Mayo Clinic Proceedings Home

A Prospective Randomized Trial Comparing Stenting to Internal Mammary Artery Grafting for Proximal, Isolated De Novo Left Anterior Coronary Artery Stenosis: The SIMA Trial


      To compare coronary artery bypass grafting (CABG) with percutaneous transluminal coronary angioplasty (PTCA) in patients with proximal, isolated de novo left anterior descending coronary artery disease and left ventricular ejection fraction of 45%.


      In the multicenter Stenting vs Internal Mammary Artery (SIMA) study, patients were randomly assigned to PTCA and stent implantation or to CABG (using the internal mammary artery). The primary clinical composite end point was event-free survival, including death, myocardial infarction, and the need for additional revascularization. Secondary end points were functional class, antianginal treatment, and quality of life. Analyses were by intention to treat.


      Of 123 patients who accepted randomization, 59 underwent CABG, and 62 were treated with stent implantation (2 patients were excluded because of protocol violation). At a mean ± SD follow-up of 2.4±o.9 years, a primary end point had occurred in 19 patients (31%) in the stent group and in 4 (7%) in the CABG group (P<.OOI). This significant difference in clinical outcome is due to a higher incidence of additional revascularization in the stent group, the incidence of death and myocardial infarction being similar (7% vs 7%, respectively; P=.90). The functional class, need for antianginal drug, and quality-of-life assessment showed no significant differences.


      Both stent implantation and CABG are safe and highly effective treatments to relieve symptoms in patients with isolated, proximal left anterior descending coronary artery stenosis. Both are associated with a low and comparable incidence of death and myocardial infarction. However, similar to PTCA alone, a percutaneous approach using elective stent placement remains hampered by a higher need for repeated intervention because of restenosis.
      CABG (coronary artery bypass grafting), CCS (Canadian Cardiovascular Society), CK (creatine kinase), IMA (internal mammary artery), LAD (left anterior descending), PTCA (percutaneous trans luminal coronary angioplasty), SF -36 (Medical Outcomes Study 36-Item Short-Form Health Survey)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Mayo Clinic Proceedings
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • RITA Trial Participants
        Coronary angioplasty versus coronary artery bypass surgery: the Randomised Intervention Treatment of Angina (RITA) trial..
        Lancet. 1993; 341: 573-580
        • King III, SB
        • Lembo NJ
        • Weintraub WS
        • et al.
        Emory Angioplasty Versus Surgery Trial (EAST). A randomized trial comparing coronary angioplasty with coronary bypass surgery.
        N Engl J Med. 1994; 331: 1044-1050
        • Hamm CW
        • Reimers J
        • Ischinger T
        • Rupprecht H-J
        • Berger J
        • Bleifeld W
        • German Angioplasty Bypass Surgery Investigation
        A randomized study of coronary angioplasty compared with bypass surgery in patients with symptomatic multivessel coronary disease.
        N Engl J Med. 1994; 331: 1037-1043
        • CABRI Trial Participants
        First-year results of CABRI (Coronary Angioplasty Versus Bypass Revascularisation Investigation).
        Lancet. 1995; 346: 1179-1-111184
        • Hueb HA
        • Bellotti G
        • de Oliveira SA
        • et al.
        The Medicine. Angioplasty or Surgery Study (MASS): a prospective, randomized trial of medical therapy, balloon angioplasty or bypass surgery for single proximal left anterior descending artery stenoses.
        J Am Coll Cardiol. 1995; 26: 1600-1605
        • Bypass Angioplasty Revascularization Investigation (BARI) Investigators
        Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease.
        N Engl J Med. 1996; 335: 217-225
        • Rodriguez A
        • Mele E
        • Peyregne E
        • et al.
        ERACI Investigators. Three-year follow-up of the Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Arter Bypass Surgery in Multivessel Disease (ERACI).
        J Am Coll Cardial. 1996; 27: 1178-1184
        • Goy JJ
        • Eeckhout E
        • Burnand B
        • et al.
        Coronary angioplasty versus left internal mammary artery grading for isolated proximal left anterior descending artery stenosis.
        Lancel. 1994; 343: 1449-1453
        • Serruys PW
        • de Jaegere P
        • Kiemeneij D
        • Henestent Study Group
        • et al.
        A comparison of balloon-expandable stent implantation with balloon angioplasty in patients with coronary artery disease.
        N Engl J Med. 1994; 331: 489-495
        • Fischman DL
        • Leon MB
        • Baim DS
        • Stern Restenosis Study Investigators
        • et al.
        A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary artery disease.
        N Engl J Med. 1994; 331: 496-501
        • Campeau J
        Letter: grading of angina pectoris.
        Circulation. 1976; 54: 522-523
        • Spertus JA
        • Winder JA
        • Dewhurst TA
        • et al.
        Development and evaluation of the Seattle. Angina Questionnaire: a new functional status measure for coronary artery disease.
        J Am Coll Cardiol. 1995; 25: 333-341
        • Ware Jr, JE
        • Snow KK
        • Kosinski M
        • Gandek B
        SF-36 Health Survey: Manual and Interpretation Guide. The Health Institute. New England Medical Center, Boston. Mass1993
        • Loop FD
        • Lytle BW
        • Cosgrove DM
        • et al.
        Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events.
        N Engl J Med. 1986; 314: 1-6
        • Bonchek LI
        Hllyot D.J. Minimally invasive coronary bypass: a dissenting opinion [editorial].
        Circulation. 1998; 98: 495-497
        • Hennessy TG
        • Codd MB
        • Donnelly S
        • et al.
        long-term outcome following coronary artery bypass grading for isolated stenosis of the left anterior descending coronary arten.
        Eur Heart J. 1998; 19: 447-457
        • Frierson JH
        • Dimas AP
        • Whitlow PL
        • et al.
        Angioplasty of the proximal left anterior descending coronary artery: initial success and long-term follow -up.
        J Am Coll Cardiol. 1992; 19: 745-751
        • Topol EJ
        • Leya E
        • Pinkerton CA
        • et al.
        CAVEAT Study Group. A comparison of directional atherectomy with coronary angioplasty in patients with coronary artery disease.
        N Engl J Med. 1993; 329: 221-227
        • Versaci F
        • Gaspardone A
        • Tomai F
        • Créa E
        • Chiariello L
        • Gioffre PA
        A comparison of coronary-artery stenting with angioplasty for isolated stenosis of the proximal left anterior descending coronary artery.
        N Engl J Med. 1997; 336: 817-822

      Linked Article

      • Left Anterior Descending Artery Stenosis: The Widow Maker Revisited
        Mayo Clinic ProceedingsVol. 75Issue 11
        • Preview
          Stenosis of the proximal left anterior descending artery is regarded with considerable anxiety by patients, physicians, and surgeons alike. The appellation widow maker, which has been applied to this lesion (in part because of the large amount of myocardium that the left anterior descending artery supplies and its proximity to the distal left main coronary artery), has done nothing to allay this anxiety.
        • Full-Text
        • PDF