Download Exercise performance with pulsatile and continuous

Exercise performance with pulsatile and continuous-flow
left ventricular assist devices in patients with end-stage
heart failure
R.V Pruijsten, J.H. Kirkels, C. Klöpping, H.M. Nathoe,
J.R. Lahpor, N. de Jonge
Division of Heart and Lungs
University Medical Center Utrecht
The Netherlands
Disclosures: none
Background (1)
• Drug therapy of heart failure has improved over the years;
mortality still remains high
• End-stage heart failure: heart transplantation improves
functional capacity, quality of life and provides better life
expectancy
Background (2)
• Left ventricular assist devices (LVAD’s) are increasingly
used as bridge to transplantation and as destination
therapy
HeartMate I =
pulsatile flow
device
HeartMate II = continuous flow device
Background (3)
• Pulsatile devices result in substantial unloading of the LV
and exercise performance compatible with activities of
normal daily life (De Jonge, JACC 2001;37:1794-9; Kemperman, Clin Chemistry
2004;50:1670-2)
• Use of pulsatile devices is limited by size constraints and
long-term mechanical durability
Background (4)
• Continuous-flow rotary pumps are much smaller, silent,
and have the potential for greater long-term mechanical
reliability (Slaughter, N Engl J Med 2009; 361:2241-51)
Background (5)
• Physiology of the two designs is completely different
• Pulsatile full-to-empty mode with pump rate adjusting to
changes in LV-preload (venous return) versus continuousflow device operated at a fixed rotor speed
• Volume unloading of the LV is less with continuous-flow
devices than with pulsatile devices (Haft, Circulation 2007;116[suppl I]:I-8-I-15.)
Pulsatile and continuous-flow LVAD’s
Pulsatile and continuous-flow LVAD’s
Aim of the study
• To determine if the difference in pump physiology is
relevant for the unloading of the heart and exercise
performance after implantation
Methods (1)
• All LVAD’s implanted from 2006 were continuous-flow
devices. Historical control group (1993-2005) of pulsatile
devices.
• Exercise data from all patients who were able to perform
an exercise test 3 months after implantation of a
continuous-flow device (n=38) were compared with
patients with pulsatile devices (n=40).
Methods (2)
• Pulsatile LVAD’s in automatic mode; continuous-flow
LVAD’s at fixed rotor speed, 9400-9800 RPM (optimized
to minimize suction events)
• Exercise testing using treadmill or bicycle ergometer with
continuous breath by breath respiratory gas analysis
Methods (3)
• Peak VO2 expressed as ml/kg/min and as percentage of
predicted, according to Jones
• Unloading of the LV determined by BNP plasma levels
pre- and 3 months post LVAD implantation
General results continuous-flow LVAD implantation
• 63 patients implanted (17 female)
• 10 died, after 0, 1, 4, 14, 18, 21, 25, 87, 121 and 367
days
• 19 transplanted, after 352±226 days
• 3 explanted, after 124, 343 and 355 days
• 31 ongoing (479±412 days) (21-1333 days)
Reasons why exercise test was not (yet)
performed in all patients with continuous-flow
LVAD’s (63)
• Died before ergo:
8
• HTx before ergo:
1
• Critical illness neuropathy:
5
• Pocket infection:
1
• Other:
5
• Too early:
5
• Patients participating in study:
38
Characteristics of patients
Pulsatile LVAD (40)
Cont.-flow LVAD (38)
Age (years)
39 ± 12
43 ± 12
P = 0,14
Male / Female
36 / 4
31 / 7
P = 0,20
IHD / DCM
17 / 23
14 / 24
P = 0,49
Length (cm)
180 ± 10
178 ± 9
P = 0,35
Weight (kg)
76 ± 11
75 ± 15
P = 0,66
Results-exercise data 3 months after
implantation
