Conflict of Interest Disclosure (Relationships with Industry) An Epidemic of : The Debate Over Population Screening Membership on an advisory board, consultant, or recipient of a research grant from the following companies: Alan T. Hirsch, M.D. Professor of Medicine, Epidemiology & Community Health Director, Vascular Medicine Program, Lillehei Heart Institute University of Minnesota Medical School and School of Public Health Minneapolis, MN Research Grants: Advisory Board: Consulting: Abbott Vascular; Bristol-Myers Squibb/Sanofi-aventis Partnership; Cytokinetics; Viromed AstraZeneca; Merck ev3; Summit Doppler; Pozen Because the evidence is clear that RWI alters conclusions Prevalence of and Cancer in the U.S. 8-12 million Cancer 11 million affects the same number of Americans as cancer and is usually more deadly Sources: Cancer Facts & Figures, American Cancer Society (21); NHLBI Disease and Condition Index-Peripheral Arterial Disease (21) Personal Statement: The bottom line, right up front I do not advocate for vascular screening I do advocate that individuals with an easily detected, fatal, and treatable illness merit achievement of: an accurate, cost-effective diagnosis, linked to prompt access to care, regardless of gender, age, ethnicity, country of origin, or economic status. This is a basic principle of social justice. 1
Assumptions Regarding the Potential Benefits of Screening Programs Most arterial diseases are associated with a prolonged asymptomatic phase The first clinical event may be morbid or mortal (fatal or non-fatal MI or stroke) There is therefore a detection gap between the asymptomatic phase and clinically apparent disease. Detection is now feasible Effective treatments exist Pasternak RC et al. JACC 23; 41:1863-1874 Goals of Screening Programs Detection of subclinical vascular disease in populations is feasible (e.g, cimt/carotid duplex, ABI, renal duplex, aortic US); Detection of unrecognized clinical disease is possible in a well-specified target population; Therefore, treatment could be initiated at an earlier phase, preventing morbid events. Additional health goals include: Public education Other societal goals: Promotion of health systems, professional societies, and private business What is Vascular Screening? I------------- Detection Gap -------------I Risk Factor Exposure Subclinical Disease Clinical Disease PARTNERS: Prevalence of and Other CVD in Primary Care Practices 29% of Patients in a Target Population Were Diagnosed With Using An Office-Based ABI Diagnosed Cohort Treated Cohort I Detection Fraction I I- Treatment Fraction -I 29% 44% 56% Creation of a chain of proven efficacy is not easy to establish, prove, disseminate, and maintain in at screening program format. Patients diagnosed with only and CVD 8 ABI=ankle-brachial index; CAD=coronary artery disease; CVD=cardiovascular disease. Hirsch AT et al. JAMA. 21;286:1317-24. 2
Existing disease Heart Protection Study: Vascular Event by Prior Disease Incidence of events Previous MI 23.5 29.4 Other CHD 18.9 24.2 No prior CHD or CBV disease 18.7 23.6 24.7 3.5 Diabetes 13.8 18.6 All patients 19.8 25.2 Statin Control Risk vs Control (n=1,269) (n=1,267) Statin favored Placebo.4.6.8 24% Reduction (P<.1) 1. 1.2 1.4 Reprinted with permission from Heart Protection Study Collaborative Group. Lancet. 22;36:7-22 from Elsevier. 9 % of patients with only 6 5 4 3 2 1 Relative Control of Cardiovascular RFs in Patients With only or + CAD Patients with only 46.2 28.6 RF control All RFs controlled In 26: % of patients with +CAD 6 5 4 3 2 1 Patients with + CAD 25.2 Risk Factor Control defined as: Systolic BP <14 mmhg, diastolic BP <9 mmhg, glycemia <1.1 g/l, total cholesterol <2. g/l, not smoking for >12 months 51.4 RF controlled All RF controlled Individuals with, c/w CAD, achieve only half of their risk reduction goals. Cacoub et al. Atherosclerosis. 28 Oct 31. [Epub ahead of print] Examples of Current Non-Vascular Health Screening Programs These other disease detection programs were based on a robust evidence Cervical base; cancer The testing strategy Mammography was prospectively evaluated in diverse practice Colorectal settings; screening These programs Prenatal were also detection initially of controversial; common Payor funding congenital for these screening disorders programs (blood, amniotic required establishment fluid, of a ultrasound) societal consensus. Have we reached this level of evidence and consensus? Leg Alert Examples of Vascular Screening Programs Program Sponsor Dates Goals Step Lively A Step Ahead National Council on Aging (SIR) Hoechst Marion Roussel Society for Vascular Nursing 1987-199 detection 1988-199 detection 199-1996 detection MN U of Minnesota 1996-1997 detection Legs for Life PARTNERS AVA Society for Interventional Radiology Academic SC; (BMS-Sanofi) Society for Vascular Surgery 1998-present detection, expanded to AAA, CBVD, venous dz 1999-21 detection 21-present Modified from: Hirsch et al. J Vasc Surg 24;39:474-81, AAA, carotid disease 3
