CORRESPONDENCE: LETTER TO THE EDITOR
Percutaneous Coronary Intervention or Coronary Artery Bypass Graft for Unprotected Left Main Coronary Artery Disease: The Endless Debate
Emanuele Meliga, MD,
Marco Valgimigli, MD, PhD,
Pawel Buszman, MD, FACC, FESC and
Patrick W. Serruys, MD, PhD, FACC, FESC*
* Director of the Interventional Cardiology Department, Thoraxcenter, Erasmus Medical Center, Eramus University, Dr Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands (Email: p.w.j.c.serruys{at}erasmusmc.nl).
The "state-of-the art" paper written by Taggart et al. (1) calls into question the current evidence in support of percutaneous coronary intervention (PCI) for the treatment of unprotected left main stem disease. In view of the fact that current guidelines still indicate coronary artery bypass grafting (CABG) as the "standard of care," the authors conclude that the use of drug-eluting stents (DES) in "off-label" cases should be discouraged and that good surgical candidates with unprotected left main coronary artery (ULMCA) disease should undergo surgical revascularization. These conclusions, although absolutely reasonable, raise 2 questions: 1) Is CABG really proven to perform better than PCI in this subset of patients? 2) Is CABG to be recommended in all good surgical candidates?
In an attempt to justify their conclusion, the authors presented 6 studies conducted in patients with ULMCA disease who had undergone CABG. Of note, none of these studies had clinical follow-up periods of longer than 2 years, and only 2 out of 6 had a clinical follow-up longer than 1 year (Lu et al. [2] and Yeatman et al. [3]). The mortality rate of 5% to 6% reported by these studies is truly encouraging. However, the authors did not mention the impressive occurrence of post-procedural morbidity in these patients. In the study conducted by Lu et al. (2) on 1,197 patients who underwent CABG for ULMCA, the rates of in-hospital adverse events were the following: mortality 2.8%, renal failure 3.9%, gastrointestinal complications 3.6%, stroke 2.2%, post-procedural myocardial infarction 7.1%, reoperation for bleeding 2.8%, sternal wound infection 4.2%, chest infection 5.3%, ventilation >48 h 6%, stay after operation >14 days 9.3%. The incidence of death in patients undergoing CABG for ULMCA disease was reported to be 11.3% at 1 year in the Cleveland Clinic Foundation Data (4), 12.8% at 3 yeas in the New York Bypass Surgery Registry (5), 13.2% at 5 years in the study conducted by d'Allonnes et al. (6), and 22.6% at 5 years in the Duke Cardiology Database (7). These results are far worse than those reported by the authors and do not appear to be superior to those reported in several PCI studies.
In discussing the experience with bare-metal stents (BMS), the authors presented the results from earlier PCI studies that enrolled almost exclusively high-risk patients. The "poor" late outcomes after ULMCA stenting with BMS are compared with the excellent results obtained in the SoS (Stent or Surgery) trial. This comparison of "apples versus pears," i.e., left main disease in high-risk patients versus 2- to 3-vessel disease in stable patients, is not a proper scientific argument. In that specific study, the comparison between CABG and PCI resulted in no statistically significant differences in terms of death, myocardial infarction, or stroke at 1-year follow-up (8). With regard to DES implantation, the authors describe a selection of studies that presents an important nonhomogeneity in terms of trial design: consecutive (e.g., Valgimigli et al. [9], Lee et al. [10]) vs. selective (de Lezo et al. [11]) patient enrollment and, in some studies, the use of DES was not exclusive (e.g., approximately 40% of patients from the Bologna Registry received BMS). Moreover, the authors did not take into account the importance and influential outcomes of the various stenting techniques used for distal left main disease.
It therefore seems difficult to draw any conclusions from the pooling of these results and, furthermore, compare them with the outcomes obtained in the surgical literature. In the DELFT (Drug Eluting stent for LeFT main) registry (12), the 3-year incidence of cardiac death, target vessel revascularization, and major adverse cardiovascular events (MACE) in the elective subgroup was 6.2%, 16%, and 30.5%, respectively. Recent studies conducted on patients with ULMCA who underwent surgical revascularization reported a similar incidence of death, a lower incidence of TVR, but an apparently greater incidence of MACE (9,13).
