Myocardial Revascularization: Which Way to Go?
What's Hot in Medicine, November/December 2010
By David W. Sharp
At the end of August this year the European Society for Cardiology (ESC), working with the European Association of Cardio-Thoracic Surgery (EACTS), issued a 55-page set of guidelines on myocardial revascularization. The recommendations cover diagnosis and classification and not just which technique to use, though there is plenty of material on that much-discussed topic.
Simple medical therapy apart, there are two choices of intervention: surgery in the form of coronary-artery bypass grafting (CABG) and the less-invasive percutaneous procedures (PCI), these days usually stenting of various types. The ESC/EACTS guidelines emphasize, as others do (R.A. Lange, L.D. Hillis, New Engl. J. Med.,360[10]:1024-6, 2009), the need for a multidisciplinary approach. In the end, clinicians (and patient) have to decide.
The need to review all the information means that in severe disease ”coronary revascularization should not be performed at the time of diagnostic angiography (Lange and Hillis). An important piece of the jigsaw of evidence is an international randomized trial published in March, 2009 (paper #6; it was #12 last time).
Figure 1
Coronary Artery Bypass Grafting. From the
National Heart and Blood Institute.
View larger figure and read full description in the tab below.
CABG has been around for over 40 years, roughly twice as long as stenting, but by 2006 PCI procedures in the United States far outnumbered CABG operations, and they still do. This is also true in the U.K., but the difference is less striking and the absolute numbers of annual procedures per million population are far lower. Stents used to be simple, bare-metal expandable devices; then came drug-eluting stents (with rapamycin, paclitaxel, or sirolimus and related agents); biodegradable ones are in the pipeline.
So, in evaluating trials comparing the surgical and non-surgical approaches, and in meta-analyses, account has to be taken of the type of stent. A further difficulty is the fact that so many comparative studies have been in patients with less severe coronary-artery disease.
In the SYNTAX trial (#6) the 1,800 patients had three-vessel or left main coronary artery disease (severe) and the cardiac surgeon and the interventional cardiologist involved agreed that similar revascularization could be attained by CABG or by PCI. The main endpoint was a major cardiac or cerebrovascular event, and there were significantly more of these with PCI (17.8%) than with CABG (12.4%). A stroke was significantly more likely with CABG (2.2% vs.0.6%).
CABG should remain "the standard of care" for patients with severe disease, the trialists conclude. That was at 12 months only, but the three-year results presented by Dr. A. Pieter Kappetein at the 24th EACTS annual meeting in September, 2010, broadly supported this conclusion. Five-year follow-up is planned. The European guidelines (in their Table 9) recognize eight subsets of coronary-artery disease, and for all but one of these the evidence favors CABG.
After its first major publication in 2009 (#6) SYNTAX has generated further data, both as abstracts from meetings and as full papers. For example, we now have one-year results for the subgroup of SYNTAX patients who had left main disease; in them, the outcomes for PCI and CABG were similar. A meta-analysis of four trials (including SYNTAX) comparing CABG and PCI with drug-eluting stents has suggested similar endpoint rates for the two approaches, but the greater need for a repeat revascularization after PCI is emerging as a consistent finding (A.M. From, et al., EuroIntervention,6[2]:269-76, 2010).
Of course, for various reasons, a patient may be unsuitable either for PCI or for CABG. This happened in the SYNTAX trial, and those non-randomized patients are being followed up separately. Outside trial settings it will be interesting to see what the informed patient makes of the recent findings. Will the reduced invasiveness of PCI remain an important factor and does this, perhaps, in part explain the statistical dominance of PCI over CABG despite data from SYNTAX that seem to point the other way?
A former deputy editor of The Lancet, David W. Sharp, M.A. (Cambridge), is a freelance writer living in Minchinhampton, Gloucestershire, U.K.
What's Hot in Medicine | |||
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Rank | Paper |
Cites This Period May-Jun 10 |
Rank Last Period Mar-Apr 10 |
1 | Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team (F.S. Dawood, et al.), "Emergence of a novel swine-origin influenza A (H1N1) virus in humans," New Engl. J. Med., 360(25): 2605-15, 18 June 2009. [Writing group: Ctrs. for Disease Control & Prevent., Atlanta, GA] *458WR | 72 | 3 |
2 | J.M. Llovet, et al., "Sorafenib in advanced hepatocellular carcinoma," New Engl. J. Med., 359(4): 378-90, 24 July 2008. [22 institutions worldwide] *329FK | 62 | 7 |
3 | F.H. Schröder, et al., "Screening and prostate-cancer mortality in a randomized European study," New Engl. J. Med., 360(13): 1320-8, 26 March 2009. [15 institutions worldwide] *423VP | 58 | 10 |
4 | R.R. Holman, et al., "10-year follow-up of intensive glucose control in type 2 diabetes," New Engl. J. Med., 359(15): 1577-89, 9 October 2008. [6 U.K. institutions] *358FS | 57 | 4 |
5 | NICE-SUGAR Study Investigators (S. Finfer, et al.), "Intensive versus conventional glucose control in critically ill patients," New Engl. J. Med., 360(14): 1283-97, 26 March 2009. [Writing Committee: 4 Australian, New Zealand, and Canadian institutions] *423VP | 56 | 6 |
6 | P.W. Serruys, et al., "Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease," New Engl. J. Med., 360(10): 961-72, 5 March 2009. [9 institutions worldwide] *413WX | 54 | + |
7 | C.S. Karapetis, et al., "K-ras mutations and benefit from cetuximab in advanced colorectal cancer," New Engl. J. Med., 359(17): 1757-65, 23 October 2008. [13 institutions worldwide] *363DJ | 52 | + |
8 | Cancer Genome Atlas Research Network (L. Chin, et al.), "Comprehensive genomic characterization defines human glioblastoma genes and core pathways," Nature, 455(7216): 1061-8, 23 October 2008. [60 institutions worldwide] *363FG | 51 | 9 |
9 | T.S. Mok, et al., "Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma," New Engl. J. Med., 361(10): 947-57, 3 September 2009. [14 institutions worldwide] *490EI | 50 | + |
10 | R.J. Motzer, et al., "Efficacy of everolimus in advanced renal cell carcinoma: a double-blind, randomised, placebo-controlled phase III trial," Lancet, 372(9637): 449-56, 9 August 2008. [10 institutions worldwide] *335OD | 47 | + |
SOURCE: Thomson Reuters Hot Papers Database. Read the Legend. |
Coronary Artery Bypass Grafting:
Figure A shows the location of the heart. Figure B shows how vein and artery bypass grafts are attached to the heart.
From the National Heart and Blood Institute.
KEYWORDS: Myocardial revascularization, coronary-artery bypass grafting, CABG, percutaneous procedures, PCI, SYNTAX trial, ESC/EACTS guidelines.