Meta-analysis: DES Acceptable but Not Trouble-Free for Left Main Disease

Download this article's Factoid in PDF (& PPT for Gold Subscribers)

In treating unprotected left main disease, drug-eluting stents (DES) produce favorable outcomes that largely match those of coronary artery bypass graft (CABG) surgery through 1 year, reports a meta-analysis published online August 9, 2012, ahead of print in the American Journal of Cardiology. But the less invasive treatment nearly quadruples the risk of repeat revascularization.

Seung-Jung Park, MD, PhD, of Asan Medical Center (Seoul, South Korea), and colleagues conducted a meta-analysis of 12 clinical trials, including 3 randomized and 9 observational studies, published before August 2011. Of 5,079 patients, 2,107 underwent PCI with DES and 2,972 underwent CABG.

Pooled effects calculations showed that the odds of death and the composite of death, MI, or stroke at 1 year both trended lower with DES. However, TVR was sharply increased in DES patients (table 1). After propensity matching, adjusted estimates derived from 5 studies showed similar patterns.

Table 1. One-Year Outcomes: DES vs. CABG

In patients receiving DES, the odds of death were lower and the odds of TVR higher when observational vs. randomized trials were analyzed. Seven studies reporting MI data showed equivalent risk between the 2 treatment options, while 6 studies reporting stroke outcomes showed a significantly lower risk with DES (OR 0.23; 95% CI 0.09-0.58).

“Because CABG has a prove[n] track record of safety and efficacy in patients with [unprotected left main] disease, current practice guidelines recommend CABG as standard procedure” for that indication, Dr. Park and colleagues note. Recent research, they add, has suggested that “PCI may be an acceptable alternative or possibly even preferred strategy.” As such, the 2011 PCI guidelines from the American College of Cardiology, American Heart Association, and Society for Cardiovascular Angiography and Interventions endorsed the possibility of stenting for patients with low lesion complexity and clinical characteristics predicting high surgical risk.

Weighing the Impact of TVR

David P. Taggart, MD, PhD, of the University of Oxford (Oxford, United Kingdom), told TCTMD in a telephone interview that the meta-analysis provides no new insight and “actually confuses things,” noting that Park et al rightly acknowledge the paper’s limitations.

Among them are heterogeneity and the relatively short duration of follow-up. “We already have the 4-year results of SYNTAX. It’s the most definitive piece of work on left main,” he said, referring to findings presented at the 2011 Transcatheter Cardiovascular Therapeutics scientific symposium in San Francisco, CA. The study “essentially shows that overall there’s no difference in [the composite of death, stroke, MI, and repeat revascularization],” though patients with less complex disease did better with DES.

In a telephone interview with TCTMD, Jeffrey W. Moses, MD, of Columbia University Medical Center/Weill Cornell Medical Center (New York, NY), pointed out that TVR, though nearly 4 times more frequent after DES, was still rare. Approximately 10% of DES patients and 3% of CABG patients needed repeat treatment. A number needed to treat of 14 surgeries to prevent 1 TVR with DES “seems to be kind of a heavy burden,” he commented.

Dr. Taggart agreed that TVR should not necessarily deter physicians from performing left main PCI. “[O]n the other hand, repeat revascularization shouldn’t be totally dismissed as a nonevent because it does have some important adverse implications for patients,” he added. “One would accept that it’s not the same as having a stroke, but it’s not a completely benign condition either.”

Regarding whether the findings of the meta-analysis are realistic, Dr. Park responded positively.

“Originally, we aimed to ascertain whether PCI with DES could substitute for bypass surgery in a real-world population,” he said in an e-mail communication with TCTMD. “However, the decision to perform DES implantation or bypass surgery is dependent upon various conditions such as the patient’s comorbidity, urgency of revascularization, appropriateness of interventional procedure, and readiness of surgical back-up.”

Nine of the included reports were observational studies with matched cohorts or consecutive patients. “Therefore, in spite of any [differences in] inclusion criteria across studies, the results obtained from the present meta-analysis can reflect real-world clinical practice,” Dr. Park noted.

Anticipating EXCEL

Recent results and updated guidelines have put the option of DES on the table, Dr. Moses said, stressing that “you’re not an ‘off-the-grid’ interventionalist if you’re entertaining it or doing it.”

He noted that the EXCEL (Evaluation of Xience Prime Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial, pitting everolimus-eluting stents against CABG in left main patients, is the only new data on the horizon. With recruitment still underway, “that’s years in the making. In the meantime, we have what we have,” Dr. Moses said, adding that improvements in pharmacotherapy and newly available DES are likely to have improved results over what has been seen with first-generation paclitaxel-eluting stents in SYNTAX.

Similarly, Dr. Taggart said there is now “broad agreement” about how to treat left main disease with various lesion types and anatomical complexity. Both European and US guidelines “have lifted some of the previous very strict restrictions on PCI,” he continued. “People aren’t wholly comfortable that it’s the same as CABG, but this will be resolved pretty certainly by the EXCEL trial. But bear in mind that EXCEL . . . is excluding the highest-risk patients and those with the most severe disease. For Syntax scores above 33, there seems to be a clear benefit with surgery.”

Dr. Park agreed that newer DES iterations are apt to produce better outcomes. Beyond EXCEL, he said, the NOBLE (Nordic-Baltic-British Left Main Revascularization) trial will provide data regarding repeat revascularization rates in DES PCI vs. CABG.

“On the whole, I do anticipate that DES may fare well in the future and will become a more preferred revascularization option in patients with left main coronary artery disease,” he concluded. “In addition, it should be noted that the incidences of safety outcomes including death, myocardial infarction, or stroke are comparable between PCI and CABG in our study.”

 

---

Source:
Jang J-S, Choi K-N, Jin H-Y, et al. Meta-analysis of three randomized trials and nine observational studies comparing drug-eluting stents versus coronary artery bypass grafting for unprotected left main coronary artery disease. Am J Cardiol. 2012;Epub ahead of print.

Disclosures:

• The paper contains no statement regarding conflicts of interest.
• Dr. Taggart reports serving as the surgical committee chairman for the EXCEL trial.
• Dr. Moses reports serving as a consultant for Boston Scientific and Cordis.
  

Related Stories:

• Japanese Registry Confirms PCI, CABG ‘Comparable’ for Less Complex Left Main Disease
• PCI for Left Main Disease Uncommon in US Clinical Practice
• Randomized Trial Clouds Debate Over DES, CABG in Left Main Disease