Interact CardioVasc Thorac Surg 2007;6:632-635. doi:10.1510/icvts.2007.159798
© 2007 European Association of Cardio-Thoracic Surgery
Institutional report - Coronary |
Initial clinical impact of drug eluting stents on coronary artery bypass graft surgery
Shinji Kanemitsu*,
Keizo Tanaka,
Jin Tanaka,
Hitoshi Suzuki and
Toshihiko Kinoshita
Department of Thoracic and Cardiovascular Surgery, Anjo Kosei Hospital, 28 Higashihirokute, Anjo-cho, Anjo, Aichi, 446-8602, Japan
Received 21 May 2007;
received in revised form 19 June 2007;
accepted 21 June 2007
*Corresponding author. Tel: +81-88-837-3000; fax: +81-88-837-6766.
E-mail address: skanemitsu70{at}yahoo.co.jp (S. Kanemitsu).
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Abstract
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Drug eluting stents (DESs) reduce the incidence of restenosis after percutaneous coronary intervention (PCI) and have been predicted to decrease the number of patients referred for coronary artery bypass grafting (CABG). We studied about the impact of DESs on CABG. We compared our isolated CABG patients over two years (May 2002–April 2004) before the introduction of DESs (non DES term) with those over the two years (May 2004–April 2006) after the implementation of DESs (DES term). We studied a total of 136 CABG cases in the non DES term and 138 CABG cases in the DES term. In the non DES term, of 3650 coronary angiographies (CAGs), 794 (21.8%) underwent PCI, and 65 (1.9%) underwent CABG. In the DES term, of 4003 CAG, 1091 (27.3%) underwent PCI, and 70 (1.7%) underwent CABG. Among CABG patients, there was no significant difference in the age, sex, and ejection fraction. Patients in the DES term were more likely to have severe diabetes and severe renal failure. The clinical introduction of DESs was associated with a modest decrease in the percentage of CAG patients referred for CABG. Moreover, preoperative conditions have become more serious.
Key Words: Coronary artery bypass; Off-pump; Drug eluting stent; Angioplasty
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1. Introduction
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The long-term benefits of coronary angioplasty are limited by the occurrence of restenosis. DESs reduce the incidence of restenosis after percutaneous coronary intervention (PCI) compared with bare-metal stents [1–3]. Consequently, this is likely to influence the surgical treatment of coronary artery disease. Accordingly, the use of DESs has been predicted to decrease the number of patients referred for coronary artery bypass grafting (CABG). The purpose of this retrospective study was to determine the initial clinical impact of DESs on the volume and characteristics of patients referred for CABG.
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2. Patients and methods
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2.1. Study population
In Japan, the Cypher (Cordis, Miami, Lakes, FL), a sirolimus eluting stent, was approved for clinical use in 2004. In our institute, Anjo Kosei Hospital, DESs were introduced for clinical use in May 2004. We, therefore, studied all patients undergoing coronary angiography (CAG), PCI, and isolated CABG for two years before the introduction of DESs at our institution (non DES term: May 2002 through April 2004), and for the two years after full implementation of the use of DESs at our institution (DES term: May 2004 through April 2006).
2.2. Statistical analysis
StatView 5.0 (SAS Institute, Inc, Cary, NC) was used for statistical analysis. Continuous variables were compared using Student's t-tests. A two-sided P-value <0.05 was required for statistical significance.
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3. Results
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The procedural volume data are presented in Table 1. In our hospital, in the non DES term, of 3650 CAG patients, 794 (21.8%) underwent PCI and 65 (1.9%) underwent CABG. In DES term, of 4003 CAG patients, 1091 (27.3%) had PCI and 70 (1.7%) had CABG. The remaining patients in both periods who required no treatment, were treated medically, or were referred for a procedure other than isolated CABG. In the non DES term, 21.8% of the CAG patients underwent PCI and 1.9% underwent CABG. Similarly, in the DES term, 27.3% underwent PCI, and 1.7% underwent CABG. Though the number of patients who underwent PCI increased, there was a reduction in the proportion of CAG patients referred for CABG. This difference in the proportion of patients undergoing PCI between the non DES and DES terms was significant. During the same period, there was an 11% reduction in the number of patients undergoing CAG who subsequently underwent CABG.
