Response to Comments: Non-Invasive Fractional Flow Reserve (FFR) for Ischemic Heart Disease

Language clarification – stenosis range <50% vs. 40% (received from 4 commenters).

In patients with non-obstructive CAD (<50% stenosis) who have persistent symptoms despite maximized medical management the pathway leads to options for further evaluation with CCTA or stress test. If CCTA is performed and ≥40-90% stenosis is found on this new study than FFRCT may be used to aid in further evaluation.⁵

General agreement with statement submitted by SCCT: Inclusion of Intermediate-risk patients with acute chest pain and no known coronary artery disease, with coronary artery stenosis of 40-90% in proximal or middle coronary artery on CCTA.

The policy will remain consistent with the 2021 AHA/ACC Guidelines1. The restriction from <50% to <40% was revised in draft for consistency.

Language clarification (received from 3 commenters) – persistent symptoms definition

Question raised as to definition of “persistent symptoms”. Does this mean that symptoms persist despite optimal medical therapy, or does it mean that the symptoms have been present for some period of time (whether or not optimal medical therapy was instituted)?

Persistent is defined by symptoms that persist despite optimal medical therapy. Optimal medical therapy is defined by ISCHEMIA trial protocol² as unacceptable ischemia-related symptoms despite maximally tolerated medical therapy. This includes at least two anti-anginal drugs from different drug classes added to beta-blocker therapy and titrated to maximally tolerated doses before medical therapy is considered to have failed. This has been added to the policy for clarification.

Location of stenoses (received from 2 commenters).

In the indication that addresses FFR for stable CAD, there is no requirement that the stenosis be in the proximal or middle segment of the coronary artery, as is the case for acute CAD indications. Is this intentional or is it an oversight? We suspect it is an oversight because, in general, distal CAD is not managed with revascularization in which case FFR is not particularly helpful in clinical decision making.

The 2021 AHA/ACC/ASE/ CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain states “For intermediate-high risk patients with stable chest pain and known coronary stenosis of 40% to 90% in a proximal or middle coronary segment on CCTA, FFR-CT can be useful for diagnosis of vessel-specific ischemia and to guide decision-making regarding the use of coronary revascularization ”. The policy will remain consistent with the 2021 Guidelines.

Concurrent use with stress testing (3 commenters).

Patients who have undergone stress testing are excluded from consideration for FFR. We suggest that the authors consider the following:
a. If stress testing is inconclusive, CCTA and FFR may have a role in patient management.
b. If stress testing is performed without imaging, and is positive, and CCTA shows more than one obstructive lesion, FFR may be useful in determination of the flow limiting significance of each lesion thereby guiding PCI decisions.

If stress testing is inconclusive, CCTA and FFR may have a role in patient management. We agree that FFR-CT may be a reasonable alternative when stress test is inconclusive, and policy updated accordingly. If stress testing is performed without imaging, and is positive, and CCTA shows more than one obstructive lesion, FFR may be useful in determination of the flow limiting significance of each lesion thereby guiding PCI decisions. This was not accompanied by supporting literature if such literature is published, please submit with reconsideration.

CTA Imaging Limitations (due to prosthetic valves, pacemaker and defibrillator leads) (4 commenters).

Remove restrictions related to image quality, valves (Restriction 1), known severe aortic stenosis (Restriction 2) and pacemaker or defibrillator leads (Restriction 8).

There are several reasons we will not remove these limitations at this time:

a. This policy is foundational so covers any technology that would provide equivalent service. If a new product that is equivalent to what is currently available emerges it will be held to the requirements within this policy. While current technology returns the images if quality is low, we cannot assume that will be the case for all future technologies.

b. To ensure safety and accurate of results literature is needed to support the removal of these limitations. Pivotal trails consistently excluded patients with prior percutaneous coronary interventions.

c. Incomplete reporting of coronary artery anatomy defeats the purpose of this diagnostic test therefore does not meet the requirements for payment.

If literature or guidelines provide support for the safety and accuracy for CCTA and FFRCT in this population that can be evaluated with reconsideration.

Impact of coronary plaque on CCTA (and subsequent FFRct determinations) (3 commenters).

With the development of new technologies in CCTA, presence of extensive plaque or calcification does not necessarily exclude the use of FFRCT³. We recommend the use of FFRCT if there is adequate image quality. Recommend removing “If extensive plaque is present a high quality CCTA is unlikely and stress testing is preferred.” Syntax 3 and FAME studies were submitted in support of this position.

The Syntax 3 study⁴ suggests that the overestimation of CTA-SS was corrected by FFR-CT, resulting in higher correlation to invasive angiogram than CTA alone. This was reproduced in the FAME trial.⁵ Therefore, the statement regarding excessive plaque formation is removed from the policy.

Accuracy in the setting of severe Aortic Stenosis (4 Commenters).

All requestors favored the removal of this prohibition of usage from the policy. All cited the same evidence noted below.

The 2021 CAST-FFR study supports FFR-CT in the setting of severe aortic stenosis so this limitation is removed from the policy.⁶

Intracoronary metallic stents (3 commenters).

One technology asserted that it can process FFRCT results on patients who have had stents to one vessel. However, they can only interpret the vessels without stent. The Indications for Use state that there are 3 scenarios where FFRCT cannot be utilized (and therefore would be appropriate to not cover):

a. Stent is present in the left main coronary artery

b. A stenosis > 30% in the left main coronary artery and 1 or more stent in the left system

c. Stents present in 2 or more coronary systems

a. This policy is foundational so covers any technology that would provide equivalent service. If a new product that is equivalent to what is currently available emerges it will be held to the requirements within this policy. While current technology returns the images if quality is low, we cannot assume that will be the case for all future technologies.

b. To ensure safety and accurate of results literature is needed to support the removal of these limitations. Pivotal trails consistently excluded patients with prior percutaneous coronary interventions.^4,7

c. Incomplete reporting of coronary artery anatomy defeats the purpose of this diagnostic test therefore does not meet the requirements for payment.

If literature or guidelines provide support for the safety and accuracy for CCTA and FFRCT in this population that can be evaluated with reconsideration.

Inclusion of stable and acute chest pain (3 commenters).

Request for inclusion of both indications based on ACC/AHA Guidelines cited in both requests.

“Stable and acute chest pain” has been added to align with ACC/AHA Chest Pain Guidelines.¹

Combine the two indications for “no known” and “known” CAD (1 commenter).

One request was received to combine the two indications for “no known” and “known” CAD into one, as once a CCTA is performed and FFRCT ordered, CAD is always “known”.

In the 2021 AHA/ACC/ASE/ CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain¹ the algorithm for suspected ACS at Intermediate Risk with No Known CAD and Known CAD are separate. Based on this algorithm FFRCT is a sequential test, therefore the evaluation and treatment plan may lead to CCTA in defined clinical scenarios. Based on the CCTA results the patient may benefit from FFR-CT or stress testing. As there is a possible divergence of clinical pathways, the policy language will remain consistent with the 2021 Guidelines.

Inclusion of Additional Diagnoses Codes other than R93.1 (1 commenter).

One request was received to add additional diagnoses codes other than R93.1-Abnormal findings on diagnostic imaging of heart and coronary circulation.

After substantial discussion, it was decided to maintain this diagnosis as uniquely accurate as the clinical decision to use this service (of data reprocessing) is based on the abnormal findings on previously obtained diagnostic imaging.