Anemia and morbidity and mortality in coronary bypass surgery

Prognostic Interplay of Chronic Kidney Disease, Anemia, and Diabetes in Coronary Bypass Surgery

BACKGROUND

Chronic kidney disease and anemia often coexist and may accompany diabetes; all 3 conditions are associated with worse cardiovascular outcomes. This study investigated the prognostic implications of anemia and chronic kidney disease for mortality among patients undergoing coronary artery-bypass grafting surgery and examined whether outcomes are related to the presence of diabetes.

METHODS

This retrospective study included 1180 patients undergoing coronary artery-bypass grafting. Long-term mortality (mean follow-up, 8.6 ± 4.2 years) was examined in relation to preoperative anemia, chronic kidney disease, and diabetes. Prognostic interplay of the 3 risk factors was evaluated.

RESULTS

Chronic kidney disease, anemia, and diabetes (20%, 25%, and 43% of patients, respectively), were independent risk predictors for mortality. Compared with patients with neither chronic kidney disease nor anemia, the adjusted hazard ratios (HRs) for mortality were 1.87 (95% confidence interval [CI], 1.35 to 2.59) in chronic kidney disease only, 1.75 (95% CI, 1.30 to 2.35) in anemia only, and 2.69 (95% CI, 1.91 to 3.78) in patients with both conditions. The pattern of association of chronic kidney disease and anemia with mortality was similar in patients with and without diabetes. However, mortality risk was higher in patients with diabetes in each risk category-neither chronic kidney disease nor anemia: HR, 1.69 (95% CI, 1.20 to 2.39) vs HR, 1 (reference); chronic kidney disease only: HR, 2.68 (95% CI, 1.59 to 4.52) vs HR, 2.10 (95% CI, 1.38 to 3.20); anemia only: HR, 2.73 (95% CI, 1.83 to 4.07) vs HR, 1.94 (95% CI, 1.23 to 3.08); and both chronic kidney disease and anemia: HR, 4.44 (95% CI, 2.88 to 6.85) vs HR, 2.72 (95% CI, 1.58 to 4.69).

CONCLUSIONS

In patients undergoing coronary artery-bypass grafting, anemia and chronic kidney disease have significant prognostic implications for long-term mortality. Their effect on mortality was cumulatively associated with adverse impacts of diabetes.

Low Hemoglobin Concentration Is Associated With Poor Outcome After Peripheral Arterial Surgery

Objective:

To assess the influence of low hemoglobin (Hb) concentration on major adverse cardiac events (MACE) and mortality in patients undergoing peripheral arterial surgery.

Methods:

This was a retrospective cohort study of patients undergoing peripheral arterial reconstructive surgery at a tertiary vascular center. Preoperative factors linked with the occurrence of MACE and death on univariate analysis ( P ≤ .1) were included in a multivariate model to confirm the independent association with the outcome variables.

Results:

A total of 360 consecutive patients (238 men) with a mean (standard deviation) age of 69 (10.7) years and Hb of 13.0 (2.12) g/dL treated under the care of a single specialist between January 2004 and December 2011 were included in the analysis. Of these, 193 (53.6%) were anemic. In all, 26 (7%) had a postoperative MACE and 18 (5%) died. On multivariate analysis, age > 80 years (odds ratio [OR] = 3; 95% confidence interval [CI] [1.2-7.5]; P = .025), renal impairment (OR = 3.2; 95% CI [.99-10.2]; P = .053), coronary disease (OR = 3.6; 95% CI [1.5-8.7]; P = .005), and low Hb (OR for each 1 g/dL drop below the mean = 1.4 [1.13-1.7]; P = .002) were independent risk factors for MACE. Unplanned surgery (OR = 4.5; 95% CI [1.2-16.9]; P = .025) and low Hb (OR for each 1 g/dL drop below the mean = 1.5; 95% CI [1.14-1.86]; P = .002) were independent risk factors for death.

Conclusion:

In peripheral arterial surgery, preoperative low Hb is associated with MACE and death. Further investigation is necessary to elucidate whether this relationship is causal. Meanwhile, consideration should be given to treating preoperative anemia as a significant risk factor for adverse outcome in this setting.

Preoperative anemia associated in-hospital mortality and morbidity in isolated coronary artery bypass graft surgery

Anemia is an indisputable finding in patients scheduled for coronary artery bypass graft (CABG) that can occur any time preoperatively. In presence of severe coronary artery disease, anemia can dramatically affect surgical outcomes. Therefore, we conducted this study to determine the effect of low preoperative hemoglobin (Hgb) on postoperative outcome in patients who underwent coronary artery bypass graft (CABG). In all, 4432 patients who had undergone isolated CABG at Tehran Heart Center over the 2-year period from March 2006 to February 2008 were studied. All medical records of the aforementioned patients were derived from our hospital surgery data bank. After adjustment for confounders, the association of different preoperative levels of Hgb with risk of cardiac, pulmonary, infectious, and ischemic complications, and also with prolonged ventilation and resource utilization, were assessed in a multivariable model. After adjustment for confounders that may affect mortality and morbidities, we found that cardiac, infectious, ischemic, and pulmonary complications, as well as postoperative mortality, were significantly higher in anemic patients compared to those with normal Hgb levels. In addition, total ventilation time, total intensive care unit hour stay (ICU), hospital length of stay (HLOS), and postsurgery length of stay (PLOS) were significantly longer in anemic patients. We concluded that isolated CABG patients with preoperative anemia have significantly higher mortality and morbidity, and use more health care resources. Preoperative anemia is an independent variable for increased resource utilization, morbidity, and mortality.