In:
Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 116, No. suppl_16 ( 2007-10-16)
Abstract:
Cardiac multi-detector computed tomography (MDCT) with retrospective ECG-gating permits the determination and quantification of coronary calcifications. High calcium scores are known to be associated with elevated all-cause mortality. Moreover, low response to clopidogrel influences cardiovascular outcome after coronary stent placement. We sought to evaluate whether elevated calcium scores are associated with a low response to clopidogrel. Methods 62 patients were enrolled in this trial (52 male, mean age 64.8 ± 8.9 years). Coronary calcium scoring (expressed as Agatston score equivalent, ASE) was measured with multi-slice computed tomography (Sensation 64™ [n=19] and Somatom Definition ™ [n=43], Siemens, Forchheim, Germany) prior to stent implantation. Responsiveness to clopidogrel was assessed by ADP (20 micromol/L)-induced aggregometry at least 6 h after administration of a loading dose of 600 mg clopidogrel. Results Median calcium score was 736 ASE [range 0 –3126] and mean platelet inhibition was 35±19% [range 0 –70] . There was a significant negative correlation between ASE and response to clopidogrel (r 2 =0.135, p=0.0033, slope 7.809 ± 2.549). Patients within the first quartile of ASE had significantly better response to clopidogrel than other patients (p 〈 0.05). Establishing a threshold of 200 ASE responsiveness to clopidogrel could be predicted with a positive predictive value of 80% and a specificity of 91%. Conclusions We could demonstrate that elevated ASE is associated with a low response to clopidogrel. Patients with a low coronary plaque burden are more likely to have a good response to clopidogrel. Coronary calcium scoring might help to identify low responders to clopidogrel prior to stent placement and aggregometry.
Type of Medium:
Online Resource
ISSN:
0009-7322
,
1524-4539
DOI:
10.1161/circ.116.suppl_16.II_612-b
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2007
detail.hit.zdb_id:
1466401-X
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