Predictors of Postoperative Acute Renal Failure in Type A Aortic Dissection Repair – Analysis of the Society of Thoracic Surgeons Adult Cardiac Surgery Database

A. Palaniappan¹, D. Blitzer M.D.², H. Takayama², L. Bonnell³, T. Kaneko⁴, R. Habib³, F. Sellke^5
1Brown University, Providence, Rhode Island ²Columbia University, New York, New York ³The Society of Thoracic Surgeons, Chicago, Illinois ⁴Washington University in St. Louis, St. Louis, Missouri ⁵Brown University/Rhode Island Hospital, Providence, Rhode Island

Purpose: Acute renal failure (ARF) occurs frequently following acute type A aortic dissection (ATAAD) repair surgery with high rates of associated mortality, morbidity, and resource utilization. We analyzed the national ATAAD experience in the Society of Thoracic Surgeons Adult cardiac surgery database (STS-ACSD) to identify potential modifiable risk factors of ARF.

Methods: Non-elective open aorta repair for ATAAD cases were identified from the STS-ACSD between July 1, 2014 and December 31, 2022. Patients were excluded if chronic dissection, prior aorta repair, case was an endovascular procedure, if patient was on preoperative ECMO, or patient in renal failure (creatinine>4 mg/dL or dialysis) before surgery. Postoperative ARF was the primary study outcome and, hence, patients who expired in the operating room were excluded. ARF was defined as threefold increase in serum creatinine, creatinine>4 mg/dL with an increment ≥0.5 mg/dL, or a postoperative initiation of hemodialysis. Trends in ATAAD and postoperative ARF were explored. Preoperative and intraoperative risk factors for ARF were identified using multivariable logistic regression with backward selection (parameters were retained in the model if p-values < 0.10). Annualized overall hospital ATAAD volume categories were also investigated as candidate predictors. A secondary analysis identified the bivariate associations between postoperative ARF and other major outcomes.

Results: A total of 32,467 unique patients [age: 60.2±13.7 years (mean±standard deviation); 66.2% male] from 965 STS-ACSD participating hospitals met study inclusion and exclusion criteria. Postoperative ARF was frequent at 17.4% (n=5,646). Both annual ATAAD case counts and ARF rates modestly increased over the study period (Figure 1a). A large number of preoperative and intraoperative patient variables were identified as protective or risk factors associated with ARF following ATAAD. Figure 1b highlights selected major predictors of ARF following open ATAAD repair. Female sex and urgent versus emergency surgical priority status and aorta repair performed at specialized high ATAAD volume centers (>50 cases/year; 9/965 programs) were found to be protective. Increasing age, higher preoperative creatinine, hypertension diagnosis, acute MI within 24 hours, cardiogenic shock, dissections extending to descending aorta, and salvage versus emergency priority status were major preoperative risk factors. Longer time on
cardiopulmonary bypass, elephant trunk procedures, and transfusion were significant intraoperative risk factors (figure 1b). Rates of operative mortality (22.8% vs. 11.4%), permanent stroke (24.5% vs. 8.0%), reoperation (87.6% vs. 40.5%), prolonged ventilation (9.4% vs. 5.6%), and longer postoperative length-of-stay (14.4 days vs 6.0 days) were all increased among patients that developed ARF compared to those that did not.

Conclusion: Multiple predictors of postoperative ARF following open surgical repair of ATTAAD were identified from the contemporary nationwide US experience. Focusing future efforts on the modifiable subset of predictors may help reduce occurrence of ARF and associated perioperative morbidity. The finding of worse renal outcomes in male patients warrants further investigation.

Identify the source of the funding for this research project: The data for this research were provided by The Society of Thoracic Surgeons’ National Database Access and Publications Research Program.