|
Recommendations for
Imaging for Anatomic Assessment |
|
COR |
LOE |
Recommendations |
|
I |
B-NR |
Duplex ultrasound, computed
tomography angiography (CTA), or magnetic resonance angiography
(MRA) of the lower extremities is useful to diagnose anatomic
location and severity of stenosis for patients with symptomatic
PAD in whom revascularization is considered.118,120–122
|
|
See Online Data Supplement
6. |
For symptomatic patients in whom
ABI/TBI confirms PAD and in whom revascularization is considered,
additional imaging with duplex ultrasonography, CTA, or MRA is
useful to develop an individualized treatment plan, including
assistance in selection of vascular access sites, identification of
significant lesions, and determination of the feasibility of and
modality for invasive treatment. All 3 of these noninvasive imaging
methods have good sensitivity and specificity as compared with
invasive angiography.118,120–122 Renal function does not affect the safety
of duplex ultrasonography, although duplex offers lower spatial
resolution than CTA and MRA in the setting of arterial
calcification. The tomographic data from CTA and MRA afford
3-dimensional reconstruction of the vessels examined. The iodinated
contrast used in CTA confers risk of contrast-induced nephropathy
and (rarely) severe allergic reaction123,124; CTA uses ionizing radiation. MRA does not
use ionizing radiation; however, gadolinium contrast used frequently
in MRA studies confers risk of nephrogenic systemic sclerosis for
patients with advanced renal dysfunction and is therefore
contraindicated in this population.125 The choice of the
examination should be determined in an individualized approach to
the anatomic assessment for each patient, including
risk–benefit assessment of each study type. If these
noninvasive tests are nondiagnostic, then invasive angiography may
be required to delineate anatomy and plan revascularization. |
|
I |
C-EO |
Invasive angiography is useful
for patients with CLI in whom revascularization is
considered. |
|
N/A |
By definition, CLI results from
extensive PAD that limits tissue perfusion. Because timely diagnosis
and treatment are essential to preserve tissue viability in CLI, it
is often most effective and expeditious to pursue invasive
angiography with endovascular revascularization directly, without
delay and potential risk of additional noninvasive imaging. |
|
IIa |
C-EO |
Invasive angiography is
reasonable for patients with lifestyle-limiting claudication
with an inadequate response to GDMT for whom revascularization
is considered. |
|
N/A |
For patients with lifestyle-limiting
claudication despite GDMT (including structured exercise therapy)
for whom revascularization is being considered, proceeding directly
to invasive angiography for anatomic assessment and to determine
revascularization strategy is reasonable. In certain clinical
settings, noninvasive imaging studies for anatomic assessment (ie,
duplex ultrasound, CTA, or MRA) may not be available because of lack
of local resources or expertise. In addition, there are clinical
scenarios in which noninvasive studies for anatomic assessment may
be perceived to confer greater risk to the patient than invasive
angiography (eg, patient with advanced chronic kidney disease for
whom contrast dose for invasive angiography would be lower than that
required for CTA). |
|
III: Harm |
B-R |
Invasive and noninvasive
angiography (ie, CTA, MRA) should not be performed for the
anatomic assessment of patients with asymptomatic
PAD.123,124,126
|
|
See Online Data Supplements 6 and
7. |
Angiography, either noninvasive or
invasive, should not be performed for the anatomic assessment of
patients with PAD without leg symptoms because delineation of
anatomy will not change treatment for this population. This lack of
benefit occurs in the setting of risk of contrast-induced
nephropathy, patient discomfort, and allergic reactions.123,124,126 This recommendation does not address
assessment of lower extremity aneurysmal disease or
nonatherosclerotic causes of arterial disease, which is beyond the
scope of this document. |
|