Abstract
Background
Preoperative cardiac surgical status (elective and urgent) and socioeconomic deprivation may have an impact on outcomes after cardiac surgery. We sought to examine differences in 30-day postoperative outcomes (resource utilization and mortality) by preoperative cardiac surgical status and socioeconomic deprivation and association of socioeconomic deprivation with 30-day outcomes.
Methods
Adults who underwent coronary artery bypass grafting or valve surgery at an urban medical center (January 1, 2019–December 31, 2023) were included in this study. Preoperative status was elective or urgent, with stratification into quartiles by level of socioeconomic deprivation within each cohort. Socioeconomic deprivation was measured by the Area Deprivation Index (ADI; score range, 1 [least deprivation] to 100 [most deprivation]). Analyses included multivariable regression modeling.
Results
The elective cohort (n = 2419) had a mean age of 62 ± 12 years (70% male; 77% White); the urgent cohort (n = 603) had a mean age of 62 ± 13 years (70% male; 70% White). Median (interquartile range) hospital length of stay was longer in the urgent vs elective cohort (11 [8-18] days vs 4 [3-6] days; P < .001) and at higher ADI quartiles in both cohorts. Discharge to home was significantly less frequent and 30-day readmission was significantly more frequent in the urgent cohort. Discharge to home was significantly less frequent at higher ADI quartiles in the elective cohort. Thirty-day mortality differed by cohort (elective, 1.5%; urgent, 2.7%; P = .049) but not by ADI quartile. After adjustment for sociodemographic and clinical characteristics, a higher ADI quartile was significantly associated with discharge to a nonhome location in the elective cohort.
Conclusions
Understanding the effect of preoperative surgical status and socioeconomic deprivation on post–cardiac surgical outcomes provides actionable information to enhance patient care and to improve outcomes.
In Short.
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Outcomes differed by preoperative cardiac surgical status (elective or urgent); the urgent cohort used more health care resources and had higher early mortality rates compared with the elective cohort.
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Within each cohort, resource use was higher with more socioeconomic deprivation, measured by the Area Deprivation Index.
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On multivariable analyses, discharge to a nonhome location was associated with worse socioeconomic deprivation (ie, a higher Area Deprivation Index level) in the elective cohort.
Adverse social determinants of health (SDOH; eg, educational disadvantage, economic instability, unfavorable social/built environment, and limited health care quality and access) correlate with cardiovascular health by influencing one’s ability to optimize health and to treat disease.1 SDOH risk factors have been examined after cardiac surgery. Most reports used composite measures of socioeconomic deprivation (eg, Area Deprivation Index [ADI]2 and Distressed Communities Index3). Socioeconomic deprivation generally predicted short-term survival4, 5, 6; findings were contradictory for resource utilization (ie, readmissions).4,6,7 Furthermore, there is a paucity of research on the impact of SDOH on other components of resource utilization (eg, hospital length of stay [LOS] and discharge location).7 In addition, the impact of SDOH on outcomes after urgent cardiac surgery is limited.5,8 Therefore, we sought to examine the differences in 30-day postoperative outcomes (resource utilization and mortality) by preoperative cardiac surgical status (elective and urgent) and socioeconomic deprivation and the association of socioeconomic deprivation with 30-day outcomes.
Patients and Methods
Design, Sample, and Site
We performed a retrospective study (January 1, 2019–December 31, 2023) including adults (≥18 years) who underwent coronary artery bypass grafting (CABG) or valve surgery (mitral, aortic, tricuspid, or pulmonic) at a single midwestern urban academic medical center. Preoperative surgical status was elective or urgent, with stratification into quartiles by level of socioeconomic deprivation within each of these cohorts. Data were abstracted from The Society of Thoracic Surgeons Adult Cardiac Surgery Database, approved by the Northwestern University Institutional Review Board (STU00008001, approved September 2, 2005, through January 16, 2026), allowing data collection under a waiver of informed consent.
Data Collection
Data included sociodemographic characteristics, preoperative and postoperative clinical variables, and outcomes (ie, intensive care unit [ICU] or hospital LOS, discharge location, readmission within 30 days, and 30-day mortality).
