Surgery is the best intervention for severe coronary artery disease
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《英国医生杂志》
1 John Radcliffe Hospital, Oxford OX3 9DU david.taggart@orh.nhs.uk
A multidisciplinary approach is essential, but best evidence favours surgery over percutaneous intervention
For the past two decades coronary artery bypass grafting has been the standard treatment for patients with severe multivessel ischaemic heart disease.1 In the past few years, however, it has been increasingly challenged by percutaneous coronary intervention. Indeed, in many parts of the developed world percutaneous coronary intervention is done twice as often as coronary artery bypass grafting. Why has this change in practice occurred? I believe that it is not evidence based, does not represent best value for money, and that patients are not appropriately informed of its limitations.
Research evidence
Coronary artery bypass grafting is probably the most intensively studied surgical procedure, with follow up data extending over 20 years.2 It is highly effective in relieving the symptoms of ischaemic heart disease and improving life expectancy in patients with certain anatomical patterns of disease; these benefits are magnified in patients with more severe disease and with impaired left ventricular function.1 Furthermore, coronary artery bypass grafting is remarkably safe. Improvements in medical, anaesthetic, and surgical management have ensured that hospital mortality has remained around 2% over the past decade despite the treatment being used in older and sicker patients.3
On the other hand, until recently percutaneous coronary intervention has been used to treat patients with coronary disease in only one or two vessels. Its current use in patients with more widespread disease has largely mirrored its development from simple balloon angioplasty to a procedure that uses (multiple) stents. The conventional Achilles' heel of simple angioplasty is restenosis, affecting up to 40% of procedures, and this is halved by stents. Most recently, drug eluting stents have been claimed to effectively eliminate restenosis.
Applicability of research
So is percutaneous coronary intervention really as effective as coronary artery bypass grafting? Ten randomised trials have compared percutaneous coronary intervention and coronary artery bypass grafting in patients with multivessel ischaemic heart disease. Overall, the trials broadly agreed that survival was similar with both interventions but that surgery greatly reduced the need for further intervention (from 20% with percutaneous coronary intervention to 5% with coronary artery bypass grafting). However, 80% of the participants had single or double vessel disease and normal ventricular function,4 a population already known not to benefit prognostically from coronary artery bypass grafting.1 By largely excluding patients with severe three vessel coronary artery disease, who predominantly constitute the population having surgery in the real world, the trials were, in effect, inherently biased against the prognostic benefit of surgery.
Positron emission tomogram of blocked coronary artery
Credit: GELTMAN/SOBEL/WASHINGTON V/SPL
Subsequent reporting of these trials in the medical literature was misleading. Because the papers were styled and titled as trials of multivessel ischaemic heart disease, the highly unrepresentative nature of their patient populations was apparent only to expert readers who were prepared to pursue the small print. Accompanying editorials, invariably written by cardiologists, either ignored or fleetingly mentioned this fundamental limitation.
Safety of non-surgical treatment
Despite this, these trials are now used to justify percutaneous coronary intervention in patients with true multivessel disease. The danger of this approach was highlighted in a recent study from the Cleveland clinic, in which propensity matched patients with severe coronary artery disease had a 2.5-fold increase in five year mortality when treated by percutaneous coronary intervention rather than coronary artery bypass grafting.5 This reinforced the findings of a large prospective study on around 3000 diabetic patients with triple vessel coronary artery disease showing that those treated with percutaneous intervention rather than coronary artery bypass grafting had a twofold increase in five year mortality.6 This increase in mortality with percutaneous intervention rather than surgery belies the over-simplified cardiological justification that the patient "Did not want an operation." Patients generally want what is in their best interest. To most, a week in hospital and six weeks recuperation is a good trade-off for a procedure offering an excellent prospect of long term relief of symptoms and a gain in life expectancy.
