The AHA Guidelines and Scientifi c Statements Handbook
similar to the AHA/ACC guideline approach, TASC
recommendations are assigned a level of evidence,
though the grading system is different. TASC-II rec-
ommendations are denoted as A, B, and C. Grade A
recommendations are based upon “at least one ran-
domized, controlled clinical trial as part of the body
of literature of overall good quality and consistency
addressing the specifi c recommendation.” Grade B
recommendations are based upon “well-conducted
clinical studies [in the absence of] good quality ran-
domized clinical trials.” Grade C recommendations
are based upon “evidence obtained from expert
committee reports or opinions and/or clinical expe-
riences of respected authorities.”
Since TASC-II recommendations are based upon
much of the same literature that was available at the
time of preparation of the ACC/AHA PAD Guide-
line, there is broad consensus between both docu-
ments, such as specifi c recommendations in the
areas of cardiovascular risk factor reduction, use of
pharmacotherapies and exercise, assessment of co-
existent atherosclerotic disease in other arterial beds,
such as the cardiac or cerebrovascular systems,
and appropriate use of diagnostic imaging and phys-
iologic studies (e.g., primary use of the ABI test
to diagnose lower extremity PAD). The differences
are most notable in areas written specifi cally for
the practicing vascular specialist. TASC-II pro-
vides detailed recommendations for the indications,
merits, and performance of endovascular and surgi-
cal therapies for lower extremity arterial disease. For
example, recommendations range from indications
and contraindications for catheter-directed throm-
bolysis, performance of completion arteriography
after surgical arterial embolectomy, and use of ana-
tomic-based recommendations for angioplasty and
stent use in the infrainguinal circulation (based
upon the TASC classifi cation of lesion anatomy).
Finally, unlike the ACC/AHA Guideline, the TASC
Guideline focus is primarily upon occlusive disease
and generally does not address management of indi-
viduals with abdominal aortic or peripheral arterial
aneurysms (except for lower extremity thromboses
that manifest as limb ischemia due to popliteal
artery aneurysms).Ongoing trials and future directions on
PAD care
As for other cardiovascular care fi elds, evidence-based
recommendations are created from pro-spectively
designed clinical trials, supported by epidemiologic
surveys, case series, and expert opinion. Since original
Guideline publication in 2006, selected new studies
have become available or are in progress. This chapter
is not designed to review such studies nor to alter care
recommendations emplaced in a peer-reviewed,
intersocietal guideline. However, studies that may
merit review upon guideline update may include the
BASIL study of revascularization strategies for critical
limb ischemia, which has demonstrated parity of
endovascular care to open surgical revascularization
for individuals with critical limb ischemia [6]; the
ABSOLUTE trial, which has demonstrated short-
term benefi t from primary stenting of the superfi cial
femoral artery compared with balloon angioplasty
alone, though evidence for longer term (multiyear)
benefi t remains lacking [7]; and the NHLBI-
sponsored Claudication: Exercise vs. Endoluminal
Revascularization (CLEVER), which has offered a
PAD trial design template that should provide com-
parative effi cacy and safety data from a “strategy of
care” perspective [8].
New insights regarding the risk of lower extremity
PAD conferred by ethnicity have been demonstrated
in the NHLBI-sponsored Multi-Ethnic Studies of
Atherosclerosis (MESA) study [9]. Major new
insights confi rming the superiority of antiplatelet
therapy vs. warfarin has been provided from the
WAVE trial of warfarin vs. aspirin in prevention of
ischemic events in individuals with PAD, demon-
strating the superiority of antiplatelet medications
[10].References available online at http://www.Wiley.com/go/
AHAGuidelineHandbook.