Socioeconomic Deprivation
Socioeconomic deprivation was measured by the ADI, a validated tool of neighborhood-level socioeconomic disadvantage.2 Four domains are addressed: income, education, employment, and housing quality. The score range is 1 (least deprivation) to 100 (most deprivation).2
Statistical Analyses
Descriptive statistics were reported as mean with standard deviation or median with interquartile range for continuous variables. Categorical variables were summarized by counts and percentages. Comparisons across ADI quartiles were performed by 1-way analysis of variance or the Kruskal-Wallis test. Categorical variables were analyzed across ADI quartiles by Pearson χ2 test or Fisher exact test. Comparisons between preoperative surgical status cohorts (elective vs urgent) were performed similarly by the 2-sample t-test, Wilcoxon sum rank test, Pearson χ2 test, or Fisher exact test.
To determine associations of socioeconomic deprivation with post–cardiac surgical outcomes, univariable regression models were created, followed by multivariable regression modeling. Multivariable logistic regression models were used to evaluate the impact of the ADI on 30-day outcomes, including mortality, readmission, and discharge location. Association between the ADI and continuous outcomes, including ICU and hospital LOS, was evaluated with linear regression models. All models were adjusted for age, sex, body mass index, diabetes, chronic pulmonary disease, heart failure, race, New York Heart Association class, smoking status, alcohol consumption, CABG, and type of valve surgery.
Statistical significance was determined at a 2-sided 5% level. All analyses were performed with SAS software (version 9.4; SAS Institute).
Results
Overall Description of the Cardiac Surgical Cohorts
Of 3022 cardiac surgical procedures, 2419 (80%) were elective and 603 (20%) were urgent (Supplemental Figure 1).
The elective cohort had a mean age of 62.3 ± 12.3 years and was 70% male and 77% White (Supplemental Table 1). The most frequent comorbidities were hypertension and cardiac arrhythmias. The most frequent postoperative complication was atrial fibrillation (Supplemental Table 2).
The urgent cohort had a mean age of 61.7 ± 12.8 years and was 70% male and 70% White (Supplemental Table 1). The most frequent comorbidities were hypertension and prior myocardial infarction. The most frequent postsurgical complication was atrial fibrillation (Supplemental Table 2).
Comparison of Outcomes by Cardiac Surgical Cohort
The urgent cohort had a significantly longer median ICU LOS (51 [29-95] hours vs 41 [26-70] hours) and median hospital LOS (11 [8-18] days vs 4 [3-6] days) compared with the elective cohort (Table 1). Discharge location also differed significantly by cohort (discharge to home: elective cohort, 89%; urgent cohort, 74%). Readmission rates within 30 days were also significantly higher in the urgent cohort (17%) than in the elective cohort (11%). Finally, 30-day mortality (elective, 1.5%; urgent, 2.7%) differed significantly by cohort.
Table 1.
Outcomes of 3022 Patients Undergoing Elective or Urgent Cardiac Surgery
| 30-Day Outcomes | N Total (by status) | Entire Cohort (N = 3022) | Surgical Status |
P Value | ||||
|---|---|---|---|---|---|---|---|---|
| Elective (n = 2419) | Urgent (n = 603) | |||||||
| Total ICU length of stay, h | 3018 (2416, 602) | 44.2 | (26.1-72.6) | 40.7 | (25.8-69.6) | 50.6 | (29.0-95.4) | <.001 |
| Total length of stay, d | 3005 (2409, 596) | 5 | (3-9) | 4 | (3-6) | 11 | (8-18) | <.001 |
| Discharge location | 2963 (2382, 581) | <.001 | ||||||
| Extended care, transitional care unit, or rehabilitation | 395 | (13.3) | 252 | (10.6) | 143 | (24.6) | ||
| Home | 2544 | (85.9) | 2112 | (88.7) | 432 | (74.4) | ||
| Nursing home | 21 | (0.7) | 16 | (0.7) | 5 | (0.9) | ||
| Other | 3 | (0.1) | 2 | (0.1) | 1 | (0.2) | ||
| Readmission | 2943 (2372, 571) | 349 | (11.9) | 255 | (10.8) | 94 | (16.5) | <.001 |
| Mortality | 3022 (2419, 603) | 52 | (1.7) | 36 | (1.5) | 16 | (2.7) | .049 |
Categorical variables are presented as number (percentage). Continuous variables are presented as median (interquartile range).
ICU, intensive care unit.
