I27.83

Chronic thrombotic pulmonary embolism

Chronic thrombotic pulmonary embolism (CTPE) is a clinical condition defined by the long-term persistence of organized blood clots within the pulmonary arterial tree, typically remaining for at least three months following an initial acute event. While many acute pulmonary emboli (PE) resolve via the body's endogenous fibrinolytic mechanisms, in patients with CTPE, the thrombi undergo a process of organization and remodeling into fibrous vascular tissue. This tissue becomes incorporated into the vessel wall (intimal thickening), leading to mechanical obstruction and narrowing of the pulmonary arteries. This pathology increases pulmonary vascular resistance and is the primary driver of Chronic Thromboembolic Pulmonary Hypertension (CTEPH), categorized separately under I27.24. Identification of I27.83 is critical for guiding therapeutic interventions such as pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), or lifelong anticoagulation, as these patients often do not respond to standard vasodilator therapies used for other forms of pulmonary hypertension.

Clinical Symptoms

  • Progressive exertional dyspnea (shortness of breath during physical activity)
  • Severe and chronic fatigue
  • Reduced exercise tolerance
  • Exertional chest pain or pressure (angina-like symptoms)
  • Exertional lightheadedness, near-syncope, or syncope
  • Palpitations and tachycardia
  • Peripheral edema (swelling of the ankles and legs)
  • Hemoptysis (coughing up blood)
  • Jugular venous distention (JVD)
  • Hepatomegaly or abdominal bloating from ascites (in advanced right heart failure)
  • Cyanosis in late-stage disease
  • Accentuated P2 component of the second heart sound

Common Causes

  • Incomplete resolution or recurrence of acute pulmonary embolism
  • Prior history of deep vein thrombosis (DVT)
  • Factor V Leiden mutation
  • Protein C or Protein S deficiency
  • Antithrombin III deficiency
  • Antiphospholipid syndrome (APS)
  • Elevated Factor VIII levels
  • Non-O blood groups (associated with higher risk of venous thromboembolism)
  • History of splenectomy
  • Chronic inflammatory conditions (e.g., Inflammatory Bowel Disease, Osteomyelitis)
  • Ventriculoatrial shunts for hydrocephalus
  • Malignancy-associated hypercoagulability
  • Indwelling central venous catheters or pacemakers

Documentation & Coding Tips

Explicitly distinguish between acute and chronic pulmonary embolism in the clinical narrative to ensure accurate code selection.

Example: Patient seen for follow-up of persistent shortness of breath. Repeat CT pulmonary angiography at six months post-index event demonstrates organized, eccentric thrombi adherent to the vessel walls of the segmental pulmonary arteries, consistent with chronic thrombotic pulmonary embolism. Diagnosis: Chronic thrombotic pulmonary embolism (I27.83). Plan: Lifelong anticoagulation with Warfarin (Z79.01) and referral for right heart catheterization to assess for secondary pulmonary hypertension.

Billing Focus: Documentation must confirm that the embolism is no longer in the acute phase and has persisted or organized, supporting I27.83 over I26 series codes.

Link the chronic thrombotic pulmonary embolism to any resulting pulmonary hypertension or right heart strain.

Example: Clinical evaluation of patient with known chronic thrombotic pulmonary embolism (I27.83) reveals signs of right heart failure including peripheral edema and jugular venous distension. Echocardiogram shows right ventricular hypertrophy and a pulmonary artery systolic pressure of 55 mmHg, confirming Group 4 chronic thromboembolic pulmonary hypertension (I27.24).

Billing Focus: Identify the causal relationship between the chronic thrombus and pulmonary hypertension to support the use of both I27.83 and I27.24.

Document the specific functional class using the WHO or NYHA classification systems for patients with chronic PE.

Example: Patient with chronic thrombotic pulmonary embolism (I27.83) remains symptomatic despite anticoagulation. Currently WHO Functional Class III, noting marked limitation of physical activity; comfortable at rest, but less than ordinary activity causes undue dyspnea or fatigue. This status necessitates evaluation for pulmonary thromboendarterectomy.

Billing Focus: Functional classification provides clinical evidence of the condition's impact on health status, supporting medical necessity for advanced procedures.

Always record the current status of anticoagulation therapy in the medical record.

Example: Management of chronic thrombotic pulmonary embolism (I27.83) continues with long term use of Apixaban (Z79.01). Patient remains stable with no evidence of recurrent acute events or bleeding complications. INR monitoring is not required for this agent.

Billing Focus: Required Z-codes for long-term drug use provide essential data for pharmacy-based risk adjustment and quality reporting.

Specify the diagnostic modality used to confirm chronicity, such as V/Q scan or CTA.

Example: Ventilation-Perfusion (V/Q) scan performed on 10/12/2025 shows multiple segmental perfusion defects with normal ventilation, occurring more than 3 months after the initial event. These findings are diagnostic of chronic thrombotic pulmonary embolism (I27.83).

Billing Focus: Detailed diagnostic evidence supports the transition from acute (I26) to chronic (I27.83) coding during audits.

Relevant CPT Codes