World Journal of Cardiovascular Diseases, 2013, 3, 573-580 WJCD
http://dx.doi.org/10.4236/wjcd.2013.39090 Published Online December 2013 (http://www.scirp.org/journal/wjcd/)
Incremental value of preprocedural coronary computed
tomographic angiography to classical coronary
angiography for prediction of PCI complexity
in left main stenosis
Imre Benedek, Monica Chitu, Istvan Kovacs, Bajka Balazs, Theodora Benedek
University of Medicine and Pharmacy of Tirgu Mures, Tirgu Mures, Romania
Received 24 October 2013; revised 25 November 2013; accepted 6 December 2013
Copyright © 2013 Imre Benedek et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Introduction: The aim of our study was to assess the
incremental value of Coronary Computed Tomogra-
phy Angiography (CCTA) added to classical coro-
nary angiography, for complex characterization of
coronary lesions and prediction of procedural com-
plexity in patients with significant left main (LM)
stenoses. Material and Methods: Thirty-six patients
with LM disease were enrolled in the study, and each
subject underwent CCTA followed by coronary an-
giography and percutaneous revascularization. Re-
sults: Logistic regression analysis indicated a good
correlation between the angiographic-calculated and
the CCTA-derived Syntax scores for the whole group
(r = 0.87, p < 0.0001) and for the high risk subgroup
(r = 0.86, p < 0.0001), but not for the low and inter-
mediate risk (r = 0.38, p = 0.21 and r = 0.62, p = 0.07
respectively). In cases which required complex PCI
procedures, both angiographic and CCTA Syntax
score were significantly higher than those who did not
require complex revascularization procedures (24.5
+/− 11.5 vs 32.2 +/− 14.6, p = 0.09 for Angio Syntax,
35.3 +/− 11.5 vs 25.2 +/− 11.3, p = 0.01 for CCTA). In
the same time, Ca scoring was significantly higher
and plaque volumes were significantly larger in cases
requiring complex revascularization procedures
(299.5 +/− 359.6 vs 917.3 +/− 495.4, p = 0.04 for cal-
cium score, 79.7 +/− 28.5 vs 108.7 +/− 25.3 mm3, p =
0.002 for plaque volumes). Multivariate analysis iden-
tified the following CCTA parameters as significant
predictors of increased risk for complex intervention
in LM lesions: plaque volume (OR 8.00, p = 0.008),
Ca scoring (OR 6.37, p = 0.02) and CCTA Syntax
score (OR 6.87, p = 0.01). Conclusions: CCTA de-
rived parameters provide incremental information to
classical coronary angiography for preoperative as-
sessment of lesion severity in complex left main steno-
sis. CCTA derived Syntax score significantly corre-
lates with the classical Coronary Angiography Syntax
score and identifies the subgroup of patients who will
be more exposed to procedural complications during
the revascularization interventions.
Keywords: Left Main; Syntax Score; Coronary
Computed Tomographic Angiography
1. INTRODUCTION
The coronary angiography has become nowadays the
gold standard technique for diagnosis of coronary artery
stenoses, including those located in the left main (LM)
coronary artery.
A positive coronary angiography showing severe nar-
rowing of the LM indicates an urgent need for revas-
cularization, which could improve the tolerance to is-
chaemic events in other coronary territories and reduce
the progression of the associated ventricular dysfunction
[1,2]. Percutaneous coronary revascularization has been
recently recognized to represent a viable therapeutic
alternative in patients with severe left main (LM) steno-
sis. Despite of the well-known high risk associated with
complex interventional procedures in unprotected LM
diseases, percutaneous interventions are increasingly
used in the treatment of complex LM lesions [3].
Many studies attempted to reveal the role of interven-
tional revascularization in such cases, as an alternative to
the traditional coronary artery bypass grafting. The SYN-
TAX trial (The Synergy between Percutaneous Coronary
Intervention with TAXUS and Cardiac Surgery) in-

I. Benedek et al. / World Journal of Cardiovascular Diseases 3 (2013) 573-580 574
cluded 3.075 patients with left main coronary disease or
three-vessel disease or both, who were randomized to
surgical or percutaneous revascularization [4,5]. The re-
sults of the trial revealed the role of percutaneous reva-
scularization in several subsets of patients, especially
those with isolated left main disease or left main disease
associated with one vessel disease, and led to develop-
ment of the Syntax score.
