Abstract 3702: Anemia as an Independent Predictor of Perioperative and Long Term Cardiovascular Outcome in Patients Scheduled for Elective Vascular Surgery
BACKGROUND: Anemia has been shown to be an independent risk factor for adverse cardiac outcome in various populations. This study evaluated the predictive value of anemia in patients scheduled for elective vascular surgery.
METHODS: In total, 1211 patients (76% male, age 68 ± 11 yrs) were enrolled. Anemia was defined as serum hemoglobin < 13 g/dL for men and < 12 g/dL for women, as defined by WHO. Anemia was divided into tertiles to compare mild, moderate and severe anemia with non-anemic patients. Outcome measures were 30-day and 5-year cardiac events (CE) (cardiac death or myocardial infarction). Mean follow up was 3.4 ± 3.2 years. Multivariable linear and Cox regression analysis was used, adjusting for age, sex, type of surgery and baseline characteristics, including angina, myocardial infarction, heart failure, diabetes and renal failure. Data are presented as HRs, with 95% confidence intervals.
RESULTS: In total, 74 (6%) patients experienced a 30-day CE and 199 (16%) a 5-year CE. Anemia was present in 399 (33%) patients, of which 133 were mild, 133 moderate, and 133 severe anemia. The presence of anemia was associated with renal failure, diabetes and heart failure. CE free survival at 30 days and 5 years was worse for patients with anemia (Figure⇓). After adjustment for all clinical risk factors, the 30-day HRs for a CE per anemia group were; mild 1.8, 1.0 – 4.1, moderate 2.9, 1.4 – 6.2, and severe 7.6, 4.1–13.1, and 5-year HRs for CE per anemia group were; mild 2.2, 1.3–3.8, moderate 3.6, 2.4 –5.6, and severe 6.6, 4.6 –9.6.
CONCLUSION: The presence and severity of preoperative anemia are significant predictors of 30-day and 5-year cardiac events in patients undergoing elective vascular surgery.