Page 26 - Cardiac testing for coronary artery disease in potential kidney transplant recipients

Summary of results (Continued)

None of the studies included a cost-effectiveness evaluation. MPS is known to be more expensive than DSE, although both are less
expensive than the reference standard, coronary angiography.

CAD - coronary artery disease; CI: confidence interval; CIMT: carotid intimal medial thickness; DSE: Dobutamine stress echocardio-
graphy; MPS: Myocardial perfusion scintigraphy

pertrophy and decreased coronary flow reserve, all of which could
account for reduced specificity of MPS in kidney transplant can-
D I S C U S S I O N didates (Houghton 1990).
Causes of false negative results in MPS in the general population
Summary of main results include balanced triple vessel disease and submaximal heart rate
during stress. Although the reason for lower sensitivity in kidney
Preliminary findings of comparisons of DSE and MPS versus
coronary angiography have been published by our review team transplant candidates compared with the general population re-
mains unclear, differences in the effect of the stress agent drug
(Wang 2011), but this systematic review represents more index
tests and several studies that were since identified. Of the many among patients with CKD and the general population offers a pos-
sible physiological reason for the difference in sensitivity. Dipyri-
screening tests available, most studies investigated the accuracy of
DSE and MPS. Two systematic reviews were conducted that com- damole, the drug routinely used in MPS, causes vasodilation of
coronary blood vessels by promoting accumulation of adenosine,
pared DSE and MPS in the general population. These reviews re-
portedthatMPS wasmore sensitive indetectingCAD,butexercise an endogenous vasodilator. Dipyridamole infusion leads to va-
sodilation of normal coronary arteries, which is interpreted as an
stress echocardiography had higher specificity (Fleischmann 1998;
Schinkel 2003). Findings from our review indicate that DSE and appropriate normal increase in cardiac perfusion. The decreased
perfusion resulting from reduced vasodilator response of diseased
MPS have moderate levels of sensitivity and specificity to detect
severe coronary artery stenosis. vessels is interpreted as reversible ischaemia. A corresponding rise
in heart rate also generally occurs during dipyridamole infusion
Our key findings are presented in Summary of results. On di-
rect analysis, DSE had a higher point estimate of sensitivity and and is thought to be secondary to vasodilatation, mediated in part
by the cardiac nerves. Heart transplant recipients have been shown
specificity compared with MPS. This was statistically significant
for both the overall indirect comparison analysis (P = 0.02) and to have limited vasodilator response to dipyridamole, which has
been attributed to increased resting myocardial blood flow in the
the sensitivity analysis which included only studies that avoided
partial verification (P = 0.03). There was no statistical evidence transplanted heart resulting from increased cardiac workload and
cardiac de-innervation (Rechavia 1992). Similarly, patients with
that DSE had higher diagnostic accuracy in the sensitivity anal-
ysis which included only studies that avoided partial verification CKD (particularly those who have diabetes) may also experience
a degree of functional de-innervation as part of an autonomic
and had reference standard thresholds ≥ 70% stenosis (P = 0.09).
However, because results from studies that applied this common neuropathy, which would potentially reduce the relative efficacy
of dipyridamole. CKD is also invariably associated with arterial
threshold were similar to the overall analysis, the lack of statistical
significance may have resulted from a reduction of power due to calcification and reduced coronary artery flow reserve (Niizuma
2008; Sezer 2007). This may also potentially lead to a decrease
the smaller number of included studies. Although there were few
direct comparisons, in two studies that compared DSE and MPS in responsiveness to the vasodilating properties of dipyridamole.
On the other hand, dobutamine which is commonly used in stress
in the same population, DSE had a higher specificity and equiva-
lent or better sensitivity than MPS. echocardiography, has direct inotropic effects on the cardiac my-
ocyte and potentially may be less affected by the mechanism de-
That DSE had a higher specificity than MPS is consistent with the
principle that reversible systolic dysfunction (detected by DSE) scribed.
There was also more variability in the spread of the MPS test results
usually occurs after reversible perfusion abnormalities (detected
by MPS). In the general population, MPS should have higher sen- in SROC space compared with DSE. This is probably because
MPS isamore subjective test. Several studiesof MPS demonstrated
sitivity but lower specificity than stress echocardiography because
systolic dysfunction often occurs only when severe CAD is present. considerable inter- and intra-patient result variability, which may
limit its diagnostic utility (Akesson 2004; Burkhoff 2001). Vari-
Patients with ESKD often have hypertension, left ventricular hy-
Cardiac testing for coronary artery disease in potential kidney transplant recipients (Review) 24
Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.