Severe anemia associated with increased risk of death and myocardial ischemia in patients declining blood transfusion

Abstract

Background: There are limited data on morbidity and mortality in severely anemic patients for whom blood transfusion is not an option, with most data coming only from surgical patients and no data on the rate of myocardial ischemia associated with severe anemia. We sought to determine rates of all-cause mortality and myocardial ischemia in severely anemic hospitalized patients declining transfusion.

Study design and methods: With institutional review board approval, we conducted a retrospective review of all hospital admissions for adult blood refusal patients between January 2004 and September 2015 at a single institution. Severe anemia was defined as hemoglobin (Hb) level of not more than 8.0 g/dL at any time during hospital admission. Outcomes measured included all-cause mortality within 30 days of nadir Hb and myocardial ischemia as defined by abnormal troponin (>0.10 ng/mL). We studied the association of patient's nadir Hb with outcomes via multivariable repeated measures generalized estimating equations (GEEs).

Results: Of 1306 blood refusal patients with hospital admissions during the study period, 263 had at least one admission with Hb level of not more than 8.0 g/dL. The rate of all-cause mortality within 30 days was 19.8%, and the multivariable GEE model indicated a 55% increase in odds of mortality per 1 g/dL decrease in nadir Hb (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.25-1.91; p < 0.0001). Rate of myocardial ischemia was 10.5% and in the multivariable model risk increased with decreasing nadir Hb (per 1 g/dL decrease; OR, 1.42; 95% CI, 1.07-1.90; p = 0.016).

Conclusions: Severe anemia is associated with increased myocardial ischemia and mortality in patients declining transfusion, with risk increasing with decreasing nadir Hb.