Complex relationship between low albumin level and poor outcome after lower extremity procedures for peripheral artery disease

Abstract

Objective: A low albumin level has been associated with poor outcome, including death, in surgical patients. The mechanistic relationship, however, is more complex than simply nutritional. As studies are scant in the vascular population, we sought to examine the association of low albumin level with outcomes in patients undergoing open and endovascular lower extremity procedures for peripheral artery disease.

Methods: Patients with peripheral artery disease undergoing lower extremity procedures (2008-2015) were selected from Cerner Health Facts database (Cerner Corporation, Kansas City, Mo) using International Classification of Diseases, Ninth Revision diagnosis and procedure codes. Age, sex, disease severity, and other comorbidities were captured. Outcomes were identified using codes and encounter data. A χ²analysis and multivariable logistic regression were performed.

Results: There were 6170 patients evaluated; 4562 (74%) underwent endovascular procedures and 1608 (26%) underwent open surgery. Low albumin level (<3.5 g/dL) was associated with age ≥80 years (23.1% vs 16.3% normal; P < .0001), black race (21% vs 11.6% normal; P < .0001), tissue loss (38% vs 16.4% normal; P < .0001), and higher Charlson index (mean, 3.1 vs 2.2 in the normal group; P < .0001). Low albumin level was also associated with longer length of stay (4.9 vs 2.2 days normal; P < .0001), higher in-hospital mortality (1.9% vs 0.3% normal; P < .0001), and higher 30-day readmission (15% vs 12.7% normal; P = .02). Multivariable analysis demonstrated that low albumin level was strongly associated with in-hospital death (odds ratio [OR], 5.23; 95% confidence interval [CI], 2.00-13.70), infection (OR, 2.51; 95% CI, 1.96-3.22), renal failure (OR, 2.61; 95% CI, 1.79-3.79), and cardiac complications (OR, 2.59; 95% CI, 1.69-3.96). After multivariable adjustment, there was no association between albumin level and 30-day readmission.

Conclusions: Low preoperative albumin levels are associated with in-hospital death, prolonged length of stay, and severe morbidity after open and endovascular lower extremity procedures. As the majority of lower extremity procedures are elective, serious consideration should be given to deferring elective procedures until albumin levels have been optimized. Because of the pleiotropic effects of albumin, including antiplatelet and inflammatory function, study of this complex relationship may offer insights into how best to integrate this novel biomarker into vascular surgery decision-making.

Keywords: Albumin; Morbidity; Mortality; Outcome; Peripheral arterial disease.