Peripheral arterial disease increases risk of a cardiovascular event
Dr Alan Begg discusses why the inclusion of peripheral arterial disease in the QOF indicators for 2012/13 is so important and how primary care should achieve them
The inclusion of peripheral arterial disease (PAD) in the 2012/13 update of the quality and outcomes framework (QOF) is long overdue (see Table 1, below).1,2 The introduction of these indicators fills a significant gap in the management of patients with vascular disease—an issue that has been apparent since 2004.3 Peripheral arterial disease has an annual incidence of 0.2% and increases the risk of all-cause mortality.2,4
Symptoms of intermittent claudication may be the first indication that a patient has underlying occlusive vascular disease. Previously, such patients have not been included in the QOF unless they have diabetes, hypertension, or have experienced a prior cerebrovascular or coronary heart disease (CHD) event. A survey of patients with intermittent claudication who attended a PAD clinic showed that 24% did not have CHD, diabetes, or hypertension,5 and would therefore not be considered in previous QOF guidance.
Cardiovascular risk in patients with PAD
Data from the REduction of Atherothrombosis for Continued Health (REACH) registry gives a good indication of the risk of a subsequent vascular event in patients with PAD.6
The REACH trial recorded 55,499 patients at baseline with symptomatic disease, of whom 39,675 were eligible for 3-year follow up. Of these (at baseline):6
- 6.3% (2485) had PAD only
- 5.7% (2271) had PAD plus coronary artery disease
- 1.5% (614) had PAD plus cerebrovascular disease
- 1.9% (748) had PAD plus coronary artery disease plus cerebrovascular disease.
Patients recruited to the trial with PAD had the highest 3-year event rate of myocardial infarction (MI)/stroke/death/hospitalisation (40.4%).6 The rehospitalisation rate for a vascular event other than MI/stroke/vascular death was also highest for people with PAD (33.6%) compared with 23% for those with coronary artery disease and 18.7% for patients with any cerebrovascular disease. Over the 3-year period, patients with only PAD at baseline had the highest risk of progressing to involvement of disease in another vascular bed.6 Almost 10% of patients with PAD progressed to polyvascular disease over 3 years compared with around 4% with either coronary artery disease or cerebrovascular disease at baseline.
Disease progression on a percentage basis was as follows:6
- 6.1% of patients with PAD developed coronary artery disease
- 3.8% of patients with PAD developed cerebrovascular disease
- 3.7% of patients with cerebrovascular disease developed coronary artery disease.
|Table 1: Indicators for peripheral arterial disease1,2|
|PAD1||The practice can produce a register of people with peripheral arterial disease||2||-|
|PAD2||The percentage of patients with peripheral arterial disease with a record in the preceding 15 months that aspirin or an alternative antiplatelet is being taken||2||40–90%|
|PAD3||The percentage of patients with peripheral arterial disease in whom the last blood pressure reading (measured in the preceding 15 months) is ≤150/90 mmHg||2||40–90%|
|PAD4||The percentage of patients with peripheral arterial disease in whom the last measured total cholesterol (measured in preceding 15 months) is ≤5 mmol/l||3||40–90%|
|Smoking 5||The percentage of patients with any or any combination of the following conditions: CHD, PAD, stroke or TIA, hypertension, diabetes, COPD, CKD, asthma, schizophrenia, bipolar affective disorder, or other psychoses whose notes record smoking status in the preceding 15 months||25||50–90%|
|Smoking 6||The percentage of patients with any or any combination of the following conditions: CHD, PAD, stroke or TIA, hypertension, diabetes, COPD, CKD, asthma, schizophrenia, bipolar affective disorder, or other psychoses who smoke whose notes contain a record of an offer of support and treatment within the preceding 15 months||25||50–90%|
CHD=coronary heart disease; PAD=peripheral arterial disease; TIA=transient ischaemic attack; COPD=chronic obstructive pulmonary disease; CKD=chronic kidney disease
Peripheral arterial disease increases risk of a cardiovascular event continued
New indicators for PAD
This new domain aims to improve the identification and management of PAD and ensure that all patients, including those without established risk factors already covered in QOF, are managed for their cardiovascular risk.2
Indicator PAD1 should include all people with symptomatic PAD, most of whom will have presented with the symptom of intermittent claudication. There is no specific READ Code for PAD so these patients may be currently coded in a variety of different ways (see Table 2, below).
