Modifiable Risk Factors for Early Mortality in Low-Risk Penn Class Aa Acute Type A Aortic Dissection Patients – A Descriptive Study

Abstract

Background: Acute Type A aortic dissection (ATAAD) without end-organ or generalized ischemia is Penn class Aa and considered low-risk. Nevertheless, surgical mortality can be considerable in this subgroup and may be related to modifiable factors. The objective of this study was to analyze 30-day mortality among ATAAD Penn class Aa patients with special reference to modifiable perioperative factors. Methods: Among all patients operated for ATAAD from 1990 to 2010, all Penn class Aa patients dying within 30 days were included in a retrospective descriptive study. Pre- and intraoperative variables related to 30-day mortality were retrieved from medical records and analyzed according to avoidable or modifiable errors such as initial misdiagnosis, preoperative delay, adverse events, and forced and unforced additional procedures. Results: Overall 30-day mortality was 13% (31/235). Intraoperative death occurred in 32% (10/31) of patients. Among patients not dying intraoperatively, stroke was the most common complication (48%) and cause of death overall, followed by reoperation for bleeding (33%), respiratory failure (24%), and renal failure (14%). Preoperative errors were detected in 48% of patients; one-third had initial misdiagnosis and/or diagnostic delay ≥ 24 hours. Intraoperative error(s) was noted in 74% of patients, mainly involving adverse event(s), forced additional procedures, and assisted bleeding control, with each affecting approximately 45% of patients. Conclusion: Modifiable errors in pre- and intraoperative management are not uncommon among Penn class Aa patients and may contribute to 30-day mortality. Efforts should be made to mitigate the effects of modifiable factors to reduce early mortality in low-risk ATAAD.