CTA is an accurate, noninvasive alternative to invasive coronary angiography (ICA) for initial CAD evaluation in patients with stable chest pain and intermediate pretest probability for obstructive CAD. Evidence from trials such as PROMISE and SCOT-HEART show that an initial CTA strategy results in similar cardiovascular outcomes as functional testing and is associated with a lower incidence of major adverse cardiovascular events compared to usual care. CTA has excellent sensitivity for identifying flow-limiting disease and high negative predictive value, making it well-suited for initially ruling out CAD. However, factors such as a history of prior stenting, obesity, arrhythmias, or breathing issues may favor ICA over CTA for initial evaluation.

1. CT Angiography Or Invasive
Coronary Angiography For Initial CAD
Evaluation ,How To Decide
Dr Awadhesh Kr Sharma, DM Cardiology, FACC(USA), FSCAI(USA)
Associate Professor
LPS Institute of Cardiology, GSVM Medical College, Kanpur (UP)

2. NON-Invasive or Less invasive investigative
modalities are the choice of everyone

3. Myths regarding Angiography

4. Google Gyan………..

5. But………….

6. Which one to choose or good in initial CAD
evaluation is matter of discussion today……..

7. Introduction
 CT angiography (CTA) - an accurate, noninvasive alternative to invasive coronary
angiography (ICA).
 CTA is advised in patient with stable chest pain and intermediate pretest
probability for obstructive CAD.
 However, the comparative effectiveness of CT and ICA in the management of
CAD to reduce the frequency of major adverse cardiovascular events is
uncertain.

8. Invasive Coronary Angiography (ICA)
 ICA is the reference standard for the diagnosis of obstructive
CAD and enables coronary revascularization during the same
procedure.
 However, elective ICA is associated with rare but major
procedure-related complications.

9. CTA VS ICA
 CTA is associated with -
 More radiation exposure as ICA
 More contrast volume
 Require strict rate control (HR<70)
 Difficult in morbid obese patient
 Inaccurate to assess severity in heavily calcified vessel
 Less sensitive in patient with prior Stent due to blooming effect of metallic scaffold

10. Evidences….

11. Evidences….
 PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial-
As compared with an initial strategy of functional testing (exercise
electrocardiography, nuclear stress testing, or stress echocardiography), an initial CT
strategy in patients with stable symptoms was associated with similar cardiovascular
outcomes at 25 months.
 SCOT-HEART (Scottish Computed Tomography of the Heart) trial-
The use of CT was associated with a significantly lower incidence of major
adverse cardiovascular events, which were defined as death from CAD or nonfatal
myocardial infarction at 4.8 years (hazard ratio, 0.59)

14. PretestProbabilities of
ObstructiveCADin
SymptomaticPatients
AccordingtoAge,Sex,and
Symptoms.
14
Colorscorrespondto
theClassof
Recommendationin
Table1.
CAC indicatescoronary
artery calcium;and CAD,
coronaryarterydisease.

15. Indexof SuspicionThatChest“Pain”IsIschemic inOrigin
ontheBasisof Commonly UsedDescriptors.
15

18. Stable chest pain
1. No Known CAD:
 Appropriate as the first line test in stable typical or atypical chest pain, or other
symptoms which are thought to represent a possible anginal equivalent (e.g.
dyspnoea on exertion, jaw pain).
 After a nonconclusive functional test, in order to obtain more precision
regarding diagnosis and prognosis, if such information will influence subsequent
patient management.
 May be appropriate in some asymptomatic high-risk individuals, such as those
with a higher likelihood of non-calcified plaque.
 Rarely appropriate in very low-risk symptomatic patients – those under age 40
with non-cardiac symptoms – or those with low- to intermediate-risk
asymptomatic patients.

19. Indications..
2. Known CAD:
 It is appropriate to perform CTA as a first line test for evaluating patients with
known CAD who present with stable typical or atypical chest pain, or other
symptoms which are thought to represent a possible anginal equivalent (e.g.
dyspnea on exertion, jaw pain).
3. Functional imaging:
 It may be appropriate to perform CT derived FFR and CT myocardial perfusion
Imaging to evaluate the functional significance of intermediate stenoses on
CTA (30-70% diameter stenosis).
 Add FFRCT and stress-CTP to CTA to increase specificity, positive predictive
value, and diagnostic accuracy.
 CTP can be a valuable alternative when CT-FFR is technically difficult.

