Elevated coronary calcium scores are associated with higher residual platelet aggregation after clopidogrel treatment in patients with stable angina pectoris.
High coronary 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 measured by cardiac computed tomography are associated with a higher residual platelet aggregation (RPA) after treatment with clopidogrel. Thus, in 62 patients coronary calcium scoring was measured prior to stent implantation. RPA was assessed by ADP (20 micromol/L)-induced aggregometry at least 6 h after administration of a loading dose of 600 mg clopidogrel. We found a significant correlation between ASE and RPA (r2 = 0.135, p = 0.0033, slope 7.809 +/- 2.549). Patients within the first quartile of ASE had significantly lower RPA after administration of 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%. In conclusion, we could demonstrate that patients with a low coronary plaque burden are more likely to have low RPA. Coronary calcium scoring might help to identify low responders to clopidogrel prior to stent placement and aggregometry.
Burgstahler
Christof
C
Geisler
Tobias
T
Lindemann
Stephan
S
Brodoefel
Harald
H
Reimann
Anja
A
Heuschmid
Martin
M
Gawaz
Meinrad
M
Schroeder
Stephen
S
D000368:Aged; D000787:Angina Pectoris / Q000188:drug therapy* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D000077144:Clopidogrel; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects* / Q000502:physiology; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D002118:Calcium