Where angioplasty and stents to open blocked coronary arteries fit into the treatment of stable angina, guidelines say it should be reserved for patients who are not doing well antianginal drugs but in actual practice, many people are treated with angioplasty with minimal or no treatment with antianginal drugs, which include beta blockers and calcium channel blockers.
Researchers who presented results from the ORBITA-2 trial today at the American Heart Association’s Scientific Sessions in Philadelphia said their findings could solve the problem by providing evidence that first-line angioplasty without antianginal drugs is an effective approach to treating stable angina. one who prefers treating patients with drugs first
“We hope to have now offered a choice between two first-line evidence-based pathways,” said Rasha Al-Lamee, MBBS, Ph.D., Reader (Equivalent to Associate Professor) in Cardiology, British Heart Foundation Intermediate Research Fellow and Interventional Consultant cardiology 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 patients treated with angioplasty, known as percutaneous coronary intervention, still had angina symptoms.
Al-Lamee, one of the ORBITA-2 investigators, told a news briefing that she believes guidelines that currently place angioplasty as a second-line treatment after antianginal drugs “may systematically select patients who benefit least” from the procedure.
The stage for the ORBITA-2 trial was set by results from the original ORBITA trial, published in 2017, which overturned opinion on angioplasty when it showed that it did not improve angina and performance on standardized physical activity tests any more than a placebo procedure. Al-Lamee said, however, that the antianginal drugs taken by the volunteers in the ORBITA study may have weakened the positive effects of angioplasty. One of the unusual features of the ORBITA-2 trial design is that the trial volunteers stopped taking antianginal medications after they were enrolled.
“We did this because we had one primary question, which was whether coronary angioplasty without angina drugs improves angina compared to placebo,” Al-Lamee said. To protect against any harm from treatment discontinuation, study volunteers had around-the-clock access to the clinicians involved in the trial and could receive antianginal intervention if they developed chest pain.
The trial involved 301 patients at 14 sites in the UK. The researchers designed a new system for measuring angina that included angina symptoms, antianginal drug use, and acute coronary syndromes on a weighted basis. Volunteers in the study tracked their angina symptoms with a smartphone app.
At the end of the study’s prescribed 12 weeks, patients who had angioplasty were more than twice as likely to have improved this adjusted angina symptom, the primary endpoint, than those randomized to the placebo group. A press release about the study states that study volunteers in the angioplasty groups were three times more likely to be free of angina than those who received a placebo. The results also showed that the angioplasty group performed better on the exercise test.
Another notable feature of the trial was the lengths the researchers went to to blind the study volunteers from knowing whether they were being treated with angioplasty or were on a placebo. They randomized patients to angioplasty or a sham procedure after the patients were sedated with benzodiazepines and opiates.