Positive findings from their placebo-controlled trial show that angioplasty is an evidence-based, first-line treatment for patients with stable angina and that they needn't necessarily be treated first with antianginal medications, say the ORBITA-2 investigators.
Where angioplasty and stents to open up clogged coronary arteries fit into the treatment of stable angina has been quandary, with guidelines saying it should be reserved for patients who don’t do well on antianginal medications but in actual practice, many people are treated with angioplasty with minimal or no treatment with antianginal medications, which include beta blockers and calcium channel blockers.
Researchers presenting the results of the ORBITA-2 trial today at the American Heart Association Scientific Sessions meeting in Philadelphia said their findings may resolve the issue by providing evidence that an angioplasty-first approach without antianginal medication is an effective approach to treating stable angina as is one that preferences first treating patients with medications
“We hope that we’ve now offered a choice of two, first-line, evidence-based pathways,” said Rasha Al-Lamee, M.B.B.S., Ph.D., reader (equivalent to associate professor) in cardiology,British Heart Foundation intermediate research fellow and an interventional cardiology consultant at Imperial College London and Imperial College Healthcare NHS Trust.
The positive results for angioplasty in ORBITA-2 come with the caveat that 59% of the patients treated with angioplasty, known formally as percutaneous coronary intervention, still had angina symptoms.
Al-Lamee, one of the ORBITA-2 investigators, said at a press briefing that she believes that guidelines that currently position angioplasty as a second-line treatment after antianginal medication “may systematically select patients with the least to gain” from the procedure.
The stage was set for the ORBITA-2 trial was set by results from the original ORBITA trial, reported in 2017, which upended the thinking about angioplasty when it showed that it did not improve angina and performance on standardized tests of physical activity any more than a placebo procedure. Al-Lamee said, though, that the antianginal medications that the ORBITA study volunteers were taking may have attenuated the positive effects of angioplasty. One of the unusual features of the ORBITA-2 trial’s design is that the study volunteers stopped taking antianginal medications once they were enrolled.
“We did this because we had one primary question, which was does coronary angioplasty without angina medication improve angina improve angina compared to placebo,” said Al-Lamee, To guard against any harm from cessation of treatment, the study volunteers had around-the-clock access to clinicians involved in the trial and could get antianginal mediation if they started experiencing chest pain.
The trial included 301 patients enrolled at 14 sites in the United Kingdom. The investigators devised a novel system for measuring angina that included angina symptoms, use of antianginal medications and acute coronary syndromes on a weighted basis. The study volunteers tracked their angina symptoms with a smartphone application.
At the end of study’s prescribed 12 weeks, the patients who had angioplasty were more than two times more likely to have improved on this bespoke angina symptom, which was the primary end point, than those randomized to the placebo arm. A press release about the study said the study volunteers in the angioplasty groups were three times more likely to be free from angina than the those in the placebo. The results also showed the angioplasty group performed better on an exercise test.
Another notable feature of the trial is the lengths the investigators went to blind the study volunteers from knowing whether they had been treated with angioplasty or were in the placebo. They randomized patients to angioplasty or the sham procedure after the patients were rendered unconscious with benzodiazepines and opiates.