Correspondence
Coronary-Stent Placement Compared with Balloon Angioplasty
N Engl J Med 1995; 332:536-538February 23, 1995
- Article
To the Editor:
The Benestent1 and Stent Restenosis (STRESS)2 studies (Aug. 25 issue) raise important questions about strategies for coronary-stent placement. Should coronary stents be considered for all patients with new focal lesions in large coronary arteries that have a high likelihood of dissection,3 or should they be used only on a conditional basis if balloon angioplasty does not achieve the desired degree of dilation?
Although the randomized studies1,2 showed that coronary-stent placement reduced the rate of clinical restenosis, the only component of the composite end point that was favorably affected was the need for a second intervention involving the original coronary lesion. Coronary-stent placement did not reduce the risk of death or major complications such as myocardial infarction, because stent thrombosis occurred in 3 to 4 percent of patients up to two weeks after treatment and was usually associated with death or myocardial infarction. Other drawbacks of coronary-stent placement included major hemorrhage in 7 to 14 percent of patients1,2 and rates of angiographic restenosis1,2 that fell short of the values needed to produce a cost savings.4
An intraprocedural strategy of conditional stent placement for patients with stenoses of more than 25 to 30 percent after balloon angioplasty should be considered. Such a strategy is reasonable because dilation with balloon angioplasty is required in all patients before they undergo coronary-stent placement, and the rate of angiographic restenosis depends on the luminal diameter at the time of the procedure, not on the dilating procedure itself.2,5 If dilation with balloon angioplasty can achieve a “stent-like” result, the benefits of a large postprocedural luminal diameter should be conferred without the need for coronary-stent placement. The safety of the conditional approach is suggested by the results of the Benestent study, in which no complications occurred in patients undergoing elective bypass surgery who underwent bailout coronary-stent placement after failed balloon angioplasty.1
5 ReferencesJohn A. Bittl, M.D.
Brigham and Women's Hospital, Boston, MA 021151
Serruys PW ,de Jaegere P ,Kiemeneij F , 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
Full Text | Web of Science | Medline2
Fischman DL ,Leon MB ,Baim DS , 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
Full Text | Web of Science | Medline3
Topol EJ . Caveats about elective coronary stenting. N Engl J Med 1994;331:539-541
Full Text | Web of Science | Medline4
Cohen DJ ,Breall JA ,Ho KK , et al. Evaluating the potential cost-effectiveness of stenting as a treatment for symptomatic single-vessel coronary disease: use of a decision-analytic model. Circulation 1994;89:1859-1874
Web of Science | Medline5
Kuntz RE ,Gibson CM ,Nobuyoshi M ,Baim DS . Generalized model of restenosis after conventional balloon angioplasty, stenting and directional atherectomy. J Am Coll Cardiol 1993;21:15-25
CrossRef | Web of Science | Medline
To the Editor:
The two recently published studies comparing the implantation of a Palmaz–Schatz stent and balloon angioplasty are the first major studies to demonstrate a favorable effect on restenosis.1,2 Although the authors correctly qualify the generalizability of the results, they do not address two important issues.
First, as the accompanying editorial suggests,3 information on the timing of restenosis after stenting is incomplete as compared with what is known about events after balloon angioplasty. The serial angiographic study of Nobuyoshi et al.4 established that only 6 percent of cases of restenosis after balloon angioplasty occur after six months. The trials of stenting ended their follow-up at seven months1 and six months2 and would have missed a delayed process of renarrowing after stent placement if such a process indeed occurred.
Second, neither study was designed to examine the issue of the care of patients in whom restenosis develops after the index procedure. It has been shown that second balloon angioplasties for restenotic lesions after angioplasty are exceptionally safe, with a lower risk than first-time procedures and an acceptable rate of restenosis (31 percent).5 Early data, however, suggest that the management of restenotic lesions in a stent may be problematic, since the incidence of restenosis after balloon angioplasty of such lesions is possibly as high as 54 percent.6
Until information based on longer follow-up is available from these two excellent studies,1,2 the use of elective stent implantation as a general approach to the treatment of new native coronary-artery lesions does not seem justified.
