SYNTAX score reproducibility and variability between interventional cardiologists, core laboratory technicians, and quantitative coronary measurements.
BACKGROUND
In the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) trial, the SYNTAX score was useful in risk stratifying patients with complex coronary artery disease. The reproducibility of this score may affect its clinical utility. We therefore assessed SYNTAX score interobserver and intraobserver variability among a group of interventional cardiologists (ICs) and an experienced group of angiographic core laboratory (ACL) technicians.


RESULTS
After basic training from the SYNTAX score website, 3 ICs and 4 ACL technicians, each working independently, assessed the SYNTAX score of 30 multivessel disease angiograms. The ICs then underwent an intensive training session with ACL technicians, after which the SYNTAX score from 50 additional angiograms were assessed independently by both groups. Interobserver Fleiss κ statistic values were determined. A third assessment was performed using quantitative coronary angiography (QCA). The ACL technician interobserver strength of agreement from both periods was substantial or greater (k=0.82; 95% CI [0.72, 1.00] and 0.84 [0.76, 1.00]) and not different than QCA. The IC interobserver agreement was initially estimated to be at least slight (k=0.33 [0.18, 0.44]), improving to substantial or greater after advanced training (k=0.76 [0.64, 1.00]). Despite advanced training, ICs underscored the number of lesions, bifurcations, and small-vessel disease (P<0.001), resulting in a lower score than ACL technicians (mean difference=7.5, P<0.001).


CONCLUSIONS
Highly reproducible SYNTAX score measurements were quickly achieved by experienced ACL technicians. In contrast, agreement among ICs after the basic tutorial was initially poor but improved considerably after further training with the ACL, although differences still remained in interpretation of several lesion types. These findings have important implications for adoption of SYNTAX score methodology in routine practice and future clinical trials.
Columbia University Medical Center and the Cardiovascular Research Foundation, 111 E 59th Street, New York, NY 10022, USA.
Philippe
P
Généreux
Tullio
T
Palmerini
Adriano
A
Caixeta
Ecaterina
E
Cristea
Roxana
R
Mehran
Raquel
R
Sanchez
Dana
D
Lazar
Ivana
I
Jankovic
Maria D
MD
Corral
Ovidiu
O
Dressler
Martin P
MP
Fahy
Helen
H
Parise
Alexandra J
AJ
Lansky
Gregg W
GW
Stone
D002309:Cardiology; D002983:Clinical Competence; D003200:Computer User Training; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000145:classification* / Q000175:diagnosis / Q000000981:diagnostic imaging*; D006801:Humans; D059232:Laboratory Personnel; D015588:Observer Variation; D011379:Prognosis; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013038:Specialization