Intracoronary Stenting and Antithrombotic Regimen Trial - ISAR


Antiplatelet vs. anticoagulant therapy following intracoronary stenting.


To compare antiplatelet therapy with conventional anticoagulation following intracoronary stenting.

Study Design

Study Design:

  • Randomized

Patients Enrolled: 602
Mean Follow Up: 1 year
Mean Patient Age: Mean age 67 years
Female: 24

Patient Populations:

Successful PTCA and intracoronary stent placement
No absolute indication for anticoagulant therapy


Contraindications to the use of aspirin, ticlopidine, or phenprocoumon
Pastients receiving stents as bridge to CABG
Cardiogenic shock
Need for mechanical ventilation before undergoing PTCA

Primary Endpoints:

Cardiac: Composite death from cardiac causes, myocardial infarction, bypass surgery, or repeat angioplasty
Noncardiac: Death from noncardiac causes, cerebrovascular accident, severe hemorrhage, and peripheral vascular events

Secondary Endpoints:

Any cardiac or noncardiac event

Drug/Procedures Used:

Ticlopidine/Aspirin or heparin/phenprocoumon/aspirin

Concomitant Medications:

Heparin and aspirin prior to PTCA

Principal Findings:

Of the 257 patients assigned to antiplatelet therapy, 1.6% reached a primary cardiac endpoint compared to 6.2% of the 260 patients assigned to anticoagulant therapy (relative risk 0.25, 95% CI, 0.06 to 0.77).

A primary noncardiac endpoint was reached by 1.2% of patients on antiplatelet therapy compared to 12.3% of patients on anticoagulant therapy (relative risk 0.09; 95% CI, 0.02 to 0.31.)

The cumulative rate of any cardiac or noncardiac event was significantly lower for patients receiving antiplatelet therapy. Among the patients given antiplatelet therapy, the last event occurred on day 7, while complications continued to occur throughout the 30-day follow-up period for the anticoagulated group.


Combined antiplatelet therapy after the placement of intracoronary stents reduces the incidence of cardiac and hemorrhagic events. The adoption of warfarin following intracoronary stenting was done on an empiric basis; ISAR and other randomized trials of antiplatelet therapy have directed clinical practice away from routine post-stent anticoagulation.


1. N Engl J Med 1996;334:1084-9. Final results

Clinical Topics: Anticoagulation Management, Invasive Cardiovascular Angiography and Intervention

Keywords: Risk, Follow-Up Studies, Platelet Aggregation Inhibitors, Phenprocoumon, Warfarin, Heparin, Coronary Disease, Ticlopidine, Stents

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