In patients with symptomatic single-vessel coronary chronic total occlusion (CTO), PCI for CTO improved angina beyond placebo, according to findings from the ORBITA-CTO trial presented at ACC.26 and simultaneously published in JACC.

The multicenter, blinded trial randomized 50 patients with single-vessel CTO, but without bystander coronary disease, to either CTO PCI or placebo. Blinding was maintained using auditory isolation and deep conscious sedation. For all patients, antianginal medications were stopped at randomization and re-introduced on a patient-initiated protocol. Researchers repeated assessments at six-months follow-up. The primary efficacy outcome was the angina symptom score, assessed by the ORBITA-app, anti-anginal use and override events. Secondary outcomes included symptom and quality-of-life (QoL) questionnaires and blinding fidelity.

While the results showed that angina scores improved in the placebo group, overall results found CTO PCI resulted in an immediate and sustained improvement in angina symptom score compared with placebo, largely due to a reduction in the number of angina episodes. On average during the 168-day follow-up period, patients who received CTO PCI cohort had 31 more angina-free days than those in the placebo group.

CTO PCI patients also saw a statistically significant improvement in their QoL scores and a reduction in the physician-assessed severity of their angina, compared with those in the placebo group. No patients died, had a heart attack or had to withdraw from the study due to worsening angina.

“Our results demonstrate in a randomized, double-blinded study design that coronary angioplasty and stenting is an effective treatment for patients who have a chronic total occlusion and chronic anginal chest pain,” said principal investigator John Davies, MRCP, PhD. “These results provide hope for both patients with CTO and their doctors that angioplasty with stenting can be successful and can result in reduced angina pain and better quality of life.”

The study has several limitations. With just 50 patients, it was relatively small, and all patients were treated in specialized centers by experienced operators. Patients with the most complex CTO features were also excluded from the study, and the results cannot be extrapolated to these patients. Further research is required to determine the effectiveness of CTO angioplasty in patients with highly complex CTO and to identify more precisely the patients likely to benefit the most from CTO angioplasty, Davies said.

In a related editorial comment, Ziad A. Ali, MD, DPhil, writes that ORBITA-CTO “demonstrates that the benefit of CTO PCI is not purely an artifact of expectation, while also reminding us that the magnitude of that benefit is measured and patient-specific.” He goes on to add that “for a field that has long relied on technical accomplishment as a surrogate for clinical effect, this kind of evidence is invaluable. …The next challenge for the field is to determine when, and for whom, it works best.”

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Chronic Angina

Keywords: ACC Annual Scientific Session, ACC26, Percutaneous Coronary Intervention, Angina, Stable, New Orleans