ORBITA: First Placebo-Controlled Randomized Trial of PCI in CAD Patients
Findings from the ORBITA study presented at TCT 2017 and published in the Lancet suggest that in patients with medically treated angina and anatomically and hemodynamically severe coronary stenosis, percutaneous coronary intervention (PCI) may not increase exercise time, compared to placebo. This is the first placebo-controlled randomized trial of PCI in this patient population.
ORBITA randomized 200 patients with severe (≥70%) single-vessel stenoses to either PCI (n=105) or placebo (n=95) using a blinded sham procedure where neither patients nor their physicians knew which group they were assigned. All patients underwent cardiopulmonary exercise testing, symptom questionnaires, and dobutamine stress echocardiography before and six weeks after the procedure. The primary endpoint was difference in exercise time increment between arms
Overall findings showed no significant difference in the primary endpoint of exercise time increment between arms. However, PCI did significantly reduce ischemia as assessed by FFR, iFR and stress echo.
In terms of significant adverse events, researchers reported four wire complications in the placebo group requiring PCI and five major bleeding events, two in the PCI group and three in the placebo group.
"The results are consistent with the clinical experience that patients with stable angina report symptom relief after unblindedPCI," researchers said. "ORBITA shows that this relief relies on both the true physical effect and the placebo effect."
In a corresponding editorial, David L. Brown, MD, FACC, and Rita F. Redberg, MD, FACC, question whether the ORBITA results are the "last nail in the coffin for PCI in stable angina." They write: "Health care providers should focus their attention on treating patients with stable coronary artery disease with optimal medical therapy, which is very effective, and on improving the lifestyle choices that represent a large proportion of modifiable cardiovascular risk, including heart-healthy diets, regular physical activity, and abstention from smoking."
However, ACC.org Editor-in-Chief Kim Eagle, MD, FACC, urges caution before nailing the coffin shut given the very small study and no differences in hard endpoints. "Much larger studies are needed before one could justify this approach in patients. What really matters is how patients feel and how long they survive without serious complications. A much larger study to properly address those questions is badly needed in the contemporary era."
ACC Board of Governors Chair Hadley Wilson, MD, FACC, also urges additional studies. "Even though exercise time was not significantly improved with PCI, ischemia was reduced by objective testing, which has been correlated in findings from the COURAGE nuclear sub-study and other studies with improved long-term outcomes," he said.
Keywords: Coronary Artery Disease, Coronary Artery Bypass, TCT17, Transcatheter Cardiovascular Therapeutics
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