Outcomes by ADI Level in Elective and Urgent Cardiac Surgical Cohorts
Higher quartiles in both cohorts represented more rural and distressed urban locations (Supplemental Figures 2 and 3). Demographic and clinical characteristics for the 2 cohorts by level of socioeconomic deprivation are presented in Supplemental Tables 3 and 4.
Elective cohort median ICU LOS differed significantly between ADI quartiles; higher quartiles had longer stays (Table 2). Median hospital LOS also differed significantly by quartile; the highest quartile had a longer stay. Discharge to home differed significantly by quartile (Q): Q1, 93%; Q2, 89%; Q3, 87%; Q4, 86%. Thirty-day rates of readmission were similar between quartiles (range, 9%-12%). Thirty-day mortality (range, 1.3%-1.9%) was low and did not differ by quartile.
Table 2.
Outcomes of 2419 Patients Undergoing Elective Cardiac Surgery by Level of Socioeconomic Deprivation
| 30-Day Outcomes | N Total (by quartile) | Entire Cohort (N = 2419) | Area Deprivation Index Quartile |
P Value | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Q1 (1-17) (n = 597) |
Q2 (18-33) (n = 612) |
Q3 (34-50) (n = 590) |
Q4 (51+) (n = 620) |
|||||||||
| Total ICU length of stay, h | 2416 (596, 612, 589, 619) | 40.7 | (25.8-69.6) | 31.6 | (25.2-54.3) | 37.4 | (25.5-68.2) | 45.1 | (26.7-73.4) | 44.8 | (26.4-74.2) | <.001 |
| Total length of stay, d | 2409 (596, 609, 587, 617) | 4 | (3-6) | 4 | (3-6) | 4 | (3-6) | 4 | (3-7) | 5 | (3-7) | <.001 |
| Discharge location | 2382 (590, 604, 578, 610) | .019 | ||||||||||
| Extended care, transitional care, or rehabilitation | 252 | (10.6) | 42 | (7.1) | 58 | (9.6) | 71 | (12.3) | 81 | (13.3) | ||
| Home | 2112 | (88.7) | 546 | (92.5) | 539 | (89.2) | 502 | (86.9) | 525 | (86.1) | ||
| Nursing home | 16 | (0.7) | 2 | (0.3) | 7 | (1.2) | 4 | (0.7) | 3 | (0.5) | ||
| Other | 2 | (0.1) | 0 | (0) | 0 | (0) | 1 | (0.2) | 1 | (0.2) | ||
| Readmission | 2372 (588, 600, 575, 609) | 255 | (10.8) | 60 | (10.2) | 52 | (8.7) | 69 | (12.0) | 74 | (12.2) | .166 |
| Mortality | 2419 (597, 612, 590, 620) | 36 | (1.5) | 8 | (1.3) | 8 | (1.3) | 11 | (1.9) | 9 | (1.5) | .849 |
Categorical variables are presented as number (percentage). Continuous variables are presented as median (interquartile range).
ICU, intensive care unit; Q, quartile.
Urgent cohort median ICU LOS differed significantly by quartile; quartile 1 had the lowest LOS (Table 3). Median hospital LOS also varied significantly by quartile; the highest quartile had the longest stay. Discharge location did not differ significantly by quartile. Most quartiles were discharged to home (range, 69%-80%). Thirty-day readmission rates did not differ by quartile (range, 13%-19%). Thirty-day mortality (range, 1.4%-3.4%) was low and similar between quartiles.
Table 3.
