An angiographic tool grading the complexity of coronary artery disease A semiquantitative visual score that will help us to be aware of the anatomical.

SYNTAX SCORE An angiographic tool grading the

complexity of coronary artery disease A semiquantitative visual score that will

help us to be aware of the anatomical complexity and to anticipate procedural difficulties

One drawback in these comparisons is that there is heterogencity in the complexity of CAD of the patients enrolled.

Absence of grading of severity of CAD and lack of comparison of lesion complexity between various groups severely limits the interpretation of results.

For example pts with distal LM trifurcation disease with occluded RCA is pooled together as TVD with patients with 3 focal lesions in midportion of the 3 coronary arteries.

The first has a greater therapeutic challenge for PCI and both have completely different prognosis regardless of revascularisation.

SYNTAX TRIAL SYNTAX (Synergy between PCI with

TAXUS stent and cardiac surgery) trial was organised for patients with significant lesion in LM and /or TVD.

The syntax score has been used in this study to categorize the coronary vasculature with respect to the number of lesions their functional impact,location and complexity.

The SYNTAX score has been developed based on the following:

1. The AHA classification of the coronary tree segments modified for the ARTS study

2. The Leaman score 3. The ACC/AHA lesions classification system 4. The total occlusion classification system 5. The Duke and ICPS classification systems

for bifurcation lesions 6. Consultation of experts

AHA DEFINITION OF CORONARY TREE SEGMENTS

Arterial tree is divided into 16 segments This system has been adopted for the

syntax scoring.

LEAMAN SCORE Based on severity of luminal diameter

narrowing Weighed according to usual blood flow

to LV by each vessel

SEVERITY OF LUMINAL DIAMETER NARROWING significant lesion-50% reduction in

lumen diameter by visual assessment in vessels >1.5mm in diameter.

Less severe lesions not included Percent diameter stenosis is not

included Only occlusive lesions (100% stenosis)-

MF 5 And non occlusive lesions (50-99%

stenosis)-MF 2

In right dominant system -RCA supplies 16% -LCA supplies 84% of flow to LV Of the 84%,66% is by LAD and 33% by

LCX. The LM supplies approximately 5

times ,the LAD app.3.5 times and LCX app.1.5 times blood as the RCA to the LV.

For left dominant system -LM supplies 100%(hence

multiplication factor 6) -LAD 58% (MF-3.5) -LCX 42% (MF-2.5) The contribution is used as a

multiplication factor

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ACC/AHA LESION CLASSIFICATION SYSTEM Type A (high success ,low risk) Type B (mod success ,mod risk) Type C (low success ,high risk)

TOTAL OCCLUSION CLASSIFICATION SYSTEM No antegrade flow is visible distal to

lesion Distal segments may be filled via

bridging ,ipsilateral or contralateral collaterals.

Parameters included are -Age of occlusion -blunt stump -presence of bridging collaterals -presence of side branch -occlusion length

DUKE AND ICPS BIFURCATION LESION CLASSIFICATION Defined as junction of main vessel and a

side branch (1.5mm) Not involving ostium(A,B,C) Involving ostium(D,E,F,G)

DUKE AND ICPS BIFURCATION LESION CLASSIFICATION

BIFURCATION SEGMENTS 5/6/11 6/7/9 7/8/10 11/13/12a 13/14/14a 3/4/16 13/14/15

TRIFURCATION SEGMENTS 3/4/16/16a 5/6/11/12 11/12a/12b/13 6/7/9/9a 7/8/10/10a

DEFINITIONS Aorto ostial: A lesion is classified as aorto-

ostial when it is located immediately at the origin of the coronary vessels from the aorta (applies only to segments 1 and 5, or to 6 and 11 in case of double ostium of the LCA).

Severe tortuosity: One or more bends of 90° or more, or three or more bends of 45° to 90° proximal of the diseased segment.

Length >20mm: Estimation of the length of that portion of the stenosis that has ≥ 50% reduction in luminal diameter in the projection where the lesion appears to be the longest. (In case of a bifurcation lesion at least one of the branches has a lesion length of >20mm).

DEFINITIONS Heavy calcification: Multiple

persisting opacifications of the coronary wall visible in more than one projection surrounding the complete lumen of the coronary artery at the site of the lesion.

Thrombus: Spheric, ovoid or irregular intraluminal filling defect or lucency surrounded on three sides by contrast medium seen just distal or within the coronary stenosis in multiple projections

SCORING METHOD The SYNTAX score is lesion based A separate number calculated per lesion is

Summed to generate the total SYNTAX score Questions 1-3: determine dominance, total

no. of lesions(max.12) and vessel segments/lesion

Questions 4-12: detail adverse lesion characteristics; are repeated for each lesion.

The SYNTAX score is calculated after answering a set of sequential, interactive self-guided questions

LIMITATION Does not entail any clinical variable Comorbidities are known to impact early

outcomes of patients undergoing revascularisation.

Hence limited use in guiding decision making between CABG and PCI.

Relies on pure visual interpretation of lesion severity and subjective variables.

SYNTAX DERIVED SCORES

CLINICAL SYNTAX SCORE Syntax score + Age Creatinine EF

SYNTAX SCORE II Anatomical syntax score Age Creatinine clearance LVEF ULMCA Peripheral Vascular Disease Female sex COPD

EURO SCORE-EUROPEAN SYSTEM FOR CARDIAC OPERATIVE RISK EVALUATION

broadly accepted instrument to help predict early outcomes in patients who undergo coronary artery bypass grafting (CABG).

MACCE to 5 years by Syntax Score Tercile

Left Main Disease

CABGPCI or CABG

PCI or CABG

CONCLUSIONThe SYNTAX population represents the

most complex patients ever studied for PCI in a randomised trial.

The more complex patients are better treated by CABG, but PCI is an acceptable alternative for those with less complex disease(ie, SYNTAX Scores 22 or less).

CONCLUSION The SYNTAX score is a new, innovative tool

to describe the complexity of vasculature The raw SYNTAX score is a good predictor

of MACE PCI patients with lower raw SYNTAX scores

have similar 12-month MACE rates to CABG patients.

Increasing SYNTAX scores (and lesion complexity) are related to increased adverse outcomes in PCI, whereas outcomes of CABG are independent of SYNTAX score.

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