Cardiac Imaging

What Is the Best Imaging for Preoperative Planning in Noncoronary Cardiac Surgery?

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What Is the Best Imaging for Preoperative Planning in Noncoronary Cardiac Surgery?

A 68-year-old male with progressively worsening dyspnea on exertion is scheduled for an elective mitral valve repair. His past medical history is significant for hypertension and atrial fibrillation, but he has never undergone cardiothoracic surgery. As the consulting cardiologist, you are tasked with obtaining the necessary preoperative imaging to provide the surgical team with a detailed anatomical and functional roadmap. The core question is which study will best delineate the valvular pathology, assess cardiac function, and screen for potential surgical hazards like intracardiac thrombus. For this specific scenario—an adult with no prior cardiothoracic surgery needing preprocedural imaging for noncoronary cardiac surgery—the American College of Radiology (ACR) finds that a Transesophageal Echocardiogram (TEE) is Usually appropriate.

Who Fits This Clinical Scenario?

This guidance applies to a well-defined patient population: adults who are scheduled for a noncoronary cardiac surgical procedure and have no history of prior cardiothoracic surgery. The context is preoperative planning, not an acute diagnostic workup.

Inclusion Criteria:

  • Patient: Adult.
  • Procedure Type: Noncoronary cardiac surgery. This includes procedures like valve repair or replacement (aortic, mitral, tricuspid), septal defect closure, myectomy for hypertrophic cardiomyopathy, or surgery on the aortic root and ascending aorta.
  • Surgical History: No previous cardiothoracic operations. The absence of prior surgery means there is no scar tissue, bypass grafts, or prosthetic material to complicate imaging and surgical access.
  • Goal: Preprocedural planning to define anatomy, assess function, and guide the surgical approach.

Exclusion Criteria (These Route to Different Workflows):

  • Coronary Artery Disease Surgery: Patients scheduled for Coronary Artery Bypass Grafting (CABG) fall under a different ACR variant, as the imaging focus shifts to coronary artery anatomy.
  • History of Cardiothoracic Surgery: Patients with a prior sternotomy have altered anatomy and potential for adhesions, which requires a distinct preoperative imaging strategy.
  • Thoracic (Non-Cardiac) Surgery: Patients undergoing lung resection or other non-cardiac thoracic procedures have different preoperative requirements, focusing on pulmonary and mediastinal structures.

What Diagnoses Are You Working Up in This Scenario?

In preoperative planning for noncoronary cardiac surgery, the goal is not to establish a new diagnosis but to precisely characterize known pathology and screen for conditions that could alter the surgical plan. The imaging study must provide a comprehensive assessment of cardiac structure and function.

Valvular Heart Disease: This is the most common indication. The surgeon needs to know the exact mechanism and severity of stenosis or regurgitation. For a mitral valve repair, for example, imaging must clearly define leaflet morphology, chordal integrity, and annular dimensions to determine the feasibility and type of repair.

Intracardiac Thrombus: Particularly in patients with atrial fibrillation, screening for thrombus in the left atrial appendage (LAA) is critical. The presence of a thrombus can significantly increase the risk of perioperative stroke and may necessitate a change in surgical timing or technique, such as concomitant LAA exclusion.

Aortic Pathology: For procedures involving the aortic valve or root, precise measurement of the aortic annulus, sinuses of Valsalva, and ascending aorta is essential. Undiagnosed aortic root dilation or aneurysm could require a combined, more extensive procedure than initially planned.

Ventricular Function and Chamber Size: Accurate assessment of left and right ventricular systolic function, wall thickness, and chamber dimensions is fundamental. This information helps predict perioperative risk and guides postoperative management. The presence of regional wall motion abnormalities may also suggest underlying, undiagnosed coronary artery disease.

Congenital Defects: In some adults, an incidental patent foramen ovale (PFO) or atrial septal defect (ASD) may be discovered. Identifying these is important as they can be closed at the time of the primary surgery to prevent future paradoxical embolism.

Why Is Transesophageal Echocardiography the Recommended Study for This Presentation?

The ACR rates Transesophageal Echocardiography (US echocardiography transesophageal) as Usually appropriate for this scenario because it provides superior anatomical detail of the specific structures most relevant to noncoronary cardiac surgery, without exposing the patient to ionizing radiation (0 mSv).

TEE’s primary advantage is the proximity of the transducer in the esophagus to the posterior cardiac structures. This results in high-resolution images of the mitral valve, aortic valve, left atrium, and interatrial septum—views that are often suboptimal on a standard transthoracic echocardiogram (TTE). For a surgeon planning a complex mitral valve repair, the detailed leaflet and subvalvular apparatus anatomy provided by TEE is indispensable. It is also the most sensitive noninvasive test for detecting left atrial appendage thrombus, a critical safety check.

While several other studies are rated for this scenario, they serve different or complementary roles:

  • US echocardiography transthoracic resting (TTE): Also rated Usually appropriate, a TTE is an excellent initial, noninvasive study and is often performed before a TEE. However, it may not provide the granular detail needed for surgical planning, especially for posterior structures. It is often considered the baseline test, with TEE providing the definitive preoperative roadmap.
  • CTA coronary arteries with IV contrast: Rated May be appropriate. This study excels at defining coronary artery anatomy and is a noninvasive alternative to coronary angiography for ruling out significant stenosis. It also provides excellent visualization of the aorta. However, it offers limited information on valvular morphology and function and involves both ionizing radiation (☢☢☢ 1-10 mSv) and iodinated contrast. It is best used when coronary or aortic anatomy is the primary question.
  • Arteriography coronary: Also rated Usually appropriate. This remains the gold standard for assessing coronary artery disease. It is often performed based on risk factors or noninvasive testing, as concurrent significant coronary disease would typically be addressed with bypass grafting during the same operation.

