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Left Anterior Descending Artery Stenosis: The Widow Maker Revisited

      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.
      In the earliest days of interventional cardiology, the proximal left anterior descending artery was an attractive target for a percutaneous-based approach. Access to this region was nontortuous, and visualization was good; thus, even with early equipment, guidewires and balloons could usually be delivered to that segment. Indeed, the first patient who underwent percutaneous transluminal coronary angioplasty (PTCA) in September 1977 had such a lesion and has done well since that time.
      • Giruntzig A
      Transluminal dilatation of coronary-artery stenosis [letter].
      In the more recent era, this lesion site remains attractive for the same reasons, particularly when some of the larger, less-flexible PTCA devices have been employed.
      Cardiovascular surgeons have also been attracted to this anatomical segment, particularly when the left internal mammary artery could be used as a conduit. It has been well documented that the grafting of a patent left internal mammary artery to the left anterior descending artery results in excellent long-term patient survival.
      • Loop FD
      • Lytle BW
      • Cosgrove DM
      • et al.
      Influence of the internal-mammary-artery grall on lt)-year survival and other cardiac events.
      Selection of the “optimal” means of revascularizing this specific segment has generated considerable controversy; while there have been relatively little controlled data, there has been no dearth of opinion. In developing the early Bypass Angioplasty Revascularization Investigation (BARI),
      • Bypass Angioplasty Revascularization Investigation (liARI) Investigators
      Comparison of coronary bypass surgery wilh angioplasty in patients with multivessel disease.
      consideration was given to randomizing patients with an isolated, diseased proximal left anterior descending artery to either surgery or PTCA. This was not believed to be possible at many centers because opinions about the correct approach to treatment were so strongly held. This controversy is associated with the shortcomings of both an interventional approach and a surgical approach because of the improved initial angiographic results.
      From the standpoint of interventional cardiology, with conventional balloon angioplasty, treatment of proximal left anterior descending artery stenosis was associated with increased restenosis rates, the potential for artery dissection, and acute or threatened vessel closure, which may propagate retrogradely to involve the left main coronary artery. Thus, even with conventional balloon angioplasty, a substantial amount of myocardium may remain at risk for ischemic injury. Optimal interventional treatment of this segment has been studied in randomized trials with various approaches, such as directional coronary atherectomy, debulking plus stent implantation, and stent implantation alone.
      • Goy JJ
      • Keckhout K
      • Burnand U
      • et al.
      Coronary angioplasty versus left internal mammary artery grafting for isolated proximal left anterior descending artery stenosis.
      • Versaci F
      • Gaspardone A
      • Tomai F
      • Crea F
      • Chiariello L
      • Gioffre PA
      A comparison of coronary-artery stenting with angioplasty for isolated stenosis of the proximal left anterior descending coronary artery.
      • Topol EJ
      • Leya F
      • Pinkerton CA
      • et al.
      A comparison of directional atherectomy with coronary angioplasty in palients with coronary artery disease.
      • Frierson JH
      • Dimas AP
      • Withlow PL
      • et al.
      Angioplasty of the proximal left anterior descending coronary artery: initial success and long-term follow-up.
      Currently, stent implantation remains the most common approach.
      • Suwaidi J
      • Berger PB
      • Holmes Jr, DR
      Coronary artery stents.
      • Hannan EL
      • Racz MJ
      • Arani DT
      • McCallister HD
      • Walford G
      • Ryan TJ
      A comparison of short- and long-term outcomes for balloon angcoplasty and coronary stent placement.
      From the standpoint of cardiovascular surgery, there are also shortcomings. In some patients, albeit a small number, the left internal mammary artery may not be satisfactory as a conduit. In addition, an operation is a surgical procedure, and some patients would likely want to avoid or postpone surgery. The specific surgical approach has also been controversial-conventional open chest surgery, open chest surgery off pump, or minimally invasive direct coronary artery bypass (MIDCAB).
      • Bonchek LI
      Ullyot DJ. Minimally invasive coronary bypass: a dissenting opinion [editorial].
      In addition to the shortcomings of each approach, controversy also relates to the end points used to compare the 2 revascularization strategies. Potential end points range widely (Table 1). Depending on the specific end point and its importance for the patient, family, and physician, the results of comparing treatment options will vary. For example, if a patient wants to avoid surgery, then treatment with surgery would be an adverse end point. Alternatively, if a patient wants to avoid any repeated procedures, then an initial catheter-based intervention will result in an increase in adverse end points because of restenosis.
