GENERAL INFORMATION

It is an expectation that all patients receive care/services from a licensed clinician.  All appropriate supporting documentation, including recent pertinent office visit notes, laboratory data, and results of any special testing must be provided.  If applicable: All prior relevant imaging results and the reason that alternative imaging cannot be performed must be included in the documentation submitted. 

Where a specific clinical indication is not directly addressed in this guideline, medical necessity determination will be made based on widely accepted standard of care criteria. These criteria are supported by evidence-based or peer-reviewed sources such as medical literature, societal guidelines and state/national recommendations.

Policy 
IINDICATIONS FOR CHEST CTA
Chest computed tomography angiography (CTA) is ordered for evaluation of the intrathoracic blood vessels. Chest CT and chest CTA should not be approved at the same time.

Suspected Pulmonary Embolism (PE)^1,2,3,4,5

• High risk for PE based on shock or hypotension, OR a validated pre-test high probability score (such as Well’s > 6, Modified Geneva score > 11 — see Background),(D dimer is NOT needed for high risk; can approve high risk even with normal D dimer)
• Intermediate and low risk require elevated D dimer (see Background)⁶ (NOTE: A normal D-dimer obviates the need for PE imaging in hemodynamically stable patients with a low or intermediate clinical likelihood of PE.)

Vascular Disease

• Superior vena cava (SVC) syndrome⁷
• Subclavian Steal Syndrome after positive or inconclusive ultrasound^8,9
• Thoracic Outlet Syndrome^10,11
• Takayasu’s arteritis¹²
• Clinical concern for acute aortic dissection^13,14
  • Sudden painful ripping sensation in the chest or back and may include:
    • New diastolic murmur
    • Cardiac tamponade
    • Distant heart sounds
    • Hypotension or shock

Initial/Screening for Thoracic Aortic Disease^15,16,17

• Echocardiogram or chest X-ray show aneurysm 
• Initial study for a suspected aneurysm
• Screening of first-degree relatives of individuals with a known thoracic aortic aneurysm (defined as > 50% above normal) or known dissection
• Evaluation in patients with known or suspected connective tissue disease or geneticcondition that predisposes to aortic aneurysm or dissection, such as Marfan’s, Ehlers Danlos, get a one-time study or for Loeys-Dietz syndrome- allow imaging at diagnosis and then every two years, or more frequently if abnormalities are found (Imaging may include head, neck, chest, abdomen and pelvis)^{14, 20} (MRA preferred due to cumulative radiation risk)
• Screening of the thoracic aorta after a diagnosis of a bicuspid aortic valve (dilation of the ascending aorta may not be seen on echocardiogram)¹⁸
  • If normal, re-image every three to five years
• Screening of first-degree relatives of patients with a bicuspid aortic valve 
• Turner’s syndrome — Screen for coarctation or aneurysm of the thoracic aorta
  • If normal results, screen every 5 – 10 years 
  • If abnormal, screen annually 
• Suspected vascular cause of dysphagia or expiratory wheezing with other imaging is suggestive or inconclusive

Follow-Up After Established Thoracic Aortic Aneurysm (TAA)^15,16,17

• Six months follow-up after initial finding of a dilated thoracic aorta, for assessment of rate of change 
  • Aortic root or ascending aorta (in cm)
    • 3.5 to 4.4 annual
    • 4.5 to 5.5 or growth rate ≥ 0.5 cm/year — Every 6 months
  • Genetically mediated (Marfan syndrome, aortic root or ascending aorta) (in cm)
    • 3.5 to 4.4 annual
    • 4.5 to 5.0 or growth rate ≥ 0.5 cm/year — Every 6 months
    • Surgery generally recommended over 5.0 cm 
  • Descending aorta (in cm)¹⁹
    • 4.0 to 5.0 annual
    • 5.0 to 6.0 every 6 months
• Follow-up post medical treatment of aortic dissection:
  • Acute dissection: 1 month, 6 months, then annually
  • Chronic dissection: annually
• Follow-up TEVAR surveillance at 1 month, then I year post op and if stable, then annually
• Follow-up open repair if no residual aortopathy within first post op year, then every 5 years (if have residual aortopathy or abnormal findings on surveillance, annual follow up in then needed)
• Re-evaluation of known ascending aortic dilation or history of aortic dissection with a change in clinical status or cardiac exam or when findings may alter management.