Results-exercise data 3 months after
implantation
3 months after HTx: 24.0±3.9
Results-exercise data 3 months after
implantation
Functional impairment (Weber)
Class
A
B
C
D
E
Severity
mild to none
mild to moderate
moderate to severe
severe
very severe
VO2
AT
ml/kg/min
ml/kg/min
> 20
16-20
10-16
6-10
<6
> 14
11-14
8-11
5-8
<4
Results-BNP: Pre- and 3 months post
implantation
4000
3500
3000
pg/ml
2500
2000
1500
1000
500
0
Pulsatile
pre
Pulsatile
3 mnd
2283 + 1287 119 + 92
Reduction:
91%
Continuous
flow pre
2132 + 1329
Continuous
flow 3 mnd
248 + 279
86%
p=0.28
Summary
• Peak VO2, 3 months after implantation is not different in
patients with pulsatile and continuous-flow devices
• Both types of LVAD result in impressive BNP reduction
after implantation, does not differ between pulsatile and
continuous-flow devices
Conclusion-1
• Exercise performance at 3 months after LVAD
implantation is comparable between pulsatile and
continuous-flow rotary pumps
• BNP levels suggest excellent hemodynamic unloading,
without significant difference between both pumps
Conclusion-2
• Based on similar performance, combined with the
advantage of smaller size, silent operation and better
durability, continuous-flow devices are the devices of
choice as bridge to transplantation and also seem to be a
more realistic alternative for heart transplantation than
pulsatile devices
Thank you for your attention
Activities in relation to peak VO2
VO2
Activity
3.5-10
driving car, walking normal pace, cooking, vacuum cleaning
10-16
walking briskly (4.8 km/hr), golf, cycling (16 km/hr), gardening
16-20
walking moderate (6.4 km/hr), ice skating, tennis (doubles)
20-25
walking fast (7.5 km/hr), mowing lawn, canoeing
25-30
skiing (downhill), running (8.8 km/hr), cycling (21 km/hr)
30-35
skiing (cross-country), walking briskly uphill
(ml/kg/min)
Results-exercise data 3 months after
implantation
Anaerobic threshold
(ml/kg/min)
Pulsatile LVAD (40)
Cont.-flow LVAD
(38)
P
14.8 + 3.1
12.6 + 2.8
0.004
Echocardiographic data
Pulsatile flow LVAD (n=42)
Cont.-flow LVAD (n=23)
_______________________________________________________________________
LVEDd (mm) Baseline
3 months
80 + 10
72 + 12
p=0,04
58 + 15 (- 36%)
59 + 13 (- 17%)
p=0,22
________________________________________________________________________
(p=0,005)
Echocardiographic data
Pulsatile flow LVAD (n=42)
Cont.-flow LVAD (n=23)
_______________________________________________________________________
LVEDd (mm) Baseline
3 months
80 + 10
72 + 12
p=0,04
58 + 15 (- 36%)
59 + 13 (- 17%)
p=0,22
(p=0,005)
________________________________________________________________________
(Haft, Circulation 2007;116[suppl I]:I-8-I-15.)
Pulsatile flow LVAD (n=16)
Cont.-flow LVAD (n=18)
_______________________________________________________________________
LVEDd (mm) Baseline
3 months
74 + 12
73 + 11
p=ns
50 + 9 (- 30%)
60 + 10 (- 18%)
p<0,05
________________________________________________________________________
(p<0,05)
Results-exercise data 3 months after
implantation
Pulsatile flow LVAD (n = 40)
Cont.-flow LVAD (n = 38)
__________________________________________________________________________
Peak VO2 (ml/kg/min)
20.2 ± 4.8
18.6 ± 5.0
__________________________________________________________________________
(Haft, Circulation 2007;116[suppl I]:I-8-I-15.)
Pulsatile flow LVAD (n=16)
Cont.-flow LVAD (n=18)
__________________________________________________________________________
Peak VO2 (ml/kg/min)
15.4 ± 4.0
15.6 ± 4.7
___________________________________________________________________________