Hybrid Coronary Revascularization in the Era of Drug-Eluting Stents

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Hybrid Coronary Revascularization in the Era of Drug-Eluting Stents Gavin J. Murphy, FRCS, Alan J. Bryan, FRCS, and Gianni D. Angelini, FRCS

Left internal mammary artery to left anterior descending coronary artery bypass grafting integrated with percutaneous coronary angioplasty (hybrid procedure) offers multivessel revascularization with minimal morbidity in high-risk patients. This is caused in part by the avoidance of cardiopulmonary bypass–related morbidity and manipulation of the aorta coupled with minimally invasive techniques. Hybrid revascularization is currently reserved for particularly high-risk patients or those with favorable anatomic variants however, largely because of the emergence of off-pump coronary artery bypass grafting, which permits more complete multivessel revascularization, with low morbidity in high-risk groups. The wider introduction of hybrid revascularization is limited chiefly by the high number of repeat interventions compared with off-pump coronary artery bypass grafting, which occurs because of the target vessel failure rate of percutaneous coronary intervention. Other demerits are

the costs and logistic problems associated with performing two procedures with differing periprocedural management protocols. Recently, drug-eluting stents have reduced the need for repeat intervention after percutaneous coronary intervention, and this has raised the possibility that the results of hybrid revascularization may now equal or even better those of off-pump coronary artery bypass grafting. Although undoubtedly effective at reducing in-stent restenosis, drug-eluting stents will not address the issues of incomplete revascularization or the logistic problems associated with hybrid. Uncertainty regarding the long-term effectiveness of drug-eluting stents in many patients, as well as their high cost when compared with those of off-pump coronary artery bypass grafting surgery, also militates against the wider introduction of hybrid revascularization. (Ann Thorac Surg 2004;78:1861–7) © 2004 by The Society of Thoracic Surgeons

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supersede hybrid revascularization was based on the fact that multivessel CABG had lower reintervention rates than multivessel PCI [2]. Off-pump CABG was also shown to result in superior short-term and equivalent midterm outcomes compared with conventional CABG, at a reduced cost [3– 6]. More recently, the apparent success of drug-eluting stents (DES) at reducing reintervention rates compared with PCI using non-DES, coupled with the desire of interventional cardiologists to broaden the scope of PCI, has led to the suggestion that hybrid revascularization may now equal or even better the results of beating heart surgery. This article reviews the strengths and weaknesses of hybrid compared with OPCAB procedures for patients with multivessel disease and considers whether DES will lead to a reemergence of this technique.

ybrid or integrated coronary revascularization strategies evolved in the mid 1990s as a result of the desire to effectively treat patients with multivessel disease while at the same time lowering procedure-related morbidity by combining minimal access coronary surgery with percutaneous techniques [1]. At the time this was heralded as innovative, representing as it did a blurring of the boundaries between interventional cardiology and cardiac surgery. Hybrid revascularization represented the natural evolution of the two disciplines, in which the former were increasingly more aggressive in their percutaneous treatment of coronary lesions (PCI), and surgeons were developing minimally invasive techniques with smaller incisions and performing anastomoses on the beating heart. It also, and possibly more importantly, challenged the paradigm that existed in most cardiac surgery centers, that coronary artery bypass grafting (CABG) required cardiopulmonary bypass (CPB) and cardioplegic or other form of arrest. There followed a resurgence of interest in performing CABG on the beating heart, and by the end of the decade off-pump or beating heart CABG (OPCAB) had become an established technique worldwide. The ability of OPCAB to

Accepted for publication July 14, 2004. Address reprint requests to Prof Angelini, Bristol Heart Institute, Bristol Royal Infirmary, Bristol BS2 8HW, UK; e-mail: g.d.angelini@ bristol.ac.uk.

© 2004 by The Society of Thoracic Surgeons Published by Elsevier Inc

Material and Methods The MEDLINE and PubMed databases (1996 through March 2004) were searched using the medical subject headings (MeSH) for “coronary artery bypass” combined with the following phrases used as text words: “hybrid,” “integrated,” “MIDCAB” (minimally invasive CABG), “minimally invasive,” “LAST” (left anterior small thoracotomy), “OPCAB,” “off pump,” “beating heart,” “angioplasty, transluminal, percutaneous, coronary,” and “coronary arteriosclerosis” combined with the text words “drug-eluting stent,” “rapamycin,” “paclitaxel,” “reste0003-4975/04/$30.00 doi:10.1016/j.athoracsur.2004.07.024

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Bristol Heart Institute, University of Bristol, Bristol, United Kingdom

SD ⫽ standard deviation. PCI ⫽ percutaneous coronary intervention; TLR ⫽ target lesion revascularization; LIMA ⫽ left internal mammary artery;

b a Calculated on a per patient basis (more than one reintervention occurred in some patients). d Included revision or stenting of LIMA graft. revascularization procedure.