Syntax trial led to development of the Syntax score, a
complex angiographic score based on characterization of
coronary lesions according to specific angiographic para-
meters, such as tortuosity, bifurcation, the presence of a
total occlusion or intracoronary thrombus, calcification,
the dominance, type and number of lesions [6,7].
A Syntax score below 22 classifies the lesion in the
low-risk category, a score between 22 and 32 is associa-
ted with medium risk, while a score above 33 indicates a
high-risk lesion.
This score system became widely accepted in clinical
practice immediately after the Syntax trial and nowadays
many cases of left main disease are referred for surgical
or interventional treatment based on the calculated Syn-
tax score, the general recommendations being in favor of
percutaneous revascularization in cases of low or me-
dium Syntax scores and in favor of surgery in cases with
high Syntax scores [8,9].
However, calculation of Syntax score relies only on
the information provided by coronary angiography. De-
spite the recent widespread use of Coronary Computed
Tomographyc Angiography (CCTA), key information
provided by this technique such as calcium scoring or
plaque volumes is rarely taken into consideration when
establishing the indication for percutaneous coronary in-
tervention (PCI) in LM diseases [10]. However, CCTA
provides incremental value to classical coronary angio-
graphy with regard to complex characterization of coro-
nary lesions. As CCTA offers the unique opportunity for
assessment of atheromatous plaque burden and calcium
content, together with a three-dimensional representation
of the lesion, it could predict a more complex interven-
tional procedure in cases with high calcium burden, large
plaques or difficult anatomy.
The aim of our study was to assess the incremental
value of CCTA on the top of information provided by the
classical coronary angiography, for complex characteri-
zation of left main stenoses and prediction of procedural
complexity in patients with significant LM stenoses.
2. METHODS
2.1. Study Population
This was a single center prospective non-randomized
study to evaluate the incremental value of the informa-
tion provided by CCTA on the top of those obtained by
classical coronary angiography in complex characteri-
zation of coronary lesions in patients with significant left
main disease.
Thirty-six patients with LM disease at the clinical pre-
sentation were enrolled in the study, and each subject
underwent 64 multi-slice CT followed by coronary an-
giography and percutaneous revascularization. All pa-
tients gave written informed consent, and the study pro-
tocol was approved by the ethics committee of the center
where the study was conducted.
The inclusion criteria were age >18 years, documented
significant (>50%) stenosis of the LM coronary artery
and willingness to participate in the study. Patients with
contraindications for the repeated administration of con-
trast agents were excluded from the study.
2.2. CCTA Analysis
All CT acquisitions were made using multi-slice 64 So-
matom Sensation CT (Siemens, Germany) with a 64 ×
0.5 mm detector collimation. During an inspiratory
breath-hold, 60 ml of an iodinated contrast agent (Iopa-
midol, 370 mg I/ml, Bayer Healthcare, Germany) was
infused at a speed of 4.0 ml/sec followed by 20 ml at 2.0
ml/sec. All examinations were preceded by the admini-
stration of a short-acting betablocker to achieve the de-
sired heart rate and were conducted only after achieving
a stable heart rate below 60 beats/min. All acquired
images were transferred to a workstation (Siemens, Ger-
many) for data processing, measurements and inter-
pretation
The following information provided by CCTA have
been used for assessing the severity of the lesions and to
calculate the CCTA-Syntax score: degree of calcification
in the left main lesion, global calcium burden expressed
by calcium score, coronary stenosis severity (in the left
main and in the rest of the coronary tree), length and
diameter of the left main, involvement of the origin of
left anterior descending artery and circumflex artery,
anatomic distribution (type of dominance), extension of
calcification at the origin of the main arteries, involve-
ment of the ostium of the left main, and the plaque
volume. All these information have been evaluated by
Angio CT multislice 64 using multiplanar 3D recon-
structions.
2.3. Coronary Angiography Analysis
Coronary angiography analysis was performed using an
Artis Zee Floor Angiograph (Siemens, Germany), using
repeated injections of 3 - 5 ml contrast material in the left
main coronary lumen and image aquisitions in different
incidences, with different angles and tiltings of the X-ray
tube.
