Type A acute aortic dissection still carries high mortality risk in contemporary era, JAMA study reveals

USA: Type A acute aortic dissection (TAAAD) still carries a high death risk in patients not receiving surgery, researchers suggest in a cohort study published in JAMA Cardiology. 

The study found that in the contemporary era, the overall mortality rate for TAAAD was 5.8% at 48 hours. The mortality rate of TAAAD for patients in the medical group was 0.5% per hour (23.7% at 48 hours). The 48-hour mortality, however, decreased to 4.4% among those in the surgical group. 

Early data showed a mortality rate of 1% to 2% per hour for acute type A aortic dissection during the initial 48 hours. This mortality rate continues to be cited despite advances in diagnostic testing and treatment. The reason for this could be a lack of contemporary data characterizing early mortality and the effect of timely surgery. 

Against the above background, Kevin M. Harris, Minneapolis Heart Institute Foundation, Abbott Northwestern Hospital, Minneapolis, Minnesota, and colleagues examined data for patients with TAAAD in the International Registry of Acute Aortic Dissection between 1996 and 2018. Grouping of the patients was done according to the mode of their intended treatment, medical or surgical. 

Assessment of mortality was done in the initial 48 hours following hospital arrival using Kaplan-Meier curves. The evaluation of in-hospital complications was also done. 

The researchers identified a total of 5611 patients with TAAAD based on intended treatment: 91.4% in the surgical group (67.1% male; mean age, 60.4 years) and 8.6% in the medical group (52.5% male; mean age, 70.9 years). 

"In the contemporary era, the mortality rate in patients recognized with TAAAD in the first 48 hours is 0.12% per hour," the researchers wrote in their study. This rate is lower compared to that reported in the 1950s and could be due to advances in surgery, imaging, and medical treatment over the past 60 years, they explained. 

48-hour mortality of medically managed patients in this study was  23.7% or 0.5% per hour. Patients who are deemed eligible for repair, most of whom ultimately receive surgery, have a lower mortality risk, with 4.4% mortality after 2 days. Importantly, a subgroup of initially stable patients experienced catastrophic and often unforeseen complications, including aortic rupture and cardiac tamponade and, and died before surgery. 

"These data serve as a sobering reminder that TAAAD merits efforts to improve recognition, as well as rapid transfer and surgical treatment protocols," the authors conclude.

Reference:

Harris KM, Nienaber CA, Peterson MD, et al. Early Mortality in Type A Acute Aortic Dissection: Insights From the International Registry of Acute Aortic Dissection. JAMA Cardiol. Published online August 24, 2022. doi:10.1001/jamacardio.2022.2718