With ORBITA-2, percutaneous coronary intervention (PCI) gets a second chance to prove it’s better than placebo for symptom relief in stable angina after the first randomized sham-controlled trial of stenting came out negative.
MedPage Today spoke with principal investigator, Rasha Al-Lamee, MD, of Imperial College London, about what to expect from the new trial.
What is the rationale behind ORBITA-2?
Al-Lamee: This trial builds on our experience from ORBITA-1. We were kind of shocked and surprised by some of the results. What we want to do now is expand the question out to study a much wider population of more clinically-applicable patients with stable angina.
ORBITA-1 left several unanswered questions, the main being whether angioplasty truly delivers symptom relief in these patients.
We saw very clearly a definitive reduction in ischemia on stress echo, instantaneous wave-free ratio, and fractional flow reserve. But the effect of angioplasty on symptoms and exercise time was much less than we expected. The only endpoint where we saw a clear difference was freedom from angina in which one in five more patients in the angioplasty arm reported complete resolution of their symptoms.
What are some differences between ORBITA-1 and ORBITA-2?
Al-Lamee: ORBITA-2 is double the size of ORBITA-1, at 400 patients, and with a longer follow-up period of 12 weeks. The wider inclusion criteria now also include patients with a range of disease from single vessel disease up to multivessel disease — but not chronic total occlusion or left main disease. These are patients presenting to normal clinical pathways with normal angina symptoms on real-world medication.
Also, the primary endpoint is no longer treadmill exercise time, but based more on a patient-centered outcome: anginal frequency on a smartphone application.
Another key difference is that while operators were blinded to physiology in ORBITA-1 (so that we could find the physiology cutpoint for angina relief), in ORBITA-2 it is unblinded, so the operator must provide evidence of ischemia on an invasive or non-invasive test.
Do you expect ORBITA-2 to be a hard trial to enroll?
Al-Lamee: Patients are being enrolled at three centers in the U.K. With our wider inclusion criteria, we are finding it easier to find patients because patients with single vessel disease were hard to find for ORBITA-1. We’re doing very well at counseling patients to the importance of being in the trial. And having the ORBITA-1 results is helping in the recruiting.
We hope to expand the number of participating sites in [the] future to further help recruitment.
When can we expect to see the results and what is the status of the trial now?
Al-Lamee: It’s always difficult to say with clinical trials, but we hope to present the data in 3 years or so.