TCT 2016: Hybrid sirolimus-eluting stent does not meet primary endpoint versus everolimus-eluting stent
A prospective, randomized trial failed to show non-inferiority of a hybrid sirolimus-eluting stent with biodegradable polymer versus an everolimus-eluting stent with durable polymer with regards to the primary endpoint of in-segment late lumen loss among patients who had successful chronic total occlusions recanalization.
After nine months, patients who received the Orsiro hybrid sirolimus-eluting stent also had a significantly higher rate of binary restenosis compared with those who received the Xience everolimus-eluting stent. The FDA has approved the Xience stent, but it has not approved the Orsiro stent.
The researchers mentioned the study was not powered for clinical endpoints, so the results should be interpreted as hypothesis-generating.
Lead researcher Koen Teeuwen, MD, presented the findings Nov. 2 in a first report investigations session at the Transcatheter Cardiovascular Therapeutics scientific symposium in Washington, D.C.
The results were simultaneously published online in the Journal of the American College of Cardiology: Cardiovascular Interventions.
Biotronik and Abbott Vascular funded the study. Biotronik manufactures the Orsiro stent, and Abbot Vascular manufactures the Xience stent.
In this trial, known as PRISON IV, the researchers enrolled 330 patients at two Belgian and six Dutch high-volume PCI centers between February 2012 and June 2015. All patients were at least 18 years old and had successfully recanalized native total or chronic total coronary occlusions. They were excluded if they had total occlusions of venous or arterial bypass grafts or in-stent occlusions.
The mean age was 62 years old, while 89.2 percent of patients in the Orsiro group and 95.2 percent of patients in the Xience group had an occlusion for at least three months. The mean length of the occlusion was 20.4 mm and 20.9 mm, respectively, while the mean stent length was 52.4 mm and 52.3 mm, respectively. None of the differences were statistically significant.
The researchers said the primary non-inferiority endpoint of in-segment late lumen loss was not met. The mean late lumen loss was 0.13 mm in the Orsiro group and 0.02 mm in the Xience group. The in-stent late lumen loss was 0.12 mm and 0.07 mm, respectively, while the incidence of in-stent/in-segment binary restenosis was 8 percent and 2.1 percent, respectively. Further, the reocclusion rates were 2.2 percent and 1.4 percent, respectively.
The researchers acknowledged a few limitations of the study, including that their definitions of total coronary occlusions and chronic total occlusions differed from the accepted definition. They defined a total coronary occlusion as absence of antegrade flow of contrast distal to the occlusion or minimal antegrade flow of contrast distal to the occlusion TIMI 1 flow in the presence of bridging collaterals. They defined chronic total occlusion as a total coronary occlusion with an estimated duration of at least three months.
“Future developments in stent technology should focus on the challenging characteristics of CTOs to improve device efficacy and clinical outcomes.” Teeuwen said in a news release.
Executive Editor
Tim Casey joined TriMed Media Group in 2015 as Executive Editor. For the previous four years, he worked as an editor and writer for HMP Communications, primarily focused on covering managed care issues and reporting from medical and health care conferences. He was also a staff reporter at the Sacramento Bee for more than four years covering professional, college and high school sports. He earned his undergraduate degree in psychology from the University of Notre Dame and his MBA degree from Georgetown University.