5.7 (1.8) 3.54 (2–12) 11 33 17 72 83 76 66 (8) 62 (36–86) 66 (9)

CABG ⫽ coronary artery bypass grafting;

Composite endpoint of death, cardiac event, or c

12%d

14%d

7 0 12

Redo CABG required subsequent CABG.

87% 83% 1 0 1

87% 93% 92% 0 0

6–24 1–44 0–24 24 (1–60) 12 (1–23) 18 (5–33) 13%d 0

1 1 18 11 6% 10%

100 100 100 100 100 100 98 100 92 11 6 0 4 21

0 0 0 0 0 0 0 0 2 5 (1.5) 2.7 (1.0) 7.5 (4) 4.4 (1.7) 3.4 (2.1)

21 (10) 39 (23) 47 (14) 50 (39) 28 (20) 40 72 (53) 58 49 (36) 18 32 35 50 14 37 57 63 42 11 25 23 42 29

18 31 35 50 14 37 57 54 42

78 71 83 74 93

30-Day Mortality Hospital Stay (SD/range) Vessels Grafted Diabetes (%) Male (%)

63 (35–87) 69 (48–86) 57 (7) 54 (20) 72 (9)

TLRa (%)

Follow-Up Mean (Range) (Months) Immediate LIMA Patency (%) In-Hospital Morbidity (%) N Vessels PCI (Stented)

[7] [8] [9] [10] [11] [12] [13] [14] [15]

The results of published series of hybrid procedures are listed in Table 1. These series, although representing a

n

Hybrid Revascularization

Study (Reference)

Results

Table 1. Results of Hybrid Revascularization

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nosis,” “RAVEL” (randomized study with the sirolimuseluting, velocity balloon-expandable stent in the treatment of patients with de novo coronary artery lesions), “SIRIUS” (sirolimus-eluting stent), “ASPECT” (Asian Paclitaxel-Eluting Stent Clinical Trial), “TAXUS” (feasibility study evaluating safety of the NIRx paclitaxelcoated, conformer coronary stent for the treatment of de novo coronary lesions), “RESEARCH” (RapamycinEluting Stent Evaluated at Rotterdam Cardiology Hospital), or “randomized controlled trial.” In addition, the reference lists from relevant articles, abstracts, and reviews were also searched for additional trials. Randomized controlled trials, noncontrolled prospective studies, and retrospective series, in which morbidity, mortality, angiographic patency, target lesion revascularization (TLR), major adverse cardiac events (MACE), or costs were reported, were selected for inclusion. Letters and editorials, publications in languages other than English, and duplicate publications were excluded. Individual case reports, pilot studies, and small retrospective studies were not considered when higher levels of evidence were available

Redo CABGb

Abbreviations and Acronyms ASPECT ⫽ Asian Paclitaxel-Eluting Stent Clinical Trial BARI ⫽ Bypass Angioplasty Revascularization Investigation BHACAS ⫽ Beating Heart Against Cardioplegic Arrest Studies CABG ⫽ coronary artery bypass grafting DES ⫽ drug-eluting stent MACE ⫽ major adverse cardiac event MIDCAB ⫽ minimally invasive coronary artery bypass grafting OPCAB ⫽ off-pump coronary artery bypass grafting PCI ⫽ percutaneous coronary intervention RAVEL ⫽ randomized study with the sirolimus-eluting, velocity balloonexpandable stent in the treatment of patients with de novo coronary artery lesions RESEARCH ⫽ Rapamycin-Eluting Stent Evaluated at Rotterdam Cardiology Hospital SIRIUS ⫽ sirolimus-eluting stent TAXUS ⫽ feasibility study evaluating safety of the NIRx paclitaxel-coated, conformer coronary stent for the treatment of de novo coronary lesions TLR ⫽ target lesion revascularization

89% 90%

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Event-Free Survivalc (%)

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Mean Age (SD/ range)

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relatively small patient cohort, demonstrate low procedural morbidity, low mortality, and a short hospital stay with this technique. Other advantages are the low frequency of septic complications and use of homologous blood products, and virtual absence of neurologic injury. These are attributed to smaller incisions plus avoidance of CPB and manipulation of the aorta, which have proven to be particularly beneficial in the elderly and in those with poor ventricular function, renal impairment, morbid obesity, and chronic obstructive airways disease. Twenty-six percent of patients in one study had a Parsonnet predicted mortality of 20%, with an overall mortality in the series of 0 [8]. Zenati and colleagues [16] compared actual outcome to predicted risk–adjusted mortality in 20 high-risk patients undergoing minimally invasive coronary revascularization, including 7 patients who underwent hybrid procedures. This showed a 30-day mortality of 0 in a patient cohort with a predicted mortality of 26%. Furthermore, in this cohort the predicted stroke risk, calculated using the Multicenter Perioperative Stroke Index, was 22%, with an actual stroke frequency of 0. Despite these excellent early results, hybrid revascularization still has a limited role in multivessel revascularization [8, 13]. Reiss and associates [13], in the largest series of hybrid procedures published to date, performed only 57 hybrid procedures during 4 years, compared with 239 OPCAB and 2,305 conventional CABG using CPB. This represented only 2.2% of the surgical workload. The failure of hybrid revascularization to enter widespread use has been attributed to the emergence of OPCAB surgery [13, 15], which combines many of the benefits of minimal invasiveness by avoiding CPB and, when necessary, aortic manipulation, while at the same time overcoming many of the limitations of hybrid revascularization by permitting unrestricted access to every vessel on the heart and uncompromising selection of the best sites for coronary anastomoses. Several large series have also highlighted excellent results after OPCAB in those patient groups thought to benefit most from hybrid procedures, notably the elderly [17], obese [18], diabetics [19], or those with poor left ventricular function [20]. The principal benefits of OPCAB compared with hybrid procedures relate to the need for repeat revascularization procedures associated with PCI, the limitations of the MIDCAB procedure, and the logistic issues associated with performing two procedures, involving two specialists, with different procedural protocols, particularly with respect to anticoagulation.