Additionally, it was noted by the authors that distal left main disease is a major and independent predictor of MACE at mid-term follow-up (9) and argued that: "the precise anatomical location and complexity of left main stenosis ... have negligible influence on the success of CABG." Two issues deserve further clarification with respect to this statement: 1) In patients undergoing PCI, distal left main disease is associated with a higher risk for reintervention but not necessarily death or myocardial infarction, which are predominantly affected by surgical risk status. 2) To the best of our knowledge, there are no data supporting the notion that outcomes after surgery are not affected by the location of the lesion within the left main stem. Distal left main disease may simply be a marker of severe, diffuse coronary disease and, as such, carry with it a worse prognosis irrespective of the final revascularization strategy.
In all major institutions, current standard approach to patients presenting with significant ULMCA disease is to have them evaluated by both interventional cardiologists and cardiac surgeons and to reach the decision to opt for PCI or surgery by consensus, on the basis of: 1) hemodynamic conditions; 2) lesion characteristics; 3) vessel size; 4) the presence of comorbidities; 5) quality of arterial and/or venous conduits for grafting; and 6) patient and/or referring physician preferences. Patients are always fully informed about the potential risks and outcomes of both the surgical and the percutaneous approaches. Stating that "patients are influenced into making a pre-ordained choice" and that cardiologists "instigate" patients in making these choices is speculative.
Should all good candidates for surgery go to surgery and poor candidates to PCI? So far, there is no strong evidence that one approach is better than the other in terms both of clinical outcomes and quality of life (QoL). A recent meta-analysis by Bravata et al. (14) of 23 randomized controlled trials showed no difference between PCI and CABG in terms of mortality at 10 years' follow-up. Health-related QoL is of particular value in coronary artery disease, because the objective of intervention is not only to avoid clinical adverse outcomes but also to relieve symptoms and improve function and ability to participate in daily activities. Long-term studies comparing QoL related to these 2 therapeutic strategies are not available but the results coming from the available literature reported so far no major differences (15–18).
Current guidelines still recommend surgical revascularization as the primary procedure in ULMCA patients, but considering them as "the body of criminal law" is not always appropriate. Guidelines are dynamic and in constant flux and have to be updated according to new evidences coming from clinical experience, and not vice-versa. It is important to realize that new-generation DES approved for clinical use, new technical strategies, and prolonged dual-antiplatelet treatment have significantly decreased the risk of adverse events (including late in-stent thrombosis) after PCI.
Randomized clinical trials are necessary to shine a light on this endless debate. The LEMANS trial (19) is the only reported randomized trial comparing PCI versus CABG for ULMCA disease. The increased short-term complication rate in the CABG group appeared to be minimized by stressing similar 1-year MACE results in the 2 groups. Moreover, no late in-stent thrombosis occurred both in the BMS and in the DES groups, demonstrating that percutaneous treatment of ULMCA is safe. Results of the complete SYNTAX (TAXUS Drug-Eluting Stent Versus Coronary Artery Bypass Surgery for the Treatment of Narrowed Arteries) study, which enrolled 700 randomized patients with ULMCA disease, will be presented at the 2008 European Society of Cardiology congress. Until then, judicious individual assessment of each patient should prevail, that is to say, we should keep trying to treat patients—that do not fit in the current recommendations—according our current clinical experience and judgment. "On the mountains of truth you can never climb in vain: either you will reach a point higher up today, or you will be training your powers so that you will be able to climb higher tomorrow."
