Preoperative Anemia is Associated with Increased Intraoperative Mortality in Patients Undergoing Cardiac Surgery.

OBJECTIVES: We sought to investigate the incidence of preoperative anemia in cardiac surgery and its association with outcomes. METHODS: A retrospective review of clinical, laboratory, and transfusion data for all patients who underwent cardiac surgery at Sultan Qaboos University Hospital between 2008 and 2014 was performed. Patients were divided into two groups, anemic and non-anemic, with anemia defined as hemoglobin levels < 13 g/dL (males) and < 12 g/dL (females). Clinical variables were compared using chi-square and independent t-test. Factors influencing preoperative mortality were analyzed using multivariate binary logistics regression. RESULTS: A total of 599 patients (69.9% males and 30.1% females) were included in the study; 69.3% underwent coronary artery bypass surgery. Preoperative anemia was found in 76.1% of females and 26.7% of male patients. Rates of intraoperative red blood cell transfusions were higher among anemic patients (75.9% vs. 52.3%, p < 0.001). Anemic patients had a worse risk profile with higher incidence of diabetes mellitus (53.8% vs. 38.9%, p < 0.001), congestive heart failure (51.4% vs. 28.3%, p < 0.001), arrhythmia (16.5% vs. 8.6%, p = 0.004), and cerebrovascular disease (10.0% vs. 4.9%, p = 0.015). In addition, they had a higher risk of overall mortality (6.4% vs. 2.6%, p = 0.023). Preoperative anemia remained a risk factor for intraoperative mortality after logistic regression (odds ratio = 4.08, 95% confidence interval: 1.43-11.66; p = 0.009). CONCLUSIONS: Preoperative anemia in cardiac surgery is independently associated with increased intraoperative mortality and early readmission rates post-surgery.

Impact of Blood Transfusion on Troponin I Levels and Outcomes after Cardiac Surgery: A Cohort Study.

OBJECTIVES: Increased cardiac troponin I (TI) has been suggested to be a sensitive indicator of intraoperative myocardial injury. We investigated the association of transfusion on TI levels post-surgery and outcomes in patients undergoing elective cardiac surgeries. METHODS: We conducted a retrospective review of 542 patients. Patients were divided into two groups based on TI levels at 24 hours (TI24) (> 6.5 µg/L vs. ≤ 6.5 µg/L). The impact of transfusion on TI levels was estimated using logistic regression and adjusted for using a multivariable model that included aortic cross-clamp time and preoperative ejection fraction. The effect of TI on the clinical outcomes was examined. RESULTS: Red blood cell (RBC) transfusion was found to be associated with high TI levels (odds ratio (OR) = 2.33, p = 0.007, 95% confidence interval (CI): 1.30-4.30). A trend was observed when aortic cross-clamp time and preoperative ejection fraction were adjusted for (OR = 2.06, p = 0.080, 95% CI: 0.90-4.70). An association was found between aortic cross-clamp time and high TI levels in the multivariable model (OR = 1.01, p = 0.028, 95% CI: 1.00-1.02). Elevated TI levels was associated with higher mortality (OR = 4.15, p = 0.017, 95% CI: 1.29-13.08), renal failure (OR = 2.99, p = 0.004, 95% CI: 1.41-6.32), and increased length of stay in-hospital (OR = 4.50, p = 0.020, 95% CI: 0.69-8.30). CONCLUSIONS: RBC transfusion is associated with increased TI24 post-cardiac surgery and worse outcomes, albeit a confounding effect cannot be excluded. Larger studies are required to confirm these findings.

Discriminatory power of the intraoperative cell salvage use in the prediction of platelet and plasma transfusion in patients undergoing cardiac surgery.

INTRODUCTION: We aim to assess the discrimination of transfused salvaged blood in predicting perioperative platelet and plasma transfusion. METHODS: Retrospective review was performed on all patients undergoing cardiac surgery with cell saver (CS) support. The area under the receiver operating characteristics curve was calculated. RESULTS: The discrimination achieved by transfused CS volumes in predicting perioperative platelet and plasma transfusion was poor (AUC 0.642 and 0.613 respectively). None of the covariates included (preoperative platelets, cardiopulmonary bypass use and time, aortic cross clamp time and use of aspirin or clopidogrel within 7 days of surgery) were statistically significant predictors. CONCLUSION: Volumes of transfused CS blood have poor discrimination in predicting platelet and plasma transfusion.