Repeat Revascularization The need for repeat revascularization after hybrid procedures is a reflection of the limitations of PCI: high reintervention rates that occur owing to incomplete revascularization at the time of the primary procedure as well as post angioplasty or in-stent restenosis [21]. Incomplete revascularization in the Bypass Angioplasty Revascularization Investigation (BARI) trial, which compared multivessel angioplasty with conventional CABG, occurred in 43% of patients in the PCI arm [22] owing to a large subgroup of patients for

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whom PCI was not suitable, notably chronically occluded, small, calcified, or tortuous vessels or long atherosclerotic lesions. Although in some hybrid series completeness of revascularization is as high as 100% [7, 10], in studies with broader inclusion criteria, completeness of revascularization occurred in as few as 68% of patients [8]. Revascularization of the left anterior descending coronary artery with the left internal mammary artery is associated with improved survival, freedom from cardiac events, and long-term patency compared with PCI and stenting [23–25]. The rationale for integrating this with PCI to the circumflex and right coronary arteries was that the results of PCI with stents, which have early restenosis rates in isolated short lesions as low as 30%, were comparable to the long-term survival of saphenous vein grafts [26]. Vein grafts, which have a patency of 60% at 10 years [27], are still used in the vast majority of CABG procedures despite the superior long-term patency of arterial grafts largely owing to their ready availability and the multivessel nature of the disease [27]. In the “real world,” stents have much higher restenosis rates, however, because the pattern of disease is often complex, involving bifurcations and sequential and long, diffuse, or calcified lesions, in which reocclusion rates can be as high as 60% [28]. This has been shown in randomized trials in which PCI and stenting is still associated with higher repeat revascularization rates compared with OPCAB or conventional CABG [29, 30]. After hybrid procedures restenosis of lesions originally treated with PCI is the most common cause of target vessel failure, TLR, or MACE, with TLR rates ranging from 12% to 14% at 18 to 24 months’ follow-up (Table 1). In contrast, in patients undergoing OPCAB surgery as part of the Beating Heart Against Cardioplegic Arrest Studies (BHACAS) trial, the TLR rate was 2% at a mean follow-up of more than 2 years (standard deviation, 9 months) [3]. Similarly, in patients randomized to OPCAB in the Octopus study [4], TLR rates were 3.5% at 1 year of follow-up, with 1-year graft patency in a randomized selection of OPCAB patients of 91%. In the Surgical Management of Arterial Revascularization Therapies (SMART) randomized trial of off-pump versus on-pump CABG [6], 1-year angiographic graft patency after OPCAB surgery was 94%. Hybrid revascularization, unlike OPCAB, has also not been shown to significantly reduce costs compared with conventional CABG [4 – 6, 31]. In a randomized trial of hybrid versus conventional CABG, although there was a trend toward a lower initial operative cost in the hybrid group (€8,100 ⫾ €987 versus €9,700 ⫾ €2,500), this difference was counterbalanced by the extra cost of percutaneous transluminal coronary angioplasty (total hybrid cost, €10,622 ⫾ €1,329 versus conventional CABG cost, €9,699 ⫾ €2,500; not significant). At 2 years the overall cost in the hybrid group had increased because of the need for repeat revascularization in 3 patients, although this was not significantly different from the cost of conventional CABG [31].

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Table 2. Summary of Randomized Trials of Drug-Eluting Stents Versus Non-Drug-Eluting Stents

Sirolimus RAVEL [36] DES/control SIRIUS [37] DES/control Paclitaxel TAXUS-1 [38] DES/control TAXUS-2 [39] MR/control ASPECT [40] HD/LD/control a

n

Mean Vessel Length (mm)

Mean Vessel Diameter (mm)

Overall Diabetics (%)

6-Month Outcome (%) TLR

MACE

Restenosisa

238

9.6

2.6

16

0/26

3/27

0/26

1058

14.4

2.8

26

4.1/16.6

4.9/17.7

8.6/21.0

61

11.3

3.0

18

0/7

269

10.4

2.7

12

3.1/14.6

177

10.9

2.9

20

3.3/3.4/3.4

1-Year Outcome (%) TLR MACE 0/26

6/29

0/10

0/10

3/10

7.8/20.6

5/20

7/19

10/21

8.3/12.1/16.9

6.6/20.6/45.8

Restenosisa 0/26

Calculated on a per patient basis (more than one reintervention occurred in some patients).

