Association of Anemia with Outcomes in Patients Undergoing Percutaneous Peripheral Vascular Intervention: Insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2 VIC)

OBJECTIVES: To evaluate the clinical features and outcomes of patients with anemia undergoing percutaneous peripheral vascular intervention (PVI) in a contemporary registry. METHODS: We evaluated the differences in the clinical features and outcomes of patients with and without anemia undergoing PVI in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2 VIC) registry. Anemia was defined using World Health Organization criteria. RESULTS: Baseline anemia was present in 42.3% of 15,683 patients undergoing PVI. Compared to patients without anemia, those with anemia were older (mean age, 67 years vs 71 years), were more often black (16% vs 29%), and had higher comorbidities. Anemic patients were twice as likely to present with acute limb ischemia (5% vs 11%) and undergo urgent PVI (6% vs 15%) or below-the-knee PVI (18% vs 35%). Many in-hospital adverse events were higher in anemic patients. In a propensity-matched cohort, any adverse outcome (3.4% vs 8.4%; odds ratio [OR], 2.58; 95% confidence interval [CI], 1.94-3.42) or major cardiovascular event, defined as death, myocardial infarction, stroke, or amputation (1.1% vs 3.2%; OR, 2.96; 95% CI, 1.83-4.79) was more likely in anemic patients. Of all adverse events, the highest odds were observed for post-PVI transfusions and amputations in anemic patients. Multivariable logistic regression showed that baseline hemoglobin (1 g/dL below the normal value) was associated with greater risk of any adverse event (OR, 1.57; 95% CI, 1.47-1.68). CONCLUSION: The prevalence of anemia was high among PVI patients and was associated with significantly greater likelihood of amputation, any adverse event, and major cardiovascular events. Whether preprocedure correction of anemia has the potential to decrease post-PVI adverse events remains to be studied.