Alphabet Soup…ABI in PAD and CVD for the ASA April Frego RN, CDE, CFCN April 30, 2009
PAD Diagnosis Roussin A, et al. Can J Cardiol 2005;21(12):997-1006. Slide from Canadian Cardiovascular Society Consensus Conference
Research • Low ABI is associated with increased risk of CVD independent of metabolic syndrome & other major CVD risk factors Wild, S., Diabetes Care, 29(3), 637-642. • Change in ABI predicts Adverse CVD Outcome • ABI decline >0.15 was significant and independently associated with increased CVD risk • Patients with decreasing ABI may be candidate for intensive cardiovascular risk factor management Criqui, M., et al. Journal of the American College of Cardiology, 52(21), 1736-1742.
Doppler Ultrasound • Peripheral vascular examination • An objective, non invasive assessment of the circulation in the foot • 90% sensitive and 95% specific for diagnosis of LEAD (lower extremity arterial disease) • Converts blood (flow) velocity into sound with a 8-9 megahertz probe • Easily measured in the Primary Care setting Fleck, C. Advances in Skin & Wound Care, 20(12), 645
Ankle Brachial Index Doppler Ultrasound systolic ankle pressure mm Hg ------------------------------- systolic arm (brachial artery) pressure mm Hg = ABI
Beware of Calcified vessels: Falsely high readings Diabetics (30%)
Diabetic foot: BEWARE!! • Doppler studies • Vessels are calcified – Doppler pressure studies are inaccurate +/- 30% of patients • Ankle pressure much greater than arm pressure • Ankle Doppler signal still heard when pressure >250 mmHg • ABI>1.25 beware – Calcified vessels • Toe Pressures should always be done
Referrals • Home Care: SWAT, WRHA Home Care Best Practice Team, Clinical Nurse Specialist • Acute Care: Hospitals: ET, Wound Consultant • Long Term Care: SWAT, Clinical Nurse Specialist • Vascular Labs: Grace & Health Science Centre • Vascular Medicine • Vascular Surgeon
References • Abramson, BL., Huckell, V., Anand, S., et al. Canadian Cardiovascular Society Consensus Conference: Peripheral arterial disease – Executive summary. Can J Cardiol 2005;21(12):997-1006 • Criqui, M., Ninomiya, J., Wingard, D., Ji, M., & Fronek, A. (2008, November 18). Progression of peripheral arterial disease predicts cardiovascular disease morbidity and mortality. Journal of the American College of Cardiology, 52(21), 1736-1742. • Fleck, C. (2007, December). FAQs. Measuring ankle brachial pressure index. Advances in Skin & Wound Care, 20(12), 645. • Fowkes FG, Housley E, Cawood EH, Macintyre CC, Ruckley CV, Prescott RJ. Edinburgh Artery Study: prevalence of asymptomatic and symptomatic peripheral arterial disease in the general population. Int J Epidemiol. 1991 Jun;20(2):384-92. • Hiatt, W. (2008, November 18). Can measuring the ankle-brachial index improve public health?. Journal of the American College of Cardiology, 52(21), 1743-1744. • Wild, S., Byrne, C., Smith, F., Lee, A., & Fowkes, F. (2006, March). Low ankle-brachial pressure index predicts increased risk of cardiovascular disease independent of the metabolic syndrome and conventional cardiovascular risk factors in the Edinburgh Artery Study. Diabetes Care, 29(3), 637-642.