EPIDEMIOLOGY, PATHOPHYSIOLOGY AND NATURAL HISTORY OF ARTERIOPATHY OF THE LOWER LIMB & ISCHEMIC DIABETIC FOOT Giuseppe Biondi Zoccai Ospedale San Giovanni Battista “Molinette” Università di Torino Minicorso GISE: Interventistica per gli arti inferiori e per il piede diabetico Genova, martedì 2 ottobre 2007 –

DISCLOSURE Consultant: Boston Scientific, Cordis, Mediolanum Cardio Research Lecture fees: Bristol-Myers Squibb

LEARNING GOALS Epidemiology Pathophysiology Natural history of lower limb atherosclerotic disease and ischemic diabetic foot

LEARNING GOALS Epidemiology Pathophysiology Natural history of lower limb atherosclerotic disease and ischemic diabetic foot

ACUTE ISCHEMIA IS NOT THE FOCUS OF THIS MINICOURSE ACC/AHA, Circulation 2005

CLINICAL PRESENTATION OF PAD PATIENTS

THE TIP OF THE ICEBERG

BURDEN OF PAD Transient ischemic attack Ischemic stroke Transient ischemic attack Ischemic stroke Angina pectoris (Stable, Unstable angina) Myocardial infarction Angina pectoris (Stable, Unstable angina) Myocardial infarction Renovascular HTN, Ischemic renal injury Peripheral arterial disease Critical limb ischemia, claudication, gangrene, necrosis Peripheral arterial disease Critical limb ischemia, claudication, gangrene, necrosis

CLASSIFICATION Mukherjee et al, AHJ 2005

CASE FATALITY OF PAD

LONG-TERM PROGNOSIS 16,440 index patients diagnosed with peripheral arterial disease in Saskatchewan, Canada between 1985 and 1995, with follow-up complete to March 1998 Caro et al, BMC Cardiovasc Dis 2005

TASC, EJVES 2007 OVERLAP IN ATHEROTHROMBOSIS

PAD IN ITALY

COMPARING SEVERITY

ATHEROSCLEROSIS

LARGE VS SMALL VESSELS

RISK FACTORS FOR PAD TASC, EJVES 2007

LEARNING GOALS Epidemiology Pathophysiology Natural history of lower limb atherosclerotic disease and ischemic diabetic foot

CRITICAL LIMB ISCHEMIA

CLASSIFICATION Mukherjee et al, AHJ 2005

CRITICAL LIMB ISCHEMIA

DIABETES AND ULCER Diabetes is 1st cause of lower extremity amputation in Europe Lifetime risk of ulcer: 15% (up to 25%) Foot disorders –Major cause of morbidity –A leading cause of hospitalization –Costly when result in amputation: > $6 billion

PRIMARY REASONS FOR FOOT PROBLEMS IN DIABETES Microvascular: Peripheral neuropathy & loss of protective sensation –~50% of people having diabetes > 15 years have a peripheral sensory neuropathy, lack protective sensation –Vulnerable to physical & thermal trauma Macrovascular: Vascular insufficiency (peripheral vascular disease) -> risk of limb ischemia Metabolic disorders: Hyperglycemia -> dries skin, facilitates growth of pathogens; contributes to microvascular Impaired immune system: Decreased host response Trauma: Repetitive and acute Foot deformities: Excess plantar pressures

PATHOPHYSIOLOGY OF PAD/ISCHEMIC DIABETIC FOOT Older age Male gender Diabetes (especially diabetes duration, HbA 1 c, insulin use, and retinopathy) Chronic kidney failure Hyperuricemia Smoke Body weight (BMI, WHR) Dyslipidemia History of CAD

CLAUDICATION IN DIABETICS?

TASC, EJVES 2007 CAUSES OF FOOT ULCERS

CAUSES OF ULCERS % Causal Pathways NEUROPATHYNeuropathy: 78%  Minor trauma:79% DEFORMITYDeformity:63%  Behavioral issues ? MINOR TRAUMA - Mechanical (shoes) POOR SELF- - ThermalFOOT CARE - Chemical ULCER Diabetes Care 1999; 22:157