A significant left main stenosis was defined as a >50%

I. Benedek et al. / World Journal of Cardiovascular Diseases 3 (2013) 573-580 575
narrowing of the LM lumen at coronaty angiography in
at least one incidence.
Angiographic assessment included the following para-
meters which served for calculation of Syntax scores,
according to the algorhythm available on the web
(www.syntaxscore.com): coronary dominance, number
and location of lesions, presence of a total occlusion in
one coronary artery, bifurcation or aorto-ostial lesion,
severe tortuosity, lesion length, presence of calcification
or thrombus. All these parameters were assessed for
every individual lesion, the final Syntax score being re-
presented by the sum of individual scores of all coronary
lesions.
According to their Syntax score, patients were divided
into three groups: low risk (Syntax score <22)—12
patients; intermediate risk (Syntax score between 23 and
32)—8 patients, and high risk (Syntax score above 33)—
16 patients.
2.4. Percutaneous Coronary Intervention
All PCI procedures were performed according to stan-
dard practice and the complexity of PCI was retrospec-
tively assessed immediately after the intervention. A
complex PCI was defined when each of the following
parameters were recorded during the procedure: use of
kissing balloon, use of high-pressure balloons or postdi-
latation, radiation time >25 min or usage of >400 ml
contrast media. Complex PCI was required for 20 pa-
tients, while 16 patients underwent non-complex PCI.
The study objectives were as follows:
1) To demonstrate the correlation between CCTA—
derived Syntax score and coronary angiography-derived
Syntax score in significant LM lesions, in the global
population of the study and in the subsets of patients
with low, medium and high risk lesions.
2) To demonstrate the correlation between Ca scoring
determined by CCTA and Syntax score determined by
CCTA and Coronary Angiography.
3) To identify the significant CCTA and angiogra-
phic-derived predictors of complex PCI procedures in
significant LM stenoses.
2.5. Statistical Analysis
All statistical analyses were performed using the Graph
Pad InStat software, version 3.1, (GraphPad software
Inc., San Diego, California, MA, USA). Categorical va-
riables are expressed as percentages. Fisher’s exact test
was used for comparing the categorical variables. Con-
tinuous values are expressed as the mean and standard
deviation, and statistical significance was determined
using the Mann-Whitney test. Multivariate logistic re-
gression was used to assess the predictors for need of
complex PCI intervention. Statistical significance was
considered for a p value <0.05, and all p values were
2-sided.
3. RESULTS
Baseline characteristics of the 36 patients with LM dis-
eased included in the study are listed in Table 1. We
recorded the predominance of gender male (67.4%) and a
significant presence of risk factors: hypertension in
58.3%, hyperlipidemia in 41.6%, diabetes in 33.33% and
smoking in 36.1% of cases. CCTA characteristics at
baseline indicated an average calcium score of 784.9 +/−
77.6 and a mean LM plaque burden of 96.6 +/− 30.0
mm3.
3.1. Correlation between CCTA—Derived
Syntax Score and Coronary
Angiography-Derived Syntax Score in
Significant LM Lesions
There were no significant differences between the mean
Syntax score calculated by angiography and those calcu-
lated by CCTA.
Angio Syntax score was slightly lower than the one
calculated by CCTA in the global population of the study
(29.1 +/− 13.9 versus 31.6 +/− 12.6, p = 0.4), however
this difference was not statistically significant. We per-
Table 1. Baseline characteristics of study population (n = 36).
Characteristic Values n (%)
Age, years 62.9 +/− 9.5
95% CI 59.7 - 69.2
Gender, male 29 (67.4)
Left Ventricular Ejection Fraction 49.2 +/− 7.2
95% CI 46.7 - 51.7
Cardiovascular risk factors
Hypertension 21 (58.3)
Hyperlipidemia 15 (41.6)
Diabetes 12 (33.3)
Smoker* 13 (36.1)
Obesity (BMS > 25 km/m2) 11 (30.5)
CCTA analysis
Calcium scoring 784.9 +/− 77.6
95% CI 627.1 - 942.7
LM plaque burden 224.3 +/− 45.0
95% CI 132.8 - 315.8
*Past or present; Data are represented as mean+/− standard deviation or as
number (percentage).

