Trial shows relief for those living with chronic angina

A new UK-led study has found that a procedure to reopen a fully blocked heart artery can significantly reduce chest pain and improve people’s quality of life.

Researchers from Anglia Ruskin University (ARU) say this is the first time the treatment, known as chronic total occlusion percutaneous coronary intervention (CTO PCI) has been tested in a rigorous, placebo‑controlled trial. The results have been published in the JACC journal.

The ORBITA‑CTO study involved 50 patients, median age 64, across two UK hospitals. All had a chronic total occlusion (CTO), which is a complete blockage of one of the arteries supplying blood to the heart, for at least three months and had experienced angina for around a year despite medication. Patients were randomly assigned to either CTO intervention, also known as angioplasty, or a placebo procedure, where no angioplasty was performed.

The research team then tracked daily angina episodes, recorded using a smartphone app, medication use, quality‑of‑life scores and doctors’ assessments of angina severity.

Patients in the CTO angioplasty group were four times more likely to have improved angina scores. On average during the 168-day follow-up period, the patients who received CTO angioplasty had 31 more angina-free days than those in the placebo group.

Patients in the intervention group also saw a statistically significant improvement in their quality-of-life scores and a reduction in the physician-assessed severity of their angina, compared with those in the placebo group.

CTOs usually occur because fatty deposits build up over time. Unlike a heart attack, which is caused by a sudden clot, CTOs develop slowly and often lead to ongoing angina – the chest pain felt particularly during physical activity. Up to 30% of people having a coronary angiogram are found to have a CTO, and the figure is over 50% among people who previously had bypass surgery. Risk factors include smoking, high blood pressure, high cholesterol, diabetes, and a family history of heart disease.

Despite how common it is, CTO is often left untreated because fixing it can be technically challenging. Angioplasty works by inflating a tiny balloon inside the artery and placing a stent to keep it open.

But in CTO cases the artery is completely blocked, often with hardened plaque that has built up over many years. This makes the procedure more complex, taking around three hours instead of under an hour, and requiring specialist skills and equipment.

The authors say 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.

The study was funded by a grant from Abbott Vascular. The Essex Cardiothoracic Centre is part of Mid and South Essex NHS Hospitals Trust.