Background. Surgery for acute type A aortic dissection confers a risk for significant bleeding. We analyzed the impact of massive bleeding on complications after surgery for acute type A aortic dissection.

Methods. Patients undergoing surgery for acute type A aortic dissection from the retrospective multicenter Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) database 2005-2014 were eligible. Massive bleeding was defined according to the Universal Definition of Perioperative Bleeding. The primary outcome measure was early mortality and secondary outcome measures were perioperative stroke, mechanical ventilation more than 48 h, new-onset dialysis, and intensive care unit stay. Propensity score matching was performed to adjust for differences in covariates.

Results. Nine hundred ninety-seven patients were included, of whom 403 (40.4%) had massive bleeding. In the propensity score-matched cohort (344 pairs), patients with massive bleeding had higher 30-day mortality (17.2 versus 7.6%, p < .001), mechanical ventilation more than 48 h (52.8 versus 22.6%, p < .001), perioperative stroke (24.3 versus 14.8%, p = .002), new-onset dialysis (22.5 versus 4.9%, p < .001), and longer intensive care unit stay (6 versus 3 days, p < .001), compared with patients without massive bleeding. Risk factors for massive bleeding were previous cardiac surgery, preoperative clopidogrel or ticagrelor therapy, DeBakey type I dissection, and localized or generalized malperfusion.

Conclusions. Massive bleeding in surgery for acute type A aortic dissection is associated with a markedly increased risk for severe complications as well as early death. Further improvement of surgical technique and pharmacological optimization of coagulation is paramount to possibly improve outcomes in acute type A aortic dissection repair.