6 ReferencesLeonard Schwartz, M.D.
Toronto Hospital, Toronto, ON M5G 2C4, Canada1
Serruys PW ,de Jaegere P ,Kiemeneij F , 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
Full Text | Web of Science | Medline2
Fischman DL ,Leon MB ,Baim DS , 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
Full Text | Web of Science | Medline3
Topol EJ . Caveats about elective coronary stenting. N Engl J Med 1994;331:539-541
Full Text | Web of Science | Medline4
Nobuyoshi M ,Kimura T ,Nosaka H , et al. Restenosis after successful percutaneous transluminal coronary angioplasty: serial angiographic follow-up of 229 patients. J Am Coll Cardiol 1988;12:616-623
Web of Science | Medline5
Black AJ ,Anderson HV ,Roubin GS ,Powelson SW ,Douglas JS Jr ,King SB III . Repeat coronary angioplasty: correlates of a second restenosis. J Am Coll Cardiol 1988;11:714-718
CrossRef | Web of Science | Medline6
Baim DS ,Levine MJ ,Leon MB ,Levine S ,Ellis SG ,Schatz RA . Management of restenosis within the Palmaz-Schatz coronary stent (the U.S. multicenter experience). Am J Cardiol 1993;71:364-366
CrossRef | Web of Science | Medline
Author/Editor Response
The authors reply:
To the Editor: By the time the results of large trials such as the Benestent and STRESS studies are published, their clinical implications are already to some extent obsolete, and interventional practice and the care of patients have evolved substantially. The reported limitations and drawbacks of coronary stenting as done in our study are fully appreciated and acknowledged by the Benestent investigators, as well as by Dr. Bittl.
In order to reduce the incidence of adverse events associated with elective stenting, Dr. Bittl proposes that stent placement should be performed only in selected patients — those in whom primary balloon angioplasty fails1,2 or does not result in an optimal residual luminal diameter.1,2 Such an intraprocedural strategy of conditional stenting is not without merit and was indeed used for patients in Benestent who were randomly assigned to the balloon-angioplasty group. In accordance with the recommendations of the reviewers and the editors of the Journal, a crossover to bailout stenting was not counted as a clinical event but, rather, was deemed to be an integral component of the balloon-angioplasty package. Thus, it may be considered that as reported, Benestent has already demonstrated that the primary strategy of elective stenting is superior to that of elective balloon angioplasty with the option of bailout stenting.
The specific residual stenosis (10 percent, 20 percent, 30 percent, or 35 percent of the diameter, or some other value) after primary balloon angioplasty at which conditional stenting should be considered would be difficult to determine in the context of a prospective trial with on-line quantitative coronary angiography.3 Dr. Bittl's proposal of relying on the achievement of a large luminal diameter by balloon angioplasty suggests that he does not believe that stenting works by preventing restenosis — an opinion to which we do not subscribe.4,5
Rather than withhold elective stent placement from patients undergoing angioplasty, the Benestent investigators are attempting to reduce the incidence of stent-related adverse events by incorporating a heparin coating on the stent and replacing the combination of anticoagulant drugs (heparin and coumadin) by a combination of platelet-antiaggregatory drugs (ticlopidine and aspirin) in Benestent II. In so doing, we anticipate that the drawbacks of prolonged hospitalization, hemorrhagic complications, and subacute stent occlusion will be eliminated, partially or completely, so that elective stenting of new coronary lesions will become an attractive and superior alternative to balloon angioplasty.
Dr. Schwartz's concern about the possible temporal discordance in the degree of luminal renarrowing after balloon angioplasty and after stenting can be dispelled. The results of the 1-year follow-up of the Benestent study demonstrate that the clinical benefit observed at 7 months is indeed preserved at 12 months, with 12-month event rates of 32 percent and 23 percent for balloon angioplasty and stenting, respectively. As for the management of stent restenosis, on this question, too, we can reassure Dr. Schwartz that the rate of restenosis after angioplasty of restenotic stented lesions was 15 percent.
5 ReferencesPatrick W. Serruys, M.D., Ph.D.
Erasmus University, 3000 DR Rotterdam, the Netherlandsfor the Benestent Investigators
1
Keane D ,Roubin G ,Marco J ,Fearnot N ,Serruys PW . GRACE -- Gianturco Roubin stent in Acute Closure Evaluation: substrate, challenges and design of a randomized trial of bailout therapy. J Intervent Cardiol 1994;7:333-339
CrossRef | Web of Science2
Serruys PW ,Keane D . The bailout stent: is a friend in need always a friend indeed? Circulation 1993;88:2455-2457
Web of Science | Medline3
Haase J, Keane D, DiMario C, Escaned J, Slager CJ, Serruys PW. How reliable are geometric coronary measurements? In vitro and in vivo validation of digital and cinefilm-based quantitative coronary analysis systems. In: Serruys PW, Foley DP, de Feyter PJ, eds. Quantitative coronary angiography in clinical practice. Vol. 145 of Developments in cardiovascular medicine. Dordrecht, the Netherlands: Kluwer Academic, 1994:27-49.
4
Foley D, Keane D, Serruys PW. Does the method of transluminal coronary revascularization influence restenosis? A comparison of balloon angioplasty, atherectomy and stents. Br J Clin Pract (in press).
