“Diabetic foot”
PAD
INFECTION
Sensory
Autonomic
Motor
ULCER
TRAUMA
NEUROPATHY
1
Diabetic foot ulceration

Neuropathic: 45-60%

Purely ischaemic: 10%

Mixed neuroischaemic: 25-40%
2
Diabetes and PAD
Spectrum of disease

Intermittent claudication
Rest pain
Ulceration/gangrene

Incidental/Screening


3
Intermittent claudication
4
Intermittent Claudication
Prevalence: 5.3% in patients aged 45-74yrs
 Quality of life: Significantly impaired
 Limb Outlook: Relatively benign
10% require intervention to prevent limb loss
1% per year require amputation
 Life expectancy: 2-4 X ↑ mortality

5
Peripheral Arterial Disease and AllCause Mortality
1.00
Normal subjects
Survival
0.75
Asymptomatic PAD†
0.50
Symptomatic PAD†
Severe symptomatic PAD†
0.25
0.00
0
2
4
6
8
10
12
Year
•*Kaplan-Meier
survival curves based on mortality from
all causes
• †Large-vessel PAD
•1.
Criqui MH. Vasc Med 2001; 6(suppl 1): 3–7.
6
Odds ratio for risk factors for
intermittent claudication
Odds Ratio
Protective
Harmful
-2 -1 0 1 2 3
4
Male gender (cf female)
Age (per 10 years)
Diabetes
Smoking
Hypertension
Hypercholesterolemia
Fibrinogen
Alcohol
Dormandy JA et al. J Vasc Surgery. 2000;31(1 Part 2):S1-S296.
7
Intermittent Claudication
and diabetes



Prevalence: 2 x ↑
Diabetics – 20% of PAD population
Limb Outlook: Worse
2x ↑ rest pain, 6x ↑gangrene
 80% of amputations occur in diabetics


Life expectancy: 8 x ↑ mortality
8
Diagnosis: History

Intermittent claudication
cramp like pain in muscles
Location: buttock, thigh, calf ,foot
occurs on exercising
relieved by rest

Atypical symptoms
are common
9
Diagnosis – clinical examination
Examination of pulses
Peripheral pulses- HIGHLY SUBJECTIVE

Rotterdam study
60% inaccurate

10
Pulses & PAD

Collins 206, 403 pts screened
PAD prevalence :16.6%
 Sensitivity of a non detectable pedal pulse -18%
 Specificity: 98%


Post tibial pulse: sensitivity 33%, specificity 66%
( Brealey S et al)

Probability of agreement of an absent pedal
pulse between experienced examiners : 0.49-0.59
(Marinelli et al)
11
Ankle Brachial Pressure Index (ABPI)
12
Ankle Brachial Pressure Index (ABPI)
Ankle pressure (mm Hg)
ABPI =
Brachial pressure (mm Hg)
Value <0.9 indicates PAD
13
ABPI – DIAGNOSIS & PROGNOSIS
McKenna et al, atherosclerosis, 1991
14
ABPI

Reliable
Positive predictive value -95%
 Negative predictive value-99%
 But a normal ABPI at rest and classical
symptoms may indicate need for exercise ABPI



ESSENTIAL FOR DIAGNOSIS
Do we have expertise in the community?
15
Diabetes and ABPI



Medial calcification: non compressible (nc)
arteries
ABPI in diabetics : 5-10% too high
Alternatives: Elevate foot
Toe pressures
16
Toe pressures


Cuff placed around proximal phalanx
Normal pressures are less than ankle pressures


average 24± 7 – 41± 17mmHg
Normal ratios compared to brachial 0.72-0.91
17
CLAUDICATION:
SURGICAL TREATMENT
First line : Prolong life
Risk factor management

Improve symptoms
Exercise
Medical therapy
Revascularisation

18
Treatment








*Statin for all
*Screen for diabetes/ Glycaemic control
*BP control
Smoking cessation: NRT
Anti-platelet therapy
Increase exercise
ACE inhibitor (HOPE study)
Review: ? For revascularisation
19
STATIN worse
VASCULAR EVENT by PRIOR DISEASE
MRC/BHF Heart Protection Study
Baseline
feature
STATIN
(10269)
PLACEBO
(10267)
1007
1255
452
597
CVD
182
215
PVD
332
427
Diabetes
279
369
Previous MI
Other CHD (not MI)
Risk ratio and 95% CI
STATIN better STATIN worse
No prior CHD
ALL PATIENTS
2042
(19.9%)
2606
(25.4%)
24%SE 2.6
reduction
(2P<0.00001
0.4
0.6
0.8
1.0
1.2
1.4
20
Diabetes and PAD