Summary points
Most studies of percutaneous coronary intervention have been done on patients with single or double vessel disease and have limited follow up
Nevertheless percutaneous coronary intervention is being increasingly used to treat multivessel ischaemic heart disease
By contrast, studies of coronary artery bypass grafting have established its safety and long term effectiveness
Patients must be given all the evidence to enable an informed choice about treatment
What of the safety and economics of drug eluting stents? Most studies of these stents have follow ups of less than a year. The early promise that they eliminate restenosis seems increasingly improbable as registry rates of restenosis, reflecting outcome in real practice, are reported at 10-20% in more complex lesions7 8 and as high as 28% in bifurcating lesions.9 And as these stents inhibit endothelialisation, the patient is at subsequent risk of myocardial infarction even up to a year later if antiplatelet drugs are stopped.10 These limitations reinforce the National Institute for Clinical Excellence's caution in 2003 that a long overdue expansion of coronary artery bypass grafting with its proved benefits is jeopardised by the widespread use of these expensive stents.11
Informing patients
So how best should we advise patients with severe multivessel ischaemic heart disease? Percutaneous coronary intervention should become the default treatment only when evidence from relevant trials shows that it is really as safe and effective as coronary artery bypass grafting. The current tendency of some cardiologists to exclusively investigate and treat patients with severe multivessel disease without a surgical opinion not only belittles the traditional multi-disciplinary approach but ensures that the best and most balanced advice is unlikely to be consistently offered. Most importantly, by effectively denying patients the opportunity of making a fully informed choice, it falls far short of best practice.
Competing interests: None declared.
Contributors and sources: DPT has studied, practised, and published widely on several aspects of coronary artery bypass grafting and in particular its benefits in comparison to percutaneous coronary intervention.
References
Yusuf S, Zucker D, Peduzzi P, Fisher LD, Takaro T, Kennedy JW, et al. Effect of coronary artery bypass graft surgery on survival: overview of 10-year results from randomised trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration. Lancet 1994;344: 563-70.
Scott R, Blackstone EH, McCarthy PM, Lytle BW, Loop FD, White JA, et al. Isolated bypass grafting of the left internal thoracic artery to the left anterior descending coronary artery: late consequences of incomplete revascularization. J Thorac Cardiovasc Surg 2000;120: 173-84.
Keogh BE, Kinsman R. Fifth national adult cardiac surgical database report. London: Society of Cardiothoracic Surgeons of Great Britain and Ireland, 2003.
Taggart DP. Angioplasty versus bypass surgery. Lancet 1996;347: 271-2.
Brener SJ, Lytle BW, Casserly IP, Schneider JP, Topol EJ, Lauer MS. Propensity analysis of long-term survival after surgical or percutaneous revascularization in patients with multivessel coronary artery disease and high-risk features. Circulation 2004;109: 2290-5.
Niles NW, McGrath PD,Malenka D, Quinton H, Wennberg D, Shubrooks SJ, et al. Survival of patients with diabetes and multivessel coronary artery disease after surgical or percutaneous revascularization: Results of a large regional prospective study. J Am Coll Cardiol 2001;37: 1008-15.
Lemos PA, Hoye A, Goedhart D, Arampatzis CA, Saia F, van der Giessen WJ, et al. Clinical, angiographic, and procedural predictors of angiographic restenosis after sirolimus-eluting stent implantation in complex patients: an evaluation from the rapamycin-eluting stent evaluated at Rotterdam Cardiology Hospital (RESEARCH) study. Circulation 2004;109: 1366-70.
Lansky AJ, Costa RA, Mintz GS, Tsuchiya Y, Midei M, Cox DA, et al. Non-polymer-based paclitaxel-coated coronary stents for the treatment of patients with de novo coronary lesions: angiographic follow-up of the DELIVER clinical trial. Circulation 2004;109: 1948-54.
Tanabe K, Hoye A, Lemos PA, Aoki J, Arampatzis CA, Saia F, et al. Restenosis rates following bifurcation stenting with sirolimus-eluting stents for de novo narrowings. Am J Cardiol 2004;94: 115-8.
McFadden EP Stabile E, Regar E, Cheneau E, Ong AT, Kinnaird, et al. Late thrombosis in drug-eluting coronary stents after discontinuation of antiplatelet therapy. Lancet 2004;64: 1519-21.
