Stent Restenosis Study I - STRESS I


Stenting vs. PTCA for angiographic restenosis in CAD.


Stents may reduce the chance of restenosis by decreasing the elastic recoil of the vessel and sealing intimal flaps, thus providing a wider, smoother coronary lumen.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 410
Mean Follow Up: 6 months
Mean Patient Age: 60
Female: 22
Mean Ejection Fraction: 61 ±12 (stent); 61 ±11 (PTCA)

Patient Populations:

Symptomatic ischemic heart disease and new lesions of the native coronary circulation
≥70% stenosis
Lesion <15 mm in length and could be spanned by a single stent
Vessel diameter of at least 3.0 mm


Myocardial infarction (MI) within the previous seven days

Contraindication to aspirin, dipyridamole, or warfarin sodium

Left ventricular ejection fraction of 40% or less

Angiographic evidence of the following:
coronary thrombus, presence of multiple focal lesions
diffuse disease
serious disease in the left main coronary artery
ostial lesions
severe vessel tortuosity

Primary Endpoints:

Angiographic evidence of restenosis, defined as at least 50% stenosis on the follow-up angiogram.

Secondary Endpoints:

Angiographic endpoints included evidence of procedural success and the absolute minimal luminal diameter after the procedure and at follow-up. (Success was defined as a reduction in stenosis to 50% or less, by quantitative analysis.)

Clinical endpoint was a composite endpoint and defined as whichever of the following occurred first: death, MI, coronary bypass surgery, or the need for a repeat PTCA within the first 6 months (±60 days) after the initial revascularization.

Drug/Procedures Used:

Stent placement, PTCA

Concomitant Medications:

Nonenteric aspirin, 325 mg/day; dipyridamole, 75 mg tid; treatment with a calcium-channel antagonist initiated at least 24 hours before the procedure; low-molecular weight dextran 40, IV dose of 100 mL /hour for two hours before stenting and at a dose of 50 mL/hour during and after the procedure (for a total volume of 1 liter); heparin, initial bolus injection of 10,000 to 15,000 U during the procedure and supplemented as needed to maintain an activated clotting time of more than 300 seconds; warfarin sodium and heparin, until a prothrombin time of 16 to 18 seconds was achieved (international normalized ratio, 2.0 to 3.5

Principal Findings:

The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 ±0.46 vs. 1.23 ±0.48 mm, P <0.001), and a larger luminal diameter immediately after the procedure (2.49 ±0.43 vs. 1.99 ±0.47 mm, P < 0.001).

At six months, the patients with stented lesions continued to have a larger luminal diameter (1.74 ±0.60 vs. 1.56 ±0.65 mm, P = 0.007) and a lower rate of restenosis (31.6 percent vs. 42.1 percent, P = 0.046) than those treated with balloon angioplasty.

There were no coronary events (death; myocardial infarction; coronary-artery bypass surgery; vessel closure, including stent thrombosis; or repeated angioplasty) in 80.5 percent of the patients in the stent group and 76.2 percent of those in the angioplasty group (P = 0.16).

Revascularization of the original target lesion because of recurrent myocardial ischemia was performed less frequently in the stent group than in the angioplasty group (10.2 percent vs. 15.4 percent, P = 0.06).

At 1 year, 154 patients (75%) assigned to stent implantation and 141 (70%) to PTCA were free of all clinical events (death, myocardial infarction, or any revascularization procedure), and 162 stent patients (79%) and 149 PTCA patients (74%) were free from death, myocardial infarction, or target lesion revascularization.


In selected patients, placement of an intracoronary stent, as compared with balloon angioplasty, results in an improved rate of procedural success, a lower rate of angiographically detected restenosis, a similar rate of clinical events after six months, and a less frequent need for revascularization of the original coronary lesion.


1. N Engl J Med 1994;331:496-501. Final results
2. Am J Cardiol 1998;81:860-5. 1-year follow-up
3. J Am Coll Cardiol 1998;31:307-11. Small vessel subgroup

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Cardiac Surgery, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, EP Basic Science, Aortic Surgery, Cardiac Surgery and Arrhythmias, Lipid Metabolism, Statins

Keywords: Myocardial Infarction, Warfarin, Heparin, Coronary Circulation, Constriction, Pathologic, Dextrans, Angioplasty, Balloon, Coronary, Stents, International Normalized Ratio, Calcium Channels, Prothrombin Time, Thrombosis, Coronary Artery Bypass, Dipyridamole

< Back to Listings