Over half of patients hospitalized for acute MI and undergoing PCI developed hospital-acquired anemia, which was associated with higher rates of mortality and worse health status, according to the results of the TRIUMPH trial published in the July edition of Circulation: Cardiovascular Quality Outcomes.

“Anemia is common in patients hospitalized with acute MI and is associated with increased mortality rates, higher hospitalization rates and worse health-related quality of life,” the authors wrote. “Little research has focused on hospital-acquired anemia, which develops acutely during acute MI admission in those with normal baseline hemoglobin (Hgb).”

To make the data regarding hospital-acquired anemia more robust, Adam C. Salisbury, MD, of the Saint Luke’s Mid America Heart Institute in Kansas City, Mo., and colleagues looked at incidence and outcomes of hospital-acquired anemia in patients who survived hospitalization for acute MI (AMI) and who had no signs of anemia at hospital admission.

The researchers enrolled 4,340 patients into the TRIUMPH (Translational Research Investigation Underlying disparities in acute MI Patients’ Health status) study between April 11, 2005, and Dec. 31, 2008. After excluding patients who underwent CABG, due to its tendency to be associated with anemia, the researchers identified 2,909 patients eligible to participate in the study.

During the study, researchers defined anemia using age-,sex- and race-specific criteria to identify hemoglobin values of being less than 13.7 g/dL for white men aged 20-59, 13.2 g/dL for white men 60 or over, 12.9 g/dL for black men aged 20-59, 12.7 g/dL for black men aged 60 or over, 12.2 g/dL for white women and 11.5 g/dL for black women.

Additionally, the researchers classified anemia as severe (Hgb less than or equal to 9 g/dL), moderate (Hgb 9.1 to 11 g/dL) or mild (Hgb less than 11 g/dL). Bleeding episodes were also recorded using thrombolysis in MI (TIMI) classifications.

Of the 2,909 AMI patients who presented without anemia at hospital admission, 45.4 percent developed hospital-acquired anemia. Of the cases that developed anemia, 973 were mild, 292 were moderate and 56 were severe.

Additionally, the researchers found that while in-hospital bleeding events were more common in patients with hospital-acquired anemia that those without, 86.5 percent of those with hospital-acquired anemia did not have documented bleeding events.

Even in the 56 cases of severe anemia, half of the patients had no reported bleeding events; however, researchers did find that in-hospital bleeding held a higher risk of acquiring anemia.

Being female, a white male, having chronic kidney disease, presenting with STEMI or being treated with glycoprotein IIb/IIIa inhibitors were all characteristics that produced a higher risk of developing hospital-acquired anemia.

Mortality rates were lower in patients who did not acquire hospital-based anemia (2.6 percent). For those with mild, moderate and chronic cases of anemia, mortality rates were recorded to be 3.6 percent, 8.4 percent and 12.6 percent, respectively.

“Although inpatient bleeding was a strong independent predictor of hospital-acquired anemia, most patients with hospital-acquired anemia did not have a documented bleeding event during hospitalization, suggesting that hospital-acquired anemia is not simply a surrogate for in-hospital bleeding events,” the authors wrote.

The researchers offered that there may be ample room to bulk up on the prevention efforts surrounding hospital-acquired anemia. They offered that reducing exposure to risks of acute anemia treatments such as blood transfusions, improving clinical outcomes and reducing costs could be some of the beneficial results seen from preventing cases of hospital-acquired anemia.

Additionally, because hospital-acquired anemia was associated with bleeding incidence, researchers suggest using radial artery access sites during PCI, include closure devices, smaller sheathes or the use of bivalirudin (Angiomax, Medicines Company) rather than unfractionated heparin.

“Further studies are needed to better define specific causes of hospital-acquired anemia, to develop the tools that can prospectively identify patients at high risk for hospital-acquired anemia at the time of admission, and to study the feasibility, comparative clinical effectiveness and cost effectiveness of various hospital-acquired anemia prevention strategies (such as reducing phlebotomy and the use of bleeding avoidance strategies), so that the most effective and least costly measures can be adopted,” the authors concluded.

“The first step in this process, however, is to raise awareness about the incidence and prognostic importance of hospital-acquired anemia, which is the main objective of our study.”