Using red blood cell distribution width to predict death after abdominal aortic aneurysm rupture

BMC Cardiovascular Disorders · 4 authors, 2 centres

AI SUMMARY

FIDELITY 100%

POPULATION392 U.S. adults (aged ≥ 18) with ruptured abdominal aortic aneurysm admitted to ICU, identified from the MIMIC-III database (2001–2012)

INTERVENTIONStratification by red blood cell distribution width level (11.7–13.8%, 13.9–14.9%, 15.0–21.6%)

COMPARISONLower RDW level (11.7–13.8%) vs. higher RDW levels (13.9–14.9% and 15.0–21.6%)

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AGENT 01 · STRUCTURED SUMMARY

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TL;DR

This retrospective cohort study of 392 ICU patients with ruptured abdominal aortic aneurysm (rAAA) from the MIMIC-III database found that higher red blood cell distribution width (RDW > 13.8%) was significantly associated with increased 30-day and 90-day all-cause mortality. After multivariable adjustment, patients with elevated RDW had approximately 2.2–2.5 times higher odds of death compared to those with lower RDW. The findings suggest that RDW, a low-cost and readily available lab value, may serve as a useful prognostic marker in rAAA patients, though its predictive performance (AUC 0.624) was lower than SAPSII scores (AUC 0.753).

Full summary

4,140 CHARS

**Background:** Abdominal aortic aneurysm (AAA) is a life-threatening enlargement of the abdominal aorta, with rupture carrying a mortality risk up to 81%. Current screening with ultrasonography is underutilized due to cost and availability barriers. Red blood cell distribution width (RDW), a standard component of the complete blood count, has been associated with cardiovascular outcomes but had not been studied specifically in ruptured AAA (rAAA). This study aimed to investigate associations between RDW levels and all-cause mortality in rAAA patients and develop predictive models.

**Methods:** This retrospective cohort study used the MIMIC-III v1.3 database (2001–2012), which contains data on over 50,000 ICU patients from Beth Israel Deaconess Medical Center. The study included 392 U.S. adults (aged ≥ 18) with concurrent AAA rupture identified by ICD-9 codes 441.3 and 441.4. Patients without RDW measurements or with > 5% missing data were excluded. RDW was measured within 24 hours of ICU admission and categorized into three groups: 11.7–13.8% (n = 140, 35.7%), 13.9–14.9% (n = 117, 29.8%), and 15.0–21.6% (n = 135, 34.5%). Primary outcomes were 30-day and 90-day all-cause mortality, identified via the Social Security Death Index. Covariates included demographics, comorbidities, vital signs, laboratory measurements, and scoring systems (SOFA, SAPSII). Statistical analyses included chi-square tests, t-tests, single-factor and multivariable logistic regression (three models each for 30-day and 90-day mortality), and ROC curve analysis with DeLong's method. Sensitivity analyses were performed across subgroups including gender, ethnicity, and comorbidities.

**Key Results:** The mean age across RDW groups was 72.56 (SD ± 22.37), 76.28 (SD ± 9.25), and 75.95 (SD ± 9.27) years, respectively. Patients with higher RDW (> 13.8%) had significantly higher rates of congestive heart failure (45.19% vs. 24.29% in lowest group, P = 0.001), renal failure (26.67% vs. 3.57%, P < 0.001), and coagulopathy (28.15% vs. 12.14%, P < 0.001). They also had lower hemoglobin, hematocrit, MCV, and red blood cell count, and higher chloride, creatinine, sodium, and BUN (all P < 0.05). SOFA and SAPSII scores increased across RDW groups (SOFA: 5.04 vs. 5.74 vs. 6.46, P = 0.001; SAPSII: 37.84 vs. 41.19 vs. 44.07, P = 0.002). Thirty-day mortality was 8.57% in the lowest RDW group, 17.09% in the middle, and 20.74% in the highest (P = 0.016). Ninety-day mortality was 11.43%, 23.93%, and 25.93%, respectively (P = 0.005). In multivariable logistic regression, patients with RDW ≥ 13.8% had significantly higher odds of 30-day mortality (fully adjusted AOR = 2.25, 95% CI: 1.05–4.81, P = 0.037) and 90-day mortality (fully adjusted AOR = 2.22, 95% CI: 1.12–4.41, P = 0.022). The AUC for RDW predicting mortality was 0.624, compared to 0.675 for SOFA and 0.753 for SAPSII. The difference between RDW and SAPSII AUCs was statistically significant (P = 0.0009), but not between RDW and SOFA (P = 0.337). Sensitivity analyses showed significant interactions between RDW and ethnicity (P = 0.003), congestive heart failure (P = 0.001), renal failure (P = 0.033), coagulopathy (P = 0.003), and renal replacement therapy (P = 0.001) for 30-day mortality.

