Late Breaking Science Trial: ORBITA Debate at Scientific Sessions 2018

“Life is like riding a bicycle. To keep your balance you must keep moving.” -Albert Einstein.

There may scarcely be any other sphere of medicine than interventional cardiology where the quote is more applicable. In 2017, the paradigm shifting ‘Objective Randomised Blinded Investigation With Optimal Medical Therapy of Angioplasty in Stable Angina’ – ORBITA  trial was presented and published.The results of this trial indicated that among patients with stable angina, percutaneous coronary intervention/PCI does not result in greater improvements in exercise times or anginal frequency compared with a sham/placebo procedure. This was despite the presence of anatomically and functionally significant stenoses. PCI did however resolve ischemia more effectively, as ascertained by follow-up stress.

This was clearly a landmark trial, but several issues were put forward as limiting factors. The trial was well conducted, with careful assessments of ischemia pre- and post-procedure, and appropriate use of antianginal medications-which unfortunately has been hard to replicate outside of the controlled setting of a trial, in the tribulations of real-world medical practice. Although powered for exercise treadmill-based endpoints, the trial has been noted to be too small to address a question of clinical benefits with PCI. Moreover, changes in Duke treadmill score and exercise time were both numerically higher in the PCI arm, and it is unknown if a larger sample size would have detected more modest improvements in exercise capacity.

The controversies and ‘buzz’ had prompted me to follow the data as a early career interventionist-and I cued in keenly for the short debate session on the same at the Annual Scientific Sessions of the American Heart Association 2018 (#AHA18) .Dr. Brahmajee Nallamothu, Editor of the Circulation: Quality and Outcomes and a Professor of Medicine at the University of Michigan- speaking in favor (PRO) of the findings from the ORBITA trial mentioned that while the myth that percutaneous coronary intervention’s prolong the life has long been debunked, a commonly held notion, and indeed one of the main reasons for performing PCI was to improve the quality of life in patients with significant coronary artery disease and symptoms. And ORBITA actually indicated that in a relatively healthy patient population, in a carefully conducted placebo controlled trial, the postulated benefits imparted with PCI were likely minimal. He went on to note that the trial was representative of a “real world” population of middle-aged patients with symptomatic coronary artery disease and  also referred to images from the original Lancet publication which indicated that the lesions that were treated appeared quite significant indeed. He concluded that in spite of  ongoing debates, results from ORBITA changed the way he discussed planned coronary intervention with his patients where he has changed his practice by incorporating a more tempered discussion on anticipated benefits with PCI, and has had greater conviction in advocating for more aggressive “medical” therapy.

Dr. Jay Giri from the University of Pennsylvania next took the stand in presenting the antagonistic (CON) version of the debate. Vying away from the anticipated track of discussing largely well publicized limitations of ORBITA, Dr. Giri took an innovative approach in going back to the fundamentals of the expected benefits from PCI. He presented data from recent studies which showed that PCI did reduce symptoms in patients with significant ischemia to a greater extent than optimal medical therapy alone. He also pointed to the fact that PCI reduced ischemia as well, and based on current understanding may mean favorably impacting future risk of subsequent adverse cardiac events including spontaneous myocardial infarctions (although that hypothesis is under evaluation with the on going ISCHEMIA trial). He honed in on the fact that the results from ORBITA had been sensationalized in both directions by ardent proponents and the media alike, while the “reality” was probably in between. With ongoing sub group analyses from the ORBITA trial itself, as well as follow-up studies being conducted, this is a rapidly evolving arena- and trainees /early career interventionists would do well in keeping themselves abreast of the nuances of the evolving data.


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