Transfusion in Elective Aortic Root Replacement: Analysis of the STS Adult Cardiac Surgery Database

Utilization of machine learning to model the effect of blood product transfusion on short-term lung transplant outcomes

The objective of this study was to identify the relationship between blood product transfusion and short-term morbidity and mortality following lung transplantation utilizing machine learning. Preoperative recipient characterstics, procedural variables, perioperative blood product transfusions, and donor charactersitics were included in the model. The primary composite outcome was occurrence on any of the following six endpoints: mortality during index hospitalization; primary graft dysfunction at 72 h post-transplant or the need for postoperative circulatory support; neurological complications (seizure, stroke, or major encephalopathy); perioperative acute coronary syndrome or cardiac arrest; and renal dysfunction requiring renal replacement therapy. The cohort included 369 patients, with the composite outcome occurring in 125 cases (33.9%). Elastic net regression analysis identified 11 significant predictors of composite morbidity: higher packed red blood cell, platelet, cryoprecipitate and plasma volume from the critical period, preoperative functional dependence, any preoperative blood transfusion, VV ECMO bridge to transplant, and antifibrinolytic therapy were associated with higher risk of morbidity. Preoperative steroids, taller height, and primary chest closure were protective against composite morbidity.

Blood transfusion in aortic root surgery impairs midterm survival

Objective

To evaluate the effect of perioperative allogeneic packed red blood cell (RBC) transfusion during aortic root replacement.

Method

We reviewed patients undergoing aortic root replacement at our institution between March 2014 and April 2020. In total, 760 patients underwent aortic root replacement, of whom 442 (58%) received a perioperative RBC transfusion. Propensity score matching was used to account for baseline and operative differences resulting in 159 matched pairs. All-cause mortality was assessed with Kaplan-Meier curves. Data were obtained from our institutional Society of Thoracic Surgeons database and chart review.

Results

After propensity score matching, the RBC-transfused and -nontransfused groups were similar for all preoperative characteristics. Cardiopulmonary bypass time, crossclamp time, and lowest operative temperature were similar between the transfused and nontransfused groups (standardized mean difference <0.05). RBC transfusion was associated with more frequent postoperative ventilation greater than 24 hours (36/159 [23%] vs 19/159 [12%]; P = .01), postoperative hemodialysis (9/159 [5.7%] vs 0/159 [0%]; P = .003), reoperation for mediastinal hemorrhage (9/159 [5.7%] vs 0/159 [0%]; P = .003), and longer intensive care unit and hospital length of stay (3 vs 2 days and 8 vs 6 days respectively; P < .001). Thirty-day operative mortality after propensity score matching was similar between the cohorts (1.9%; 3/159 vs 0%; P = .2), and 5-year survival was reduced in the RBC transfusion cohort (90.2% [95% confidence interval, 84.1%-96.7%] vs 97.1% [95% confidence interval, 92.3%-100%] P = .035).

Conclusions

Aortic root replacement frequently requires RBC transfusion during and after the operation, but even after matching for observed preoperative and operative characteristics, RBC transfusion is associated with more frequent postoperative complications and reduced midterm survival.

Proximal aortic repair in dialysis patients: A national database analysis

OBJECTIVES

Dialysis is a well-established risk factor for morbidity and mortality after cardiovascular procedures. However, little is known regarding the outcomes of proximal aortic surgery in this high-risk cohort.

METHODS

Perioperative (in-hospital or 30-day mortality) and 10-year outcomes were analyzed for all the patients who underwent open proximal aortic repair with the diagnosis of nonruptured thoracic aortic aneurysm (aneurysm, n = 325) or type A aortic dissection (dissection, n = 461) from 1987 to 2015 using the US Renal Data System database.

RESULTS

In patients with aneurysm, perioperative mortality was 12.6%. The 10-year mortality was 81% ± 3%. Age 65 years or more (hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.03 to 1.78; P = .03), chronic obstructive pulmonary disease (HR, 1.68; 95% CI, 1.01-2.82; P = .047), and Black race (HR, 1.46; 95% CI, 1.09-1.97; P = .01) were independently associated with worse 10-year mortality. In patients with dissection, perioperative mortality was 24.3% and 10-year mortality was 87.9% ± 2.2%. Age 65 years or more (HR, 1.49; 95% CI, 1.19-1.86; P < .001), congestive heart failure (HR, 1.39; 95% CI, 1.11-2.57; P = .004), and diabetes mellitus as the cause of dialysis (HR, 1.75; 95% CI, 1.2-2.57; P = .004) were independently associated with worse 10-year mortality. Black race (HR, 0.74; 95% CI, 0.6-0.92; P = .008) was associated with a better outcome.