**Clinical Implications:** This study provides evidence that elevated RDW (> 13.8%) is independently associated with increased short-term (30-day) and medium-term (90-day) mortality in patients with ruptured AAA. Given that RDW is a low-cost, routinely available laboratory value from a complete blood count, it could serve as an accessible risk stratification tool in clinical practice. The authors suggest RDW could help identify high-risk rAAA patients who may benefit from more aggressive management, though its predictive performance was inferior to SAPSII scores. The study is limited by its retrospective, single-center design, potential selection bias, and inability to account for unmeasured confounders such as medication use and genetic biomarkers. The findings require validation in larger, prospective, multicenter studies before clinical implementation can be recommended.

PICO

PPOPULATION

392 U.S. adults (aged ≥ 18) with ruptured abdominal aortic aneurysm admitted to ICU, identified from the MIMIC-III database (2001–2012)

IINTERVENTION

Stratification by red blood cell distribution width level (11.7–13.8%, 13.9–14.9%, 15.0–21.6%)

OOUTCOME

30-day and 90-day all-cause mortality

STUDY TYPE

cohort

SPECIALTY

vascular surgery

SUMMARISED BY

AI pipeline

FIDELITY CHECK

100% · A

ORIGINAL PAPER

PMC10061891

Using red blood cell distribution width to predict death after abdominal aortic aneurysm rupture

BMC Cardiovascular Disorders

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ABSTRACT

Background An abdominal aortic aneurysm is a life-threatening enlargement in the major vessel at the abdomen level. This study investigated the associations between different levels of red blood cell distribution width and all-cause mortality among patients with abdominal aortic aneurysm rupture. It developed predictive models for all-cause mortality risk. Methods This was a retrospective cohort study using 2001 to 2012 MIMIC-III dataset. The study sample included 392 U.S. adults with abdominal aortic aneurysms who were admitted to ICU after the aneurysm rupture. Then we used two single-factor and four multivariable logistic regression models to examine the associations between different levels of red blood cell distribution and all-cause mortality (30 days and 90 days), controlling for demographics, comorbidities, vital signs, and other laboratory measurements. The receiver operator characteristic curves were calculated, and the areas under the curves were recorded. Results There were 140 (35.7%) patients with an abdominal aortic aneurysm in the red blood cell distribution width range between 11.7 and 13.8%, 117 (29.8%) patients in the range between 13.9 and 14.9%, and 135 (34.5%) patients in the range between 15.0 and 21.6%. Patients with higher red blood cell distribution width level (> 13.8%) tended to have a higher mortality rate (both 30 days and 90 days), congestive heart failure, renal failure, coagulation disorders, lower hemoglobin, hematocrit, MCV, red blood cell count, higher levels of chloride, creatinine, sodium, and BUN (All P < 0.05). Results of multivariate logistic regression models indicated that patients with higher red blood cell distribution width levels (> 13.8%) had the highest statistically significant odd ratios of 30 days and 90 days of all-cause mortality than lower red blood cell distribution width levels. The area under the RDW curve was lower ( P = 0.0009) than that of SAPSII scores. Conclusions Our study found that patients with abdominal aortic aneurysm rupture with a higher blood cell distribution had the highest risk of all-cause mortality. Using the blood cell distribution width level in patients with abdominal aortic aneurysm rupture to predict mortality should be considered in future clinical practice.

CITATION EXPORT

Wanghai Li, Tao Liao, Yan Zhang et al.. Using red blood cell distribution width to predict death after abdominal aortic aneurysm rupture. BMC Cardiovascular Disorders. (2023). https://doi.org/10.1186/s12872-023-03191-1

AUTHORS

4 · 2 CENTRES

Wanghai Li, Tao Liao, Yan Zhang, Chengzhi Li

1grid.412601.00000 0004 1760 3828Department of Interventional Radiology and Vascular Surgery, The First Affiliated Hospital of Jinan University, Guangzhou, 510630 China
2grid.443573.20000 0004 1799 2448Department of Critical Care Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan City, 442000 People’s Republic of China