NEW YORK — Stent grafts for patients with type B aortic dissections may be no better than best medical management alone in terms of mortality, according to preliminary data presented at the Veith symposium on vascular medicine sponsored by the Cleveland Clinic.
“At 1 year, a slightly higher but not statistically different rate of all-cause mortality was observed in the stent graft arm,” said Dr. Christoph A. Nienaber, head of cardiology and vascular medicine at the University of Rostock (Germany).
In the Investigation of Stent Grafts in Patients with Type B Aortic Dissection (INSTEAD) trial, Dr. Nienaber and his colleagues evaluated 1-year all-cause mortality for patients with uncomplicated type B aortic dissections when treated by stent graft as an adjunct to best medical therapy or by best medical treatment alone.
The study was conducted at seven centers across Europe and involved 136 patients. Patients were included if they had a type B dissection between 2 and 52 weeks of duration, the diameter of the target vessel was no larger than 6 cm, and aortic kinking was less than 75 degrees. Patients were excluded if they had thrombocytopenia or were receiving anticoagulation therapy, had renal failure and/or a serum creatinine level greater than 2.4 mg/dL, complete thrombosis of the false lumen, ongoing infection, or cancer with a life expectancy less than 1 year.
In all, 70 patients were randomized to receive thoracic stents (Talent stent graft by Medtronic Inc.) and tailored antihypertensive therapy, while 66 patients were treated with tailored antihypertensive therapy alone.
Patients were clinically evaluated and imaged at 3, 12, and 24 months. Mortality at 1 year was 10% for the stent group and 3% for the medical management group. Of note, seven patients originally in the medical therapy group crossed over to the stent group and two patients originally in the stent group crossed over to the medical therapy group.
“Early complications within 30 days seemed to be more prevalent in the active treatment group … whereas the later complications, beyond the first month to the end of the first year, were more prevalent and more frequent in the medical group,” said Dr. Nienaber.
Standard treatment for Stanford classification type B aortic dissections has been medical management (antihypertensives). However, 1-year survival for patients treated medically is thought to be about 20%, based on various trials and registries.
Dr. Nienaber disclosed that he has no conflicts of interest.