      Table 1Potential End Puints for Comparing Revascularization Strategies
      DeathQuality of life
      Myocardial infarctionFunctional class
      Stroke or other central nervous system eventFunctional/stress testing
      Economic cost
      Return to workRepeated hospitali/ation
      Need for repeated proceduresNeed for crossover procedures
      The randomized trial by Goy et al
      • Goy J-U
      • Kaufmann U
      • Goy-Eggenberger D
      • SIMA Investigators
      • et al.
      A prospective randomized trial comparing stenting to internal mammary artery grafting for proximal, isolated de novo left anterior coronary artery stenosis: the SIMA Trial.
      is an important addition to the scientific literature on the treatment of isolated proximal left anterior coronary artery stenosis, in that it compares stent implantation with surgery (including MIDCAB in some patients). In this randomized study of 123 patients, 121 of whom received treatment, the primary end point was a composite of cardiac death, myocardial infarction, and repeated revascularization. Secondary end points included angina functional class, exercise tolerance, quality of life, and drug therapy. Although the study will be completed at the end of 2002, this is an interim 2-year report. Because this study enrolled patients several years ago, it used old equipment including the Palmaz-Schatz stent (Johnson & Johnson, Warren, NJ), and only 6 patients had a MIDCAB procedure. Whether using later generations of stents or enrolling only patients with MIDCAB procedures would have made a significant difference is unclear. Of the 59 patients assigned to surgery, 5 (8%) elected to have stent implantation instead. Of the 62 patients assigned to stent implantation, none crossed over to surgery, although in 1 patient, a stent could not be delivered; this patient was treated with conventional dilation without untoward incident. In-hospital outcome was excellent in both groups: no deaths in the coronary artery bypass grafting group and 1 death in the stent group (2%), and 1 Q-wave infarction in the surgical group (2%) and none in the stent group (neither of which was statistically significant). Minor complications differed, with atrial and ventricular arrhythmias, bleeding, and creatine kinase-MB elevation significantly more frequent in the surgical group.
      The mean ± SD follow-up in the Goy et al study was 2.4±0.9 years. Two deaths occurred in the surgical group. Additional revascularization procedures were necessary in 15 patients (24%) in the stent group. The primary composite end point of cardiac death, myocardial infarction, and repeated revascularization was reached in 19 patients (31%) in the stent group and in 4 (7%) in the surgical group (P<.001). However, the data could be interpreted differently. By the intention-to-treat analysis, in the surgical group, an additional 5 patients (those who were randomized to surgery but declined) required a procedure besides the initial randomized procedure. With this approach, 9 patients (15%) in the surgical group and 19 (31%) in the stent group had an adverse composite primary end point. This narrows the difference between the 2 treatment strategies considerably, but there is still a difference.
      Of the secondary end points measured, including anginal functional class, functional testing, quality of life, and need for antianginal medications, none was significantly different. A discouraging note is that, although lipid-lowering drugs were used in more patients in the stent group, they were used in only 12 (21% of those patients.
      What can be concluded from this trial? (1) In patients with isolated proximal left anterior descending artery stenosis, revascularization with either coronary artery bypass grafting or stenting results in excellent outcome in terms of survival and survival free of myocardial infarction at 2.4 years, as well as excellent relief of angina and improvement in exercise tolerance. (2) Restenosis still remains an issue, although it is less with stenting than with conventional dilation. Continued development of alternative strategies such as brachytherapy or drug-coated stents is still necessary.
      • Goy JJ
      • Keckhout K
      • Burnand U
      • et al.
      Coronary angioplasty versus left internal mammary artery grafting for isolated proximal left anterior descending artery stenosis.
      • Teirstein PS
      • Massullo V
      • Jani S
      • et al.
      Catheter-based radiotherapy to inhibit restenosis after coronary stenting.
      • Herdeg C
      • Oberhoff M
      • Karsch KR
      Antiproliferative stent coatings: tavol and related compounds.
      (3) Despite restenosis, of patients initially treated with stents for proximal left anterior descending artery disease, at 2.4 years of follow-up, 55 (89%) had avoided surgery. (4) Finally, the relative importance of each end point is open to discussion.
      Accordingly, we agree wholeheartedly with the authors that this is a situation in which shared decision making with the patient should be implemented. At the end of the day, either revascularization approach should enable physicians to treat the widow maker and prevent more widows or widowers.

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