CLINICAL RESEARCH: CLINICAL TRIAL
10-Year Follow-Up of a Prospective Randomized Trial Comparing Bare-Metal Stenting With Internal Mammary Artery Grafting for Proximal, Isolated De Novo Left Anterior Coronary Artery StenosisThe SIMA (Stenting versus Internal Mammary Artery grafting) Trial
Jean-Jacques Goy, MD, FESC*,*,
Urs Kaufmann, MD, FESC ,
Michel Hurni, MD*,
Stéphane Cook, MD,
Francesco Versaci, MD ,
Patrick Ruchat, MD*,
Osmund Bertel, MD, FESC, FACC ,
Michael Pieper, MD||,
Bernhard Meier, MD, FESC, FACC,
Luigi Chiarello, MD,
Eric Eeckhout, MD, FESC, PhD* for the SIMA Investigators
* Service de Cardiologie, University Hospital, Lausanne, Switzerland
Kardiologie Abteilung, University Hospital, Bern, Switzerland
Policlinico Tor Vergata, Tor Vergata University, Rome, Italy
HerzGefässZentrum, Zürich, Switzerland
|| Herzzentrum Bodensee, Kreuzlingen, Switzerland
Manuscript received November 26, 2007;
revised manuscript received May 20, 2008,
accepted May 27, 2008.
* Reprint requests and correspondence: Dr. Jean-Jacques Goy, Clinique Cecil, Avenue Ruchonnet 33, 1003 Lausanne, Switzerland (Email: jjgoy{at}goyman.com).
 |
Abstract
|
|---|
Objectives: This study was designed to compare the long-term clinical outcome of coronary artery bypass grafting (CABG) with intracoronary stenting of patients with isolated proximal left anterior descending coronary artery.
Background: Although numerous trials have compared coronary angioplasty with bypass surgery, none assessed the clinical evaluation in the long term.
Methods: We evaluated the 10-year clinical outcome in the SIMA (Stent versus Internal Mammary Artery grafting) trial. Patients were randomly assigned to stent implantation versus CABG.
Results: Of 123 randomized patients, 59 underwent CABG and 62 received a stent (2 patients were excluded). Follow-up after 10 years was obtained for 98% of the randomized patients. Twenty-six patients (42%) in the percutaneous coronary intervention group and 10 patients (17%) in the CABG group reached an end point (p < 0.001). This difference was due to a higher need for additional revascularization. The incidences of death and myocardial infarction were identical at 10%. Progression of the disease requiring additional revascularization was rare (5%) and was similar for the 2 groups. Stent thrombosis occurred in 2 patients (3%). Angina functional class showed no significant differences between the 2 groups.
Conclusions: Both stent implantation and CABG are safe and highly effective in relieving symptoms in patients with isolated, proximal left anterior descending coronary artery stenosis. Stenting with bare-metal stents is associated with a higher need for repeat interventions. The long-term prognosis for these patients is excellent with either mode of revascularization.
Key Words: CABG • stenting • proximal LAD stenosis
|
Abbreviations and Acronyms
| | CABG = coronary artery bypass grafting | | LAD = left anterior descending | | PCI = percutaneous coronary intervention |
|
The SIMA (Stent versus Internal Mammary Artery grafting) prospective randomized trial compared clinical outcome of coronary artery bypass grafting (CABG) with percutaneous transluminal coronary angioplasty with bare-metal stent implantation (percutaneous coronary intervention [PCI]) in patients with isolated proximal left anterior descending (LAD) coronary artery. After 2.4 years of follow-up, overall survival and incidence of myocardial infarction was similar for the 2 strategies (1). Data on long-term follow-up after PCI and internal mammary grafting for single-vessel disease are scarce (2). The SIMA trial data provides a unique opportunity to study these issues in a very homogenous group of patients.
|
Methods
|
|---|
The SIMA trial enrolled 123 patients (at 6 European sites) to be treated with either stent implantation or CABG for isolated proximal LAD stenosis and left ventricular ejection fraction >45%. Follow-up was conducted until all patients had reached their 10-year follow-up.
