85 / 92
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 4, July/August 2016
AFRICA
e15
was increased from 6 000 to 9 200 rpm; the pump flow was 4.5
l/m, pulse index was 5.7, pump power was 5.5 W, and mean blood
pressure was 60 mmHg. Protamine was administered slowly. The
intra-aortic balloon pump was removed, and an open repair of
the left femoral artery was performed. Dobutamine and dopamine
maintained the RV contractility and decreased the RV afterload.
The patient’s condition stabilised, and he was transferred to
the intensive care unit. The endotracheal tube was removed the
next day. More than 12 hours following cf-LVAD implantation,
when the chest tube drainage decreased to ≤ 50 ml/h and the
coagulation profile returned to normal levels, an intravenous
heparin infusion was started to maintain activated partial
thromboplastin time between 50 and 70 s. Aspirin (100 mg)
was administered once daily after extubation, and warfarin was
administered to maintain the international normalised ratio
(INR) between 2.0 and 3.0. Heparin infusion was continued
until the INR target range was attained. He was discharged one
month after the operation and was categorised as New York
Heart Association functional class II.
Discussion
The prevalence of end-stage HF is on the increase, however,
the availability of donor hearts remains limited. Therefore, the
number of patients requiring long-term support with cf-LVAD
implantation has increased. HeartMate II is a new-generation
cf-LVAD used as BTT and DT in patients with end-stage HF.
1,3
The waiting time for cardiac transplant recipients has
increased, and so has BTT by using the support device in
clinical settings. We occasionally encounter patients who require
unexpected long-term device support. In addition to being a
life-saving treatment, cf-LVADs currently also provide long-term
survival with favourable quality of life for patients with severe
HF. Consequently, long-term cf-LVAD implantation has become
a valuable alternative to cardiac transplantation for treating
end-stage HF.
Studies have reported that post-transplant survival at
one, two, five and 10 years is approximately 90, 80, 70 and
50%, respectively.
1
The survival of patients receiving DT with
cf-LVADs within this cohort at one, three and five years was
80–83, 75 and 61%, respectively.
1,4
Prolonged post-transplant survival in patients receiving BTT
can reduce the need for cardiac transplantation as a first-line
replacement therapy. However, it is too premature to draw
conclusions about survival comparisons because of the lack
of head-to-head comparative data. Furthermore, considering
the frequent readmissions in this population, patient survival,
quality of life, and healthcare costs should be considered before
drawing conclusions.
1
Current cf-LVADs provide satisfactory
long-term survival, but rehospitalisation for specific reasons is
common in this population.
1
Despite this progress, cf-LVAD implantation is still associated
with a risk of complications, which challenges patient selection
and adversely impacts on outcomes. The incidence of RVF in
this population ranges from 10 to 50% and is a risk factor for
peri-operative and postoperative mortality and morbidity in
patients undergoing cf-LVAD implantation.
2,4,5
Moreover, some reports have suggested that cf-LVAD
implantation in patients with pre-operative hepatic failure
entails considerable mortality.
2
cf-LVAD recipients who develop
postoperative RVF have poor outcomes, including increased
incidences of multi-organ failure, postoperative haemorrhage,
pulmonary complications, thromboembolic events, and migration
of intracardiac air to the coronary arteries, causing transient
myocardial ischaemia.
5
In this setting, the function of the right
heart becomes critical to patient survival, and RVF remains a
considerable postoperative complication that affects mortality.
In a previous study, 33.4% of patients experienced RVF
postoperatively and 10–15% required RV support.
2,5
RVF
after cf-LVAD implantation is occasionally unavoidable in a
deteriorated heart. Therefore RVF is a contraindication for
receiving cf-LVAD implantation because it may require the use
of a biventricular assist device. The setting of RVF is associated
with a poor prognosis and influences early outcomes.
5
The prediction and treatment of RVF are crucial to improve
survival after cf-LVAD implantation. The ratio of central venous
pressure to pulmonary capillary wedge pressure and secondary
pulmonary hypertension is a critical predictor of RVF after
cf-LVAD implantation; RVF significantly reduces survival after
cf-LVAD implantation.
5
Careful evaluation of central venous
pressure, pulmonary capillary wedge pressure, and laboratory
data may help to predict postoperative RVF.
Furthermore, secondary TR is common among patients
with RVF who undergo cf-LVAD implantation. Although the
repair of TR in combination with cf-LVAD implantation is
not an established approach, recent reports have suggested that
concomitant tricuspid valve repair may reduce postoperative
RVF.
5
In our case, tricuspid valve repair was performed by the
de Vega annuloplasty procedure to decrease the risk of RVF.
To determine whether tricuspid valve repair is useful to rescue
patients from possible RVF, a randomised study is required.
HeartMate II may transiently worsen the right ventricular
function in the initial post-implant period because of a higher
cardiac output resulting in increased venous return and
right ventricular preload.
2
In addition, this initial temporary
cholestasis resulting from RV dysfunction has been documented
previously.
2
Although laboratory parameters tend to normalise
with successful cf-LVAD implantation, the effect appears to
dissipate over time. A gradual improvement in RVF caused by
improved LV unloading is observed in the majority of patients.
Survival rates have increased because major adverse events,
such as stroke, bleeding and infection, have decreased. The
occurrence of thrombosis ranges from annualised rates of 2–4%
and that of haemolysis ranges from 2–3%.
3
The major high-
risk factors, such as female gender, young age, implantation
technique, and inflow cannula malposition, are related to
the development of pump thrombosis.
3
Other risk factors,
such as sub-therapeutic INR, non-compliance, hypercoagulable
disorder, and infection require pre-operative optimisation, intra-
operative techniques, and postoperative management strategies.
3
The pre-operative period of haemodynamic and fluid balance is
optimised when possible.
Some reports have evaluated heparin antibodies, aspirin
resistance and baseline platelet function where possible.
3
An
adequate pump pocket depth is critical to allow favourable
positioning of the cf-LVAD and inflow cannula angle, which
should lie parallel to the septum and oriented to the central
LV and mitral valve. Echocardiography is essential to enable
surgeons and anesthaesiologists to make prompt decisions during
cf-LVAD implantation and is necessary for detecting cardiac