Why NOBLE and EXCEL Are Consistent With Each Other and With Previous Trials
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- clinical trials as topics
- coronary artery disease
- patient outcome assessment
- percutaneous coronary intervention
The optimal management of patients with left main coronary artery disease (CAD) has been the subject of intense investigation for decades. Since the Yusuf meta-analysis of 1994 that demonstrated the survival advantage of coronary artery bypass grafting (CABG) surgery over medical management alone, clinical practice has often favored revascularization-based approaches.1 Over the past decade, improvements in stent technology and advances in medical therapy have led to clinical trials comparing CABG, the gold standard, with percutaneous coronary interventions (PCI). At the 2016 Transcatheter Cardiovascular Therapeutics annual meeting held in Washington, DC, 2 important clinical trials comparing PCI with CABG for left main CAD were presented and simultaneously published. These studies were the NOBLE trial (Nordic-Baltic-British Left Main Revascularization),2 and the EXCEL trial (Evaluation of XIENCE versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization).3 Both trials had a noninferiority design, attempting to demonstrate that the experimental treatment, PCI, was not substantially worse than the control treatment, CABG, within a predefined acceptable extent of clinical difference based on both statistical reasoning and clinical judgment. At first glance, the apparently disparate findings of these trials may have triggered a perfect storm for guideline panelists; however, it is our opinion that the findings from these 2 trials are consistent with each other and with other modern trials that compared PCI with CABG for the treatment of advanced CAD.
The NOBLE study reported that PCI was inferior to CABG with regard to the primary end point of major adverse cardiac and cerebrovascular events, with 46% excess hazard with PCI over CABG at 5 years (P=0.01).2 Criticisms formulated about NOBLE include the …