ASPECT ⫽ Asian paclitaxel-eluting stent clinical trial; DES ⫽ drug-eluting stent; HD ⫽ high dose; LD ⫽ low dose; MACE ⫽ major adverse cardiac event; MR ⫽ moderate release; RAVEL ⫽ randomized study using the sirolimus-eluting velocity balloon expandable stent for the treatment of patients with de novo coronary artery lesions; SIRIUS ⫽ multicenter sirolimus-eluting stent study; TAXUS-1, TAXUS-2 ⫽ feasibility study evaluating safety of the NIRx paclitaxel (new intravascular rigid flex) coated conformer, coronary stent for the treatment of de novo coronary lesions; TLR ⫽ target lesion revascularization; TVF ⫽ target vessel failure.

Morbidity Associated With Minimally Invasive Coronary Artery Bypass Grafting

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Minimally invasive CABG, whether combined with PCI or not, also has a procedure-specific morbidity associated with the nature of the incisions and the restricted operating field that offsets the benefits of avoiding median sternotomy. Case-controlled cohort studies demonstrate less pain in the days after MIDCAB compared with OPCAB procedures [32], but report a higher rate of late wound complications in the MIDCAB patients, including late pain associated with rib retraction and intercostal neuralgia, and lung herniation [33]. In addition, several studies have reported higher rates of wound infection after MIDCAB [33, 34], attributed to duration of the procedure and excessive skin retraction. One recent study even reported higher rates of graft occlusion, reintervention, and MACE after MIDCAB as opposed to single-vessel OPCAB [35]. This was thought to be caused by a combination of conduit damage during harvest and the technical difficulty of performing a beating heart anastomosis with suboptimal access.

Logistics Other issues regarding the sequence of, as well as the logistics of, performing hybrid procedures remain unresolved. Performing PCI first has the advantage of permitting aggressive multivessel treatment, with the proviso that in the event of PCI failure or complication early surgical revascularization is planned. The patency of stents may be compromised by the need to discontinue anticoagulation or antiplatelet therapy for surgery, particularly when ticlopidine, glycoprotein IIb/IIIa inhibitors, or even heparin have been administered to treat a complication of PCI. In addition, delay in surgery occur-

ring as a consequence of PCI complications will increase hospital stay and costs, and reduce the overall benefit ratio. Performing PCI after surgery permits early angiographic assessment of graft patency and protection by the patent left internal mammary artery graft during PCI, and avoids the risk of stent thrombosis in the perioperative period. In the event of a PCI complication or failure, further emergency CABG may be required, however. One way of addressing many of these issues is to perform PCI and surgery at the same time under general anesthetic. This raises logistic issues relating to the workforce planning of two specialists, the cost of developing special hybrid operating theaters, and the provision of adequate training. None of these issues are insurmountable, although using two specialists, multiple stents, and specialized equipment and the risk of restenosis with current PCI would increase cost considerably. The main limiting factor to performing both procedures at the same time is the need to administer antiplatelet drugs, including in some cases glycoprotein IIb/IIIa inhibitors, to maintain stent patency, while at the same time performing MIDCAB. Reoperation, either for bleeding after antiplatelet administration [15], or, as shown in our series [7], for stent thrombosis if these agents are not used, again significantly reduces the cost– benefit ratio.

Drug-Eluting Stents The DES has been hailed as the answer to in-stent restenosis. Their use, combined with left internal mammary artery to left anterior descending coronary artery grafting in hybrid procedures in particular, offers the prospect of minimally invasive revascularization with excellent long-term outcomes. Summaries of the results of several landmark clinical trials of DES versus non-DES