DIABETIC NEUROPATHY

TASC, EJVES 2007 NEUROPATHY VS ISCHEMIA

CHARCOT FOOT

FOOT TRAUMA

DIABETIC FOOT TRIAD TRAUMA Neuropathy Ischemia ULCER Infection

BILATERAL INVOLVEMENT

TASC, EJVES 2007 RISK FACTORS FOR CLI

PATHOPHYSIOLOGY OF DIABETIC FOOT ULCERS The development of a foot ulcer has traditionally been considered to result from a combination of peripheral vascular disease (PVD), peripheral neuropathy (PNP) and infection There has been no convincing evidence that infection is a direct cause, but it rather complicates an established ulcer and impedes its healing Other factors have been identified such as repetitive stress and pressure on insensitive feet, poor glycaemic control and others

PATHOPHYSIOLOGY OF DIABETIC FOOT ULCERS Patients with DM have a high risk of atherosclerotic PVD. PVD alone is rarely a cause of ulceration but usually in combination with PNP and minor trauma leads to tissue Breakdown. It also has a major role in delayed wound healing and the development of gangrene. Reduced lower limb transcutaneous oxygen tension (TcPO2) and reduced large vessel perfusion were associated with the increased risk of DFU. A TcPO2 < 30 Hg was a very strong predictor for DFU. Diabetic patients also appear to have an increased risk of coagulability and thrombosis and this may have a role in the impairment of tissue perfusion. Foot deformities such as Charcot deformity and claw toes are also risk factors for DFU.

RISK FACTORS FOR DIABETIC FOOT ULCERS Peripheral sensory neuropathy Structural foot deformity Trauma and improperly fitted shoes Callus History prior ulcers/amputations Prolonged, elevated pressures on foot Limited joint mobility Uncontrolled hyperglycemia Duration of diabetes Blindness/partial sight Chronic renal disease Older age

RISK FACTORS FOR DIABETIC FOOT ULCERS Diabetes mellitus (DM) is one of the most important and common metabolic disorders affecting 2–5% of the population in Europe and between 1 and 20% of the population in various other parts of the world It is characterised by multiple long-term complications affecting almost every system in the body Foot ulcers are one of the main complications of DM, with a 15% lifetime risk for foot ulcers in all diabetic patients There is wide variation reported in the incidence and prevalence of diabetic foot ulcers (DFU), with the incidence ranging from 1.0 to 4.0% and prevalence between 5.3 and 10.5%. Twenty percent of diabetic patients are admitted to hospital because of foot problems. DFU precede 85% of lower extremity amputations (LEAs). There is a two-fold increase in mortality rate in patients with DFU.

WOUND CLASSIFICATION

DIABETIC VASCULOPATHY

ATHEROSCLEROSIS: DIABETICS VS NON-DIABETICS

FOOT ULCERS IN DIABETES Precipitate 85% of amputations: “Rule of 15” 15% of diabetes patientsFoot ulcer in lifetime 15% of foot ulcersOsteomyelitis 15% of foot ulcersAmputation Clinical Care of the Diabetic Foot, 2005

AMPUTATIONS IN DIABETES Tragic “Rules of 50” 50% of amputations transfemoral/transtibial level 50% of patients 2 nd amputation in  5y 50% of patients Die in  5y Clinical Care of the Diabetic Foot, 2005

RISK FACTORS FOR AMPUTATION Absence of protective sensation Arterial insufficiency: ABI<0.45 Foot deformity / decreased joint mobility Autonomic neuropathy Poor glucose control Low HDL Infection Lack of diabetes education Decreased vision Obesity Improper foot wear Foot ulcer or previous amputation

TASC, EJVES 2007 PROGNOSIS OF CLI

PROBABILITY OF HEALING Documento di Consenso internazionale sul Piede Diabetico 1999

QUESTIONS?

TAKE HOME MESSAGES PAD prevalence and incidence are increasing in developed countries PAD may be asymtomatic, symptomatic for claudication, or critical limb ischemia Diabetes is one of the most important pathophysiologic factors underlying PAD and CLI A comprehensive appraisal of causes and mechanisms of PAD and CLI, beyond revascularization, is pivotal to maximize clinical success

THE RISK OF PROGRESSION IS HIGH

SHOULD WE TREAT OR PREVENT?

ALGORITHM FOR FOOT ULCER

PAD in patients with CAD

PULSE PALPATION

ABI

PVR

TcPO2

OSSIMETRIA TRANSCUTANEA

DOPPLER ECHOGRAPHY

ALGORITMO STANDARD

APPROPRIATE SHOES

ALGORITHM

DEBRIDEMENT

VASCULAR SURGERY

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