Approximately 20% of people over the age of 60 years have PAD, but only 25% of these patients have symptoms.2 Only 20% of this symptomatic group will develop severe and progressive disease—with a very small proportion (1%–2%) of people with claudication undergoing limb amputation.7,8
The draft version of the NICE guideline on lower-limb PAD8 suggests following a series of assessment stages for patients with suspected PAD:8
- Using structured questioning about the symptoms of intermittent claudication and critical limb ischaemia
- Examining the:
- leg and foot for evidence of critical limb ischaemia (e.g. presence of ulceration)
- femoral, popliteal, and foot pulses
- Measuring ankle brachial pressure index (ABPI).
A diagnosis of PAD is usually confirmed by measurement of ABPI, which is also an independent predictor of cardiovascular and cerebrovascular mortality and morbidity.2,7 A cut-off point of 0.9 is used for the ABPI, which clinical studies have shown to be 95% sensitive in detecting angiogram-positive disease and 99% specific in identifying healthy subjects.9 However, a normal ABPI does not exclude the presence of PAD.8 A summary of the recommended SIGN method for measuring ABPI is described in Box 1 (see below).9
Although the QOF indicators do not explicitly state that measurement of ABPI is expected, the supporting guidance discusses the use of ABPI and its inclusion in the SIGN guideline on PAD.2
|Table 2: READ Codes for peripheral arterial disease|
|G73.00||Other peripheral vascular disease|
|G73zz00||Peripheral vascular disease NOS|
|8HlP.00||Referred for peripheral artery disease assessment|
|585a.00||ABPI—ankle brachial pressure index|
|8IAW.00||Ankle brachial pressure index test declined|
|9hS..00||Exception report: peripheral arterial disease quality indicator|
Peripheral arterial disease increases risk of a cardiovascular event continued
|Box 1: Measuring ankle brachial pressure index|
Brachial systolic pressure
Ankle systolic pressure
Ankle brachial pressure index
|ABPI=ankle brachial pressure index|
Effective early introduction of preventative therapies is important because patients with PAD are at a higher risk of secondary cardiovascular events.Achievement of PAD2 requires a record of the percentage of patients with PAD who are taking aspirin or an alternative antiplatelet.1,2
The evidence underpinning the use of antiplatelet therapy comes from the Antithrombotic Trialists’ Collaboration (ATC) meta-analysis.10 This study showed a 23% reduction in serious vascular events in a subgroup of 9214 people with PAD who were treated with antiplatelet drugs. The ATC found no statistically significant difference between antiplatelet agents.
However, the Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events (CAPRIE) trial demonstrated the benefit of clopidogrel as an alternative antiplatelet therapy to aspirin in patients with PAD;11 interestingly it was this benefit which indicated that clopidogrel may have an advantage over aspirin in patients with vascular disease. The use of clopidogrel as an option to prevent occlusive vascular events in people who have established PAD has been approved by NICE.12 Although PAD2 refers to the use of aspirin or an alternative antiplatelet, there is no indication for the use of aspirin in addition to warfarin in the majority of people with stable vascular disease because of the high bleeding risk.13
Studies in the UK have shown that patients with PAD are not prescribed statin and antiplatelet therapy and do not receive sufficient advice on smoking cessation; moreover they also have poor control of blood pressure.7 It is recommended that patients with PAD should receive treatment to reduce high blood pressure on the basis that they are at high risk of a subsequent vascular event.2 The audit standard of 150/90 mmHg is accepted as the minimal target for all patients receiving treatment for PAD and hypertension as there is no definitive ideal target level.2
Statin therapy is recommended for all patients with evidence of CVD,14 which includes individuals with PAD. Cholesterol levels should be lowered to an audit standard of 5 mmol/l.1,2 The Heart Protection Study is the largest trial providing evidence on the benefits of lowering cholesterol with a statin in patients with PAD—the PAD subgroup demonstrated a significant reduction in vascular events (p<0.0001).15 In the Lower Extremity Arterial Disease Event Reduction (LEADER) study of 1568 men with PAD, it was noted that bezafibrate 400 mg daily had a beneficial effect on the incidence of non-fatal coronary events, but did not reduce the incidence of total fatal or non-fatal cardiovascular events (CHD or stroke, relative risk 0.96, 95% confidence interval 0.76–1.21).16
Peripheral arterial disease has also been added to the QOF list of conditions for which smoking status and offer of support and treatment in the previous 15 months should both be recorded.1,2 The SIGN Guideline Development Group for SIGN 89 on Diagnosis and management of peripheral arterial disease did not find convincing evidence for improved cardiovascular outcomes or symptoms in patients with PAD as a result of smoking cessation advice;9 however, both patients with PAD and individuals who smoke are at high cardiovascular risk so it seems reasonable that every effort should be made to ensure that patients with PAD stop smoking.