Congenital Malformations (chest magnetic resonance angiography preferred if pediatrics or repeat imaging)

• Thoracic malformation on other imaging (chest X-ray, echocardiogram, gastrointestinal study, or inconclusive CT)^20,21,22,23
• Congenital heart disease with pulmonary hypertension²⁴ or vascular anomalies
• Pulmonary sequestration²⁵

Pulmonary Hypertension (based on other testing)^26,27

• Echocardiogram
• Right heart catheterization

Atrial Fibrillation With Ablation Planned²⁸

Preoperative/Procedural Evaluation 

• Pre-operative evaluation for a planned surgery or procedure
• Pre-transplant CT or CTA/MRA chest approvable for surgical planning (to evaluate for vascular anatomy, mediastinal pathology, malignancy screening etc.)

Post-Operative/Procedural Evaluation

• Post-operative complications^{29, 30}
• See above indications for TAA follow up

Chest CTA and Abdomen CTA, Abdomen/Pelvis CTA or Abdominal Arteries CTA

• Transcatheter aortic valve replacement (TAVR)^14,31
• Acute aortic dissection
• Takayasu’s arteritis¹²
• Post-operative complications^29,30
• To evaluate for an embolic source of lower extremity vascular disease (may also approved as a combination chest CTA and Abdominal Arteries CTA when LE runoff disease needs to be evaluated as well). Echocardiography is also often needed, since the heart is the most commonly reported source of lower extremity emboli, accounting for 55 to 87 percent of events.³²

Other Indications
Further evaluation of indeterminate findings on prior imaging (unless follow up is otherwise specified within the guideline):

• For initial evaluation of an inconclusive finding on a prior imaging report that requires further clarification
• One follow-up exam of a prior indeterminate MR/CT finding to ensure no suspicious interval change has occurred. (No further surveillance unless specified as highly suspicious or change was found on last follow-up exam.)

Rationale
Computed tomography angiography is a non-invasive imaging modality that may be used in the evaluation of thoracic vascular problems. Chest CTA (non-coronary) may be used to evaluate vascular conditions, e.g., pulmonary embolism, thoracic aneurysm, thoracic aortic dissection, aortic coarctation, or pulmonary vascular stenosis. The vascular structures as well as the surrounding anatomical structures are depicted by CTA.

Pulmonary Embolism (PE)

Methods utilizing clinical assessment to determine probability for PE include:

Modified Geneva Score³⁴

OVERVIEW
Coarctation of the aorta — Coarctation of the aorta is a common vascular anomaly characterized by a constriction of the lumen of the aorta distal to the origin of the left 
subclavian artery near the insertion of the ligamentum arteriosum. The clinical sign of coarctation of the aorta is a disparity in the pulsations and blood pressures in the legs and arms. Chest CTA/MRA may be used to evaluate either suspected or known aortic coarctation and patients with significant coarctation should be treated surgically or interventionally. It may also assist in the identification of postoperative complications.

Central venous thrombosis — CTA/MRA is useful in the identification of venous thrombi. Venous thrombosis can be evaluated by gadolinium-enhanced 3D MRA as an alternative to CTA, which may not be clinically feasible due to allergy to iodine contrast media or renal insufficiency. 