No clinical trials have been set up specifically to
investigate glycaemic control.
Type 2 diabetes, glycaemia (HbA1C)   risk
of cardiovascular morbidity and mortality (1)
Each 1% difference in HbA1C  21% (95% CI
15-27%) change in the risk of diabetes-related
death and a 14% reduction in fatal and nonfatal
myocardial infarction over 10 years (2)
Turner RC, et al.. BMJ 1998; 316: 823-8.
Stratton IM et al,. BMJ. 2000;321(7258):405-12.
21
HOPE study
Effects of ramipril on patients with
1. symptomatic PAD
2. Asymptomatic PAD (ABPI ≤ 0.9) plus an additional
coronary risk factor were analysed.
 Only 50% of the patients were defined as hypertensive.
 In both groups-  ~ 25% reduction in the primary
combined outcome of cardiovascular mortality,
myocardial infarction or stroke with ramipril.
 (ABPI) was measured unconventionally

Ostergren J, et al. Eur Heart J 2004; 25: 17-24.
22
Diabetes and PAD
Spectrum of disease

Intermittent claudication
 Rest
pain
 Ulceration/gangrene

Incidental/Screening
23
Severe limb ischaemia
Rest pain>2/52,
Tissue loss
ABPI <0.5
24
Severe limb ischaemia
Rest pain>2/52,
Tissue loss
ABPI <0.5
Critical limb ischaemia
Absolute ankle pressure
<50mmHg
25
Diabetic foot ulceration



Neuropathic: 45-60%
Purely ischaemic: 10%
Mixed neuroischaemic: 25-40%
26
27
Diabetes & foot ulcers



15% develop a foot ulcer
12-24% require amputation
Leading cause of lower limb amputation
28
Will the ulcer heal?
Study of patients with foot ulcers and toe amputations
Non-heeling occurred in(Ramsey et al)






92% of limbs with ankle pressure <80mmHg
But also in 45% of limbs with higher ankle pressures
95% of limbs with toe pressures <30mmHg
But only in 14% of limbs with higher toe pressures
Toe pressures – greater prognostic value
PPV 67%, NPV 77% (Kaloni et al, 1999;Diabetes Care)
29
Investigation of PAD in patients with
diabetes




Duplex scan
Angiography
CT angiography
MRA/MRI
30
Figure 1.2
A
B
C
D
31
Diabetes: distribution of PAD

Atherosclerosis in :
 Classical sites: aortoiliac, Fem artery

Medium-sized
vesselsperoneal/tibial vessels
Foot vessels spared
32
Revascularisation


Angioplasty
By-pass
33
Figure 3.8
34
35
Amputation

Minor- infection, osteomyelitis
Possible if good blood supply
Major – extensive soft tissue infection or
Insufficient blood supply
 80% of amputees have diabetes

36
When to refer ?

Symptoms:
Intermittent claudication
Rest pain ( nb neuropathy)

Signs:
low/nc ABPIs
Ulceration
Gangrene

? ? Screening – value for risk factor Mx
37
Asymptomatic PAD




Relatively common
Associated with increased mortality
Can early treatment prevent events ?
2 Major trials will report ‘06/’07
Potential to save lives using ABPI:
a simple non-invasive screening test
38
Aspirin
vs
placebo
£
British
Heart
Foundation
Aspirin for
Asymptomatic
Atherosclerosis
(AAA) Trial
ABPI<0.95
N=3334
3- 4 Year
Follow-up
Fowkes & Douglas, personal communication 2002
Study Population:
men and women
>50 years of age
Endpoints
Cardiovascular
• Events
• Deaths
39
Royal College
of Physicians
Diabetic
Registry
Group
£
Medical
Research
Council
NO clinical
evidence of
vascular
disease
Low ABPI in
20.1%
POPADAD
ABPI <0.99
Diabetes
Men & women
aged>40 years
N=8000
Endpoints
Cardiovascular
• Events
• Deaths
40
41
42