CONCLUSIONS

We described challenging perioperative and 10-year outcomes for dialysis patients undergoing proximal aortic repair. The present study suggests the need for careful patient selection in the elective repair of proximal aortic aneurysm for dialysis-dependent patients, whereas it affirms the feasibility of emergency surgery for acute type A aortic dissections.

Autologous blood transfusion in acute type A aortic dissection decreased blood product consumption and improved postoperative outcomes

Objective

To evaluate the effect of autologous blood use on blood product consumption and outcomes after acute type A aortic dissection repair.

Methods

From 2010 to October 2020, 497 patients underwent open acute type A aortic dissection repair, including those with autologous blood harvesting before cardiopulmonary bypass and transfusion after cardiopulmonary bypass (autologous blood transfusion [ABT], n = 397) and without autologous blood harvesting and transfusion (No-ABT, n = 100). The median ABT volume was 900 mL. Using propensity score matching, 89 matched pairs were identified based on age, sex, body mass index, preoperative hemoglobin, acute preoperative stroke, previous cardiac surgery, and cardiogenic shock.

Results

After propensity score matching, both groups were similar in demographic characteristics and aortic procedures. The ABT group required significantly less intraoperative transfusion of blood products (6 vs 11 units; P < .0001), including packed red blood cells (2 vs 4), fresh frozen plasma (2 vs 4), platelets (2 vs 2), and cryoprecipitate (0 vs 1); and combined intraoperative and postoperative transfusion (9 vs 13; P < .001). ABT was protective against intra- and postoperative blood product transfusion (odds ratio, 0.28; P = .01). The ABT group had significantly less sepsis, acute renal failure requiring dialysis, reintubation, and shorter intubation times and postoperative lengths of stay. Operative mortality was 6.7% in the ABT group versus 13% in the No-ABT group (P = .14). The midterm survival was similar between the 2 groups (5 year: 76% vs 74%). ABT had a hazard ratio of 0.81 for midterm mortality (P = .41).

Conclusions

Autologous blood transfusion was associated with better short-term outcomes and could be used routinely for acute type A aortic dissection repair. External multicenter prospective validation would be warranted.

Transfusion in Root Replacement for Aortic Dissection: STS Adult Cardiac Surgery Database Analysis

BACKGROUND

Transfusion in acute aortic syndromes has been studied in a limited fashion. We sought to describe contemporary transfusion practice for root replacement in acute (Stanford) type A aortic dissection (ATAAD).

METHODS

The STS Adult Cardiac Surgery Database was interrogated to identify patients who underwent primary aortic root replacement for ATAAD (July 2014 - June 2017). Patients (n = 1558) were stratified by type of root replacement. Multivariate regression was used to determine those variables associated with transfusion and postoperative morbidity.

RESULTS

Transfusion was required in 90.5% of cases (n = 1410). Operative mortality for all patients was 17.3% (261 deaths). Intraoperative red blood cell (RBC) transfusion portended reduced short-term survival (odds ratio {OR} 2.00, p = 0.025). Massive postoperative transfusion was associated with prolonged ventilation (OR 13.47, p < 0.001), sepsis (OR 4.13, p < 0.001), and new dialysis-dependent renal-failure (OR 2.43, p < 0.001). Females were more likely to require transfusion (OR 3.03, p < 0.001), as were patients who had coronary bypass (OR 1.57, p = 0.009), and those in shock (OR 2.27, p < 0.001). Valve-sparing aortic root replacement (VSARR) was associated with reduced transfusion requirements vs. composite roots. Institutional case volume was not appreciably correlated with transfusion.

CONCLUSIONS

Most patients undergoing root replacement for aortic dissection require blood products. Composite root replacement is associated with a greater likelihood of transfusion than a valve-sparing operation. Transfusion independently foreshadows greater operative mortality.

STS Adult Cardiac Surgery Database: 2021 Update on Outcomes, Quality, and Research

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It has been the foundation for quality measurement and improvement activities in cardiac surgery, facilitated the generation of accurate risk adjusted performance benchmarks and serves as a platform for novel research. Recent enhancements have added to the database's functionality, ease of use, and value to multiple stakeholders. This report is the sixth in a series of annual reports that provide updated volumes, outcomes, database-related developments, quality improvement initiatives, and research summaries using the Adult Cardiac Surgery Database in the past year.