Improved Survival Rates Following Aortic Dissection

A new study reveals that although hospitalization rates for aortic dissection (AD) have remained stable, mortality survival rates have improved, particularly in patients undergoing surgical repair.

Researchers at the University of Texas Southwestern Medical Center (Dallas, TX, USA), Yale-New Haven Hospital (YNHH; New Haven, CT, USA), and other institutions reviewed US inpatient Medicare data from 2000 to 2011 to determine trends in hospitalization rates for AD; mortality rates were ascertained through corresponding vital status files. In all, 32,057 initial AD hospitalizations were identified. The overall hospitalization rate for AD remained unchanged, at 10 per 100,000 person-years.

The results showed that for 30-day and one-year mortality associated with AD, the observed rate decreased from 31.8% to 25.4% and from 42.6% to 37.4%, respectively. For patients undergoing surgical repair for type A dissections, the observed 30-day mortality decreased from 30.7% to 21.4%, and the observed one-year mortality decreased from 39.9% to 31.6%. For surgical repair of type B dissections, the 30-day mortality decreased from 24.9% to 21%, and the one-year rate decreased from 36.4% to 32.5%. The study was published in the November 2014 issue of Circulation: Cardiovascular Quality and Outcomes.

“The reason for the improvement in mortality in operative patients might have been subtle improvements on various fronts, such as neuroprotection, improved intraoperative and postoperative pharmacological therapy, operative algorithm and standardized cannulation techniques, and development of care teams,” concluded senior author Harlan Krumholz, MD, of YNNH, and colleagues. “Additionally, part of the improvement in mortality seen with type B dissection could be possible because of the increasing use of the endovascular approach in the treatment of surgically high-risk patients.”

AD occurs when a tear in the inner wall of the aorta causes blood to flow between the layers of the wall of the aorta, forcing them apart. In most cases this is associated with severe characteristic chest or abdominal pain, often with other symptoms that result from decreased blood supply to other organs. The Stanford classification divides AD into two groups; in type A, the ascending aorta and/or aortic arch, and possibly the descending aorta are involved. In type B, the descending aorta or the arch (distal to the left subclavian artery) is dissected, without involvement of the ascending aorta.

Related Links:
University of Texas Southwestern Medical Center
Yale-New Haven Hospital