CPT 33416 Septal Myectomy Reimbursement & Policy | OpenPayer

Summary & Overview

CPT 33416: Ventriculomyotomy/Ventriculomyectomy for Subaortic Stenosis

CPT code 33416 denotes a ventriculomyotomy or ventriculomyectomy, a cardiac surgical procedure that incises and may remove part of the ventricular muscle to relieve obstruction from idiopathic hypertrophic subaortic stenosis. This operation addresses left ventricular outflow tract obstruction and can be definitive therapy for symptomatic patients. Nationally, the code is relevant for hospital-based cardiovascular surgical services and impacts inpatient surgical case mix and cardiac specialty reimbursement.

Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical context for the procedure, typical sites of service, and the payer landscape relevant to coding and billing. The publication outlines benchmarks and policy-relevant considerations such as inpatient surgical classification, coding specificity, and common modifier use (modifiers listed in source data). It also summarizes typical clinical indications and the operative intent behind the code.

The report is intended for billing professionals, clinical coders, and health policy stakeholders seeking a concise reference on CPT code 33416, its clinical role in treating hypertrophic subaortic stenosis, and the payer coverage environment on a national level.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare33416CPTcardiac surgeryseptal myectomyventriculomyotomyinpatient surgeryleft ventricular outflow tract obstructionhypertrophic subaortic stenosis

Billing Code Overview

CPT code 33416 describes a ventriculomyotomy or ventriculomyectomy, a surgical incision into the muscular wall of the heart with possible removal of part of the muscle. The procedure is performed to relieve obstruction caused by idiopathic hypertrophic subaortic stenosis by reducing left ventricular outflow tract obstruction.

Service type: Cardiac surgical procedure (septal myectomy/ventricular muscle resection)

Typical site of service: Hospital operating room or cardiac surgery suite, inpatient setting

Clinical & Coding Specifications

Clinical Context

A 56-year-old patient with symptomatic obstructive hypertrophic cardiomyopathy (idiopathic hypertrophic subaortic stenosis) presents with exertional dyspnea, syncope, and a harsh systolic murmur. Preoperative evaluation includes transthoracic and transesophageal echocardiography demonstrating significant left ventricular outflow tract (LVOT) obstruction from septal hypertrophy and systolic anterior motion of the mitral valve, plus coronary angiography to exclude obstructive coronary disease. The surgical team schedules a septal ventriculomyotomy/ventriculomyectomy (CPT 33416) via median sternotomy on cardiopulmonary bypass.

The clinical workflow: the patient undergoes preoperative optimization by cardiology and anesthesia, informed consent discussing risks/benefits, intraoperative transesophageal echocardiography to guide resection, surgical incision into the hypertrophied interventricular septum with limited myectomy of obstructing muscle, hemostasis, and closure. Postoperative care includes monitoring in a cardiothoracic intensive care unit, serial echocardiography to confirm relief of LVOT gradient, rhythm surveillance for conduction disturbances (possible temporary pacing), pain control, and discharge planning with cardiology follow-up for functional assessment and long-term management.

Coding Specifications

Modifier	Description	When to Use
`62`	Two surgeons

CPT 33368: Cardiopulmonary Bypass During Primary TAVI/TAVR

CPT-33370-CEREBRAL-EMBOLIC-PROTECTION-TAVR

CPT 33370: Cerebral Embolic Protection During TAVR

CPT-33404-APICOAORTIC-CONDUIT-AORTIC-VALVE-BYPASS

CPT 33404: Apicoaortic Conduit (Aortic Valve Bypass)

CPT-33411-AORTIC-VALVE-REPLACEMENT-ANNULUS-ENLARGEMENT

CPT 33411: Aortic Valve Replacement with Annulus Enlargement

CPT-33440-AORTIC-VALVE-REPLACEMENT-ROSS-PROCEDURE-ANNULAR-ENLARGEMENT

CPT 33440: Aortic Valve Replacement with Pulmonary Autograft and Conduit

CPT-33417-AORTOPLASTY-SUPRAVALVULAR-STENOSIS-REPAIR

CPT 33417: Aortoplasty for Supravalvular Aortic Stenosis

CPT-33414-LEFT-VENTRICULAR-OUTFLOW-TRACT-PATCH-ENLARGEMENT

CPT 33414: Left Ventricular Outflow Tract Patch Enlargement

CPT-33365-TRANSAORTIC-TRANSCATHETER-AORTIC-VALVE-REPLACEMENT-TAVR

CPT 33365: Transaortic Transcatheter Aortic Valve Replacement (TAVR)

CPT-33410-STENTLESS-AORTIC-VALVE-REPLACEMENT

CPT 33410: Aortic Valve Replacement with Stentless Prosthetic Valve

CPT-33390-AORTIC-VALVE-REPAIR-OPEN-SURGERY-CPB

CPT 33390: Open Aortic Valve Repair with Cardiopulmonary Bypass

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Taxonomy Code	Specialty	Notes
`207RP0000X`	Cardiothoracic Surgery	Primary specialty performing septal myectomy/ventriculomyotomy.
`208000000X`	Cardiac Surgery	Surgeons specializing in cardiac procedures inclusive of obstructive HCM surgeries.
`207L00000X`	Cardiovascular Disease (Cardiology)	Preoperative and postoperative management, echocardiographic assessment and intraoperative TEE interpretation.
`2080000004`	Thoracic Surgery	Overlapping specialty; may be involved in surgical access and complex thoracic procedures.
`363A00000X`	Anesthesiology	Cardiac anesthesiologists who provide intraoperative anesthetic management and transesophageal echocardiography support.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I42.1`	Hypertrophic cardiomyopathy	Primary diagnosis of obstructive hypertrophic cardiomyopathy for which septal ventriculomyotomy/ventriculomyectomy (`CPT 33416`) is performed.
`I35.0`	Nonrheumatic aortic (valve) stenosis	May coexist with LVOT obstruction requiring evaluation; valve disease can influence operative planning.
`I45.10`	Conduction disorder, unspecified	Postoperative conduction disturbances (heart block) are possible complications needing monitoring or pacing.
`I50.9`	Heart failure, unspecified	Patients may present with heart failure symptoms secondary to LVOT obstruction and hypertrophy.
`R57.0`	Cardiogenic shock	Rare severe presentation where emergent surgical intervention for outflow obstruction may be required.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`93451`	Right and left heart catheterization with coronary angiography when performed; includes measurement of intracardiac pressures and coronary visualization.	Performed preoperatively to evaluate coronary anatomy and hemodynamics prior to `CPT 33416`.
`93312`	Transesophageal echocardiography, intraoperative, real-time with image documentation, including probe placement, interpretation and report.	Used intraoperatively for guidance of septal resection and to assess LVOT gradient after `CPT 33416`.
`33210`	Insertion of temporary transvenous cardiac pacing electrode(s) with connection to external pacemaker.	May be performed perioperatively when there is concern for conduction block or need for temporary pacing after septal myectomy.
`33405`	Repair of ventricular septal defect or other open heart repairs (example code for complex ventricular procedures) — note: used when concomitant intracardiac repairs are performed.	Used if additional intracardiac repairs are required during the same operative session with `CPT 33416`.
`99223`	Initial hospital care, typically for major surgeries, high severity.	Represents inpatient preoperative or postoperative evaluation and management associated with hospitalization for `CPT 33416`.

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