Download Bioprosthetic aortic valve changes late after insertion of a left

Bioprosthetic aortic valve changes late after insertion of a
left ventricular assist device
Katherine Khvilivitzky, MD, and Gonzalo V. Gonzalez-Stawinski, MD
a
b
Figure. (a) Transaortic and (b) left ventricular outflow views of the bioprosthetic aortic valve of the explanted heart after 18 months of left ventricular assist device
therapy.
A 60-year-old man had his aortic valve replaced and a HeartMate II
ventricular assist device (VAD) inserted; 18 months later, he received a
heart transplant. The explanted heart had a grossly fibrotic appearance
on the ventricular side, with scar tissue extending onto the cusps. VAD
therapy can lead to both acute and chronic changes in the valves, which
may be clinically significant.
A
60-year-old man with known severe aortic stenosis
presented with dyspnea. He had had multiple recent
hospitalizations for systolic (low output) heart failure
exacerbations. After several days of critical care support, he underwent aortic valve replacement with a 23-mm
Carpentier-Edwards valve and implantation of a HeartMate II
ventricular assist device (VAD). Due to the severity of systolic
dysfunction, the chances of ventricular performance recovery
with valve correction alone were thought to be poor, and the
VAD was inserted at the time of valve replacement.
After 18 months of mechanical circulatory support, the
patient went on to receive a heart transplant. The aortic valve
bioprosthesis of the explanted heart had minimal changes on
Proc (Bayl Univ Med Cent) 2013;26(1):45–46
the aortic side but a grossly fibrotic appearance on the ventricular side. There was scar tissue extending onto the cusps
(Figure).
DISCUSSION
With the prevalence of VAD therapy consistently increasing,
the phenomenon of heart valve alterations in this setting is being
recognized. Both acute and chronic changes have been noted
in bioprosthetic as well as native valves in the setting of VAD
therapy (1, 2). Gross examination of explanted bioprostheses in
the aortic valve position has disclosed endocardial fibrosis of the
sewing rings and fibrous tissue extending onto the cusps with
significant fusion (1). Histological examination of the aortic
bioprosthesis after several weeks of VAD therapy revealed recent
thrombus on the aortic surface and aggregates of macrophages
on both surfaces of the cusps (1).
From the Department of Cardiothoracic Surgery, Baylor University Medical Center
at Dallas.
Corresponding author: Katherine Khvilivitzky, MD, Department of Cardiothoracic
Surgery, Baylor University Medical Center at Dallas, 3500 Gaston Avenue, Dallas,
TX 75246 (e-mail: [email protected]).
45
The structural remodeling of the left ventricular outflow tract
during VAD therapy is related, in large part, to mechanical stress
on the tissue leading to inflammation, deterioration, and fibrosis
(3). This process could be clinically significant as a potential source
of emboli or as nidus for infection. Additionally, in the setting of
bridge-to-recovery therapy, left ventricular outflow obstruction
could limit parallel flow and elevate left ventricular end diastolic
pressures, thereby limiting myocardial recovery (2).
46
1.
2.
3.
Butany J, Leong SW, Rao V, Borger MA, David TE, Cunningham KS,
Daniel L. Early changes in bioprosthetic heart valves following ventricular
assist device implantation. Int J Cardiol 2007;117(1):e20–e23.
Baradarian S, Dembitsky WP, Jaski B, Abolhoda A, Adamson R, Chillcot S,
Daily PO. Left ventricular outflow tract obstruction associated with chronic
ventricular assist device support. ASAIO J 2002;48(6):665–667.
John R, Mantz K, Eckman P, Rose A, May-Newman K. Aortic valve
pathophysiology during left ventricular assist device support. J Heart Lung
Transplant 2010;29(12):1321–1329.
Baylor University Medical Center Proceedings
Volume 26, Number 1