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By David Fiore, MD
Professor of Family Medicine, University of Nevada, Reno
Dr. Fiore reports no financial relationships relevant to this field of study.
SYNOPSIS: Investigators conducted the first blinded, randomized trial comparing percutaneous coronary intervention with medical management.
SOURCE: Al-Lamee R, Thompson D, Dehbi HM, et al. Percutaneous coronary intervention in stable angina (ORBITA): A double-blind,randomised controlled trial. Lancet 2017 Nov 1. pii: S0140-6736(17)32714-9. doi: 10.1016/S0140-6736(17)32714-9. [Epub ahead of print].
Percutaneous coronary intervention (PCI) was born in Switzerland in 1977 with the first percutaneous transluminal coronary angioplasty (PCTA), which today is performed worldwide.1 Although it is well known that PCI does not improve mortality or prevent myocardial infarctions, it is considered by many to be the optimal treatment for control of angina. The American College of Cardiology, the American Heart Association, and the European Society of Cardiology give PCI a 1A recommendation for symptom control in patients with “unacceptable angina” despite guideline-directed medical therapy.2,3 The lack of effect of PCI on mortality or morbidity was reinforced by the COURAGE trial (2007), an open-label (unblinded) comparison of PCI and optimal medical therapy, which demonstrated no differences in death or myocardial infarction at three years (although there was a short-term benefit to PCI).4 Despite the evidence and recommendations to only perform PCI in cases in which optimal medical management is unsuccessful in controlling symptoms or is inappropriate or undesired by the patient, it is still performed in more than 500,000 patients each year. In fact, less than half the patients undergoing PCI were found to have optimal medical therapy.4 In its 40-year history, there has never been a blinded, randomized trial comparing PCI with medical management. Al-Lamee et al corrected that oversight.
The ORBITA investigators randomized 200 patients with angina and at least one severe coronary artery stenosis in a single vessel to either sham PCI or actual PCI. All patients received intensive optimal medical management and were followed for six weeks. Blinding was excellent, with no placebo patients correctly identifying their assignment. The primary outcome was change in exercise time on a treadmill. Secondary endpoints included a change in peak oxygen uptake, a change in exercise time to 1 mm ST-segment depression, angina severity, physical limitations, angina stability and angina frequency, Duke treadmill score, and a change in dobutamine stress echocardiographic (DSE) wall motion score index. The authors powered the study to detect a 30-second difference in exercise time based on previous studies, which showed that single antianginal medical therapy provides 48-55 seconds of exercise time.5 ORBITA failed to show a benefit of PCI over optimal medical therapy at six weeks.
Although there has been a buzz in the news, it is not quite the death knell for PCI for stable angina that some have touted (an editorial accompanying the trial was titled, “Last nail in the coffin for PCI in stable angina?”). The first brake on the enthusiasm for burying PCI for stable angina is that some patients may prefer an acute intervention with real, but rare complications to taking triple medical therapy indefinitely. A second concern, which is more related to this particular study, is that the exercise improvement times in both groups were much less than the anticipated improvements (11.8 seconds in the placebo group vs. 28.4 seconds in the PCI group). In addition, the PCI group exhibited more than twice the improvement over the placebo group. While the difference was not statistically significant in this study, if this was born out in a larger study, the conclusion would be quite different.
The investigators of this trial deserve to be lauded for performing the first known placebo-controlled trial of PCI. That alone should be enough to add this trial to the pantheon of ground-breaking medical studies. Hopefully, this will be followed by more placebo-controlled trials for all types of procedures, not just PCI. In the meantime, this trial clearly demonstrates that the decision to go to PCI for stable angina is not a “slam dunk” and that shared decision-making with your patient would be the most appropriate approach.
Financial Disclosure: Internal Medicine Alert’s Physician Editor Stephen Brunton, MD, is a retained consultant for Abbott Diabetes, Actavis, AstraZeneca, Becton Dickinson, Boehringer Ingelheim, Cempra, Janssen, Lilly, Merck, Novo Nordisk, Sanofi, and Teva; he serves on the speakers bureau of AstraZeneca, Boehringer Ingelheim, Janssen, Lilly, Novo Nordisk, and Teva. Contributing Editor Louis Kuritzky, MD, is a retained consultant for and on the speakers bureau of Allergan, Daiichi Sankyo, Lilly, and Lundbeck. Peer Reviewer Gerald Roberts, MD; Editor Jonathan Springston; Executive Editor Leslie Coplin; and AHC Media Editorial Group Manager Terrey L. Hatcher report no financial relationships relevant to this field of study.