References

1. American College of Radiology. ACR Appropriateness Criteria® Suspected Pulmonary Embolism American College of Radiology (ACR). Updated 2022. Accessed November 20, 2022. https://acsearch.acr.org/docs/69404/Narrative/
2. Corrigan D, Prucnal C, Kabrhel C. Pulmonary embolism: the diagnosis, risk-stratification, treatment and disposition of emergency department patients. Clin Exp Emerg Med. Sep 2016;3(3):117-125. doi:10.15441/ceem.16.146
3. American College of Chest Physicians, American Thoracic Society. Five things physicians and patients should question. Choosing Wisely Initiative ABIM Foundation. Updated October 27, 2013. Accessed November 20, 2022. https://www.choosingwisely.org/wp-content/uploads/2015/02/ACCP-ATS-Choosing-Wisely-List.pdf
4. Konstantinides SV, Torbicki A, Agnelli G, et al. 2014 ESC guidelines on the diagnosis and management of acute pulmonary embolism. Eur Heart J. Nov 14 2014;35(43):3033-69, 3069a-3069k. doi:10.1093/eurheartj/ehu283
5. Kirsch J, Brown RKJ, Henry TS, et al. ACR Appropriateness Criteria(®) Acute Chest Pain-Suspected Pulmonary Embolism. J Am Coll Radiol. May 2017;14(5s):S2-s12. doi:10.1016/j.jacr.2017.02.027
6. Moore AJE, Wachsmann J, Chamarthy MR, Panjikaran L, Tanabe Y, Rajiah P. Imaging of acute pulmonary embolism: an update. Cardiovasc Diagn Ther. Jun 2018;8(3):225-243. doi:10.21037/cdt.2017.12.01
7. Friedman T, Quencer KB, Kishore SA, Winokur RS, Madoff DC. Malignant Venous Obstruction: Superior Vena Cava Syndrome and Beyond. Semin Intervent Radiol. Dec 2017;34(4):398-408. doi:10.1055/s-0037-1608863
8. Osiro S, Zurada A, Gielecki J, Shoja MM, Tubbs RS, Loukas M. A review of subclavian steal syndrome with clinical correlation. Med Sci Monit. May 2012;18(5):Ra57-63. doi:10.12659/msm.882721
9. Potter BJ, Pinto DS. Subclavian steal syndrome. Circulation. Jun 3 2014;129(22):2320-3. doi:10.1161/circulationaha.113.006653
10. Povlsen S, Povlsen B. Diagnosing Thoracic Outlet Syndrome: Current Approaches and Future Directions. Diagnostics (Basel). Mar 20 2018;8(1)doi:10.3390/diagnostics8010021
11. American College of Radiology. ACR Appropriateness Criteria® Thoracic Outlet Syndrome. American College of Radiology. Updated 2019. Accessed November 20, 2022. https://acsearch.acr.org/docs/3083061/Narrative/
12. Keser G, Direskeneli H, Aksu K. Management of Takayasu arteritis: a systematic review. Rheumatology (Oxford). May 2014;53(5):793-801.doi:10.1093/rheumatology/ket320
13. Barman M. Acute aortic dissection. ESC e-J Cardio Pract. 2014;12(25):02Jul2014. doi:https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-12/Acute-aortic-dissection
14. American College of Radiology. ACR Appropriateness Criteria® Imaging for Transcatheter Aortic Valve Replacement. American College of Radiology. Updated 2017. Accessed November 20, 2022. https://acsearch.acr.org/docs/3082594/Narrative/
15. Erbel R, Aboyans V, Boileau C, et al. 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases: Document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC). Eur Heart J. Nov 1 2014;35(41):2873-926. doi:10.1093/eurheartj/ehu281
16. Hannuksela M, Stattin EL, Johansson B, Carlberg B. Screening for Familial Thoracic Aortic Aneurysms with Aortic Imaging Does Not Detect All Potential Carriers of the Disease. Aorta (Stamford). Feb 2015;3(1):1-8. doi:10.12945/j.aorta.2015.14-052