Outcomes of 603 Patients Undergoing Urgent Cardiac Surgery by Level of Socioeconomic Deprivation
| 30-Day Outcomes | N Total (by quartile) | Entire Cohort (N = 603) | Area Deprivation Index Quartile |
P Value | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Q1 (1-18) (n = 151) |
Q2 (19-35) (n = 149) |
Q3 (36-57) (n = 148) |
Q4 (58+) (n = 155) |
|||||||||
| Total ICU length of stay, h | 602 (151, 148, 148, 155) | 50.6 | (29.0-95.4) | 46.2 | (27.0-73.3) | 52.6 | (28.6-96.9) | 56.0 | (30.8-101.6) | 53.6 | (37.5-112.6) | .017 |
| Total length of stay, d | 596 (150, 146, 147, 153) | 11 | (8-18) | 10 | (7-15) | 11 | (8-19) | 12 | (8-20) | 13 | (10-19) | <.001 |
| Discharge location | 581 (146, 141, 144, 150) | .402 | ||||||||||
| Extended care, transitional care, or rehabilitation | 143 | (24.6) | 27 | (18.5) | 33 | (23.4) | 37 | (25.7) | 46 | (30.7) | ||
| Home | 432 | (74.4) | 116 | (79.5) | 107 | (75.9) | 106 | (73.6) | 103 | (68.7) | ||
| Nursing home | 5 | (0.9) | 2 | (1.4) | 1 | (0.7) | 1 | (0.7) | 1 | (0.7) | ||
| Other | 1 | (0.2) | 1 | (0.7) | 0 | (0) | 0 | (0) | 0 | (0) | ||
| Readmission | 571 (144, 139, 143, 145) | 94 | (16.5) | 19 | (13.2) | 22 | (15.8) | 27 | (18.9) | 26 | (17.9) | .573 |
| Mortality | 603 (151, 149, 148, 155) | 16 | (2.7) | 5 | (3.3) | 5 | (3.4) | 2 | (1.4) | 4 | (2.6) | .679 |
Categorical variables are presented as number (percentage). Continuous variables are presented as median (interquartile range).
ICU, intensive care unit; Q, quartile.
Associations Between ADI and 30-Day Outcomes by Cardiac Surgical Cohort
In the elective cohort, a higher ADI quartile was significantly associated only with discharge location (Supplemental Table 5). No significant associations with outcomes by socioeconomic deprivation were found in the urgent cohort (Supplemental Table 6).
Comment
Our findings contribute valuable information to extend existing literature. First, outcomes differed by cohort; the urgent cohort used more health care resources and had higher early mortality rates compared with the elective cohort. Within each cohort, differences were also found by ADI quartile. Resource use was higher with increased levels of socioeconomic deprivation in both cohorts, whereas mortality rates did not differ by ADI quartile in the 2 cohorts. Last, multivariable analyses revealed that discharge location was associated with ADI quartile in the elective cohort.
Prior research supports some of our findings regarding resource utilization. There were fewer discharges to home with higher ADI levels in our elective cohort. Lala and coworkers9 reported nonhome discharge after mitral valve surgery in almost one-third of cases in their study. Similar to our findings, a report from a statewide database revealed that rates of 30-day readmission after CABG were not associated with ADI levels.4 Using a national database, another study revealed greater odds of early readmission after isolated CABG in patients with a lower socioeconomic status.7
Regarding mortality, using large databases, researchers reported an increased risk of mortality with socioeconomic deprivation after cardiac surgery.4,5 Contrary to this literature, we found that early mortality was low and did not differ by ADI level in both our elective and urgent cohorts. No difference in 30-day mortality (which was low) by socioeconomic status after CABG was also reported by researchers from another academic medical center.6
Clinical implications can be derived from our findings. Assessment of post–cardiac surgical outcomes at the hospital level is important as findings may differ from those of large databases. Hospital-based quality improvement projects focused on risk factors for poor outcomes after cardiac surgery, including adverse SDOH, provide opportunities to target treatment to individuals at high risk for poor outcomes. In addition, inclusion of SDOH in cardiac surgery risk calculators provides a more complete representation of risk.10
Study limitations include retrospective review of data from a single medical center. The samples were relatively homogeneous by sex and race, which may limit generalizability. Regarding our multivariable analyses, there may have been bias from unmeasured confounding.
Understanding risks of adverse SDOH in individuals who undergo elective and urgent cardiac surgery may provide important “actionable” information for clinicians that may enhance patient care and improve outcomes.
Acknowledgments
The Supplemental Material can be viewed in the online version of this article [https://doi.org/10.1016//j.atssr.2025.09.024] on https://www.annalsthoracicsurgeryshortrep.org.
Funding Sources
Kathleen L. Grady reports financial support and statistical analysis were provided by Northwestern University–Chicago Campus.
Disclosures
Patrick M. McCarthy reports a relationship with Northwestern University–Chicago Campus that includes: board membership, consulting or advisory, and speaking and lecture fees. Douglas R. Johnston reports a relationship with Northwestern University that includes: consulting or advisory. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Supplementary Data
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