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.)
Department of Cardiology, Center for Medical Research and Information, University of Ulsan College of Medicine, Seoul, South Korea.
Seung-Jung
SJ
Park
Duk-Woo
DW
Park
Young-Hak
YH
Kim
Soo-Jin
SJ
Kang
Seung-Whan
SW
Lee
Cheol Whan
CW
Lee
Ki-Hoon
KH
Han
Seong-Wook
SW
Park
Sung-Cheol
SC
Yun
Sang-Gon
SG
Lee
Seung-Woon
SW
Rha
In-Whan
IW
Seong
Myung-Ho
MH
Jeong
Seung-Ho
SH
Hur
Nae-Hee
NH
Lee
Junghan
J
Yoon
Joo-Young
JY
Yang
Bong-Ki
BK
Lee
Young-Jin
YJ
Choi
Wook-Sung
WS
Chung
Do-Sun
DS
Lim
Sang-Sig
SS
Cheong
Kee-Sik
KS
Kim
Jei Keon
JK
Chae
Deuk-Young
DY
Nah
Doo-Soo
DS
Jeon
Ki Bae
KB
Seung
Jae-Sik
JS
Jang
Hun Sik
HS
Park
Keun
K
Lee
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