874 B3 Outcome Assessment of Intermittent Claudication in Clinical Practice
)OUR."lAL OF VASCULAR SURGERY
January 2000
47. Rofsky NM, Johnson G, Adelman MA, Rosen RJ, Krinsky GA, Weinreb IC, Peripheral vascular disease evaluated with reduced-dose
gadolinium-enhanced MR angiography. Radiology 1997;205: 163-169.
48. Huber TS, Back MR, Ballinger RJ, Culp WC, Flynn TC, Kubilis PS, et al, Utility of magnetic resonance arteriography for distal
lower extremity rcvascularization, J Vase Surg 1997;26( 3):415-423.
B3
Outcome Assessment of Intermittent Claudication in Clinical Practice (see also A
2.2, Intermittent Claudication, p 85)
A detailed assessment of outcomes necessary for clinical trials or published studies is discussed in
B6, Clinical Trial Issues (p SI27). IC is an indicator of not only blood flow-limiting lesions
within the arterial tree of the lower extremity but also clinically significant systemic atherosclerosis. As such, LC exerts a global impact on the patient. Patients so afflicted experience broad
limitations in their level of daily functioning that extend beyond the ambulatory disability. Using
a variety of quality-of-life assessment instruments, such as the SF-36 and the Nottingham
Health Profile, investigators have documented increased bodily pain and decreased physical,
emotional, social functions, and worse perceived health as well as a variety of other disturbances
in patients with claudication compared with age-matched controls.l,2,3,4,5
Appropriate therapeutic goals for the treatment of the claudicant must address both the specific
lower-extremity disability and the systemic impact of the disease. Ideally, treatment will result in
an improvement in both the vascular status of the lower extremity and the patient's general
health status, indicated by at least four attributes on the SF-36 or RAND-36, and level of functioning, indicated by at least two attributes on the WIQ. The complete assessment of the outcomes of treatment of the claudicant, therefore, requires the use of both clinical and patientbased parameters. It is impossible to define "relevant" improvement.
Recommendation 19: Success of treatment for intermittent claudication
Ideally, success of treatment for intermittent claudication should take into account an
improvement in the following:
• Objective outcome: relevant improvement in walking distance as measured by a standardized exercise test
• Symptomatic outcome: improvement on a validated disease-specific health status
questionnaire
• General quality of life: improvement on a validated generic health status questionnaire
• Postrevascularization: objective proof of patency of any revascularized segment
(ideally with imaging)
B 3.1.1
Relationship Between Clinical and Quality-of-Life Outcomes Parameters
Despite the performance of a complete clinical evaluation, physicians cannot accurately assess
the overall impact ofIC on the patient. Pell- compared quality-of-life assessments of201 claudicants before their first visit to their vascular surgeon with the surgeon's impression of the
patient's symptoms and examination. The correlation between these two assessments was poor.
Studies evaluating patients with IC by walking distance, ABPI, and quality of life have also
demonstrated a poor or limited correlation between the clinical parameters and quality-of-life
index. Assessing 157 claudicant patients with treadmill walking distance, ABPI, and the
EuroQol generic quality-of-life survey, Chettcr et al6 noted a poor correlation between the clinical parameters of treadmill walking distance and ABPI and the measured quality of life. Barletta
et al? evaluated treadmill performance and the quality of life with the McMaster Health Index
Questionnaire in 251 patients and 89 age-matched controls. These investigators documented a
JOUIU-lAL OF VASCULAR SURliERY
Volume 31, Number I, Part 2
B3 Outcome Assessmentof Intermittent Claudication ill Clinical Practice
875
reduction in physical, emotional, and social function in patients with IC compared with controls, but the reduction in these quality-of-life parameters did not correlate well with treadmill
performance.
Similarly, the clinical outcome of treatment does not directly correlate with quality-of-life outcomes. An optimal interventional result represents a step toward the achievement of an
improved functional status, but it is not indicative of an overall improvement in the patient's
quality of lite. Currie et al8 studied 186 patients undergoing treatment for claudication by unsupervised exercise, angioplasry, or surgery and documented that angioplasty and surgery
improved quality-of-life scores, but the improvement did not correlate with changes in the
ABPI. Gibbons er al? found that the only independent predictor of improved function and wellbeing in 156 patients after infrainguinal revascularization was the patients' perception of their
status at baseline: those patients who functioned better before operation reported improved
function and well-being at 6 months.
Schneider et al l O evaluated the functional status and well-being of 60 patients who had undergone successful aortobifemoral bypass grafting at least 6 months earlier. They found that physical function, role function, and perceived health were worse and bodily pain greater than in
those without symptomatic arterial occlusive disease, despite a patent bypass. These findings
indicate that clinical measures, such as ABPI, patency, and limb salvage, effectively assess the
physiological impact of vascular intervention but do not adequately describe overall patient benefit or adverse effect. This lack of correlation underscores the need to use both clinical and quality-of-life parameters to adequately determine the impact of vascular disease and its treatment on
the c1audicant (see Critical Issue 1, p 538).
