The SYNTAX score revisited: A reassessment of the SYNTAX score reproducibility

Objectives : To reassess the reproducibility of the SYNTAX score. Background : The SYNTAX score appears to have an important role to play in the evaluation of patients with complex coronary artery disease undergoing revascularisation. However, the calculation of the SYNTAX score relies on the subjective assessment of lesions using coronary angiography, and therefore is subject to intra‐and inter‐observer variability. Methods : The SYNTAX score was calculated in 100 patients randomly selected from the SYNTAX trial, on two occasions 8 weeks apart, by a team made up of three interventional cardiologists. The weighted kappa values were compared with values obtained 1 year previously, when core lab analysts assessed the intra‐observer reproducibility amongst the same patient cohort. Results : The mean ± standard deviation difference in SYNTAX score was 2.1 ± 7.6. The respective weighted kappa values for the number of lesions, bifurcation lesions, ostial lesions, and total occlusions were 0.62, 0.36, 0.66, and 0.91 compared with 0.59, 0.41, 0.63, and 0.82 in the previous core lab assessment. The weighted kappa for the intra‐observer reproducibility of the SYNTAX score grouped into deciles was 0.54, and according to the terciles ≤22, >22–≤32, >32 was 0.51 both indicating a moderate level of agreement beyond the level of chance. In the previous assessment, the comparative kappa values were 0.45 and 0.53. Conclusions : The SYNTAX score has moderate intra‐observer reproducibility when assessed by a team of three interventional cardiologists, which is consistent with a prior evaluation performed by core lab analysts. The scoring of bifurcation lesions remains the main source of inconsistency. © 2009 Wiley‐Liss, Inc.     

Reproducibility of computed tomography angiography data analysis using semiautomated plaque quantification software: implications for the design of longitudinal studies

Reproducibility of the quantitative assessment of atherosclerosis by computed tomography coronary angiography (CTCA) is paramount for the design of longitudinal studies. The purpose of this study was to assess the inter- and intra-observer reproducibility using semiautomated CT plaque analysis software in symptomatic individuals. CTCA was performed in 10 symptomatic patients after percutaneous treatment of the culprit lesions and was repeated after 3 years. The plaque quantitative analysis was performed in untreated vessels with mild-to-moderate atherosclerosis and included geometrical and compositional characteristics using semiautomated CT plaque analysis software. A total of 945 matched cross-sections from 21 segments were analyzed independently by a second reviewer to assess inter-observer variability; the first observer repeated all the analyses after 3 months to assess intra-observer variability. The observer variability was also compared to the absolute plaque changes detected over time. Agreement was evaluated by Bland–Altman analysis and concordance correlation coefficient. Inter-observer relative differences for lumen, vessel, plaque area and plaque burden were 1.2, 0.6, 2.2, 1.6 % respectively. Intra-observer relative differences for lumen, vessel, plaque area and plaque burden were 1.0, 0.4, 0.2, 0.4 % respectively. For the average plaque attenuation values the inter- and intra-observer variability was 5 and 2 % respectively. For the % low-attenuation-plaque the inter- and intra-observer variability was 16 and 6 % respectively. The absolute intra-observer variability for the plaque burden was 1.30 ± 1.09 %, while the temporal plaque burden difference was 3.55 ± 3.02 % (p = 0.001). The present study shows that the geometrical assessment of coronary atherosclerosis by CTCA is highly reproducible within and between observers using semiautomated quantification software and that serial plaque changes can be detected beyond observer variability. The compositional measurements are more variable between observers than geometrical measurements.     

Diagnostic value of stored electrograms in pacemaker patients

OBJECTIVE: Stored electrograms (EGMs) are diagnostic tools in modern pacemakers, providing data concerning arrhythmia occurrence and device function. We sought to validate the impact of stored EGMs on diagnosis and verification of arrhythmias presented after pacemaker implantation. METHODS AND RESULTS: We enrolled 71 consecutive patients (mean age 64 +/- 8 years, 51 men) with a standard indication for pacemaker implantation. The following pacemaker devices were implanted: DDDR = 57, VDDR = 5, VVIR = 9. EGM triggers were atrial tachycardia (AT), non-sustained ventricular tachycardia (NSVT) and ventricular tachycardia (VT). We retrieved and analysed 362 EGMs at 3 and 6 months after implantation. The EGMs were triggered by AT in 260 EGMs (72%), by NSVT in 80 (22%) and by VT in 22 (6%). In total, 243 episodes (67%) confirmed the arrhythmic events, while 119 episodes (33%) were classified as false-positive. They were divided into false-positive AT in 85 EGMs (33%), false-positive NSVT in 28 (35%) and false-positive VT in 6 EGMs (27%). The false-positive AT cases were caused by ventricular far-field sensing from the atrial channel in 34 EGMs (40%) and noise or myopotentials in 51 EGMs (60%). Most of the false-positive VT and NSVT episodes were due to atrial fibrillation or atrial tachycardias in 21 EGMs (62%), while the rest were caused by noise in 11 EGMs (32%) or ventricular T wave oversensing in 2 EGMs (6%). CONCLUSIONS: Stored EGMs in pacemaker patients were diagnostic in two thirds of arrhythmic episodes. They are useful tools to diagnose arrhythmias and identify sensing problems, and they contribute to optimal device programming and patient management.