The primary composite end point was all causes of death, myocardial infarction, and the need for additional revascularization. A secondary end point was angina functional class. These end points were evaluated at 2 and 10 years.
During the first 6 months after the procedure, patients were seen by the referring physician, who obtained the history and performed a physical examination. Noninvasive assessment was performed with a yearly stress test or cardiac scintigraphy. Additional revascularization was left to the discretion of the treating cardiologist in patients with symptomatic or silent ischemia.
Statistical analysis.
All analyses were made according to the intention-to-treat principle. Continuous variables were expressed as mean ± SD and discrete variables as counts and percentage. The event-free survival was estimated by the Kaplan-Meier method and compared by a log-rank test. Statistical significance was assigned at the p < 0.05 level. Only the most serious adverse event per patient was reported.
|
Results
|
|---|
A total of 123 patients met the inclusion criteria, but 2 patients were excluded. Thus, 121 patients were finally included. Baseline clinical and angiographic characteristics of both groups were similar. At 1 month there was no difference, with 4% of adverse events in the CABG group versus 7% in the PCI group (p = NS). At 10 years, a primary end point was reached more frequently in the PCI group than in the CABG group (Fig. 1). Mortality and myocardial infarction rates were not statistically different between the 2 groups (Fig. 1). Five patients died after PCI (8%) and 4 patients after CABG (7%). The cause of death was cardiac in 2 patients after PCI and in 1 patient after CABG. Myocardial infarction (including those of the periprocedural period) occurred in 3 patients in both groups (4%). Stent thrombosis occurred in 2 patients (3%), 1 acute and 1 late; both patients suffered fatal acute myocardial infarction.
View larger version (10K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1 Event-Free Survival Curves
Event-free survival curves for death and myocardial infarction for percutaneous coronary intervention (PCI) (red) and coronary artery bypass grafting (CABG) (black) (p = 0.9) and event-free survival curves for death, myocardial infarction, and additional revascularization for PCI (green) and CABG (yellow) (p < 0.0004).
|
|
Significantly more patients assigned to PTCA required additional revascularization (18 patients [30%] vs. 3 patients [5%]). Revascularization of the LAD was required in 15 patients in the PCI group (25%) compared with none in the CABG group (p < 0.001). Finally, 8 patients from the PCI group underwent CABG as an additional revascularization procedure. The incidence of non-LAD revascularization was similar, with 3 patients in both groups (5%) (Table 1). At 10 years, most of the patients in both groups were asymptomatic (93%) or suffered mild angina (7%). A majority of patients received antiplatelet therapy (94% PCI and 96% CABG). Rates of lipid-lowering therapy increased gradually from 24% at 2 years to 89% (88% PCI and 91% CABG) at 10 years. Beta-blockers, angiotensin-converting enzyme inhibitors, and calcium antagonists were given to more than 50% of the patients without differences between the 2 groups. Treatment varied significantly during follow-up.
|
Discussion
|
|---|
This study provides information on long-term results for 2 revascularization strategies and disease progression in a very homogenous group of patients. The data confirm that the only difference between stenting and left internal mammary artery grafting is in the need for additional revascularization early after the intervention. The relatively high incidence of restenosis and target lesion revascularization is consistent with isolated LAD artery stenosis (3,4). It is remarkable that no patients randomized to CABG required a second revascularization of the LAD. Our study results confirm the excellent outcome after CABG using this type of graft, which has been shown to remain patent in more than 95% of patients at 5 years (5). The PCI was followed by a higher rate of reintervention. The use of drug-eluting stents might minimize this difference between percutaneous and surgical strategies (6). There are no prospective controlled data comparing proximal LAD stenting with drug-eluting stents with CABG, but in 1 matched cohort observation, there was a surprisingly high incidence of reintervention after drug-eluting stent implantation (7). Furthermore, the incidence and impact of very late drug-eluting stent thrombosis remains unknown and makes it difficult to draw conclusions on whether long-term results with drug-eluting stents would compare favorably to the outcome in our study.