The totals of cases of isolated CABG studied in the non DES and DES terms were 136 and 138, respectively. These included candidate patients introduced by cardiologists in our hospital as well as those from other institutes. There was no significant difference between the number of subjects in these two groups (Table 2). The demographic data of the patients who underwent CABG in our hospital are presented in Table 3. There was no significant difference in age, sex, and ejection fraction among these patients. Moreover, although there was no significant difference in the prevalence of diabetes between the two study periods, patients in DES term were more likely to have severe diabetes and severe renal failure, and to use insulin and require hemodialysis. The demographic data concerning CABG surgery showed that in the DES term, emergent operations significantly increased. Our standard operative procedure is off-pump coronary bypass surgery, and in both periods, more than 90% of cases underwent this operation. The number of cases requiring intra-aorta balloon pumping significantly increased, but there was no significant difference in the number of grafts. There was also no significant difference in the percentage of patent grafts required, but in the DES term the logistic EuroSCORE was greater than that in the non DES term, although the difference was not significant. There was no change in mortality between the study periods.
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4. Discussion
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The management of patients with CAD is a rapidly evolving area of medicine. In general, patients with isolated CAD are managed with medical therapy or with a therapeutic intervention such as CABG or PCI. The distribution of patients into these management categories is driven by a number of factors that include patient outcomes, new technologies, invasiveness of the procedure, and patient and physician preference. Technological advancements in PCI have resulted in reduced restenosis and a broader range of lesions that can be successfully treated, thereby shifting the focus of coronary artery intervention from CABG to PCI. Two randomized clinical trials compared stent placement with coronary bypass surgery [4, 5]. The incidence of mortality and myocardial infarction was similar but the need for repeat revascularization was higher in the stented group at one year [6]. Local drug delivery at the site of vascular injury through a polymeric-coated stent is an elegant approach to achieve effective local concentration of an antiproliferative agent to prevent restenosis [7].
The expanding indications for angioplasty have already had an unquestionable impact on the practice of coronary revascularization. Many patients are still referred for surgery owing to either the occurrence or threat of stent restenosis, which occurs with an average frequency of approximately 20–30% [1–3]. It is even higher among patients with diabetes mellitus, multivessel disease, complex lesions, and small vessels [8, 9]. Recently developed drug-eluting stents may practically eliminate restenosis [10, 11]. Many have suggested that this advance will decrease dramatically the number of patients referred for coronary artery bypass surgery. Their implementation will undoubtedly impact on the balance of patients being treated for CAD. The general philosophy of our cardiologists has always been a very aggressive one. Even in the pre-DES era, only about 2% of those patients were referred for CABG; what the Japan average was is not known to us, but our rate seems low. Thus, the aggressive approach within our institution appeared to have a response. DESs have given our cardiologists a little more data and confidence in terms of a reduced restenosis rate to be even more aggressive. DESs were introduced at our institution in May 2004. During the next two years, there was a significant change in the management of patients with CAD. However, there was no real change in the proportion of patients undergoing CAG being treated with therapies other than PCI or CABG; however, of those undergoing a coronary intervention, there was a decrease in the proportion of patients undergoing CABG. As PCI indications broaden to include more complex lesions and more high-risk patients, outcomes will not necessarily remain as favorable. The patients undergoing CABG in DES term appear to be more complex with greater numbers of insulin dependent diabetes mellitus, patients on hemodialysis and emergency procedures. The increase in emergency procedures did not reflect an increase in the number of failed PCIs. Ben-Gal et al. compared results of DESs with those of CABG in patients with diabetes mellitus. They reported that the midterm clinical outcome of diabetic patients who underwent surgical arterial revascularization is better than that of patients undergoing PCI treated with a DES [12].
