Should a coronary CTA (Computed Tomography Angiography) with possible FFR (Fractional Flow Reserve) be approved for a patient with hyperparathyroidism, type 2 diabetes mellitus (DM2), hypertension (HTN), hyperlipidemia (HLD), and a history of tobacco abuse, who has a recently discovered Mobitz type 1 AV block and a family history of coronary artery disease?

Coronary CTA with FFR Should Be Approved for Preoperative Risk Assessment

This patient meets clear indications for coronary CTA as preoperative cardiac risk assessment prior to parathyroidectomy, given multiple cardiovascular risk factors (DM2, HTN, HLD, prior tobacco use), strong family history of CAD, and the need for surgical intervention. 1

Clinical Context Supporting Approval

High Cardiovascular Risk Profile

• The patient has type 2 diabetes with multiple atherosclerotic risk factors, which places him at very high cardiovascular risk according to ESC guidelines 1
• Hyperparathyroidism itself is associated with more severe coronary artery disease and increased coronary calcification scores compared to matched controls, with positive coronary calcification scores reaching the 67th percentile of control populations 2
• The combination of diabetes and hyperparathyroidism creates a three-fold higher prevalence of concurrent disease than expected, with insulin resistance mechanisms potentially worsening both conditions 3
• Strong family history of CAD further elevates his risk profile 1

Guideline-Supported Indications for CTA

ESC guidelines explicitly state that screening for CAD with coronary CT angiography may be considered (Class IIb) in patients with diabetes at high cardiovascular risk 1

The 2019 ESC guidelines recommend:

• Resting ECG is recommended in patients with diabetes and hypertension 1
• Screening for CAD with coronary CT angiography and functional imaging may be considered in diabetic patients 1
• Coronary artery calcium scoring may be considered as a risk modifier 1

Preoperative Assessment Context

This is not routine screening but rather preoperative risk stratification before parathyroidectomy, which changes the clinical calculus significantly 1

• The patient requires surgery for hyperparathyroidism, making cardiac risk assessment clinically appropriate 2
• Undiagnosed CAD could significantly impact perioperative management and outcomes 1
• The Mobitz type 1 AV block, while not requiring pacemaker currently, indicates underlying cardiac conduction system disease that warrants comprehensive cardiac evaluation before surgery 1

Role of FFR-CT in This Patient

If coronary CTA demonstrates intermediate stenoses (50-90%), FFR-CT provides critical functional assessment without additional invasive testing 1

• FFR-CT has demonstrated 89% sensitivity and 76% specificity for detecting obstructive CAD defined by invasive FFR 1
• In patients with intermediate-range coronary stenosis, FFR-CT effectively differentiates patients who do not require further testing from higher-risk patients who may need invasive angiography 1
• Non-ischemic FFR-CT results are associated with favorable prognosis and can guide perioperative management 1

Advantages of CTA in This Clinical Scenario

Coronary CTA provides comprehensive anatomical assessment with excellent negative predictive value 1

• The SCOT-HEART trial demonstrated significantly lower rates of cardiovascular death or non-fatal MI (2.3% vs 3.9% during 5-year follow-up) when coronary CTA was performed in addition to routine testing 1
• CTA allows for assessment of plaque burden and composition, which is particularly relevant given the patient's hyperparathyroidism and associated increased coronary calcification 1, 2
• Sensitivity and specificity of CCTA are 91% and 50% respectively, with negative predictive value of 83% 1

Critical Considerations and Potential Limitations

Image Quality Factors

• The patient's multiple risk factors suggest potential for significant coronary calcification, which could impair CTA image quality 1, 4
• Heavy calcification can lead to overestimation of stenosis severity and reduced specificity 1, 4
• However, modern CT technology with dose-reduction techniques and iterative reconstruction can mitigate some of these limitations 1

Mobitz Type 1 AV Block

• Mobitz type 1 is typically benign and does not contraindicate CTA, as it often occurs at the AV node level and is not associated with structural heart disease 1
• The patient is asymptomatic without palpitations or syncope, and no pacemaker is indicated 1
• Regular sinus rhythm with periods of Mobitz 1 should not significantly impact CTA image quality if heart rate is controlled 1

Alternative Approach Would Be Functional Testing

If CTA is denied, functional stress testing (stress echocardiography, nuclear perfusion imaging, or stress CMR) would be the alternative preoperative assessment 1

• Functional testing may be preferentially considered given high clinical likelihood of CAD 1
• However, functional testing provides no anatomical information and may still require subsequent CTA or invasive angiography if positive 1
• Starting with CTA is more efficient in this intermediate-risk patient requiring preoperative assessment 1

Common Pitfalls to Avoid

• Do not deny CTA based solely on Mobitz type 1 AV block, as this is not a contraindication and the patient is asymptomatic 1
• Avoid the misconception that this is "routine screening" – this is preoperative risk assessment in a high-risk diabetic patient requiring surgery 1
• Do not proceed directly to invasive angiography without non-invasive assessment first unless the patient has severe refractory symptoms or very high-risk features 1
• If significant calcification is found on CTA limiting assessment, functional testing or selective invasive angiography with FFR can be performed based on CTA findings 1, 4

Recommendation Algorithm

Approve coronary CTA with possible FFR-CT for this patient based on:

1. High cardiovascular risk (diabetes, hypertension, hyperlipidemia, tobacco history, family history) 1
2. Preoperative assessment indication before parathyroidectomy 1, 2
3. ESC guideline support for CAD screening in high-risk diabetic patients 1
4. Efficiency of anatomical assessment with option for functional correlation via FFR-CT if intermediate stenoses found 1
5. No absolute contraindications – Mobitz type 1 is not a contraindication, and patient is asymptomatic 1

If CTA demonstrates:

• No significant CAD: Proceed with surgery with standard perioperative cardiac management 1
• Non-obstructive CAD: Optimize medical therapy and proceed with surgery 1
• Intermediate stenoses (50-90%): Use FFR-CT to determine functional significance 1
• Severe stenoses (>90%) or positive FFR-CT: Consider invasive angiography and possible revascularization before surgery 1