are listed in Table 2. Sirolimus (rapamycin), a macrolide antibiotic with potent immunosuppressive and antiproliferative effects on vascular smooth muscle cells, was the first agent to be evaluated in clinical trials. The multicenter, double-blind RAVEL study evaluated the efficacy of the sirolimus-eluting Bx velocity stent (Cypher; Cordis, a Johnson & Johnson Company, Miami, FL), and reported reductions in stent restenosis from 26.6% to 0% at 210 days’ follow-up [36]. The larger US multicenter SIRIUS study also reported a reduction in target vessel failure (defined as a composite of deaths from cardiac causes, myocardial infarction, and repeat revascularization) from 21% in control patients to 8.6% in the sirolimus group, with a TLR rate of 16% and 4% in control patients and sirolimus groups, respectively [37]. Follow-up in both the RAVEL and SIRIUS studies reported almost complete abolition of in-stent neointima formation [37, 41, 42]. Paclitaxel, a taxane with antimitotic properties, has also shown remarkable efficacy in clinical trials. Restenosis rates of 0% to 4% at 6 and 12 months compared with 11% to 27% in control patients have been reported in the TAXUS 1 (feasibility study evaluating safety of the NIRx paclitaxel coated conformer coronary stent for the treatment of de novo coronary lesions) [38] and ASPECT (Asian Paclitaxel-Eluting Stent Clinical Trial) studies [40]. Similar advantages in terms of lower TLR rates and MACE have been subsequently reported in the larger TAXUS II study [39]. In TAXUS I and II, MACE were reduced from 10% to 21% in control patients to 3% to 10% in the paclitaxel groups at 1 year [38, 39]. In the smaller TAXUS III study, paclitaxel-eluting stents were shown to be effective for the treatment of in-stent stenosis [43]. The potential for these stents to increase the numbers of hybrid procedures is limited by several factors. First, the applicability of these studies to PCI practice in the real world is unclear. The RAVEL, SIRIUS, TAXUS, and ASPECT trials assessed the efficacy of DES in a highly selected group of patients, and none published the numbers of patients who were initially considered for inclusion. Day-to-day clinical practice often involves morecomplex patients than were included in these trials. There were no implantations in left mainstem disease, or vessels with chronic total arterial occlusion, ostial stenosis, in-stent restenosis, bifurcation lesions, or bypass grafts, or in patients after acute myocardial infarction [36]. The effectiveness of DES on completeness of revascularization and restenosis in these high-risk subgroups remains to be seen. The stented lesions in these studies were predominantly short lesions in large vessels, features associated with low restenosis rates with non-DES [44 – 46]. Whereas a 2.5- ⫻ 20-mm stent would be expected to have an angiographic restenosis rate of approximately 32%, a 4- ⫻ 8-mm stent would have an angiographic restenosis rate of 2% [28]. In the RAVEL study only 18% of vessels were less than 2.5 mm, and mean lesion length was small (9.6 mm) [36], with similar observations in the SIRIUS and TAXUS trials. Another consideration is that diabetics, who constitute 20% of the PCI population, still have higher restenosis rates with DES. In the SIRIUS study the 6-month in-segment restenosis rate

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in diabetics was 17.6% with a target lesion revascularization rate of 6.9%, rising to 10.5% in lesions less than 2.5 mm in diameter [37]. Multiple stents, including multivessel stenting, further increase the likelihood of restenosis as a result of the cumulative increase in restenosis risk. There is some evidence from the RESEARCH registry that DES are efficacious in high-risk subgroups in the real world [47]. The RESEARCH registry is a single-center registry that permits comparison of a recent cohort of patients in whom DES have been used without restriction with a historic control group treated before the introduction of DES. They have shown significant reductions in TLR, 5.1% versus 10.9%, and MACE, 9.7% versus 14.8%, in DES and control groups, respectively, at 1 year [47]. These benefits were observed despite a higher proportion of patients within the DES cohort having multivessel disease, multiple stents, bifurcation stenting, and type C lesions. It is noteworthy, however, that in a separate analysis of the same data set de novo in-stent restenosis within DES was associated with cases that were described as “technically complex” [48]. Second, animal and clinical studies have suggested that DES may be associated with late restenosis or thrombosis. Thrombosis has been attributed to the inhibition of endothelial regeneration by high local drug concentrations, which is undesirable, in addition to the intended inhibition of neointima formation. This results in persistently high levels of thrombogenic fibrin and few vascular smooth muscle cells around exposed stent struts [49]. An additional problem noted with sirolimus-eluting stents in the RAVEL study [42] was a higher rate of malapposition in patients with eluting stents (21%) versus control patients (4%). This may represent expansive remodeling around the stent, possibly related to apoptosis. Thrombus formation between the stent and vessel wall may propagate and lead to stent thrombosis. Late thrombosis leading to myocardial infarction has been reported with both rapamycin-eluting [49] and paclitaxel-eluting [50] stents. Late restenosis is also a possibility, as has been seen after brachytherapy, in which a delayed restenotic response occurs despite impressive early results [51]. Diminished late efficacy may be caused by a steady reduction in local tissue levels of the drug. In sirolimus-eluting stents 63% of the initial dose is eluted by 14 days; at this time arterial wall tissue levels are at a maximum (approximately 160 ␮g) and are reduced 50% by 28 days [52]. A recent study of 15 patients treated for in-stent restenosis with QuaDS stents (Quanam Medical Corporation, Santa Clara, CA) containing the paclitaxel derivative 7-hexanoyltaxol (QP2 or taxen) has unequivocally demonstrated late restenosis [53]. Although at 6 months there was minimal in-stent neointimal hyperplasia (late loss, 0.47 ⫾ 1.01 mm), at 12 months there was an aggressive increase in neointimal growth (late loss, 1.36 ⫾ 0.94 mm), resulting in a dramatic 61.5% rate of restenosis. Some series do report continued inhibition of neointima formation at up to 2 years after sirolimuseluting stent implantation [54, 55]. These were short stents (18 mm) placed in large arteries (3 to 3.5 mm) in small numbers of low-risk patients, however.

