## 1 Current Role of CCTA in Clinical Practice and Guidelines
### Plaque Burden
\begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{2}{c}{**Chronic Coronary Syndromes (CCS)**} \\ \hline
**ESC 2019** & **AHA/ACC 2012** \\ \hline Non-invasive functional imaging for myocardial ischemic or CCTA is recommended as the initial test to diagnose CAD in symptomatic patients in whom obstructive CAD cannot be excluded by clinical assessment alone & CCTA can be useful as a first-line test for risk assessment in patients with SIHD who are unable to exercise to an adequate workload regardless of interpretability of ECG \\ \multicolumn{2}{c}{**(IIa-C)**} \\ \hline It is recommended that selection of the initial non-invasive diagnostic test is done based on the clinical likelihood of CAD and other patient characteristics that influence test performance, local expertise, and the availability of tests. & CCTA may be reasonable for risk assessment in patients with SIHD who are able to exercise to an adequate workload but have an uninterpretable ECG \\ \multicolumn{2}{c}{**(I-C)**} \\ \hline CCTA should be considered as an alternative to invasive angiography if another non-invasive test is equivocal or non-diagnostic. & CCTA can be useful for risk assessment in patients with SIHD who have an indeterminate result from functional testing \\ \multicolumn{2}{c}{**(IIa-C)**} \\ \hline
**Acute Coronary Syndromes (IACS)** & **(IIa-C)** \\ \hline
**ESC 2020 (NETEMI)** & **AHA/ACC 2021 (chest pain)** \\ \hline CCTA is recommended as an alternative to ICA to exclude ACS when there is a low-to-intermediate likelihood of CAD and & For intermediate-risk patients with acute chest pain and no known CAD eligible for diagnostic testing after a negative or inconclusive evaluation for ACS, CCTA is useful for exclusion of atherosclerotic plaque and obstructive CAD \\ \multicolumn{2}{c}{**(I-A)**} \\ \hline In patients with no recurrence of chest pain, normal ECG findings, and normal levels of cardiac troponin (preferably high sensitivity), but still with a suspected ACS, a non-invasive stress test (preferably with imaging) for inducible ischaemia or CCTA is reasonable for diagnosing obstructive CAD \\ \multicolumn{2}{c}{**(I-B)**} \\ \hline
**Cardiovascular Prevention** \\ \hline
**ESC 2021** & **AHA/ACC 2019** \\ \hline In intermediate-risk (7.5–20% 10-year ASCVD risk) adults or selected borderline-risk (5–7.5% 10-year ASCVD risk) adults in whom a coronary artery calcium score is measured for the purpose of making a treatment decision: \\ Coronary artery calcium (CAC) scoring can reclassify CVD risk in addition to conventional risk factors, and may be considered & -CAC scoring is zero \(\rightarrow\) it is reasonable to withhold statin therapy and reassess in 5 to 10 years, as long as higher-risk conditions are absent (e.g., diabetes, family history of premature CAD, cigarette smoking); \\ thresholds & -CAC score is 1 to 99 \(\rightarrow\) it is reasonable to initiate statin therapy for patients \textgreater{}55 years of age; \\ \multicolumn{2}{c}{**-CAC score is 100 or higher \(\rightarrow\) it is reasonable to initiate statin therapy (IIa-B)**} \\ \hline
**CCS: chronic coronary syndromes; CCTA: coronary computed tomography angiography; CAD: coronary artery disease; SIHD: stable ischemic heart disease; ECG: electrocardiogram; ACS: acute coronary syndromes; CVD: cardiovascular disease; ICA: invasive coronary angiography; CAC: coronary artery calcium; ASCVD: atherosclerotic cardiovascular disease.** \\ \hline \hline \end{tabular}
\end{table} 
Table 1: ESC and AHA/ACC guidelines recommendations about CCTA application in chronic coronary syndromes (CCS), acute coronary syndromes (ACS), and cardiovascular prevention. adjusted hazard ratio for major adverse cardiac events (MACEs) among 1.6 and 7.1. [19]. Multiple studies showed that the number of segments involved is one of the best predictors of outcome, surpassing scores that only consider segments with mild or moderate stenosis [14; 18]. [PERSON] et al.