title: Elevated coronary calcium scores are associated with higher residual platelet aggregation after clopidogrel treatment in patients with stable angina pectoris.
abstract: 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.
authors.forename: Christof
authors.initials: C
authors.lastname: Burgstahler
authors.forename: Tobias
authors.initials: T
authors.lastname: Geisler
authors.forename: Stephan
authors.initials: S
authors.lastname: Lindemann
authors.forename: Harald
authors.initials: H
authors.lastname: Brodoefel
authors.forename: Anja
authors.initials: A
authors.lastname: Reimann
authors.forename: Martin
authors.initials: M
authors.lastname: Heuschmid
authors.forename: Meinrad
authors.initials: M
authors.lastname: Gawaz
authors.forename: Stephen
authors.initials: S
authors.lastname: Schroeder
mesh_terms: 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
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D002118:Calcium