The SIMA trial long-term data provide valuable information about disease progression in single-vessel disease receiving secondary medical prevention with antiplatelet agents and statins. The use of statins increased dramatically from <30% to >90% at 10 years. There is a strikingly low incidence of clinical adverse events attributable to disease progression, as only 5% of our patients required additional non-LAD revascularization. This is important information because use of mammary grafting is often delayed in young patients because of the feared need for further operations.
Study limitations.
Our study describes a small cohort of highly selected patients; therefore, conclusions should not be applied to other types of lesions and patients. Stents used in the SIMA study were first-generation bare-metal stents.
|
Footnotes
|
|---|
Dr. Goy is a member of the advisory board of Boston Scientific, has a research grant from Cordis, and is a consultant for Cardia. Dr. Cook has received research funding from Boston Scientific. Dr. Eeckhout has received research funding from Cordis. Dr. Meier has received research funding from Cordis, Boston Scientific, Medtronic, Abbott, and Biotronik.
|
References
|
|---|
1. Goy JJ, Kaufmann U, Goy-Eggenberger D, 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. Stenting vs Internal Mammary Artery. Mayo Clin Proc 2000;75:1116-1123.[Abstract]2. O'Keefe Jr. JH, Kreamer TR, Jones PG, et al. Isolated left anterior descending coronary artery disease: percutaneous transluminal coronary angioplasty versus stenting versus left internal mammary artery bypass grafting Circulation 1999;100:114-118II. 3. Versaci F, Gaspardone A, Tomai F, et al. 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.[Abstract/Free Full Text] 4. Cisowski M, Drzewiecki J, Drzewiecka-Gerber A, et al. Primary stenting versus MIDCAB: preliminary report-comparision of two methods of revascularization in single left anterior descending coronary artery stenosis Ann Thorac Surg 2002;74:S1334-S1339.[Abstract/Free Full Text] 5. Hayward PA, Buxton BF. Contemporary coronary graft patency: 5-year observational data from a randomized trial of conduits Ann Thorac Surg 2007;84:795-799.[Abstract/Free Full Text] 6. Morice MC, Serruys PW, Barragan P, et al. Long-term clinical outcomes with sirolimus-eluting coronary stents: five-year results of the RAVEL trial J Am Coll Cardiol 2007;50:1299-1304.[Abstract/Free Full Text] 7. Ben-Gal Y, Mohr R, Braunstein R, et al. Revascularization of left anterior descending artery with drug-eluting stents: comparison with minimally invasive direct coronary artery bypass surgery Ann Thorac Surg 2006;82:2067-2071.[Abstract/Free Full Text]
Related Article
-
Inside This Issue of JACC
J. Am. Coll. Cardiol. 2008 52: A31-A32.
[Full Text]
[PDF]
This article has been cited by other articles:
|
|
|
|
 
G. Bastarrika, Y. S. Lee, W. Huda, B. Ruzsics, P. Costello, and U. J. Schoepf
CT of Coronary Artery Disease
Radiology,
November 1, 2009;
253(2):
317 - 338.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. H. Adams, A. C. Anyanwu, J. Chikwe, and F. Filsoufi
The Year in Cardiovascular Surgery
J. Am. Coll. Cardiol.,
June 23, 2009;
53(25):
2389 - 2403.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. R. Dixon, C. L. Grines, and W. W. O'Neill
The year in interventional cardiology.
J. Am. Coll. Cardiol.,
June 2, 2009;
53(22):
2080 - 2097.
[Full Text]
[PDF]
|
|
|
|
|
|
|
O. Soran, A. Manchanda, and S. Schueler
Percutaneous coronary intervention versus coronary artery bypass surgery in multivessel disease: a current perspective
Interactive CardioVascular and Thoracic Surgery,
June 1, 2009;
8(6):
666 - 671.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. K. von Segesser
Clinical databases - a double-edged sword!
Eur. J. Cardiothorac. Surg.,
May 1, 2009;
35(5):
749 - 750.
[Full Text]
[PDF]
|
|
|
|
Top
Abstract
Methods