In-Hospital Mortality of Patients With Acute Type A Aortic Dissection Hospitalized on Weekends Versus Weekdays

In acute aortic dissection, weekend admissions are reported to be associated with increased mortality compared with weekday admissions.

This study aimed to determine whether patients with acute type A aortic dissection (ATAAD) admitted on weekends had higher in-hospital mortality than those admitted on weekdays in the Tokyo metropolitan area, where we developed a patient-transfer system for aortic dissection.

Data were collected during the first year after our transfer system began (cohort I) and in the subsequent years from 2013 to 2015 (cohort II).

We studied 2,339 patients (500 in cohort I; 1,839 in cohort II) with ATAAD. Patients with weekend admissions had higher in-hospital mortality than those with weekday admissions in cohort I. In association with increased interfacility transfer during weekends and reduced mortality at non-high-volume centers, the in-hospital mortality in the weekend group improved from 37.2% in cohort I to 22.2% in cohort II (P < 0.001). After inverse probability weighting adjustment, weekend admission was associated with higher in-hospital mortality in cohort I (odds ratio: 2.28; 95% confidence interval: 1.48 to 3.52; P < 0.001), but not in cohort II (odds ratio: 0.96; 95% confidence interval: 0.75 to 1.22; P = 0.731). On multivariable analyses, weekend admission was associated with higher in-hospital mortality in combined cohort I+II; the associations between weekend admission and mortality were not significant in cohort II.

We found a significant reduction in in-hospital mortality in patients with weekend admissions for ATAAD. No mortality difference between weekend and weekday admissions was observed in the later years of the study.