Liddico et al. from the Beth Israel Deaconess Medical Center in the USA reported on the impact of DESs [13]. Their findings were that the numbers of CABG patients decreased, but the percentage of CABG patients with LMCAD increased. They also described that patients undergoing CABG in the post-DES era were less likely to have a reduced left ventricular ejection fraction. This is an important observation because it indicates that interventional cardiologists remain concerned about intervening with PCI on LMCAD. We expected that CABG candidates would be likely to have a reduction of the ejection fraction in the latter years. We believe that patients with LMCAD tend to have relatively more preserved left ventricular function. In our institute, after the introduction of DESs, CABG volume did not decrease and left ventricular ejection fraction did not change. Often characteristics such as diffuse disease, chronic total occlusion, and complex coronary artery anatomy still limit the application of transvascular coronary revascularization. Such limitations will not be transcended by DESs. Patients undergoing surgical revascularization frequently have LMCAD or total coronary occlusion and many require combined valvular surgery or have a complex anatomy that favors surgical revascularization. Lee et al. compared CABG with PCI with DES for LMCAD, despite a higher percentage of high-risk patients; PCI with DES for LMCAD was not associated with an increase in immediate or medium-term complications compared with CABG [14].
As well, although PCI is less invasive than surgery, CABG offers more complete revascularization and better freedom from repeat revascularization. Furthermore, no long-term patency data on DESs exist, whereas excellent 10- and 20-year patency rates have been reported for the left internal mammary artery-to-left anterior descending artery graft used in most CABG procedures. Recently, the food and drug administration circulatory system devices panel have discussed about the rate ST, particularly very late ST (>1 year following PCI). The consensus of the panel was that appropriate dual antiplatelet therapy is not associated with increased incidence of death and myocardial infarction, although it is associated with increased rates of very late ST [15]. While PCI has been changing, CABG has not been a stagnant area; advances in many aspects of the CABG procedures have improved short- and long-term outcomes for CABG patients. Both CABG and PCI technologies will continue to advance, not necessarily exclusive of one another, but no data are yet available to suggest that DESs will render CABG obsolete any time soon.
The limitations of this analysis include all those inherent to a retrospective, single-institution study. There are also methodological problems; we did not follow specific patients through the system, so a patient who underwent CAG on the last day of the non DES term would have had their surgery during the DES term. If the date was later than what we believed it to be, the impact of DESs may have been underestimated. Finally, this study evaluated the initial clinical impact of DESs on the management of patients with CAD. Thus, a follow-up investigation will be required to determine the lasting effects of DESs.
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5. Conclusions
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DESs may have a significant impact on CABG. Though the number of patients who underwent PCI increased, there was a reduction in the proportion of CAG patients referred for CABG. Among CABG patients, there was no difference in age or sex. Specifically, of those patients referred for surgery after the introduction of DESs, an increasing proportion experienced renal failure and a greater logistic EuroSCORE than before the introduction of DESs. Moreover, preoperative conditions have become more serious. This trend may have been driven by new technology and the fact that these are early clinical results. In the future, a detailed definition of the role of DESs vs. CABG for coronary revascularization will require a more in-depth elucidation of the long-term outcomes of DESs compared with CABG.
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References
|
|---|