The choice of TEE as a primary planning tool is driven by its unparalleled ability to answer the specific questions a cardiac surgeon has before a noncoronary procedure: What is the precise valve pathology? Is there a thrombus? What are the exact dimensions of the relevant structures? It provides this information safely and effectively, directly guiding the operative strategy.

What’s Next After Transesophageal Echocardiography? Downstream Workflow

The results of the preoperative TEE directly influence the subsequent clinical and surgical pathway. The downstream workflow depends on whether the findings confirm the expected pathology, are inconclusive, or reveal unexpected conditions.

If the TEE is definitive and confirms the surgical plan: When the TEE provides clear, high-quality images that confirm the severity and mechanism of valvular disease, accurately size the cardiac chambers and aorta, and rule out thrombus, the patient can proceed directly to the planned surgery. The TEE report becomes a key part of the operative plan, often reviewed by the surgeon immediately before the case.

If the TEE is positive for an unexpected, significant finding: Should the TEE reveal a new, clinically important issue—such as a large, mobile thrombus in the left atrium, severe aortic atherosclerosis (“shaggy aorta”), or an unsuspected vegetation—the surgical plan may need to be altered. This could involve a period of anticoagulation before surgery, a change in the surgical approach to avoid embolization, or the addition of a procedure like aortic arch debridement.

If the TEE is technically limited or findings are equivocal: In rare cases, such as patients with esophageal strictures or poor acoustic windows, the TEE may be non-diagnostic. In these situations, a modality rated as May be appropriate becomes the next logical step. Cardiac MRI (MRI heart function and morphology) is excellent for assessing ventricular function and morphology when echo is suboptimal. Cardiac CTA (CTA chest with IV contrast) is superior for evaluating the aorta and can provide complementary information on cardiac structures, though with less functional data than echo or MRI.

Pitfalls to Avoid (and When to Get Help)

Navigating preoperative imaging requires careful attention to detail to avoid common pitfalls that can impact surgical planning and patient safety.

  • Relying on an outdated study: A TTE performed a year ago may not reflect the current state of a progressive disease like aortic stenosis. Ensure the preoperative imaging is recent enough to accurately guide the contemporary surgical decision.
  • Ignoring TEE contraindications: Do not order a TEE without first screening for absolute and relative contraindications, such as known esophageal varices, strictures, tumors, or recent esophageal surgery.
  • Incomplete LAA assessment: Failing to meticulously interrogate the left atrial appendage for thrombus is a critical error. If views are suboptimal, use multiple planes and consider contrast to improve visualization.
  • Overlooking the aorta: Even in a valve-focused study, it is crucial to image and measure the aortic root and ascending aorta, as associated aortopathy is common, particularly with bicuspid aortic valves.

If the TEE reveals complex anatomy that is difficult to fully characterize, or if there is a discrepancy between clinical findings and echo results, escalate by discussing the case in a multidisciplinary heart team meeting with surgeons, cardiologists, and radiologists to determine the best path forward.

Related ACR Topics and Tools

The ACR Appropriateness Criteria are extensive, covering thousands of clinical scenarios. For a comprehensive overview of all variants related to preoperative imaging for cardiothoracic surgery, or to explore a different clinical presentation, the following resources are essential.

Frequently Asked Questions

Is a transthoracic echocardiogram (TTE) sufficient for preoperative planning?

A TTE is also rated ‘Usually appropriate’ by the ACR and is an excellent initial test. However, for detailed surgical planning, especially for mitral or aortic valve surgery, a transesophageal echocardiogram (TEE) provides superior image resolution of the valve leaflets, subvalvular apparatus, and left atrial appendage, which is often essential for the surgeon.

When should I order a Cardiac CT or MRI instead of an echocardiogram?

A Cardiac CTA or MRA is rated ‘May be appropriate’ and should be considered when the primary clinical question concerns anatomy not well visualized by echo. For example, order a CTA to precisely measure the aortic root and ascending aorta, assess for coronary artery disease, or define pulmonary vein anatomy. Order a Cardiac MRI for the most accurate assessment of ventricular volumes and function, or for tissue characterization, especially if echo windows are poor.

Why is coronary angiography also rated ‘Usually appropriate’?

Coronary angiography is ‘Usually appropriate’ because identifying and treating significant coronary artery disease (CAD) is a critical part of the preoperative workup for major cardiac surgery. Undiagnosed CAD increases surgical risk. The decision to perform angiography is typically based on the patient’s age, risk factors, and symptoms, as concurrent coronary artery bypass grafting may be needed.

Does the patient need both a preoperative TEE and an intraoperative TEE?

Yes, they serve different purposes. The preoperative TEE is for strategic planning before the patient is in the operating room. The intraoperative TEE is used in real-time to confirm preoperative findings, guide the surgical repair (e.g., assess valve competency after a repair), and check for immediate complications before the patient leaves the OR.

What if my patient has atrial fibrillation? Does that change the imaging choice?

Atrial fibrillation reinforces the choice of TEE. TEE is the most sensitive noninvasive imaging modality for detecting thrombus within the left atrial appendage (LAA), a common source of stroke in patients with atrial fibrillation. Identifying a thrombus preoperatively is critical to prevent embolization during surgery and may alter the surgical plan.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 30, 2026