Initial results, presented at the 2015 Transcatheter Cardiovascular Therapeutics (TCT; 11-15 October, San Francisco, USA), from the Revelution trial indicate that Medtronic’s drug-filled stent is associated with early vessel healing and controlled polymer-free drug elution.
According to a Medtronic press release, the drug-filled stent is designed to eliminate potential drawbacks experienced with bioabsorbable polymers and polymer-free technologies, such as inflammation due to polymer degradation, and uncontrolled drug release in the absence of a polymer. The press release reports that the early results from the Revelution trial indicate that the device achieved rapid and well-controlled stent coverage.
Furthermore, optical coherence tomography (OCT) data from the study demonstrate an early healing profile with an average of 90% strut coverage at one month, with a low rate of malapposed struts (2%) across the six patients analysed. The rate of malapposed struts dropped by 50% within one month post-procedure, further showing the stent’s ability to allow for rapid healing within the vessel. Importantly, the data also showed minimal neointimal hyperplasia formation.
Stephen Worthley – professor at the Royal Adelaide Hospital in Adelaide, Australia and co-principal investigator of the trial – presented the data at TCT. He says: “The novel drug-filled stent truly represents an innovative stent platform with advanced stent manufacturing to optimise clinical performance without the need of a polymer. These patients implanted with the drug-filled stent have shown very promising early outcomes of strut coverage and healing that indicate the new platform may provide many clinical benefits, including shorter dual antiplatelet therapy duration, and we look forward to evaluating how well the stent continues to perform throughout the trial.”
The press release states that the device features a novel tri-layer wire design, which allows the inner sacrificial layer to become a lumen continuously coated with drug. The drug (sirolimus) is contained on the inside of the stent and is released from a single continuous inner lumen through multiple laser-drilled holes on the abluminal side (outer surface) of the stent. This allows for a controlled and sustained polymer-free drug elution over a desired period of time directly into the arterial wall thereby potentially avoiding chronic inflammation and adverse vascular responses. In patients with complex lesions, containing the drug on the inside of the stent protects the coating to reduce concerns related to coating durability during tracking.
The global drug-filled stent study is underway at multiple sites in geographies including Australia and Brazil. The study will enrol 100 patients and will evaluate late lumen loss as measured by quantitative coronary angiography.