Critical Issue 5: Outcome measures of intermittent claudication therapy in clinical practice
Several validated and established methods assess outcome of claudication therapy in clinical trials (eg, treadmill walking distance, functional status, and quality-of-life questionnaires). Future studies are needed to develop practical methods to assess outcome measures of intermittent claudication therapy that can be used in everyday clinical practice.
Clinical Measures: Walking Distance
Because the major clinical manifestation of IC is walking impairment, walking distance is the
primary objective parameter for the assessment of treatment. This is best evaluated through the
use of a standardized exercise protocol. The general details regarding the performance of a
treadmill exercise test are provided in Basic Treatment (p 580). Either the distance to the onset
of claudication (initial claudication distance [lCD]) or the absolute (maximal) claudication distance (ACD) achieved on a treadmill at a constant speed and percent incline can be used to
evaluate the success of treatment over time. The same value must be used for each subsequent
evaluation.
Walking distance may change in a manner independent of the ABPI.ll,12 Therefore, though the
ABPI is of value in determining the severity of impairment of arterial flow (see B 2.2.1, Routine
Tests, p 562) and patency of the revascularized and distal arterial segments within the lower
extremity (sec also A 3.2.9, Patency, p 542), walking distance is the most appropriate objective
measure of success of treatment of Ie.
B 3.1.2
Patient-Based Outcomes Parameters
Symptomatic outcome
The severity of PAD can be judged by classifying patients' symptoms on a scale of six categories
876 B3 OutcomeAssessment of Intermittent Claudication in Clinical Practice
JOURNAL OF VASCULAR SURGERY
January 2000
(see Table 9, p S39). Three categories are pertinent to claudication: category 1 indicates mild,
category 2 moderate, and 3 severe claudication. Symptomatic improvement of claudication
requires an upward shift of at least one category on this scale. These three levels of severity, of
help to the clinician in planning therapy, are based largely On walking ability. The Walking
Impairment Questionnaire assesses the cause and degree of walking discomfort, the patient's
estimate of walking distance, walking speed, and stair-climbing ability (see A 3.2.6, DiseaseSpecific Health Status Questionnaires, p S39). This questionnaire provides a simple measure of
symptomatic improvement beyond that indicated by treadmill testing. It is widely used for evaluation of the claudicant, increasing its value as an outcomes measure.
General quality of life
The SF-36 has been broadly applied to patients with IC before and after intervention. Though
scores do not correlate directly with clinical parameters, such as ABPI or graft patency, they
show the impact of treatment on the patient. As with other generic health status questionnaires,
the SF-36 scores may be affected by patient age.L? A younger patient, for example, mayexperience a greater overall negative impact from claudication than an older patient because of differing needs for walking. Therefore, appropriate interpretation of scores may require stratification
of the patient sample by age. The timing of patient assessment through use of a generic health
status instrument is also important, especially in the posttreatment period. Because of the
numerous comorbid conditions experienced by those with IC, patients may show changes in
their health status scores despite continued patency of the treated arterial segment. Using the
SF-36, Currie et al8 noted a significant improvement in physical function and pain scores shortly
after either balloon angioplasry or surgical intervention in the claudicant,
Pell and Lee I 3 found that improvements in these scores on the SF-36 persisted at 6 months
after treatment but continued to deteriorate in those managed without intervention in a review
of 195 patients. At 1 year after balloon angioplasty, Cook and Gallandl't documented with the
EuroQol questionnaire a decrease in perceived health scores despite maintained improvement in
walking distance in 24 patients with l'C, By 2 years after intervention with balloon angioplasty,
Whyman et aps reported no differences in quality-of-life scores between two groups of patients
with IC-those treated by angioplasty and those treated medically. These data confirm the global impact of claudication on the patient and underscore the systemic nature of the disease. The
assessment of the success of an intervention performed for the treatment oflC by a generic
health status questionnaire requires documentation of the date of intervention.
Postrevascularization
The clinical result of any intervention for IC should be documented through postprocedural
ABPI and imaging studies that detail the area of intervention. A reduction in ABPI should be
correlated with the images of the treated segment to determine whether a reduction in index
has been caused by problems within the treated segment or by progressive disease proximal or
distal to the treated segment.
Recommendation 20: Reporting intermittent claudication outcomes separately from critical limb ischemia
Results of treatment in patients with intermittent claudication should be analyzed separately from those of patients with critical limb ischemia.