17. Hiratzka LF, Bakris GL, Beckman JA, et al. 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM guidelines for the diagnosis and management of patients with Thoracic Aortic Disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons, and Society for Vascular Medicine. Circulation. Apr 6 2010;121(13):e266-369. doi:10.1161/CIR.0b013e3181d4739e
18. Borger MA, Fedak PWM, Stephens EH, et al. The American Association for Thoracic Surgery consensus guidelines on bicuspid aortic valve-related aortopathy: Full online-only version. J Thorac Cardiovasc Surg. Aug 2018;156(2):e41-e74. doi:10.1016/j.jtcvs.2018.02.115
19. Braverman A, Thompson R, Sanchez L. Diseases of the aorta. In: Bonow R, Mann D, Zipes D, Libby P, eds. Braunwald’s heart disease. 9th ed. Elsevier; 2011:1309.
20. Ferreira Tda A, Chagas IS, Ramos RT, Souza EL. Congenital thoracic malformations in pediatric patients: two decades of experience. J Bras Pneumol. Mar-Apr 2015;41(2):196-9. doi:10.1590/s1806-37132015000004374
21. Hellinger JC, Daubert M, Lee EY, Epelman M. Congenital thoracic vascular anomalies: evaluation with state-of-the-art MR imaging and MDCT. Radiol Clin North Am. Sep 2011;49(5):969-96. doi:10.1016/j.rcl.2011.06.013
22. Karaosmanoglu AD, Khawaja RD, Onur MR, Kalra MK. CT and MRI of aortic coarctation: pre-and postsurgical findings. AJR Am J Roentgenol. Mar 2015;204(3):W224-33.doi:10.2214/ajr.14.12529
23. Poletto E, Mallon MG, Stevens RM, CM A. Imaging Review of Aortic Vascular Rings and Pulmonary Sling. J Am Osteopath Coll Radiol. 2017;6(2):5-14. 
24. Pascall E, Tulloh RM. Pulmonary hypertension in congenital heart disease. Future Cardiol. Jul 2018;14(4):343-353. doi:10.2217/fca-2017-0065
25. Sancak T, Cangir AK, Atasoy C, Ozdemir N. The role of contrast enhanced three-dimensional MR angiography in pulmonary sequestration. Interact Cardiovasc Thorac Surg. Dec 2003;2(4):480-2. doi:10.1016/s1569-9293(03)00118-x
26. Ascha M, Renapurkar RD, Tonelli AR. A review of imaging modalities in pulmonary hypertension. Ann Thorac Med. Apr-Jun 2017;12(2):61-73. doi:10.4103/1817-1737.203742
27. Rose-Jones LJ, McLaughlin VV. Pulmonary hypertension: types and treatments. Curr Cardiol Rev. 2015;11(1):73-9. doi:10.2174/1573403x09666131117164122
28. Kolandaivelu A. Role of Cardiac Imaging (CT/MR) Before and After RF Catheter Ablation in Patients with Atrial Fibrillation. J Atr Fibrillation. Aug-Sep 2012;5(2):523. doi:10.4022/jafib.523
29. Bennett KM, Kent KC, Schumacher J, Greenberg CC, Scarborough JE. Targeting the most important complications in vascular surgery. J Vasc Surg. Mar 2017;65(3):793-803. doi:10.1016/j.jvs.2016.08.107
30. Choudhury M. Postoperative management of vascular surgery patients: a brief review. Clin Surg. 2017;2:1584. 
31. Achenbach S, Delgado V, Hausleiter J, Schoenhagen P, Min JK, Leipsic JA. SCCT expert consensus document on computed tomography imaging before transcatheter aortic valve implantation (TAVI)/transcatheter aortic valve replacement (TAVR). J Cardiovasc Comput Tomogr. Nov-Dec 2012;6(6):366-80. doi:10.1016/j.jcct.2012.11.002
32. Braun JD. Embolism to the lower extremities. UpToDate. UpToDate; 2023.
33. van Belle A, Büller HR, Huisman MV, et al. Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. Jama. Jan 11 2006;295(2):172-9. doi:10.1001/jama.295.2.172
34. Le Gal G, Righini M, Roy PM, et al. Prediction of pulmonary embolism in the emergency department: the revised Geneva score. Ann Intern Med. Feb 7 2006;144(3):165-71. doi:10.7326/0003-4819-144-3-200602070-00004

Coding Section

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

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