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A final concern is the high cost of stenting multiple vessels with DES. Cypher, the first DES on the market, costs approximately five times more than a conventional stent, and would therefore negate any initial cost saving associated with lower TLR rates after PCI, particularly if multiple stents are used to treat several vessels or complex lesions. Gunn and colleagues [28] calculated that despite some cost savings associated with lower restenosis rates, the use of DES would increase overall stent budgets by 256%.

Conclusions

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Hybrid procedures currently occupy a select niche in particularly high-risk patients or those with favorable anatomic variants. It remains attractive in situations such as redo procedures, in patients with significant comorbidity, and in those with severe aortic or mitral ring calcification in whom moving or elevating the heart during revascularization of the posterior coronary vessels might result in injury of the calcified ascending aorta or the mitral annulus. Other patients who may benefit are those with prior chest wall irradiation in which median sternotomy is relatively contraindicated. In the generality, however, OPCAB permits superior levels of revascularization with lower MACE and fewer TLR and similar benefits in terms of low morbidity in high-risk patients. Although undoubtedly effective at reducing in-stent restenosis, DES will not address the issues of incomplete revascularization or logistic problems associated with hybrid procedures. Uncertainty regarding the long-term effectiveness of DES in many patients as well as their high cost, when compared with OPCAB surgery, may also limit the wider introduction of hybrid procedures.

References 1. Angelini GD, Wilde P, Salerno TA, Bosco G, Calafiore AM. Integrated left small thoracotomy and angioplasty for multivessel coronary artery revascularisation. Lancet 1996;347: 757– 8. 2. Hoffman SN, TenBrook JA, Wolf MP, et al. A meta-analysis of randomized controlled trials comparing coronary artery bypass graft with percutaneous transluminal coronary angioplasty: one- to eight-year outcomes. J Am Coll Cardiol 2003;41:1293–304. 3. Angelini GD, Taylor FC, Reeves BC, Ascione R. Early and midterm outcome after off-pump and on-pump surgery in Beating Heart Against Cardioplegic Arrest Studies (BHACAS 1 and 2): a pooled analysis of two randomised controlled trials. Lancet 2002;359:1194 –9. 4. Nathoe HM, van Dijk D, Jansen EW, et al. A comparison of on-pump and off-pump coronary bypass surgery in low-risk patients. N Engl J Med 2003;348:394 – 402. 5. Ascione R, Lloyd CT, Underwood MJ, Lotto AA, Pitsis AA, Angelini GD. Economic outcome of off-pump coronary artery bypass surgery: a prospective randomized study. Ann Thorac Surg 1999;68:2237– 42. 6. Puskas JD, Williams WH, Mahoney EM, et al. Off-pump vs conventional coronary artery bypass grafting: early and 1-year graft patency, cost, and quality-of-life outcomes: a randomized trial. JAMA 2004;291:1841–9.