American Vascular Association National Screening Program CAROTID SCAN -A painless ultrasound test to reduce the risk of stroke The Public (the Market) Has Accepted Vascular Screening Thank you so much for finding my! AORTIC SCAN - To detect aneurysms that could rupture and be fatal Testing - Measurement of circulation to your legs to detect peripheral arterial disease () ABI Ankle:Brachial index Linking Evidence to Practice The Role of Clinical Guidelines (ACC/AHA) Guidelines for the Management of Patients with Peripheral Arterial Disease - 26 TransAtlantic Intersocietal Consensus - 26 United States Preventive Services Task Force (USPSTF) - 25 How Much Evidence Is There To Evaluate Benefit and Harm? Circulation. 28;118:283-2836 The first two evidence-based consensus statements evaluated the screening question from the perspective of CV risk reduction. The USPSTF did not. 4
Defining the At Risk Population for Lower Extremity Age less than 5 years with diabetes, and one additional risk factor (e.g., smoking, dyslipidemia, hypertension, or hyperhomocysteinemia) Age 5 to 69 years and history of smoking or diabetes Age 7 years and older Leg symptoms with exertion (suggestive of claudication) or ischemic rest pain Abnormal lower extremity pulse examination Known atherosclerotic coronary, carotid, or renal artery disease I IIa IIb III Asymptomatic, Ischemic Risk, and the Rationale to Establish the Diagnosis: I I IIa IIb III Individuals with asymptomatic should be screening identified criteria in order and to offer rationale, therapeutic but: interventions known to diminish their increased risk of myocardial Current data infarction, do not permit stroke, and 1A death. recommendations These are strong, consensus-driven, widely accepted IIa IIb III The resting ABI should be used to establish the lower extremity diagnosis in patients with suspected lower extremity, defined as individuals with exertional leg symptoms, with nonhealing wounds, who are 7 years and older or who are 5 years and older with a history of smoking or diabetes. Based on a targeted prevalence of > 2-25% 17 18 Cost-Effectiveness of Disease Screening: Cost per Life Year Gained Is Lower Extremity Screening Cost-Effective? $1, $8, $6, To $1.3 million Min Max This is almost certainly true, but an evidencebased answer would require both modeling and prospective testing (we are doing this) $4, $2, Pap Smear for Cervical Cancer in Elderly Women *Quality-adjusted life year. TSH for Mild Thyroid Failure* HIV Infection Mammography Occult Fecal for Breast Cancer Blood + Sigmoidoscopy for Colorectal Cancer 5
Cost-Effectiveness of Disease Screening: Cost per Death Averted $6, $5, $4, $3, $2, To > $2 million Min Max What is Vascular Screening? Ideally, it is the translation of: (a) cardiovascular epidemiology (use of risk factors and risk markers to identify a vulnerable population); (b) via selection of the highest at risk individuals; (c) to initiate proven treatments, to beneficially improve clinical outcomes Risk Factor Exposure Subclinical Disease Clinical Disease $1, Screening of Newborns for Hemoglobinopathy/ Sickle Cell Colonoscopy/ Sigmoidoscopy for Colorectal Cancer Undiagnosed Cohort Treated Cohort And I believe that this algorithm of evidence-based care should occur in office practice, based on prospective trials, and then be reimbursed. Screening for Vascular Disease: Should Nationwide Programs Be Instituted? Individual societies and hospitals may elect to initiate screening programs for myriad reasons. Private for profit firms may elect to initiate vascular screening programs, to fill a market demand. National scientific organizations and government groups should approach screening based on prospective trials, with proven clinical outcomes, and demonstrated health economic benefit. Thank you 6