Additionally, the draft NICE guideline on lower-limb PAD recommends modifying the following key risk factors in patients with PAD:8
- Diet and weight
- Management of diabetes.
Peripheral arterial disease increases risk of a cardiovascular event continued
Use of other drugs in PAD
A Cochrane review found that using beta blockers in PAD did not result in significant worsening or adverse effects on claudication symptoms or walking distances;17 however, it should be noted that the trials examined in the review were small and conducted several years ago. For patients who require a beta blocker, there may be merit in considering a drug with cardio-selective and vasodilator properties.
Angiotensin-converting enzyme inhibitors
In the Heart Outcomes Prevention Evaluation (HOPE) study 18 the use of the angiotensin-converting enzyme inhibitor, ramipril, in patients with symptomatic and asymptomatic PAD with one other risk factor, revealed a 25% reduction in the combined primary outcome of cardiovascular mortality, MI, and stroke. Only 25% of the patients were defined as hypertensive, but as the ABPI was measured unconventionally (using digital palpation) it was not possible to confirm that ramipril has any beneficial effect beyond lowering blood pressure in patients with PAD.
Symptomatic relief of PAD
Four drugs—cilostazol, naftidrofuryl oxalate, pentoxifylline, and inositol nicotinate—were evaluated by NICE for the symptomatic use of intermittent claudication in patients with PAD.19 Only naftidrofuryl oxalate was recommended as an option for the treatment of claudication in people with PAD for whom vasodilator therapy is considered appropriate after taking into account other treatment options. The SIGN guideline, however, states that cilostazol can be considered as an option if patients have intermittent claudication, in particular over a short distance.9 It recommends that cilostazol should be stopped if it proves ineffective after 3 months or if adverse effects prevent compliance.9 However, the guideline indicated that the Scottish Medicines Consortium does not recommend the use of this drug for the NHS in Scotland because its clinical and cost effectiveness was not demonstrated.20
Indications for referral
The draft NICE guideline on PAD8 suggests that a supervised exercise programme should be offered to all patients and that the use of vasodilating drugs is in line with the NICE technology appraisal.8,19 Naftidrofuryl oxalate should be discontinued after 3–6 months if there is no symptomatic benefit.8
Most patients will be managed in primary care but angioplasty and stenting should be considered if supervised exercises have not led to satisfactory improvement in symptoms and if imaging using contrast-enhanced magnetic resonance angiography has confirmed that the person is appropriate for angioplasty. Critical limb ischaemia should be referred immediately for management and the treatment approach should be determined by involvement of the multidisciplinary vascular team.
The addition of PAD to QOF is long overdue primarily because of the high cardiovascular risk in patients with this disease. For the purposes of the QOF, there is no need to confirm the diagnosis of PAD using ABPI or by specialist assessment—GPs are encouraged to use their own clinical judgement.2 This was decided on the basis that ABPI is not measured routinely in most practices and because there was a fear of overwhelming local vascular outpatient clinics. This variation in diagnostic approach may lead to wide differences in prevalence figures and GPs should be alert to the possibility that some patients may end up receiving preventative therapies that may not be required, especially in those patients where there is diagnostic uncertainty.