B 3.1.3
Impact of Outcomes Assessment on Management of Intermittent Claudication
Only through an understanding of the specific and overall effects of vascular disease on the
patient can physicians develop appropriate therapeutic plans. Management guidelines for treatment and definitions of success of treatment should consider all types of outcomes. For example, a patient with mild claudication according to the walking distance categories should be considered for treatment if his or her quality of life is severely impacted by the disease as measured
JOURNAL OF VASCULAR SURGERY
Volume 31, Number 1, Part 2
B4 Treatment of Intermittent Claudication
877
by the health-related quality-of-life measures. Conversely, a patient with severe claudication
would not require treatment if his or her quality of life is not affected by the disease. Success of
an intervention is defined as improvement of at least one category and should be considered for
each of the outcomes measures. If more than one attribute is measured for a particular outcome
measure, improvement should be defined as an upward shift of at least one category 011 at least
half of the attributes, for example, at least two attributes on the WIQ and at least four attributes
on the 5F-36/RAND-36 (see Critical Issue 5, p 575).
References
1. Bartman BA, Rosen M], Bradham DD, Weissman], Hochberg M, Revicki DA, cr al, Relationship between health status and utility measures in older claudicanrs. Qual Life Res 1998;7:67-73.
2. Pell [P on behalf of the Scottish Vascular Audit Group. Impact of intermittent claudication on quality of life. Eur J Vasc Endovasc
Surg 1995;9:469-472.
3. Khaira HS, Hanger R, Shearman CPo Quality of life in patients with intermittent claudication. Eur J Vase Endovasc Surg
1996; II :65-69.
4. Ponte E, Cattinclli S. Quality oflife in a group of patients with intermittent claudication. Angiology 1996;47:247-251.
5. deVries SO, Kuipers WD, Hunink MG. Intermittent claudication: symptom severity versus health values. J Vase Surg 1998;27:422-
430.
6. Chctter IC, Dolan P, Spark II, Scott DJ, Kester RC, ct al. Correlating clinical indicators of lower-limb ischaemia with quality of life.
Cardiovasc Surg 1997;5:361-366.
7. Barletta G, Perna S, Sabba C, Catalano A, O'Boyle C, Brcvetti G, er al, Quality of lite in patient with intermittent claudication:
relationship with laboratory exercise performance. Vase Med 1996;1: 1-3.
8. Currie lC, Lamont PM, Baird RN, Wilson YG. Treatment of intermittent claudication: the impact on quality of life. Eur J Vase
Endovasc Surg 1995;10:356-361.
9. Gibbons GW, Burgess AM, Guadagnoli E, Pomposelli FB [r, Freeman DV, Campbell DR, et al, Return to well-being and function
after infrainguinal revascularization, J Vase Surg 1\195;21(1):35-44.
10. Schneider JR, MeHorney CA, Malenka DJ, McDaniel, Walsh DB, Cronenwert JL, ct. al. Functional health and well-being in patients
with severe atherosclerotic peripheral vascular occlusive disease. Ann Vase Surg 1993;7:419-428.
11. PACK Claudication Substudy Invcsitgators. Randomized, placebo-controlled, double-blind trial of ketanserin in claudicants:
changes in claudication distance and ankle-systolic pressure. Circulation 1989;80: 1544-1548.
12. Hiatt WR, Hirsch AT, Regenstcincr JG, Brass EP, and the Vascular Clinical Trialists. Clinical trials for claudication: assessment of
exercise performance, functional status, and clinical endpoints. Circulation 1995; 91:614-621.
13. Pell [P, Lee AI- Impact of angioplasty and arterial reconstructive surgery 011 the quality of life of claudicants, The Scottish Vascular
Audit Group. Scott Med J 1997;42:47-48.
14. Cook TA, Galland RE. Quality oflife changes after angioplasty for claudication: medium-term results affected by cornorbid conditions. Cardiovasc Surg 1997;5:424-426.
15. Whyman MR, Fowkes FG, Kerracher EM, Gillespie IN, Housley E, Ruckley CV, et al. Is intermittent claudication improved by percutaneous transluminal angioplasry] '1 randomized controlled trial. J Vase Surg 1997;26:551-557.
B4
Treatment of Intermittent Claudication
B 4.1
Overall Strategy and Basic Treatment for Intermittent Claudication
B 4.1.1
Overall Strategy
The overriding issue in the management of patients presenting with IC is that they are at significant risk of developing severe and often fatal cardiovascular complications; thus, their most serious
problem is not the limitation of walking, even though that may be their only symptom. Patients
with IC are at 2 to 4 times greater risk of dying from the complications of generalized atherosclerosis than similar people without claudication (see A 2.5.2, Cause of Death in Claudicants, p 519).
Therefore, the first priority in designing a treatment plan for these patients is to try to modify the
known risk factors for the progression of atherosclerosis and development of atherothrombotic
complications. It is important to explain to the patient the rationale for this strategy and that it is
not designed to improve the claudication distance. Emphasis should be put on those risk factors
whose modification has been shown to be particularly effective in decreasing morbidity and mor-