Orlando, FL - Six months
after implantation, the AcornR Cardiac Support Device, (Acorn
Cardiovascular, Inc, St Paul, MN) appears safe for use in
patients with congestive heart failure (CHF) and, in the early
stages at least, is associated with improvement in symptoms.
German researchers reported their data on the device here
at the American College of Cardiology 50th Annual Scientific
Session.
The Acorn device is an attempt to address mechanically dilation
and remodeling of the left ventricle that occurs in the setting
of dilated cardiomyopathy. The device, basically a knitted
polyester sock, is drawn up and anchored over the ventricles,
in the hope of stemming this remodeling process and improving
left ventricular (LV) ejection fraction.
"This is the first safety study where we want to know, does
it cause constriction, does it limit coronary flow, and of
course, do we learn more about efficacy in humans?" Dr
Franz X Kleber (Unfallkrankenhaus, Berlin, Germany) told
heartwire in an interview. "We now have data
up to 1 year, and are approaching the second year in a couple
of months, and we haven't seen constriction with various parameters."
In particular, interventricular dependence measures have allowed
them to exclude the possibility of function-inhibiting constriction
by the device. "So, overall for the first year, I think it's
very encouraging," Kleber said.
The results in a nutshell
Potential constriction was evaluated through assessment of
parameters including end-diastolic LV-RV pressure difference,
LV rapid filling wave, RV end-diastolic/end-systolic pressure
ratio and interventricular dependence.
Kleber and colleagues reported that no patient showed clinical
signs of constriction on these parameters. End-diastolic LV-RV
pressure differences were preserved, they note. "Relaxation
and late diastolic function were unimpaired at operating LV
volumes, while systolic function was preserved and volumes
maintained or increased."
Coronary flow reserve studies using Doppler imaging and adenosine
revealed normal coronary reserve. "We saw, on average, a slight
to moderate decrease in heart size, but we do have some patients
with a very marked decrease in heart size and massive improvement
in symptoms," Kleber added. "The important part currently
is that even on the long-term observation, we don't see inflammation
and fibrosis within the mesh."
Early hints of efficacy
In a separate paper coauthored by Kleber, colleague Dr
Wolfgang Konertz (Charite Hospital, Berlin, Germany) presented
6-month data on the safety and initial efficacy of the device
in 29 patients, five of whom were female. Seventeen of the
patients had valve repair or replacement during the same procedure.
There were no intraoperative complications. There was a 10%
early death rate (ie < 30 days) in these patients, but no
adverse events were considered related to the device.
Among 14 patients who have now reached 6 months of follow-up,
Konertz et al reported that, besides supporting the safety
of the procedure, the trends in their data "strongly suggest"
an improvement in heart failure symptoms with the device.
At six months, patients showed improvement in NYHA class,
LVEF, LV end-diastolic dimension (EDD) and end-systolic dimension
(ESD), as well as improvement on the Uniscale, a quality of
life indicator. The results on many of these parameters reached
statistical significance among the patients who received both
a valve and the device.
Results with Acorn device only (n=5)
Endpoint
Preimplant
6 months
NYHA class
2.2
1.6
LVEDD (mm)
72.8
64.8
LVESD (mm)
65.7
56.7
LVEF (%)
18.1
31.0
Results with valve and Acorn device
(n=9)
Endpoint
Preimplant
6 months
NYHA class
2.8
2.3
LVEDD (mm)
76.0
68.8*
LVESD (mm)
66.7
58.2*
LVEF (%)
20.6
24.0*
* p < 0.05
Randomized trial underway
A randomized trial is now underway with the device in 28 centers
world-wide, including 13 in the United States, the remainder
in Germany and Australia, Kleber added. The protocol calls for
170 patients to be enrolled from the American centers, 100 from
the remainder.
Susan
Jeffrey
sjeffrey@conceptis.com
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