Thursday, February 18, 2016

AVMs - Don't Mess With Brain Tangles, Study Warns —Longer follow-up from ARUBA trial confirmed benefit of no intervention

Good luck convincing your doctor and yourself to leave a ticking time bomb in your head.
http://www.medpagetoday.com/MeetingCoverage/ISC/56272?xid=nl_mpt_cardiodaily_2016-02-18&eun=gd3r
The intimidating brain tangles that are arteriovenous malformations (AVMs) are best left alone, according to results from a long-term randomized controlled trial.
In the ARUBA study, there was a significantly increased risk of stroke or death over 5 years in AVM patients randomized to intervention compared with those who just received medical treatment for their symptoms (HR 0.31, 95% CI 0.17 to 0.56, P<0.0001), Christian Stapf, MD, of the University of Montreal, and colleagues reported here at the International Stroke Conference.
That translated to a number needed to harm of only five patients -- which further shrunk to three in per-protocol analyses, Stapf said.
"We have to recognize that with our interventions, we don't seem to be good enough to help," Stapf said. "The old reflex of taking away the 'flower of evil,' -- take it out so it cannot do harm anymore -- we actually find the doctor's intervention creates more harm than good."
There are about 5,000 new cases of AVMs every year in North America and 60% are diagnosed unruptured. The spontaneous annual hemorrhage rate is 2.1%, Stapf said.
To assess whether an interventional procedure such as endovascular, surgical, or radiotherapy treatment could offer benefit over best medical management -- treating symptoms such as headache or seizure -- the researchers randomized 226 patients, starting in 2007, to either strategy.
Patients were excluded if they had a previous AVM hemorrhage, prior AVM treatment, or if the AVM was considered untreatable for eradication, and the primary endpoint was the time to death or symptomatic stroke.
The study was stopped early in April 2013 when it was shown that doing nothing was better than doing an interventional procedure. The mean follow-up at that time was 33.3 months; in this reporting, the researchers had a mean of 50.4 months of follow-up through July 2015.
They found that a larger proportion of interventional patients hit the primary endpoint of stroke or death compared with medical management (35.3% versus 13.6%), which translated to a significant reduction for patients who were left alone (HR 0.31, 95% CI 0.17 to 0.56, P<0.0001).
The number needed to harm was only five patients, Stapf said.
Similar results turned up in the per-protocol analysis, with a higher proportion of intervention patients hitting the primary endpoint (40.6% versus 10.8%, P<0.0001) and a significant reduction in risk for medical management patients (HR 0.22, 95% CI 0.12 to 0.41, P<0.0001).
In this analysis, the number needed to harm shrank to three patients, Stapf said.
He noted that the median time from intervention to the primary endpoint in treated patients was only 1 day.
Secondary outcomes of death or disability as measured by a Modified Rankin Scale (mRS) score of 2 or higher were worse in the interventional groups in both analyses (38% versus 18% in intention-to-treat, 40% versus 17% in per-protocol). There were also more serious adverse events, including any stroke and focal deficit, in the intervention groups.
In subgroup analyses, there was no significant benefit for any group, but there was a nonsignificant trend favoring intervention among those with a Spetzler-Martin score of I. These subgroup analyses, Stapf said, may lead the way to testable hypotheses for future studies.
"We have to find ways to improve our interventions, to better target specific patient groups that still may benefit despite the risks," Stapf said. "I think this is where clinical research has to go now. We have a few details in sub-analyses that may pave the way for more studies."
"The treatment of choice is available world-wide and at low cost," he added.
Kyra Becker, MD, of the University of Washington, who was not involved in the study, called the findings "striking."
"I think there are a lot of examples like this in medicine where we actually aim to do good for the patient and find out that's not the case," Becker told MedPage Today. "Some things we've taken as gospel have been turned on end lately, like the use of hormone therapy. There are some things we've done forever in medicine and it's time to step back and say, have we been doing the right thing? This is just one of those examples."
She added that disorders "that are fairly common or fairly deadly are the ones worth looking at."

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