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7. Lloyd CL, Calafiore AM, Wilde P, et al. Integrated left anterior small thoracotomy and angioplasty for coronary artery revascularization. Ann Thorac Surg 1999;68:908 –12. 8. Zenati M, Cohen HA, Griffith BP. Alternative approach to multivessel coronary disease with integrated coronary revascularization. J Thorac Cardiovasc Surg 1999;117:439 – 44. 9. Wittwer T, Cremer J, Boonstra P, et al. Myocardial “hybrid” revascularisation with minimally invasive direct coronary artery bypass grafting combined with coronary angioplasty: preliminary results of a multicentre study. Heart 2000;83:58 – 63. 10. Cisowskia M, Morawskia W, Drzewieckib J, et al. Integrated minimally invasive direct coronary artery bypass grafting and angioplasty for coronary artery revascularisation. Eur J Cardiothorac Surg 2002;22:261–5. 11. Lewis BS, Porat E, Halon DA, et al. Same-day combined coronary angioplasty and minimally invasive coronary surgery. Am J Cardiol 1999;84:1246 –7. 12. Isomura T, Suma H, Hori T, Sato T, Kobashi T, Kanemitsu H. Minimally invasive coronary artery revascularization: offpump bypass grafting and the hybrid procedure. Ann Thorac Surg 2000;70:2017–22. 13. Riess FC, Bader R, Kremer P, et al. Coronary hybrid revascularization from January 1997 to January 2001: a clinical follow-up. Ann Thorac Surg 2002;73:1849 –55. 14. Stahl KD, Boyd WD, Vassiliades TA, Karamanoukian HL. Hybrid robotic coronary artery surgery and angioplasty in multivessel coronary artery disease. Ann Thorac Surg 2002; 74(Suppl):S1358 – 62. 15. Presbitero P, Nicolini F, Maiello L, et al. “Hybrid” percutaneous and surgical coronary revascularization: selection criteria from a single-center experience. Ital Heart J 2001;2: 363– 8. 16. Zenati M, Cohen HA, Holubkov R, et al. Preoperative risk models for minimally invasive coronary bypass: a preliminary study. J Thorac Cardiovasc Surg 1998;116:584 –9. 17. Koutlas TC, Elbeery JR, Williams JM, Moran JF, Francalancia NA, Chitwood WR Jr. Myocardial revascularization in the elderly using beating heart coronary artery bypass surgery. Ann Thorac Surg 2000;69:1042–7. 18. Ascione R, Reeves BC, Rees K, Angelini GD. Effectiveness of coronary artery bypass grafting with or without cardiopulmonary bypass in overweight patients. Circulation 2002;106: 1764 –70. 19. Magee MJ, Dewey TM, Acuff T, et al. Influence of diabetes on mortality and morbidity: off-pump coronary artery bypass grafting versus coronary artery bypass grafting with cardiopulmonary bypass. Ann Thorac Surg 2001;72:776 – 80. 20. Ascione R, Narayan P, Rogers CA, Lim KH, Capoun R, Angelini GD. Early and midterm clinical outcome in patients with severe left ventricular dysfunction undergoing coronary artery surgery. Ann Thorac Surg 2003;76:793–9. 21. Pretre R, Turina MI. Choice of revascularization strategy for patients with coronary artery disease. JAMA 2001;285:992– 4. 22. Bypass Angioplasty Revascularization Investigation (BARI) Investigators. Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease. N Engl J Med 1996;335:217–25. 23. Diegeler A, Spyrantis N, Matin M, et al. The revival of surgical treatment for isolated proximal high-grade LAD lesions by minimally invasive coronary artery bypass grafting. Eur J Cardiothorac Surg 2000;17:501– 4. 24. Drenth DJ, Winter JB, Veeger JGM. Minimally invasive coronary artery bypass grafting versus percutaneous transluminal coronary angioplasty with stenting in isolated highgrade stenosis of the proximal left anterior descending coronary artery: six months’ angiographic and clinical follow-up of a prospective randomized study. J Thorac Cardiovasc Surg 2002;124:130 –5. 25. Mariani MA, Boonstra PW, Grandjean JG, et al. Minimally invasive coronary artery bypass grafting versus coronary angioplasty for isolated type C stenosis of the left anterior descending artery. J Thorac Cardiovasc Surg 1997;114:434 –9.

26. Feit F, Brooks MM, Sopko G, et al. Long-term clinical outcome in the Bypass Angioplasty Revascularization Investigation Registry: comparison with the randomized trial. BARI Investigators. Circulation 2000;101:2795– 802. 27. Motwani JG, Topol EJ. Aortocoronary vein graft disease: pathogenesis, predisposition, and prevention. Circulation 1998;97:916 –31. 28. Gunn J, Morton AC, Wales C, Newman CM, Crossman DC, Cumberland DC. Drug eluting stents: maximising benefit and minimising cost. Heart 2003;89:127–31. 29. Serruys P, Unger F, Sousa J, et al. Comparison of coronary artery bypass surgery and stenting for the treatment of multivessel disease. N Engl J Med 2001;344:1117–24. 30. Eefting F, Nathoe H, van Dijk D, et al. Randomized comparison between stenting and off-pump bypass surgery in patients referred for angioplasty. Circulation 2003;108: 2870 – 6. 31. de Canniere D, Jansens JL, Goldschmidt-Clermont P, et al. Combination of minimally invasive coronary bypass and percutaneous transluminal coronary angioplasty in the treatment of double-vessel coronary disease: two-year follow-up of a new hybrid procedure compared with “onpump” double bypass grafting. Am Heart J 2001;142:563–70. 32. Gulielmos V, Brandt M, Dill HM, et al. Coronary artery bypass grafting via median sternotomy or lateral minithoracotomy. Eur J Cardiothorac Surg 1999;16(Suppl):S48 –52. 33. Gersbach P, Imsand C, von Segesser LK, Delabays A, Vogt P, Stumpe F. Beating heart coronary surgery: is sternotomy a suitable alternative to minimal invasive technique. Eur J Cardiothorac Surg 2001;20:760 – 4. 34. Detter C, Reichenspurner H, Boehm D, Thalhammer M, Schutz A, Reichart B. Single vessel revascularisation with beating heart techniques—minithoracotomy or sternotomy? Eur J Cardiothorac Surg 2001;19:464 –70. 35. Vicol C, Nollert G, Mair H, et al. Midterm results of beating heart surgery in 1-vessel disease: minimally invasive direct coronary artery bypass versus off-pump coronary artery bypass with full sternotomy. Heart Surg Forum 2003;6:341– 4. 36. Morice MC, Serruys PW, Sousa JE, et al, for the RAVEL Study Group. Randomized Study with the Sirolimus-Coated Bx Velocity Balloon-Expandable Stent in the Treatment of Patients with de Novo Native Coronary Artery Lesions. A randomized comparison of a sirolimus-eluting stent with a standard stent for coronary revascularization. N Engl J Med 2002;346:1773– 80. 37. Moses JW, Leon MB, Fitzgerald PJ, et al, for the SIRIUS Investigators. Sirolimus-eluting stents versus standard stents in patients with stenosis in a native coronary artery. N Engl J Med 2003;349:1315–23. 38. Grube E, Silber S, Hauptmann KE, et al. TAXUS I: six- and twelve-month results from a randomized, double-blind trial on a slow-release paclitaxel-eluting stent for de novo coronary lesions. Circulation 2003;107:38 – 42. 39. Colombo A, Drzewiecki J, Banning A, et al. TAXUS-II Study Group. Randomized study to assess the effectiveness of slow- and moderate-release polymer-based paclitaxeleluting stents for coronary artery lesions. Circulation 2003; 108:788 –94. 40. Park SJ, Shim WH, Ho DS, et al. A paclitaxel-eluting stent for the prevention of coronary restenosis. N Engl J Med 2003; 348:1537– 45. 41. Regar E, Serruys PW, Bode C, et al. Angiographic findings of the multicenter Randomized Study With the Sirolimus-

