Impact of Preoperative Anemia in Patients Undergoing Peripheral Vascular Intervention

Abstract

The Vascular Quality Initiative database was analyzed to determine whether preoperative anemia is associated with postoperative death, length of stay (LOS), and overall survival for patients undergoing peripheral vascular intervention (PVI). The national Vascular Quality Initiative database was queried for all PVIs performed between 2010 and 2019, and the outcomes were correlated with the presence of anemia. Anemia was classified as mild (10-13 g/dL for men and 10-12 g/dL for women), moderate (8-9.9 g/dL), and severe (<8 g/dL) using the World Health Organization definition of anemia. Analysis of variance or the Kruskal-Wallis test was used for continuous variables and the χ2 test for categorical variables. Multivariate logistic regression, generalized linear regression, and proportional Cox models were used to evaluate the association between preoperative anemia and postoperative 30-day mortality, total LOS, and overall survival time. A Kaplan-Meier curve was used to compare the survival time according to anemia severity. A total of 86,726 patients met the inclusion criteria. The demographics recorded included age (mean, 68 years), gender (59% male), and race (80% white). Anemia was documented in 41,627 patients (48%) and was mild in 29,687 (71%), moderate in 10,500 (25%), and severe in 1440 (4%). Demographics (age, gender, race) and comorbidities (smoking, body mass index, hypertension, chronic obstructive pulmonary disease, congestive heart failure, and a requirement for dialysis) were associated with the degree of preoperative anemia. The median follow-up was 4 years (range, 1.25-5.78 years). On univariate analysis, 30-day mortality, total LOS, and overall survival were significantly associated with the level of preoperative anemia (Table). These associations persisted in the multivariate models (Table). Kaplan-Meier survival was also associated with the degree of anemia (P < .001; Fig). The presence and degree of preoperative anemia was independently associated with 30-day mortality, total LOS, and overall survival for patients undergoing PVI. The presence and degree of anemia should be important components of preoperative risk stratification for patients undergoing PVI. Anemia should be a listed variable in all reports detailing the outcomes of PVI.TableUnivariate and multivariate analyses for overall survival, 30-day mortality, and total length of hospital stayPredictorUnivariateMultivariateHR95% CIP valueHR95% CIP valueOverall survival Normal hemoglobin1NANA1NANA Mild anemia2.232.16-2.31<.0011.501.44-1.57<.001 Moderate anemia3.533.39-3.67<.0012.021.91- 2.13<.001 Severe anemia3.503.21-3.82<.0012.141.76-2.24<.00130-Day mortalityOR95% CIP valueOR95% CIP value Normal hemoglobin1NANA1NA Mild anemia3.082.71-3.51<.0012.201.90-2.54<.001 Moderate anemia6.795.93-7.79<.0013.393.30-4.52<.001 Severe anemia8.206.41-10.38<.0013.943.11-5.35<.001Total LOSIRR95% CIP valueIRR95% CIP value Normal hemoglobin1NANA1NANA Mild anemia2.011.96-2.06<.0011.681.64-1.73<.001 Moderate anemia4.334.18-4.48<.0013.102.97-3.23<.001 Severe anemia5.975.48-6.51<.0014.984.50-5.54<.001CI, Confidence interval; HR, hazard ratio; IRR, incidence rate ratio; LOS, length of stay; NA, not applicable; OR, odds ratio.Boldface P values represent statistical significance. Open table in a new tab