Duration of dual antiplatelet therapy after implantation of drug-eluting stents.
BACKGROUND
The potential benefits and risks of the use of dual antiplatelet therapy beyond a 12-month period in patients receiving drug-eluting stents have not been clearly established.


METHODS
In two trials, we randomly assigned a total of 2701 patients who had received drug-eluting stents and had been free of major adverse cardiac or cerebrovascular events and major bleeding for a period of at least 12 months to receive clopidogrel plus aspirin or aspirin alone. The primary end point was a composite of myocardial infarction or death from cardiac causes. Data from the two trials were merged for analysis.


RESULTS
The median duration of follow-up was 19.2 months. The cumulative risk of the primary outcome at 2 years was 1.8% with dual antiplatelet therapy, as compared with 1.2% with aspirin monotherapy (hazard ratio, 1.65; 95% confidence interval [CI], 0.80 to 3.36; P=0.17). The individual risks of myocardial infarction, stroke, stent thrombosis, need for repeat revascularization, major bleeding, and death from any cause did not differ significantly between the two groups. However, in the dual-therapy group as compared with the aspirin-alone group, there was a nonsignificant increase in the composite risk of myocardial infarction, stroke, or death from any cause (hazard ratio, 1.73; 95% CI, 0.99 to 3.00; P=0.051) and in the composite risk of myocardial infarction, stroke, or death from cardiac causes (hazard ratio, 1.84; 95% CI, 0.99 to 3.45; P=0.06).


CONCLUSIONS
The use of dual antiplatelet therapy for a period longer than 12 months in patients who had received drug-eluting stents was not significantly more effective than aspirin monotherapy in reducing the rate of myocardial infarction or death from cardiac causes. These findings should be confirmed or refuted through larger, randomized clinical trials with longer-term follow-up. (ClinicalTrials.gov numbers, NCT00484926 and NCT00590174.)
Park
Seung-Jung
SJ
Department of Cardiology, Center for Medical Research and Information, University of Ulsan College of Medicine, Seoul, South Korea.
Park
Duk-Woo
DW
Kim
Young-Hak
YH
Kang
Soo-Jin
SJ
Lee
Seung-Whan
SW
Lee
Cheol Whan
CW
Han
Ki-Hoon
KH
Park
Seong-Wook
SW
Yun
Sung-Cheol
SC
Lee
Sang-Gon
SG
Rha
Seung-Woon
SW
Seong
In-Whan
IW
Jeong
Myung-Ho
MH
Hur
Seung-Ho
SH
Lee
Nae-Hee
NH
Yoon
Junghan
J
Yang
Joo-Young
JY
Lee
Bong-Ki
BK
Choi
Young-Jin
YJ
Chung
Wook-Sung
WS
Lim
Do-Sun
DS
Cheong
Sang-Sig
SS
Kim
Kee-Sik
KS
Chae
Jei Keon
JK
Nah
Deuk-Young
DY
Jeon
Doo-Soo
DS
Seung
Ki Bae
KB
Jang
Jae-Sik
JS
Park
Hun Sik
HS
Lee
Keun
K
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001241:Aspirin / Q000008:administration & dosage*; D000077144:Clopidogrel; D003327:Coronary Disease / Q000401:mortality / Q000628:therapy*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D054855:Drug-Eluting Stents; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D016016:Proportional Hazards Models; D019233:Retreatment; D020521:Stroke / Q000453:epidemiology; D013927:Thrombosis / Q000517:prevention & control; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin