CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 1, January/February 2014
AFRICA
21
An analysis of real-world cost-effectiveness of TAVI in
South Africa
Thomas A Mabin, Pascal Candolfi
Abstract
Objectives:
Transcatheter aortic valve implantation (TAVI) has
become the standard of care for inoperable patients with severe
aortic stenosis and is an alternative to conventional surgery for
high-risk aortic valve replacement (AVR) patients. There is a
positive correlation between severity of pre-operative patients
and hospital costs. The aim of this study was to compare
empirically derived costs of the two therapies in South Africa.
Methods:
The cost-comparison analysis was performed with
a MediClinic database including 239 conventional isolated
AVR (cAVR) and 75 TAVI cases. All costs are given in 2011
ZAR. The subset of cAVR patients were derived from the
relevant and available information in the database and their
costs were compared with TAVI costs.
Results:
From the 75 available subjects, mean TAVI costs
were ZAR 335.5k
±
47.9k, (median ZAR 326.5k) with a mean
(median) ICU and hospital length of stay (LoS) of 2.7 (2.0)
and 7.6 (6.5) days, respectively. The mean cAVR cost was
lower at ZAR 213.9
±
87.5k (median ZAR 193.6k) but this
included the entire population costs (i.e. low to high surgical
risk). When estimating cAVR costs, defined by LoS of more
than six and 13 days in the ICU and hospital, respectively,
and being over 75 years of age, the estimate increased to ZAR
337.9k, which was above the TAVI mean costs. In-hospital
mortality was 5.3 and 7.9% for TAVI and the entire cAVR
group, respectively. When considering the subset of cAVR
patients most likely to be high risk, it increased to 21.4%.
Conclusions:
Within the context of limited clinical data we
performed the first attempt at cost-effective analysis of TAVI vs
cAVR in South Africa. Treatment of aortic stenosis with cAVR in
a
post hoc
defined high-risk patient segment was more expensive
than TAVI in South African centres. Despite common percep-
tions on costs, adoption of TAVI as an alternative, less-invasive
therapy that has been clinically proven and recommended by
an FDA advisory panel (Partner A) to be at least as effective as
cAVR, has a viable economic argument in appropriate patients.
Keywords:
TAVI, cost effectiveness, interventional cardiology,
cardiac surgery, aortic stenosis, aortic valve
Submitted 3/3/13, accepted 9/12/13
Cardiovasc J Afr
2014;
25
: 21–26
DOI: 10.5830/CVJA-2013-090
Surgical replacement of defective aortic valves has become
almost commonplace in recent years with good outcomes
expected.
1-3
A substantial number of patients suffering from
severe aortic stenosis are considered inoperable due to existing
co-morbidities not allowing a conventional surgical aortic valve
replacement (cAVR) intervention. In the latest Euro Heart
survey, the estimated prevalence of inoperable patients with
severe aortic stenosis was 31.8%.
4
The Partner Cohort B trial
5,6
randomly assigned patients
considered unsuitable candidates for surgery into two groups:
standard therapy (including balloon aortic valvuloplasty)
or a transcatheter aortic valve implantation (TAVI) via the
transfemoral approach. The difference in rate of death from
any cause was considerable, with an absolute 20 and 24.7%
difference favouring TAVI at one and two years, respectively.
TAVI has subsequently emerged as a new standard of care for
these patients and is considered one of the most innovative
breakthroughs in medicine in recent years.
The Partner Cohort A trial
7,8
randomly assigned high-risk
patients and aimed to compare conventional surgery with TAVI
(via a transfemoral or transapical approach). Non-inferiority
was met and TAVI showed similar clinical benefit – absolute
reduction of death from any cause of 2.5% (
p
=
0.45) and
1.1% (
p
=
0.78) at one and two years, respectively. The clinical
trade off appeared to be between major vascular complications
(more frequent with TAVI) and major bleeding (more frequent
surgically). Myocardial infarction at two years, haemodynamics
(mean gradient and EOA), anaesthesia and procedure time,
recovery (assessed by ICU and hospital length of stay: LoS) were
secondary endpoints that also improved with TAVI.
Only limited cost-effectiveness studies with TAVI have been
published so far. Reynolds
et al
.
9
and Watt
et al
.
10
looked at
the cost-effectiveness of TAVI versus medical management
for patients ineligible for cAVR, based on the Partner Cohort
B trial, from the perspective of the US and UK environments,
respectively. The incremental cost-effectiveness ratio (ICER) for
TAVI in the US study was estimated at $50 200 per year of life
gained or $61 889 per quality-adjusted life years (QALY) gained,
and in the UK study at £16 100 in the base case. Both were well
within the acceptable threshold.
Gada
et al
.
11
used a Markov model, also based on the Partner
trial and derived the outcomes and costs from 10 000 simulations.
They found TAVI and cAVR cost effective when compared with
medical management, with incremental cost-effectiveness ratios
(ICERs) of $39 964/QALYs and $39 280/QALYs, respectively.
TAVI was associated with a QALY gain of 0.06 compared with
cAVR but with a greater cost ($59 503 vs $56 339), yielding an
ICER of $52 773/QALYs.
We attempted to assess a cost-effective analysis of TAVI versus
cAVR in South Africa. TAVI has not yet been fully embraced in
the South African market, largely because of concerns on the
initial cost of the device, without considering the potential cost
MediClinic Vergelegen, Somerset West, South Africa
THOMAS A MABIN, FACC, FESC FRCP
Edwards Lifesciences SA, Nyon, Switzerland
PASCAL CANDOLFI, PhD,
