Poor blood pressure control in peripheral arterial disease associated with increased risk of critical limb ischaemia: a multicentre prospective audit

Mahmud Saedon1, Athanasios Saratzis3, Magdalena Dinkel1, Ling Kho1, Asif Mahmood2, Christopher Imray2, Donald Singer1,2. 1University Of Warwick, Coventry, UK, 2University Hospitals Coventry and Warwickshire, Coventry, UK, 3Heart of England NHS Foundation Trust, Birmingham, UK

Background: Hypertension increases the incidence and severity of peripheral arterial disease (PAD). We assessed the prevalence of undertreated hypertension in patients with PAD.

Methods: We used NICE Clinical Guideline CG127 as audit standard for blood pressure (BP) control [<140mmHg systolic and <90mmHg diastolic] to assess prospectively the adequacy of BP-control in 176 patients [age 70±10 years, 32 (18%) females] who had been referred by their GPs to Vascular Surgery Clinics in two separate regions of the West Midlands. Blood-Pressure was measured according to British Hypertension Society (BHS) guidelines using a validated device. Overall, 66 (38%) patients had critical lower limb ischaemia at baseline. Fifty-five (31%) were diabetic; 132 (75%) were receiving anti-platelet agents and 138 (78%) a statin.

Results: Mean BP was 143/80±19/17mmHg and 140 patients (80%) were already on drug treatment for hypertension when referred; 90 (51%) had a systolic BP>140mmHg, 42 (24%) a diastolic BP>90mmHg, and 32 (18%) had both. Blood pressure treatment was not guideline-compliant in 101 (57%) patients. Mean BP was 148/82±21/21mmHg for those with critical-ischaemia at baseline versus 141/79±17/15mmHg for those without (p=0.02). Non-compliance with guidelines was associated with presence of critical-ischaemia (71% versus 29%, p=0.01). Use of statins [78% versus 79% (critical-ischaemia), p=0.96] and use of antiplatelets (76% versus 74%, p=0.86) was not associated with critical-ischaemia at baseline.

Conclusion: Hypertension is undertreated in peripheral arterial disease despite well-established National Guidelines. Patients with undertreated hypertension were more likely to present with critical ischaemia in this cohort. Our results support urgent review of blood pressure assessment and treatment in peripheral arterial disease, both in the community and in hospital-based services.