I. Benedek et al. / World Journal of Cardiovascular Diseases 3 (2013) 573-580 576
formed a subgroup analysis of Angio versus CCTA Syn-
tax score in the subgroups with low, intermediate and
high risk. We found that in the low risk subgroup coro-
nary angiography seems to underestimate the severity of
the lesions as compared to CCTA (Angio Syntax score
13.0 +/− 4.8 compared with CCTA Syntax score 18.9
+/− 7.6, p = 0.03). However, we did not find any statisti-
cally significant difference in Angio versus CCTA Syn-
tax scores for the intermediate risk (28.2 +/− 4.1 vs 30.7
+/− 8.1, p = 0.4) and high risk subgroups (42.4 +/− 5.9 vs
43 +/− 8.2, p = 0.8) Table 2.
Similarly with the observation recorded in the global
population of the study, in all the subgroups the Coro-
nary Angiography Syntax score seems to underestimate
the severity of coronary lesions as compared with CCTA
Syntax score.
Similarly, logistic regression analysis indicated a good
correlation between the Angiography-derived and the
CCTA-derived Syntax scores for the whole group (r =
0.87, p < 0.0001) and for the high risk subgrouo (r = 0.86,
p < 0.0001), but not for the low and intermediate risk (r =
0.38, p = 0.21 and r = 0.62, p = 0.07 respectively) Figure
1.
3.2. Correlation between Ca Scoring Determined
by CCTA and Syntax Score Determined by
CCTA and Coronary Angiography
Calcium score is a CCTA-derived parameter useful for
prediction of coronary lesions severity. We found a good
correlation between the calcium score determined by
CCTA and the Syntax scores, either as determined by
Coronary Angiography (r = 0.72, p < 0.0001) or by
CCTA (r = 0.69, p < 0.0001) Figure 2.
CCTA and angiographic-derived predictors of com-
plex PCI procedures in significant LM stenoses.
Another objective of the study was to identify CCTA
and coronary angiography-derived predictors of complex
PCI procedures. In cases which required complex PCI
procedures, both angiographic and CCTA Syntax score
were significantly higher than in those who did not re-
quire complex revascularization procedures (24.5 +/−
11.5 vs 32.2 +/− 14.6, p = 0.09 for Angio Syntax, 35.3
+/− 11.5 vs 25.2 +/− 11.3, p = 0.01 for CCTA Syntax).
In the same time, Ca scoring was significantly higher and
plaque volumes significantly larger in cases requiring
complex revascularization procedures (299.5 +/− 359.6
vs 917.3 +/− 495.4, p = 0.04 for calcium score, 79.7 +/−
28.5 vs 108.7 +/− 25.3 mm3, p = 0.002 for plaque vol-
umes) (Figure 3).
Figure 4 is an exemplification of a significant LM
stenosis with high calcium content and a large volume
atheromatous plaque in the LM, visualized by 3D CCTA
(A), multiplanar reconstruction CCTA (B) and angiogra-
phic aspect before (C) and after PCI (D), the lesion ap-
pearing much more severe in CCTA than in conventional
angiography.
On the other hand, clinical parameters such as ejection
fraction did not show any statistically significant dif-
ference between the subgroup of patients necessitating
complex PCI procedures and those who did not Table 3.
Multivariate analysis identified the following CCTA-
derived parameters as significant predictors of increased
risk for complex intervention in LM lesions: plaque
volume (Odds Ratio 8.00, p = 0.008), Ca scoring (Odds
Ratio 6.37, p = 0.02) and CCTA Syntax score (Odds
Ratio 6.87, p = 0.01). Angiography-derived Syntax score
Table 2. Low CT-attenuation plaques and IVUS-derived markers of vulnerability in culprit lesions.