REVIEW MURPHY ET AL REVASCULARIZATION AND DRUG-ELUTING STENTS

42.

43.

44.

45. 46.

47.

48.

49. 50.

51. 52. 53.

54.

55.

1867

Eluting Bx Velocity Balloon-Expandable Stent (RAVEL): sirolimus-eluting stents inhibit restenosis irrespective of the vessel size. Circulation 2002;106:1949 –568. Serruys PW, Degertekin M, Tanabe K, et al, for the RAVEL Study Group. Intravascular ultrasound findings in the multicenter, randomized, double-blind RAVEL (RAndomized study with the sirolimus-eluting VElocity balloonexpandable stent in the treatment of patients with de novo native coronary artery Lesions) trial. Circulation 2002;106: 798 – 803. Tanabe K, Serruys PW, Grube E, et al. In-stent restenosis with stent based delivery of paclitaxel incorporated in a slow-release polymer formulation. Circulation 2003;107:559 – 64. Serruys PW, Kay P, Disco C, et al. Periprocedural quantitative coronary angiography after Palmaz-Schatz stent implantation predicts the restenosis rate at six months. J Am Coll Cardiol 1999;34:1067–74. Kobayashi Y, De Gregorio J, Kobayashi N, et al. Stented segment length as an independent predictor of restenosis. J Am Coll Cardiol 1999;34:651–9. Kornowski R, Bharghava B, Fuchs S, et al. Procedural results and late clinical outcomes after percutaneous interventions using long (ⱖ25 mm) versus short (⬍20 mm) stents. J Am Coll Cardiol 2000;35:612– 8. Lemos PA, Serruys PW, van Domburg RT, et al. Unrestricted utilization of sirolimus-eluting stents compared with conventional bare stent implantation in the “real world”: the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry. Circulation 2004;109: 190 –5. Lemos PA, Saia F, Ligthart JM, et al. Coronary restenosis after sirolimus-eluting stent implantation: morphological description and mechanistic analysis from a consecutive series of cases. Circulation 2003;108:257– 60. Choi SB. CYPHER coronary stents and risk of thrombosis. Can Med Assoc J 2003;169:218. Liistro F, Stankovic G, Di Mario C, et al. First clinical experience with a paclitaxel derivate-eluting polymer stent system implantation for in-stent restenosis: immediate and long-term clinical and angiographic outcome. Circulation 2002;105:1883– 6. Kay IP, Wardeh AJ, Kozuma K, et al. Radioactive stents delay but do not prevent in-stent neointimal hyperplasia. Circulation 2001;103:14 –7. Klugherz BD, Llanos G, Lieuallen W, et al. Twenty-eight-day efficacy and pharmacokinetics of the sirolimus-eluting stent. Coron Artery Dis 2002;13:183– 8. Virmani R, Liistro F, Stankovic G, et al. Mechanism of late in-stent restenosis after implantation of a paclitaxel derivate-eluting polymer stent system in humans. Circulation 2002;106:2649 –51. Sousa JE, Costa MA, Sousa JG, et al. Two-year angiographic and intravascular ultrasound follow-up after implantation of sirolimus-eluting stents in human coronary arteries. Circulation 2003;107:381–3. Degertekin M, Serruys PW, Foley DP, et al. Persistent inhibition of neointimal hyperplasia after sirolimus-eluting stent implantation: long-term (up to 2 years) clinical, angiographic, and intravascular ultrasound follow-up. Circulation 2002;106:1610 –3.

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