Hill R, Bagust A, Bakhai A, Dickson R, Dünder Y, Haycox A, et al. Coronary artery stents: a rapid systematic review and economic evaluation. Health Technology Assessment 2004;8(35). www.ncchta.org/project.asp?PjtId=1332 (accessed 24 Jan 2005).(David P Taggart, professor of cardiovasc)
A multidisciplinary approach is essential, but best evidence favours surgery over percutaneous intervention
For the past two decades coronary artery bypass grafting has been the standard treatment for patients with severe multivessel ischaemic heart disease.1 In the past few years, however, it has been increasingly challenged by percutaneous coronary intervention. Indeed, in many parts of the developed world percutaneous coronary intervention is done twice as often as coronary artery bypass grafting. Why has this change in practice occurred? I believe that it is not evidence based, does not represent best value for money, and that patients are not appropriately informed of its limitations.
Research evidence
Coronary artery bypass grafting is probably the most intensively studied surgical procedure, with follow up data extending over 20 years.2 It is highly effective in relieving the symptoms of ischaemic heart disease and improving life expectancy in patients with certain anatomical patterns of disease; these benefits are magnified in patients with more severe disease and with impaired left ventricular function.1 Furthermore, coronary artery bypass grafting is remarkably safe. Improvements in medical, anaesthetic, and surgical management have ensured that hospital mortality has remained around 2% over the past decade despite the treatment being used in older and sicker patients.3
On the other hand, until recently percutaneous coronary intervention has been used to treat patients with coronary disease in only one or two vessels. Its current use in patients with more widespread disease has largely mirrored its development from simple balloon angioplasty to a procedure that uses (multiple) stents. The conventional Achilles' heel of simple angioplasty is restenosis, affecting up to 40% of procedures, and this is halved by stents. Most recently, drug eluting stents have been claimed to effectively eliminate restenosis.
Applicability of research
So is percutaneous coronary intervention really as effective as coronary artery bypass grafting? Ten randomised trials have compared percutaneous coronary intervention and coronary artery bypass grafting in patients with multivessel ischaemic heart disease. Overall, the trials broadly agreed that survival was similar with both interventions but that surgery greatly reduced the need for further intervention (from 20% with percutaneous coronary intervention to 5% with coronary artery bypass grafting). However, 80% of the participants had single or double vessel disease and normal ventricular function,4 a population already known not to benefit prognostically from coronary artery bypass grafting.1 By largely excluding patients with severe three vessel coronary artery disease, who predominantly constitute the population having surgery in the real world, the trials were, in effect, inherently biased against the prognostic benefit of surgery.
Positron emission tomogram of blocked coronary artery
Credit: GELTMAN/SOBEL/WASHINGTON V/SPL
Subsequent reporting of these trials in the medical literature was misleading. Because the papers were styled and titled as trials of multivessel ischaemic heart disease, the highly unrepresentative nature of their patient populations was apparent only to expert readers who were prepared to pursue the small print. Accompanying editorials, invariably written by cardiologists, either ignored or fleetingly mentioned this fundamental limitation.
Safety of non-surgical treatment
Despite this, these trials are now used to justify percutaneous coronary intervention in patients with true multivessel disease. The danger of this approach was highlighted in a recent study from the Cleveland clinic, in which propensity matched patients with severe coronary artery disease had a 2.5-fold increase in five year mortality when treated by percutaneous coronary intervention rather than coronary artery bypass grafting.5 This reinforced the findings of a large prospective study on around 3000 diabetic patients with triple vessel coronary artery disease showing that those treated with percutaneous intervention rather than coronary artery bypass grafting had a twofold increase in five year mortality.6 This increase in mortality with percutaneous intervention rather than surgery belies the over-simplified cardiological justification that the patient "Did not want an operation." Patients generally want what is in their best interest. To most, a week in hospital and six weeks recuperation is a good trade-off for a procedure offering an excellent prospect of long term relief of symptoms and a gain in life expectancy.
