31st Annual Meeting and Scientific Sessions
SAN DIEGO – Despite a previous single-center trial indicating
sustained survival for patients with nonischemic dilated cardiomyopathy who
were treated with a left ventricular assist device plus optimal medical therapy
followed by clenbuterol, a new multicenter study showed that this combination
treatment in the same population did not confer the same benefit on myocardial
For Keith D. Aaronson, MD, medical director of the Heart Failure
Program at the University of Michigan in Ann Arbor, and study researcher, the
study began with some skepticism about whether there was any potential for
clinical recovery with this treatment in patients with chronic HF.
Keith D. Aaronson, MD
“At this point, while I don’t know how much this [treatment]
brings out recovery or who will recover, I have to concede that this is a real
phenomenon worth pursuing clinically and certainly warrants further
study,” Aaronson said in a presentation.
The five-center, US-based study included nonischemic dilated
cardiomyopathy bridge-to-transplant patients (n=17; median age, 57 years) who
had received HeartMate XVE (Thoratec) and target or maximum tolerated
angiotensin receptor antagonist, beta-blocker, ACE inhibitor, digoxin and
aldosterone antagonist therapy. Patients were then given
clenbuterol and beta-1 selective betablockers for 3 months following either
plateau in reverse remodeling or 16 weeks.
Researchers withdrew four patients due to complications before treatment
with clenbuterol. Following 4 months of
therapy, the remainder of patients received clenbuterol for a median of 7
Among the 13 patients that entered phase II of the study, 12 had an
adverse event, which included muscle spasms and pain, supraventricular
tachycardia and sustained ventricular tachycardia requiring cardioversion. Of
these 12, three had a reduction in clenbuterol dose.
According to data, at the start of clenbuterol usage, LV ejection
fraction was 42.5%, which decreased markedly at 6 months (31%). However, at 18
months, LVEF rose to 45%. Overall, one of the 13 patients were explanted, while
two of the 10 evaluable patients without device complication requiring study
withdrawal had marked myocardial recovery.
Significant limitations of the study highlighted by Aaronson included
the very small sample size as well as loss of patients due to complications
unrelated to clenbuterol or study procedures. – by Brian Ellis
Disclosure: Dr. Aaronson has received grant and research support
from Thoratec, HeartWare and Terumo.
For more information:
- Aaronson K. Featured Abstract #3. Presented at: ISHLT 31st
Annual Meeting and Scientific Sessions; April 13-16, 2011; San Diego.