- Morice MC, Serruys PW, Sousa JE, Fajadet J, Ban Hayashi E, Perin M, Colombo A, Schuler G, Barragan P, Guagliumi G, Molnar F, Falotico R. RAVEL study group. A randomized comparison of a sirolimus-eluting stent with a standard stent for coronary revascularization. N Engl J Med 2002; 346:1773–1780.[Abstract/Free Full Text]
- Moses JW, Leon MB, Popma JJ, Fitzgerald PJ, Holmes DR, O'Shaughnessy C, Caputo RP, Kereiakes DJ, Williams DO, Teirstein PS, Jaeger JL, Kuntz RE. SIRIUS Investigators. Sirolimus-eluting stents vs. standard stents in patients with stenosis in native coronary artery. N Engl J Med 2003; 349:1315–1323.[Abstract/Free Full Text]
- Stone GW, Ellis SG, Cox DA, Hermiller J, O'Shaughnessy C, Mann JT, Turco M, Caputo R, Bergin P, Greenberg J, Popma JJ, Russell ME. TAXUS-IV Investigators. One year clinical results with the slow-release, polymer-based, paclitaxel-eluting TAXUS stent the TAXUS IV trial. Circulation 2004; 109:1942–1947.[Abstract/Free Full Text]
- Windecker S, Meier B. Intervention in coronary artery disease. Heart 2000; 83:481–490.[Free Full Text]
- Serruys PW, Unger F, van Hout BA, van den Brand MJ, van Herwerden LA, van Es GA, Bonnier JJ, Simon R, Cremer J, Colombo A, Santoli C, Vandormael M, Marshall PR, Madonna O, Firth BG, Breeman A, Morel MA, Hugenholtz PG. The ARTS study (Arterial Revascularization Therapies Study). Semin Interv Cardiol 1999; 4:209–219.[Medline]
- van den Brand MJ, Rensing BJ, Morel MA, Foley DP, de Valk V, Breeman A, Suryapranata H, Haalebos MM, Wijns W, Wellens F, Balcon R, Magee P, Ribeiro E, Buffolo E, Unger F, Serruys PW. The effect of completeness of revascularization on event free survival at one year in the ARTS trial. J Am Coll Cardiol 2002; 39:559–564.[Abstract/Free Full Text]
- Drachman DE, Edelman ER, Seifert P, Groothuis AR, Bornstein DA, Kamath KR, Palasis M, Yang D, Nott SH, Rogers C. Neointimal thickening after stent delivery of paclitaxel: change in composition and arrest of growth after six months. J Am Coll Cardiol 2000; 36:2325–2332.[Abstract/Free Full Text]
- Williams DO, Holubkov R, Yeh W, Bourassa MG, Al-Bassam M, Block PC, Coady P, Cohen H, Cowley M, Dorros G, Faxon D, Holmes DR, Jacobs A, Kelsey SF, King SB 3rd, Myler R, Slater J, Stanek V, Vlachos HA, Detre KM. Percutaneous coronary interventions in the current era compared with 1985–1986: the National Heart, Lung, and Blood Institute registries. Circulation 2000; 102:2945–2951.[Abstract/Free Full Text]
- Mehran R, Dangas G, Abizaid AS, Mintz GS, Lansky AJ, Satler LF, Pichard AD, Kent KM, Stone GW, Leon MB. Angiographic patterns of in-stent restenosis: classification and implications for long-term outcome. Circulation 1999; 100:1872–1878.[Abstract/Free Full Text]
- Rensing BJ, Vos J, Smits PC, Foley DP. Coronary restenosis elimination with a sirolimus eluting stent—first European human experience with 6-month angiographic and intravascular follow-up. Eur Heart J Nov 2001; 22:2125–2130.[Abstract/Free Full Text]
- van den Brand MJ, van der Giessen WJ, de Feijter PJ, Serruys PW Sousa JE, Costa MA, Abizaid AC, Rensing BJ, Abizaid AS, Tanajura LF, Kozuma K, Van Langenhove G, Sousa AG, Falotico R, Jaeger J, Popma JJ, Serruys PW. Sustained suppression on neointimal proliferation by sirolimus-eluting stents. One year angiographic and intravascular ultrasound follow-up. Circulation 2001; 104:2007–2011.[Abstract/Free Full Text]
- Ben-Gal Y, Mohr R, Uretzky G, Medalion B, Hendler A, Hansson N, Herz I, Moshkovitz Y. Drug-eluting stents vs. arterial myocardial revascularization in patients with diabetes mellitus. Thorac Cardiovasc Surg 2006; 132:861–866.[CrossRef]
- Liddicoat JR, De La Torre R, Ho KK, Nathan S, Levitsky S, Krempin J, Sellke F. Initial impact of drug-eluting stents on coronary artery bypass graft surgery. Ann Thorac Surg 2006; 81:1239–1242.[Abstract/Free Full Text]
- Lee MS, Kapoor N, Jamal F, Czer L, Aragon J, Forrester J, Kar S, Dohad S, Kass R, Eigler N, Trento A, Shah PK, Makkar RR. Comparison of coronary artery bypass surgery with percutaneous coronary intervention with drug-eluting stents for unprotected left main coronary artery disease. J Am Coll Cardiol 2006; 47:864–870.[Abstract/Free Full Text]
- Pinto Slottow TL, Waksman R. Overview of the 2006 Food and Drug Administration Circulatory System Devices Panel meeting on drug-eluting stent thrombosis. Catheter Cardiovasc Interv 2007; 69:1064–1074.[CrossRef][Medline]
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Abstract
1. Introduction