Drug-coated balloons may offer alternative to heart stents

Drug-coated balloons could offer some patients with coronary artery disease an alternative to permanently implanted metal stents. An analysis led by the University of East Anglia (UEA) found no meaningful difference between the two treatments in cardiovascular death or heart attacks. However, patients treated with balloons in larger coronary arteries may be more likely to require another procedure later.

The findings are based on data from ten randomised clinical trials involving 7,832 patients. The results add to growing interest in a "leave nothing behind" approach to coronary interventions, in which blood flow is restored without permanently placing a device inside the artery.

Balloon instead of permanent implant

Coronary artery disease occurs when arteries supplying the heart become narrowed, potentially reducing blood flow and increasing the risk of cardiovascular events. Percutaneous coronary intervention (PCI), commonly known as angioplasty, can be used to reopen narrowed arteries. Drug-eluting stents are currently widely used during these procedures. These small metal mesh tubes keep the artery open and release medication intended to reduce the risk of renewed narrowing.

Drug-coated balloons take a different approach. The balloon is inflated temporarily at the narrowed section of the artery and delivers medication directly to the vessel wall. It is then removed, leaving no permanent implant behind. The UEA researchers compared both approaches across the ten trials. According to lead researcher Natasha Corballis of Norwich Medical School, there was no meaningful difference in the most serious outcomes. Cardiovascular mortality was comparable and heart attack rates were almost identical. The findings remained similar when the researchers excluded studies involving only small coronary arteries, where drug-coated balloons already have a more established evidence base.

More repeat procedures in larger arteries

The analysis did identify a possible disadvantage. In larger coronary arteries, patients treated with drug-coated balloons were more likely to require another revascularisation procedure to reopen the vessel. The researchers caution against drawing firm conclusions from this result. There was substantial variation between the studies and the difference was strongly influenced by one clinical trial. Larger studies with longer follow-up are therefore required to determine whether drug-coated balloons can be used as broadly as conventional stents, particularly in larger vessels and patients with more complex coronary lesions.

If confirmed, avoiding a permanent implant could have several potential advantages. Senior author Vassilios Vassiliou of Norwich Medical School said the approach could reduce some longer-term complications associated with stents while preserving treatment options if coronary disease progresses. For now, however, the findings support drug-coated balloons as a potential alternative for selected patients rather than a replacement for stents in coronary interventions.

Technology improves stent assessment

At the same time, researchers are also working to make conventional stent treatment more precise. We previously reported on DeepNeo, an AI tool developed by Helmholtz Munich, the Technical University of Munich and TUM University Hospital. DeepNeo automates the assessment of coronary stents using intravascular optical coherence tomography (OCT). After implantation, tissue grows around the stent as part of the healing process. Abnormal tissue growth can contribute to renewed narrowing or blockage of the artery.

Manually assessing these patterns on OCT images is time-consuming. DeepNeo was developed to identify different healing patterns automatically and measure characteristics including tissue thickness and stent coverage. The researchers trained the system using 1,148 OCT images from 92 patient scans. In an animal model, it correctly identified unhealthy tissue in 87 percent of cases compared with detailed laboratory analysis. Analysis of human scans also showed results that closely matched assessments by clinical experts.

DeepNeo therefore addresses a different part of coronary treatment than drug-coated balloons. While AI could improve follow-up and assessment when a permanent stent is implanted, balloon treatment explores whether some patients can be treated without leaving an implant behind at all.

Personalised coronary treatment

Together, the developments illustrate how coronary interventions are moving beyond a single standard approach. Advances in drug delivery, intracoronary imaging and AI are creating opportunities to tailor treatment more closely to individual vessels and patients.

For drug-coated balloons, the key question is now whether the encouraging results can be reproduced in larger and more complex coronary arteries over longer follow-up periods. The UEA researchers conclude that further large clinical trials are necessary before broader use can be recommended. The current evidence nevertheless suggests that, for selected patients, restoring blood flow may not always require leaving a permanent metal implant behind.