MD Conference Express AHA 2011 - (Page 28)

n S E L E C T E D U P D A T E S I N P A D Peripheral Arterial Disease: State of the Art Written by Maria Vinall Peripheral artery disease (PAD) symptom severity is best described as a functional problem (walking speed and distance, oxygen consumption, level of physical activity, and quality of life; Table 1). William Hiatt, MD, University of Colorado, Aurora, Colorado, USA, gave an overview of the current state of claudication therapy. Dr. Hiatt noted that while exercise in a supervised setting and in selected patients is effective, the results may not be generalizable, and clear clinical benefit in a broad community setting is lacking. Several therapeutic approaches, such as lipid modulation, antibiotic therapy, and gene therapy, have been tried but were unsuccessful; however, PDE-3 inhibitors have shown modest efficacy. A meta-analysis of nine randomized, controlled trials that used the PDE-3 inhibitor cilostazol to treat claudication in patients showed that cilostazol was associated with a 50.7% improvement from baseline in mean walking distance versus placebo (24.3%). The absolute improvement was 42.1 meters greater than the improvement with placebo (p<0.001) over a mean follow-up period of 20.4 weeks. Continued increases were demonstrated over the 24week treatment period. Improvements in pain-free walking distance were demonstrable as well [Pande RI et al. Vasc Med 2010]. Table 1. PAD Symptom Severity. Normal Walking Speed Walking Distance Peak Oxygen Consumption Physical Activity Quality of Life 3-4 mph Unlimited 30 4 ml/kg/min 1759 kcal/week Normal 1-2 mph 1/3 limited in home 2/3 limited at half block 15 2 ml/kg/min Reduced 50% 803 kcal/week Major impairment PAD scientific knowledge exists to diagnose, treat, and even prevent PAD, awareness of PAD remains low. PAD is also expensive. Mean cumulative hospitalization costs, per patient, are estimated to be $7445, $7000, $10,430, and $11,693 for patients with asymptomatic PAD, a history of claudication, lower limb amputation, and revascularization, respectively (p=0.007) [Mahoney EM et al. Circ Cardiovasc Qual Outcomes 2010]. It is estimated that the total annual costs that are associated with vascular hospitalization in PAD patients exceed $21 billion (Figure 1) [Hirsch At et al. Cir Cardiovasc Qual Outcomes 2008]. It is suspected that a significant number of patients with PAD remain undiagnosed. In addition, in patients with PAD, there is underutilization of proven secondary prevention therapies [Pande RL et al. Circulation 2011]. Figure 1. One- and Cumulative 2-Year Costs Associated With Hospitalizations for Vascular Reasons, per Patient, by Baseline PAD Class. Surgical Risk Life Expectancy Severity of Ischemia Anatomy Vein Availability Average (>5% mortality) ≥2 years Major Tissue Loss Multi-level, TASC C/D lesions GSV or good alternative High Limited Minor ulcer Single level, TASC A-C lesions Inadequate Bypass Favored TASC=TransAtlantic Inter-Society Consensus; GSV=greater saphenous vein. Endo Favored Copyright © 2011 American Heart Association. All rights reserved. Reproduced with permission from W. Hiatt, MD The overall prevalence of PAD in the United States has been estimated at 7.2% [Allison MA et al. Am J Prev Med 2007]. This translates to about 8.5 million Americans, or roughly one in 16 individuals over the age of 40 years. The risks are significantly greater for African-Americans and Hispanics. Susan Duval, PhD, University of Minnesota, Minneapolis, Minnesota, USA, discussed a ‘nomogram’ that she and her colleagues have developed for estimating PAD probability. The system is based on data from the REACH Registry and is based on age, sex, race, diabetes status, body mass index, hypertension status, smoking status, and coronary artery disease, cardiovascular disease, and congestive heart failure status. Although the 28 January 2012 Critical limb ischemia (CLI) is defined as ischemia rest pain or tissue loss and compromised leg hemodynamics and has a high amputation and mortality rate. Therapies are limited, and no proven treatment targets have been identified. Michael S. Conte, MD, Brigham and Women’s, Boston, Massachusetts, USA, discussed the significant issues that are associated with diagnosis and management of CLI. Revascularization is effective for wound healing, functional limb preservation, and pain relief. One small study in a highly selected group of diabetic patients with CLI reported that revascularization allows the postponement of major amputation and improves survival rates compared with nonrevascularized amputated patients (Figure 2) [Faglia E. J Diab Comp 2010]. www.mdconferencexpress.com  http://www.mdconferencexpress.com http://www.mdconferencexpress.com

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