Summary points
Most studies of percutaneous coronary intervention have been done on patients with single or double vessel disease and have limited follow up
Nevertheless percutaneous coronary intervention is being increasingly used to treat multivessel ischaemic heart disease
By contrast, studies of coronary artery bypass grafting have established its safety and long term effectiveness
Patients must be given all the evidence to enable an informed choice about treatment
What of the safety and economics of drug eluting stents? Most studies of these stents have follow ups of less than a year. The early promise that they eliminate restenosis seems increasingly improbable as registry rates of restenosis, reflecting outcome in real practice, are reported at 10-20% in more complex lesions7 8 and as high as 28% in bifurcating lesions.9 And as these stents inhibit endothelialisation, the patient is at subsequent risk of myocardial infarction even up to a year later if antiplatelet drugs are stopped.10 These limitations reinforce the National Institute for Clinical Excellence's caution in 2003 that a long overdue expansion of coronary artery bypass grafting with its proved benefits is jeopardised by the widespread use of these expensive stents.11
Informing patients
So how best should we advise patients with severe multivessel ischaemic heart disease? Percutaneous coronary intervention should become the default treatment only when evidence from relevant trials shows that it is really as safe and effective as coronary artery bypass grafting. The current tendency of some cardiologists to exclusively investigate and treat patients with severe multivessel disease without a surgical opinion not only belittles the traditional multi-disciplinary approach but ensures that the best and most balanced advice is unlikely to be consistently offered. Most importantly, by effectively denying patients the opportunity of making a fully informed choice, it falls far short of best practice.
Competing interests: None declared.
Contributors and sources: DPT has studied, practised, and published widely on several aspects of coronary artery bypass grafting and in particular its benefits in comparison to percutaneous coronary intervention.
References
Yusuf S, Zucker D, Peduzzi P, Fisher LD, Takaro T, Kennedy JW, et al. Effect of coronary artery bypass graft surgery on survival: overview of 10-year results from randomised trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration. Lancet 1994;344: 563-70.
Scott R, Blackstone EH, McCarthy PM, Lytle BW, Loop FD, White JA, et al. Isolated bypass grafting of the left internal thoracic artery to the left anterior descending coronary artery: late consequences of incomplete revascularization. J Thorac Cardiovasc Surg 2000;120: 173-84.
Keogh BE, Kinsman R. Fifth national adult cardiac surgical database report. London: Society of Cardiothoracic Surgeons of Great Britain and Ireland, 2003.
Taggart DP. Angioplasty versus bypass surgery. Lancet 1996;347: 271-2.
Brener SJ, Lytle BW, Casserly IP, Schneider JP, Topol EJ, Lauer MS. Propensity analysis of long-term survival after surgical or percutaneous revascularization in patients with multivessel coronary artery disease and high-risk features. Circulation 2004;109: 2290-5.
Niles NW, McGrath PD,Malenka D, Quinton H, Wennberg D, Shubrooks SJ, et al. Survival of patients with diabetes and multivessel coronary artery disease after surgical or percutaneous revascularization: Results of a large regional prospective study. J Am Coll Cardiol 2001;37: 1008-15.
Lemos PA, Hoye A, Goedhart D, Arampatzis CA, Saia F, van der Giessen WJ, et al. Clinical, angiographic, and procedural predictors of angiographic restenosis after sirolimus-eluting stent implantation in complex patients: an evaluation from the rapamycin-eluting stent evaluated at Rotterdam Cardiology Hospital (RESEARCH) study. Circulation 2004;109: 1366-70.
Lansky AJ, Costa RA, Mintz GS, Tsuchiya Y, Midei M, Cox DA, et al. Non-polymer-based paclitaxel-coated coronary stents for the treatment of patients with de novo coronary lesions: angiographic follow-up of the DELIVER clinical trial. Circulation 2004;109: 1948-54.
Tanabe K, Hoye A, Lemos PA, Aoki J, Arampatzis CA, Saia F, et al. Restenosis rates following bifurcation stenting with sirolimus-eluting stents for de novo narrowings. Am J Cardiol 2004;94: 115-8.
McFadden EP Stabile E, Regar E, Cheneau E, Ong AT, Kinnaird, et al. Late thrombosis in drug-eluting coronary stents after discontinuation of antiplatelet therapy. Lancet 2004;64: 1519-21.
Hill R, Bagust A, Bakhai A, Dickson R, Dünder Y, Haycox A, et al. Coronary artery stents: a rapid systematic review and economic evaluation. Health Technology Assessment 2004;8(35). www.ncchta.org/project.asp?PjtId=1332 (accessed 24 Jan 2005).(David P Taggart, professor of cardiovasc)