I70.2

Atherosclerosis of native arteries of the extremities

Atherosclerosis of the native arteries of the extremities (I70.2) refers to a chronic, progressive inflammatory disease characterized by the buildup of plaque within the arterial walls, specifically affecting the non-grafted, natural arteries supplying blood to the arms and legs. This condition is a major manifestation of peripheral artery disease (PAD), predominantly impacting the lower extremities. The atherosclerotic process involves endothelial dysfunction, lipid deposition, inflammatory cell infiltration, and smooth muscle cell proliferation, leading to the formation of fibrofatty plaques that harden and narrow the arterial lumen. This narrowing restricts blood flow (ischemia) to the affected limb, leading to a spectrum of clinical manifestations ranging from asymptomatic disease to critical limb ischemia. Risk factors are multifactorial and include advanced age, smoking (a powerful independent risk factor), diabetes mellitus, hypertension, dyslipidemia (particularly elevated LDL cholesterol), obesity, physical inactivity, and a family history of cardiovascular disease. The pathophysiology involves a complex interplay of genetic predispositions and environmental factors that accelerate arterial wall damage and plaque formation. As the disease progresses, the reduced blood supply can lead to claudication (pain, cramping, or tiredness in the leg or hip muscles during exercise that goes away with rest), non-healing wounds, rest pain, and, in severe cases, tissue necrosis (gangrene) requiring amputation. Diagnosis typically involves a thorough clinical history, physical examination (e.g., palpation of pulses, assessment for bruits, trophic changes in skin/nails), and non-invasive vascular studies such as ankle-brachial index (ABI), duplex ultrasound, and toe-brachial index (TBI). More advanced imaging like computed tomography angiography (CTA) or magnetic resonance angiography (MRA) may be used to delineate the extent and severity of arterial stenosis or occlusion, guiding revascularization strategies. Management focuses on risk factor modification (smoking cessation, glycemic and blood pressure control, lipid-lowering therapy), antiplatelet agents, exercise rehabilitation, and, for symptomatic or limb-threatening disease, revascularization procedures such as angioplasty, stenting, or surgical bypass. This code specifically excludes atherosclerosis of grafts or bypasses, focusing solely on the natural arteries of the limbs.

Clinical Symptoms

  • Intermittent claudication (pain, cramping, or tiredness in leg muscles during exercise that goes away with rest)
  • Leg numbness or weakness
  • Coldness in the lower leg or foot compared with the other leg
  • Sores on the toes, feet, or legs that won't heal
  • A change in the color of the legs (e.g., pallor or cyanosis)
  • Hair loss or slower hair growth on the legs and feet
  • Slower growth of the toenails
  • Shiny skin on the legs
  • No pulse or a weak pulse in the legs or feet
  • Erectile dysfunction in men (often a sign of pelvic atherosclerosis)
  • Rest pain (pain in feet or toes even at rest, particularly at night, relieved by hanging the foot over the side of the bed)

Common Causes

  • High blood pressure (Hypertension)
  • High cholesterol (Dyslipidemia)
  • Diabetes mellitus
  • Smoking and tobacco use
  • Obesity
  • Lack of physical activity
  • Advanced age
  • Family history of peripheral artery disease, heart disease, or stroke
  • High levels of homocysteine (hyperhomocysteinemia)
  • Chronic inflammation (e.g., from autoimmune diseases)

Documentation & Coding Tips

Specify the exact clinical manifestation to ensure accurate sub-classification.

Example: Patient presents with chronic limb-threatening ischemia of the right lower extremity. Documentation confirms atherosclerosis of native arteries of the right leg with rest pain (I70.221). No ulceration or gangrene noted at this time. Current ABI is 0.42. Condition is chronic and managed with intensive statin therapy and antiplatelet agents, impacting high-risk category for cardiovascular events.

Billing Focus: Site specificity and manifestation including rest pain versus claudication.

Document laterality and precise ulcer characteristics when atherosclerosis leads to skin breakdown.

Example: Diagnosis: Atherosclerosis of native arteries of the left leg with ulceration of the left calf involving fat layer only (I70.232 and L97.222). Documentation includes the anatomical site (left calf), the laterality (left), and the depth (fat layer) to support medical necessity for advanced wound care and revascularization planning.

Billing Focus: Laterality (left) and anatomical site of ulcer (calf).

Differentiate between native arteries and bypass grafts to avoid coding errors.

Example: Assessment: Atherosclerosis of native arteries of the right extremity with intermittent claudication (I70.211). Patient has no history of peripheral bypass surgery. This distinction ensures use of I70.2 series rather than I70.3 (bypass grafts). Patient continues to smoke (F17.210), which is documented as a complicating factor for disease progression.

Billing Focus: Type of vessel involved (native artery vs. graft).

Capture the presence of gangrene as it represents the highest level of severity.

Example: Patient hospitalized for atherosclerosis of native arteries of the left leg with gangrene (I70.242). Physical exam shows necrotic tissue on the first and second toes. This documentation supports the urgent need for surgical intervention and complex inpatient management. High risk for limb loss documented.

Billing Focus: Highest level of manifestation (gangrene).

Link tobacco use or nicotine dependence as a comorbid condition influencing treatment.

Example: Atherosclerosis of native arteries of bilateral legs with intermittent claudication (I70.213). Patient has a 40 pack-year history and current nicotine dependence, cigarettes (F17.210). The documentation of active smoking is essential for justifying pharmacological interventions like cilostazol and the higher risk for procedural failure.

Billing Focus: Co-occurring nicotine dependence status.

Relevant CPT Codes