Angiographic Syntax score CCTA Syntax score p value
Global population of the study 0.4
Mean +/− SD 29.1 +/− 13.9 31.6 +/− 12.6
95% confidence interval 24.4 - 33.8 27.3 - 35.9
Low risk group (Syntax score < 22), n = 12 0.03
Mean +/− SD 13.0 +/− 4.8 18.9 +/− 7.6
95% confidence interval 9.9 - 16.1 14.1 - 23.7
Medium risk group (Syntax score 23 - 32), n = 8 0.4
Mean +/− SD 28.2 +/− 4.1 30.7 +/− 8.1
95% confidence interval 25.1 - 31.4 24.6 - 37.0
High risk group (Syntax score > 33), n = 16 0.8
Mean +/− SD 42.4 +/− 5.9 43 +/− 8.2
95% confidence interval 39.2 - 45.7 38.5 - 47.5

I. Benedek et al. / World Journal of Cardiovascular Diseases 3 (2013) 573-580 577
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
Angio Syntax
CCTASyntax
34
32
30
28
26
24
22
20
18
16
14
12
10
8
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
r = 0.87
p < 0.0001
CCTASyntax
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54
Angio Syntax
r = 0.38
p = 0.21
(A) (B)
24 25 26 27 28 29 30 31 32 33
Angio Syntax
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
Angio Syntax
CCTASynta
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
r = 0.62
p = 0.07 r = 0.86
p < 0.0001
CCTASyntax
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
(C) (D)
Figure 1. Correlation between angiography-derived and CCTA-derived Syntax scores in the global population (A) and in the low
risk (B), intermediate risk (C) and high risk (D) lesions. (A) Global population of the study; (B) Low risk; (C) Intermediate risk; (D)
High risk.
10 15 20 25 30 35 40 45 50
Angio Syntax
1900
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
r = 0.72
p < 0.0001
Ca scoring
r = 0.69
p < 0.0001
10 15 20 25 30 35 40 45 50
CCTA Syntax
1900
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
Ca scoring
(A) (B)
Figure 2. Correlation between calcium score determined by CCTA and Angio-derived (A) or CCTE-derived (B) Syntax score.
was also associated with a high risk for complex LM
intervention, however with a lower statistical signifi-
cance than the CCTA-derived parameters (Odds Ratio
4.47, p = 0.04) Table 4.
The SYNTAX trial results suggest that CABG remains
the standard of care for patients with complex disease as
expressed by a high Syntax score; however, PCI could
represent a superior alternative for revascularization in
certain subgroup of patients, mainly those with less
complex disease and lower Syntax scores [1,11].
Incorporating the CCTA information into the Syntax
algorythm could provide a more complex set of informa-
tion, thus serving for selection of a more appropriate
therapeutic strategy in complex LM cases. The main ad-
vantage of the CCTA against standard coronary an-
giography is the ability to visualise exactly the extent,
distribution and severity of calcifications at the level of
the lesion, which is of particular importance at the level
of the left main [12]. In the same time, the CCTA tech-
nique provides the unique opportunity of plaque quan-

I. Benedek et al. / World Journal of Cardiovascular Diseases 3 (2013) 573-580 578
45
40
35
30
25
20
15
10
5
0
p = 0.09
24.5
32.3
p
=0.01
35.3
25.2
N
on complex PCI Complex PCI
N
on complex PCI Complex PCI
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
(A) (B)
p = 0.04
599.5
917.3
79.7
108.7
p = 0.002
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
N
on complex PCI Complex PCI
N
on complex PCI Complex PCI
130
120
110
100
90
80
70
60
50
40
30
20
10
0
(C) (D)
Figure 3. Association between the need for complex PCI procedures and Angio Syntax score (A), CCTE Syntax score (B), CCTA
Ca score (C) and Left Main plaque volume (D). (A) Angio Syntax; (B) CCTA Syntax; (C) CCTA Ca score; (D) LM Plaque volume
(mm3).
Figure 4. Significant LM stenosis with high calcium content
and a large volume atheromatous plaque in the LM, visualized
by 3D CCTA (A), multiplanar reconstruction CCTA (B).
Angiographic aspect before (C) and after PCI (D), showing that
the lesion appeares less severe in conventional angiography
than in CCTA, due to the lack of appropriate calcium visua-
lization by angiography. The severity of the lesion is under-
estimate by angiography.
tification, allowing the determination of plaque volume.
LM plaques are usually large volume plaques which
rupture and embolise frequently during the percutaneous
revascularization procedure, therefore the preoperative
assessment of plaque volume by CCTA and characteris-
tics could help to prevent the procedure-related compli-
cations [13,14].
In this study we demonstrated that use of CCTA Syn-
tax score may better stratify the patients with significant
LM stenosis according to their risk than does the stratifi-
cation based only on angiography-derived Syntax score.