Friedrich Nietzsche (20)
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1. Taggart DP, Kaul S, Boden WE, et al. Revascularization for unprotected left main stem coronary artery stenosis: stenting or surgery J Am Coll Cardiol 2008;51:885-892.[Abstract/Free Full Text]2. Lu JC, Grayson AD, Pullan DM. On-pump versus off-pump surgical revascularization for left main stem stenosis: risk adjusted outcomes Ann Thorac Surg 2005;80:136-142.[Abstract/Free Full Text] 3. Yeatman M, Caputo M, Ascione R, Ciulli F, Angelini GD. Off-pump coronary artery bypass surgery for critical left main stem disease: safety, efficacy and outcome Eur J Cardiothorac Surg 2001;19:239-244.[Abstract/Free Full Text] 4. Ellis SG, Hill CM, Lytle BW. Spectrum of surgical risk for left main coronary stenoses: benchmark for potentially competing percutaneous therapies Am Heart J 1998;135:335-338.[CrossRef][Web of Science][Medline] 5. Mehran T. DES for the Treatment of Left Main Disease. Paper presented at: TCT 2006; July 21, 2006; Washington, DC. 6. d'Allonnes FR, Corbineau H, Le Breton H, Leclercq C, Leguerrier A, Daubert C. Isolated left main coronary artery stenosis: long term follow up in 106 patients after surgery Heart 2002;87:544-548.[Abstract/Free Full Text] 7. Garcia E. Left Main. Paper presented at: EuroPCR; May 22, 2007; Barcelona, Spain. 8. Zhang Z, Mahoney EM, Spertus JA, et al. The impact of age on outcomes after coronary artery bypass surgery versus stent-assisted percutaneous coronary intervention: one-year results from the Stent or Surgery (SoS) trial Am Heart J 2006;152:1153-1160.[CrossRef][Medline] 9. Valgimigli M, van Mieghem CA, Ong AT, et al. Short- and long-term clinical outcome after drug-eluting stent implantation for the percutaneous treatment of left main coronary artery disease: (RESEARCH and T-SEARCH) Circulation 2005;111:1383-1389.[Abstract/Free Full Text] 10. Lee MS, Kapoor N, Jamal F, et al. 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] 11. de Lezo JS, Medina A, Pan M, et al. Rapamycin-eluting stents for the treatment of unprotected left main coronary disease Am Heart J 2004;148:481-485.[CrossRef][Web of Science][Medline] 12. Meliga E, Garcia-Garcia HM, Valgimigli M, et al. DELFT Registry. Longest available clinical outcomes after drug-eluting stent implantation for unprotected left main coronary artery disease: the DELFT (Drug Eluting stent for LeFT main) Registry. J Am Coll Cardiol 2008;51:2212-2219.[Abstract/Free Full Text] 13. Chieffo A, Morici N, Maisano F, et al. Percutaneous treatment with drug-eluting stent implantation versus bypass surgery for unprotected left main stenosis: a single-center experience Circulation 2006;113:2542-2547.[Abstract/Free Full Text] 14. Bravata DM, Gienger AL, McDonald KM, et al. Systematic review: the comparative effectiveness of percutaneous coronary interventions and coronary artery bypass graft surgery Ann Intern Med 2007;147:703-716.[Abstract/Free Full Text] 15. Währborg P. Quality of life after coronary angioplasty or bypass surgery. 1-year follow-up in the Coronary Angioplasty versus Bypass Revascularization investigation (CABRI) trial. Eur Heart J 1999;20:635-636.[Web of Science][Medline] 16. Kaul P, Armstrong PW, Fu Y, et al. GUSTO-IIb Investigators Impact of different patterns of invasive care on quality of life outcomes in patients with non-ST elevation acute coronary syndrome: results from the GUSTO-IIb Canada-United States substudy Can J Cardiol 2004;20:760-766.[Web of Science][Medline] 17. Kamiya M, Takayama M, Takano H, et al. Clinical outcome and quality of life of octogenarian patients following percutaneous coronary intervention or surgical coronary revascularization Circ J 2007;71:847-854.[CrossRef][Web of Science][Medline] 18. Favarato ME, Hueb W, Boden WE, et al. Quality of life in patients with symptomatic multivessel coronary artery disease: a comparative post hoc analyses of medical, angioplasty or surgical strategies-MASS II trial Int J Cardiol 2007;116:364-370.[CrossRef][Web of Science][Medline] 19. Buszman PE, Kiesz SR, Bochenek A, et al. Acute and late outcomes of unprotected left main stenting in comparison with surgical revascularization J Am Coll Cardiol 2008;51:538-545.[Abstract/Free Full Text] 20. Human, All Too Human. 1878.
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