CPT 33420 Mitral Valve Commissurotomy Reimbursement

CPT code 33420 represents a mitral valve commissurotomy performed on the beating heart to dilate the mitral valve leaflets without cardiopulmonary bypass. Nationally, this code captures a surgical approach for treating mitral valve stenosis that avoids arresting the heart and bypass support, which can affect resource use, operative planning, and inpatient care pathways. Key payers relevant to coverage and payment analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will find a concise overview of the clinical intent of the service, how it is typically delivered (operating room or catheterization laboratory in hospital settings), and why it matters for surgical and cardiology service lines. The publication provides benchmarks for utilization and payment where available, highlights policy and coding considerations relevant to surgical cardiac services, and situates the procedure in clinical context for mitral stenosis management. Data not available in the input will be identified as such; the content focuses on national-level interpretation rather than state-specific rules.

Billing Code Overview

CPT code 33420 describes a surgical procedure to correct mitral valve stenosis by dilating the cusps (leaflets) of the mitral valve without stopping the heart and without use of cardiopulmonary bypass. This procedure is performed on the beating heart and is intended to relieve obstruction at the mitral valve.

Service type: Surgical procedure — transcatheter or open surgical commissurotomy performed on a beating heart to dilate mitral valve leaflets.
Typical site of service: Operating room or cardiac catheterization laboratory in an acute care hospital or specialized cardiac surgery center.

Data not available in the input.

Clinical Context

A typical patient is a 55–75 year-old adult presenting with symptomatic rheumatic or degenerative mitral stenosis causing exertional dyspnea, fatigue, or signs of pulmonary congestion. Pre-procedure evaluation includes transthoracic and transesophageal echocardiography confirming mitral valve area reduction and favorable leaflet anatomy, cardiac catheterization to assess hemodynamics and rule out contraindications, and routine pre-op labs and anesthesia assessment. The procedure is a surgical mitral commissurotomy/valvotomy performed on a beating heart without cardiopulmonary bypass to dilate the mitral valve leaflets and relieve stenosis. Intraoperative workflow includes general anesthesia, median sternotomy or right thoracotomy exposure as indicated, direct visualization of the valve, commissural dilation or splitting of fused cusps, valve inspection to confirm adequate orifice enlargement, hemostasis, chest closure, and postoperative transfer to an intensive care or cardiothoracic step-down unit for monitoring of rhythm, hemodynamics, and echocardiographic assessment of valve function. Typical site of service is an inpatient operating room within a hospital or an ambulatory surgery center with cardiothoracic surgical capability when admission criteria allow. Common postoperative issues addressed in the clinical workflow include monitoring for mitral regurgitation, low cardiac output, infection, arrhythmia, and anticoagulation planning when indicated.

Coding Specifications

Modifier	Description	When to Use
`62`	Two surgeons

Taxonomy Code	Specialty	Notes
207RC0000X	Cardiothoracic Surgery	Primary specialty that performs surgical mitral commissurotomy/valvotomy.
207RP0000X	Cardiac Surgery	Subspecialty focus on heart surgery; performs complex valve procedures.
207RG0300X	Thoracic Surgery	May perform approaches to the mitral valve via thoracotomy in selected cases.
208M00000X	Cardiovascular Disease (Cardiology)	Interventional cardiologists perform percutaneous mitral valvotomy; provide pre/post procedural care.
2080S0124X	Echocardiography Specialist	Provides intraoperative and perioperative imaging guidance and assessment.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I05.0`	Rheumatic mitral stenosis	Classic indication for mitral valve commissurotomy/valvotomy.
`I34.0`	Nonrheumatic mitral (valve) stenosis	Degenerative or calcific mitral stenosis that may require surgical intervention.
`I08.0`	Rheumatic disorders of both mitral and aortic valves	Combined valvular disease that influences surgical planning.
`I97.820`	Postprocedural cardiac functional disturbances	Potential postoperative diagnosis to describe complications affecting cardiac function.
`I50.9`	Heart failure, unspecified	Symptom complex that may be present preoperatively due to mitral stenosis and used to justify intervention.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`33405`	Repair of mitral valve with cardiopulmonary bypass (e.g., mitral valve commissurotomy)	Alternative open approach when cardiopulmonary bypass is used instead of beating-heart technique.
`33410`	Mitral valve replacement with cardiopulmonary bypass	Performed when valve morphology is not amenable to repair/commissurotomy and replacement is required.
`33430`	Mitral valve replacement, prosthetic, with cardiopulmonary bypass	Specific code for prosthetic valve implantation when replacement is indicated after assessment.
`93312`	Transesophageal echocardiography, intraoperative or perioperative, comprehensive	Used for intraoperative imaging to assess valve before and after commissurotomy.
`93580`	Invasive hemodynamic monitoring during cardiac catheterization	Performed preoperatively in some patients to assess pulmonary pressures and hemodynamics.

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Summary & Overview

CPT 33420: Mitral Valve Commissurotomy on Beating Heart