20. Indications..
4. Stable Coronary Artery Disease: CCTA Post-Revascularization
 In intra-coronary stent ≥ 3.0 mm, implementing measures to improve stent
imaging accuracy, such as heart-rate control, iterative, sharp kernel, and mono-
energetic reconstruction.
 CCTA is appropriate to evaluate patients with prior CABG, particularly for graft
patency, and to visualize grafts and other structures prior to cardiac surgery re-
do.
 Protocols to optimize stent imaging should be developed and followed. It may
also be appropriate to perform coronary CTA in symptomatic patients with
stents <3.0 mm, especially those known to have thin stent struts (<100 mm) in
proximal, non-bifurcation locations.

21. Indications..
5. Stable Coronary Artery Disease: CCTA in Other Conditions
Asymptomatic high risk subjects:
 may be appropriate in selected asymptomatic high risk individuals, especially in those who have
a higher likelihood of having a large amount of non-calcified plaque.
 Asymptomatic low or intermediate risk : rarely appropriate.
 Coronary artery bypass grafts : It is appropriate to perform CTA for evaluation of patients with
prior CABG, particularly if graft patency is the primary objective.

22. Other Indications:
 CTA is appropriate for coronary artery evaluation before non-coronary cardiac surgery
as an equivalent alternative to invasive angiography in patients with low-to-
intermediate probability of CAD and younger patients with primarily non-degenerative
valvular conditions.
 CTA is appropriate to exclude coronary artery disease in patients with suspected non-
ischemic cardiomyopathy.

23.  CTA is appropriate for the evaluation of coronary anomalies.
 Limited delay image CTA (60 seconds-to-90 seconds) is appropriate alternative
to TEE to exclude LA/LAA thrombus, as well as in patients where TEE-
associated risks outweigh the benefits.
 Late enhancement CT imaging may be appropriate to evaluate myocardial
viability in some patients who cannot undergo cardiac MRI if it has the
potential to impact diagnosis and treatment.

24. Evaluation Algorithm for Patients With SuspectedACS
at IntermediateRiskWithNo Known CAD.
24
Colorscorrespond to
theClassof
Recommendation in
Table1.

25. Colorscorrespond to
theClassof
Recommendation in
Table1.
EvaluationAlgorithmforPatientsWithSuspectedACS at Intermediate
RiskWithKnownCAD.
25

26. Implementation In Clinical Practice

27. 1. Medical versus Invasive Treatment
 A central aim of evaluation for CAD is to identify patients who need
appropriate revascularization to improve prognosis or symptoms not
responding to medical therapy, as well as those that can be managed with
medical therapy alone.
 Stenosis severity still remains the primary arbiter of therapeutic
decisions, but more and more data now suggest that anatomy coupled
with a physiologic correlate is a better or even possibly, a necessary way
for optimal decision-making.

28. 2. Role of CTA for guiding further non-
invasive evaluation:
 CTA facilitates decision making by dividing patients into multiple informative categories.
 Those with a negative CTA or demonstration of non-obstructive CAD would generally exclude
flow limiting CAD with high certainty and avoid downstream testing.
 CTA seems to allow for more appropriate use of statins and anti-platelet therapies better
than when using non CTA methods for CAD diagnosis.
 CTA and FFRCT may allow for even more uniform down-stream interventions and narrow the
differences between revascularization rates between men and women unlike what happens
after usual stress testing imaging.

29. Take home message
So how to decide for CTA vs ICA
 Pretest probability of CAD (intermediate vs high likelihood )
 Presentation of patient (ACS vs CCS)
 Coronary CTA should be considered as the test of choice in most symptomatic
patients without known CAD.
 CTA has excellent sensitivity for identifying flow limiting disease and has very
high negative predictive value, making it the strongest test to rule out flow
limiting CAD, especially in patients with low to intermediate risk.
 Prior history of revascularization ,PCI(blooming effect of prior stent )
 Body habitus (morbid obese patient)
 Poorly controlled Heart rate
 Inability to hold breadth due to underlying respiratory distress