Anemia identified as risk factor for illness, death after cardiac surgery
Researchers in Milan have found moderate-to-severe preoperative anemia to be a risk factor for major morbidity and operative mortality in adult patients undergoing all cardiac surgeries, according to research recently published in The Annals of Thoracic Surgery. This finding is confirmative of the role of preoperative anemia in determining adverse events in major noncardiac operations, the researchers wrote.
For this retrospective study, researchers compared the postoperative morbidity and mortality outcome of a group of moderate-to-severe anemic patients with a propensity-based matched group of patients who did not have severe anemia. All of 13,843 participants included in the study underwent cardiac operations and had a preoperative hematocrit value available; 401 patients had a severe anemia (hematocrit <30%). A control group of 401 patients of non-severely anemic patients was then selected from the total for comparison.
The researchers found nearly double the operative mortality rate in patients with severe anemia vs. patients who did not have severe anemia. Patients with severe anemia were also at increased risk for stroke (1% vs. 0%; P=.045) and prolonged mechanical ventilation, and were more likely to experience longer stays in the ICU. They also had significantly higher rates of major morbidity (27.4% vs. 17.5%; P=.001) and operative mortality (12.7% vs. 7.5%; P=.014). An additional analysis found similar results in patients with moderate anemia.
“In conclusion, we believe that preoperative anemia in cardiac surgery deserves considerable attention. Corrective measures should be tested in adequate randomized trials, in order to define the margin of correction of this risk factor,” the researchers wrote in the study.