Stenting Can Improve Chest Pain, Exercise Capacity in Stable Angina

Rasha Al-Lamee, MBBS, PhD
Credit: Imperial College London

Results of the ORBITA-2 trial, which examined use of percutaneous coronary intervention (PCI) in patients with stable angina, suggest the approach improved chest pain, exercise capacity, and quality of life compared to a placebo procedure.

Presented at the American Heart Association Scientific Sessions 2023, results of the trial, which included more than 300 patients, suggest use of PCI was associated with a reduction in mean angina symptom score greater than those in the placebo group.¹

“The key finding of this trial is that it is the first therapy initiated that seems to have the maximum effect. Although PCI is neither risk-free nor cost-free, its use as an upfront procedure can now be considered evidence-based,” said Rasha Al-Lamee, MBBS, PhD, associate professor in cardiology, a British Heart Foundation intermediate research fellow and an interventional cardiology consultant at Imperial College London and Imperial College Healthcare NHS Trust.²

Launched following the conclusion of the original ORBITA trial, ORBITA-2 trial was an investigator-initiated, multicenter, double-blind, randomized, placebo-controlled trial conducted at 14 sites in the United Kingdom. In ORBITA, investigators found stenting did not improve exercise tolerance or chest relative to a placebo procedure, but investigators, including Al-Lamee expressed concern the effector stunting may have been diminished by high levels of guideline-directed background medication. With this in mind, the ORBITA-2 trial aimed to assess the effects of stunting in the absence of antianginal medications.^1,2

Investigators considered patients eligible for participation if they were considered to be clinically suitable for PCI by the referring heart team, had angina or symptoms equivalent to those with angina, had anatomical evidence of at least 1 severe coronary stenosis that was identified on invasive diagnostic coronary angiography or coronary computed tomographic angiography, and had evidence of ischemia on the basis of noninvasive imaging or invasive coronary physiological tests. Patients were eligible to proceed to randomization if they reported at least 1 episode of angina during a 2-week prerandomization symptom assessment phase, which required patients to cease use of antianginal medications.¹

In total, 301 patients underwent randomization, with 151 randomized to PCI and 150 randomized to placebo therapy. This cohort had a mean age of 64 (Standard deviation [SD], 9) years and 79% were men. At the time of enrollment, 96% of participants had angina of Canadian Cardiovascular Society severity class 2 or 3.¹

A baseline analysis revealed ischemia was present in 1 cardiac territory in 80% of patients, in 2 territories in 17%, and in 3 territories in 2%. Additionally, in target vessels, the median fractional flow reserve was 0.63 (interquartile range, 0.49 to 0.75) and the median instantaneous wave-free ratio was 0.78 (interquartile range, 0.55 to 0.87).¹

The primary outcome of interest for the trial was the angina symptom score at week 12, which was calculated daily based on the number of angina episodes that occurred on a given day, the number of antianginal medications prescribed on that day, and clinical events, including the occurrence of unblinding owing to unacceptable angina or acute coronary syndrome or death.¹

After 12 weeks of follow-up results indicated the PCI group had a mean gain symptom score of 2.9 and the placebo group had a mean angina symptom score of 5.6 (Odds Ratio, 2.1; 95% Confidence Interval [CI], 1.41-3.47; P <.001). Investigators noted 1 patient in the placebo group had unacceptable angina leading to unblinding and acute coronary syndromes were observed among 6 patients in the placebo group compared to 4 patients in the PCI group.¹

Investigators cautioned overinterpretation of the findings from ORBITA-2. Reasons cited by investigators included a smaller-than-expected effect size on improvement in exercise time and the inability of PCI to be universally effective, with investigators pointing out 59% of those who received stents continued to report chest pain.^1,2

“I hope that the two trials will be used together to give patients and medical teams the choice of two treatment strategies with similar levels of benefit. They each have their own benefits, risks and limitations that should form part of the decision-making process,” Al-Lamee added.² “Importantly, the first therapy administered, antianginal medication or PCI as an antianginal procedure, appears to deliver most of the available symptomatic response.”

References:

1. Rajkumar CA, Foley MJ, Ahmed-Jushuf F, et al. A Placebo-Controlled Trial of Percutaneous Coronary Intervention for Stable Angina. New England Journal of Medicine. 2023; DOI: 10.1056/NEJMoa2310610
2. Heart stenting relieved chest pain and improved exercise capacity. American Heart Association. November 11, 2023. Accessed November 11, 2023. https://newsroom.heart.org/news/heart-stenting-relieved-chest-pain-and-improved-exercise-capacity.