5
Umans V, Keane D, Foley D, Boersma E, Melkert R, Serruys PW. Optimal use of directional coronary atherectomy is required to ensure long-term angiographic benefit: a study with matched procedural outcome after atherectomy and angioplasty. J Am Coll Cardiol (in press).
Author/Editor Response
Dr. Bittl raises an important issue regarding the selection of patients for stent placement when he suggests that a conditional strategy of balloon angioplasty should be followed, with stent placement only if a desired lumen is not achieved after standard angioplasty. He suggests this strategy in view of the major limitations of stent placement, including thrombosis, bleeding, and vascular complications and the resultant longer hospital stay, as reported in the two recent studies in the Journal.1,2 Dr. Bittl's strategy is attractive and deserves further consideration, but in the STRESS trial, the plan of elective stent placement was intentionally to underdilate lesions before placing the stent, to avoid dissection of the intima. Although stents have been shown to resolve dissections, placing a stent when the result of angioplasty is suboptimal has been associated with a higher incidence of stent thrombosis. Of the 14 patients randomly assigned to balloon angioplasty who underwent stent placement as a bailout procedure in the STRESS trial, thrombosis occurred in 3 (21 percent) and was associated with a major cardiac complication in each of these.
As we note in our article, the most important factor predictive of long-term angiographic patency in the STRESS trial was the luminal diameter achieved immediately after the procedure and not the particular method used. Stents reduced restenosis rates because they more often allowed the operator to achieve an optimal luminal diameter with less risk of dissection and recoil. The conditional strategy arouses the concern that attempts to achieve the optimal diameter with balloon angioplasty might result in dissection; subsequent stent placement would then be performed in a bailout situation, which might result in even higher complication rates.
We agree that the serious limitations of stenting require that patients be selected carefully. Stent placement is a rapidly evolving technique. Improvement in the techniques of deploying stents, with high-pressure balloon inflation as well as the coating of stents with antithrombotic materials, may reduce the incidence of stent thrombosis and the need for anticoagulation after the stent is deployed. Furthermore, the use of pneumatic vascular-compression devices has been associated with a marked reduction in bleeding and vascular complications.3 We believe that progress is being made to limit the serious drawbacks of thrombosis and bleeding. If these limitations are overcome, then stent placement will be even more attractive as a front-line procedure.
Dr. Schwartz asks whether stents may slow the temporal course of restenosis. Prospective serial follow-up data from our nonrandomized clinical trial demonstrated no deterioration in minimal luminal diameter between 6 and 12 months in 50 patients.4 However, we strongly agree with the need for further long-term follow-up evaluation.
4 ReferencesDavid L. Fischman, M.D.
Michael P. Savage, M.D.
Sheldon Goldberg, M.D.
Jefferson Medical College, Philadelphia, PA 191071
Fischman DL ,Leon MB ,Baim DS , 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
Full Text | Web of Science | Medline2
Serruys PW ,de Jaegere P ,Kiemeneij F , 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
Full Text | Web of Science | Medline3
Sridhar K ,Porter D ,Gupta B , et al. Reduction in peripheral vascular complications after coronary stenting by the use of a pneumatic vascular compression device. Circulation 1994;90:I-621 abstract.4
Savage MP ,Fischman DL ,Schatz RA , et al. Long-term angiographic and clinical outcome after implantation of a balloon-expandable stent in the native coronary circulation. J Am Coll Cardiol 1994;24:1207-1212
CrossRef | Web of Science | Medline
Author/Editor Response
Bittl raises the possibility of conditional stenting as a strategy for the treatment of patients who have suboptimal results with balloon angioplasty. Rodriguez et al.1 have performed a small randomized trial of 66 patients who were found to have reduced luminal diameters at the time of a second angiographic procedure 24 hours after balloon angioplasty. Among the patients assigned to receive stents (with a Gianturco–Roubin design), the restenosis rate was 21 percent, as compared with 76 percent in the balloon-angioplasty–only group (P<0.001). These data provide preliminary support for the strategy that Bittl has proposed. However, patients who do not have satisfactory results with conventional dilation may be a special group of patients with coronaryartery lesions that are not fully responsive to stenting or other interventions (atherectomy, rotablation, or laser techniques) used for this purpose. This issue can only be resolved in a randomized, controlled trial, and it is one of several important future directions for research in the area of investigational coronary stenting.
1 ReferencesEric J. Topol, M.D.
Cleveland Clinic Foundation, Cleveland, OH 44195- Citing Articles (1)
Citing Articles
1
Judit E. Puskas, Lyn G. Muñoz-Robledo, Robert A. Hoerr, John Foley, Steven P. Schmidt, Michelle Evancho-Chapman, Jinping Dong, Chris Frethem, Greg Haugstad. (2009) Drug-eluting stent coatings. Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology 1:4, 451-462
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