We found a good correlation between the angiography
derived and CCTA-derived Syntax scores especially for
cases with high Syntax scores. As in the rest of the cases
angiography seems to underestimate the severity of the
lesions, we can conclude that the incremental role of
CCTA to coronary angiography is more obvious espe-
cially in high risk lesions. These are usually heavily cal-
cified lesions, with high atheromatous burden, coronary
calcification and plaque burden being exactly the pa-
rameters easily assessed by the CCTA [15].
This superior value of CCTA relies mainly in provid-
ing incremental information to coronary angiography

I. Benedek et al. / World Journal of Cardiovascular Diseases 3 (2013) 573-580 579
Table 3. Clinical, CCTA and angiographic parameters for pre-
diction of intervention complexity in LM diseases.
Non Complex
PCI n = 20
Complex PCI
N = 16 p value
Ejection Fraction 0.6
Mean +/− SD 50 +/− 7.9 48.6 +/− 7.2
95% confidence interval 45.6 - 54.4 45.4 - 51.9
Angio Syntax score 0.09
Mean +/− SD 24.5 +/− 11.5 32.3 +/− 14.6
95% confidence interval 18.1 - 30.9 25.7 - 38.9
CCTA Syntax score 0.01
Mean +/− SD 25.2 +/− 11.3 35.3 +/− 11.5
95% confidence interval 18.9 - 31.5 30.1 - 40.5
Ca scoring 0.04
Mean +/− SD 599.5 +/− 359.6 917.3 +/− 495.4
95% confidence interval 400.4 - 798.7 691 - 1142.8
LM plaque volume 0.002
Mean +/− SD 79.7 +/− 28.5 108.7 +/− 25.3
95% confidence interval 63.9 - 95.5 97.2 - 120.2
Table 4. Multivariate predictors of intervention complexity in
patients with left main disease.
Odds Ratio (95% CI) p value
Smoker 0.55 (0.14 - 2.17) 0.5
Diabetes 1.36 (0.35 - 5.21) 0.74
Dyslipidemia 1.65 (0.43 - 6.31) 0.51
Left Ventricular
Ejection Fraction 2.43 (0.62 - 9.47) 0.3
Angio Syntax score 4.47 (1.05 - 18.9) 0.04
CCTA Syntax score 6.87 (1.55 - 30.4) 0.01
Ca scoring 6.37 (1.42 - 28.61) 0.02
LM plaque volume 8.00 (1.68 - 37.9) 0.008
with regard to lesion characterization and complex 3D
visualization of coronary plaques in the same time with
plaque quantification and determination of calcium con-
tent within the coronary arteries [15,16].
In this study we found that the most significant pre-
dictors for complex procedures in LM stenoses were the
CCTA derived parameters: Ca score, CCTA Syntax
score and plaque volume, all of them having a prediction
power superior to the conventional angiography-derived
Syntax score. We found that patients with high calcium
content in the coronary arteries, large volumes of LM
coronary plaques or high Syntax scores by CCTA were
more likely to necessitate a complex PCI procedure, ei-
ther lasting longer than usual or necessitating complex
techniques (bifurcation kissing, postdilatation, high pres-
sure balloons, more contrast, longer X-ray exposure, etc.).
This underlines the role of CCTA in providing complex
information necessary for a complex preprocedural eva-
luation in LM lesions.
3.3. Study Limitations
The CT analysis was not able to distinguish between
different low density components of coronary plaques,
which are considered as markers of vulnerability—low
density atheroma, necrotic core or thrombus. However,
identifying a high burden with coronary plaque signifi-
cantly associated with the need of complex revasculari-
zation procedure, irrespective of the differentiation be-
tween thrombus, necrotic core or very low density cho-
lesterol-rich atheroma. A high calcium score could pre-
clude a good quality CT image and this could be re-
flected in Syntax CCTA calculations. Finally, the num-
ber of patients included in the study is not extensive.
4. CONCLUSIONS
CCTA derived parameters provide incremental informa-
tion to classical coronary angiography for preoperative
assessment of lesion severity in complex left main steno-
sis. CCTA derived Syntax score significantly correlates
with the classical Coronary Angiography Syntax score
and identifies the subgroup of patients who will be more
exposed to procedural complications during the revascu-
larization interventions.
Based on these findings, CCTA could represent a new
noninvasive clinical tool, useful for preoperative evalua-
tion of patient risk and for selection of the best therapeu-
tic strategy in these cases.
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