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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 6, November/December 2016
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AFRICA
•
Formal training of the implanting team should include:
–– didactic theoretical training
–– simulator training where available
–– a visit to an experienced centre to observe TAVI cases
–– support for the initial cases at any site by a proctor until
the proctor has certified the centre to be independent.
Patient selection/mandatory prerequisites
•
Proof of severe symptomatic aortic valve stenosis.
•
Patient evaluation by a MDT.
Indications for TAVI
•
TAVI is recommended in patients who are, according to the
MDT heart team, considered to be unsuitable for convention-
al surgery because of severe co-morbidities. These include:
–– Possible procedure-specific impediment, for example:
›› porcelain aorta or severely atherosclerotic aorta
›› hostile chest
›› patent coronary artery bypass grafts crossing the midline
and/or adherent to the posterior table of the sterum
OR
–– Frailty. In the absence of validated frailty scores, this
remains the opinion of an experienced physician. We
recommend that it is the opinion of at least two physicians
of which one should be a cardiac surgeon experienced in
aortic valve replacement surgery
OR
–– Major organ compromise of two or more organ systems.
Examples include:
›› cardiac: severe left or right ventricular dysfunction,
severe pulmonary hypertension
›› pulmonary dysfunction (FEV1 or DLCO2 < 50%
predicted)
›› central nervous system dysfunction (dementia,
Alzheimer’s disease, Parkinson’s disease)
›› gastro-intestinal dysfunction (Chron’s disease, ulcera-
tive colitis)
›› liver cirrhosis, variceal bleeding.
•
TAVI is recommended in patients who are, according to the
MDT, considered to be at high risk for conventional surgery.
In line with other guidelines, the evaluation of surgical risk
should rely on the clinical judgement of an MDT rather than
quantitative risk scores as these have not been well validated
in this population. These risk scores may be used in addition,
with cut-off values of an STS (Society of Thoracic Surgeons)
risk score > 4 or a log EuroSCORE > 20 recommended. It
must be emphasised that risk scores should not be used in
isolation to determine whether a patient qualifies to undergo
a TAVI procedure. Growing evidence supports the efficacy of
TAVI in ‘intermediate-risk group’ patients.
4
The final recom-
mendation therefore remains with the MDT.
Contra-indications
•
Absence of an MDT heart team and no cardiac surgery on site.
•
Patients whose life expectancy is less than one year.
•
Clinical improvement in quality of life after TAVI limited by
co-morbidities. This may be especially relevant if the indica-
tion for TAVI is major organ compromise, as outlined above.
•
Anatomical factors
–– inadequate annulus size
–– active endocarditis
–– inadequate access site.
•
Significant other valve lesions or coronary artery disease that
requires additional valve or coronary artery bypass surgery.
•
Relative contra-indications
–– left ventricular ejection fraction (LVEF) < 20%
–– haemodynamic instability.
Establishing a TAVI programme
•
The centre should be sufficiently equipped to perform tran-
scatheter procedures safely.
1-3
•
Minimum infrastructure requirements include:
–– The ability to set up an MDT (as outlined above).
–– Immediate availability of transthoracic and transoesopha-
geal echocardiography.
–– Availability of a dedicated cardiac catheterisation labora-
tory or hybrid theatre [a theatre with mobile fluoroscopy
(‘C’-arm) screening facilities is generally not appropriate
for TAVI procedures].
–– Computed tomography (CT) scanning facilities.
–– Immediate availability of perfusion services in case emer-
gency cardiopulmonary bypass (extracorporeal circula-
tion) becomes necessary.
–– On-site availability of a surgical recovery area and inten-
sive care with staff experienced in looking after patients
following surgical aortic valve replacement.
–– Facilities for immediate renal support if necessary.
–– Immediate access to vascular surgery and interventional
radiology to deal with peripheral vascular complications.
•
The above requirements will mean that this procedure should
only be performed in a unit currently carrying out surgical
aortic valve replacement.
References
1.
Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin III JP,
Guyton RA,
et al
. 2014 AHA/ACC guideline for the management of
patients with valvular heart disease: A report of the American College
of Cardiology/American Heart Association Task Force on Practice
Guidelines.
J Thorac Cardiovasc Surg
2014 7;
148
(1): e1–e132.
2.
Vahanian A, Alfieri O, Andreotti F, Antunes MJ, Barón-Esquivias G,
et al.
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2012).
Eur Heart J
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(19): 2451–2496.
3.
Kappetein AP, Head SJ, Généreux P, Piazza N, van Mieghem NM,
Blackstone EH,
et al
. Updated standardized endpoint definitions for
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Consortium-2 consensus document (VARC-2).
Eur J Cardiothorac Surg
2012;
42
(5): S45–S60.
4.
Leon MB, Smith CR, Mack MJ, Makkar RR, Svensson LG, Kodali SK,
et al
. Transcatheter or surgical aortic-valve replacement in intermediate-
risk patients.
N Engl J Med
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374
(17): 1609–1620.