|PAD=peripheral arterial disease|
|GP commissioning take home messages for England|
written by Dr David Jenner, NHS Alliance GMS contract/PBC Lead
QOF=quality and outcomes framework; PAD=peripheral arterial disease; CVD=cardiovascular disease; ABPI=ankle brachial pressure index
- NHS Employers. Summary of 2012/13 QOF changes. 2012. Available at: www.nhsemployers.org/SiteCollectionDocuments/Summary_of_QOF_changes_for_2012-13_mh111111.pdf
- British Medical Association. NHS Employers. Quality and outcomes framework guidance for GMS contract 2012/13. London: BMA, NHS Employers, 2012. Available at: www.bma.org.uk/employmentandcontracts/independent_contractors/quality_outcomes_framework/qofchanges2012.jsp#.T5-Ude0ladc
- Begg A, Brittenden J. GP contact fails patients with peripheral vascular disease. Guidelines in Practice 2004; 7 (6). Available at: www.eguidelines.co.uk/eguidelinesmain/gip/vol_7/june_04/begg_view_jun04.htm
- Lester L. A guide to the coming QOF indicators. Pulse 2012; 24 January. Available at: www.pulsetoday.co.uk/main-content/-/article_display_list/13331413/a-guide-to-the-coming-qof-indicators
- Cassar K, Coull R, Bachoo P et al. Management of secondary risk factors in patients with intermittant claudication. Eur J Endovasc Surg 2003; 26 (3): 262–266.
- Alberts M, Bhatt D, Mas J et al; REduction of Atherothrombosis for Continued Health Registry Investigators. Three-year follow-up and event rates in the international reduction of Atherothrombosis for Continued Health Registry. Eur Heart J 2009; 30 (19): 2318–2326.
- National Institute for Health and Care Excellence. Scope for lower limb peripheral arterial disease: diagnosis and management. London: NICE, 2010. Available at: guidance.nice.org.uk/CG/Wave23/5/Scoping.
- National Clinic Guideline Centre. Lower limb peripheral arterial disease: diagnosis and management. Draft consultation. London: NICE, 2012. Available at: guidance.nice.org.uk/CG/Wave23/5
- Scottish Intercollegiate Guidelines Network. Diagnosis and management of peripheral arterial disease. SIGN 89. Edinburgh: SIGN, 2006. Available at: www.sign.ac.uk/guidelines/fulltext/89/index.html
- Antithrombotic Trialists’ Collaboration. Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. BMJ 2002; 324 (7329): 71–86.
- CAPRIE Steering Committee. A randomised blinded trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE) Lancet 1996; 348: 1329–1339.
- National Institute for Health and Care Excellence. Clopidogrel and modified-release dipyridamole for the prevention of occlusive vascular events. Technology Appraisal 210. London: NICE, 2010. Available at: www.nice.org.uk/TA210
- European Heart Rhythm Association; European Association for Cardio-Thoracic Surgery, Camm A et al. Guidelines for the management of atrial fibrillation: the Task Force for the Management of Atrial Fibrillation of the European Society of Cardiology (ESC). Eur Heart J 2010; 31 (19): 2369–2429.
- National Institute for Health and Care Excellence. Lipid modification: cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease. London: NICE, 2010. Available at: guidance.nice.org.uk/CG67
- Heart Protection Study Collaborative Group. MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised placebo-controlled trial. Lancet 2002; 360 (9326): 7–22.
- Meade T, Zuhrie R. Bezafibrate in men with lower extremity arterial disease: randomised controlled trial. BMJ 2002; 325 (7373): 1139.
- Paravastu S, Mendonca D, Da Silva A. Beta blockers for peripheral arterial disease. Cochrane Database of Syst Rev 2008; (4): CD005508.
- Ostergren J, Sleight P, Dagenais G et al. HOPE study investigators. Impact of ramipril in patients with evidence of clinical or subclinical peripheral arterial disease. Eur Heart J 2004; 25 (1): 17–24.
- National Institute for Health and Care Excellence. Cilostazol, naftidrofuryl oxalate, pentoxifylline and inositol nicotinate for the treatment of intermittent claudication in people with peripheral arterial disease. London: NICE, 2011. Available at: www.nice.org.uk/TA223
- Scottish Medicines Consortium. Cilostazol. Glasgow: SMC, 2005. Available at:
www.scottishmedicines.org.uk/SMC_Advice/Advice/Cilostazol_100mg_tablets__Pletal__174__/Cilostazol__Pletal__ (accessed 1 May 2012).G
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