, MD, FACS, director of neurovascular surgery at
the University of Chicago, said, however, that the problem with the study is
"that most patients with unruptured AVMs undergo treatment decisions to
purchase a natural risk over a life expectancy horizon of several decades and
not merely 42 months."
Another issue, he said, is that all the treatments were
combined, without the benchmarking of therapeutic objectives or outcomes.
Dr. Mohr said he would like the neurologic community to
focus not so much on problems associated with intervention but on the success
of medical management in ARUBA's patients. "We prefer to focus attention
on those who did not have the intervention," he said. "Their benign outlook
is the least arguable of all the findings."
http://journals.lww.com/neurotodayonline/blog/NeurologyTodayConferenceReportersAANAnnualMeeting/pages/post.aspx?PostID=27&cid=MR-eJP-AANNTCR-AnnualMeetingDay2-Neurology-WNT-NoPromo
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