Association of Hemoglobin Levels With Clinical Outcomes in Acute Coronary Syndromes

Abstract

Background— In the setting of an acute coronary syndrome (ACS), anemia has the potential to worsen myocardial ischemia; however, data relating anemia to clinical outcomes in ACS remain limited. Methods and Results— We examined the association between baseline hemoglobin values and major adverse cardiovascular events through 30 days in 39 922 patients enrolled in clinical trials of ACS. After adjustment for differences in baseline characteristics and index hospitalization treatments, a reverse J-shaped relationship between baseline hemoglobin values and major adverse cardiovascular events was observed. In patients with ST-elevation myocardial infarction, when those with hemoglobin values between 14 and 15 g/dL were used as the reference, cardiovascular mortality increased as hemoglobin levels fell below 14 g/dL, with an adjusted OR of 1.21 (95% CI 1.12 to 1.30, P <0.001) for each 1-g/dL decrement in hemoglobin. At the other end of the range of hemoglobin, patients with hemoglobin values >17 g/dL also had excess mortality (OR 1.79, 95% CI 1.18 to 2.71, P =0.007). In patients with non–ST-elevation ACS, with those with hemoglobin 15 to 16 g/dL used as the reference, the likelihood of cardiovascular death, myocardial infarction, or recurrent ischemia increased as the hemoglobin fell below 11 g/dL, with an adjusted OR of 1.45 (95% CI 1.33 to 1.58, P <0.001) for each 1 g/dL decrement in hemoglobin. Patients with hemoglobin values >16 g/dL also had an increased rate of death or ischemic events (OR 1.31, 95% CI 1.03 to 1.66, P =0.027). Conclusions— Anemia is a powerful and independent predictor of major adverse cardiovascular events in patients across the spectrum of ACS.

Hemoglobin Level Adds Prognostic Value to the Global Registry of Acute Coronary Events Score in Non-ST Elevation Acute Coronary Syndromes

“…This association remains significant after adjustment for other risk markers that could be related to anemia, such as age and renal impairment [3,12,13,14,15,16,17,18]. However, statistical significance in multivariate analysis is not a sufficient condition for a clinically relevant improvement in prognostic assessment.…”

“…Low hemoglobin has been established as an independent predictor of recurrent events [3]; however, it is not included in risk scores for ACS. Considering that hemoglobin values are widely available at admission, it is useful to evaluate whether this information should be considered within risk scores.…”

Impact of Hemoglobin Levels and Anemia on Mortality in Acute Stroke: Analysis of UK Regional Registry Data, Systematic Review, and Meta‐Analysis

“…Hospital‐based studies have reported prevalence up to ≈30% 1, 2. Although anemia has been independently associated with increased mortality in a variety of conditions including chronic kidney disease,3 heart failure,4 and acute coronary syndromes,5 observational studies investigating the association between anemia and mortality in stroke have shown conflicting results. Early studies found no association between anemia and stroke outcomes6, 7; however, others have found both low and high hemoglobin levels to be associated with increased mortality,8, 9, 10 suggesting a U‐shaped relationship.…”

Prognostic Impact of Chronic Kidney Disease and Anemia at Admission on In-Hospital Outcomes After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

“…[1][2][3][4][5][6] On the other hand, cardiorenal anemia syndrome, in which the simultaneous presence of CKD, anemia, and heart failure creates pathological reciprocal connections, thereby resulting in an adverse synergistic impact on morbidity and mortality, is now attracting more attention. 7,8) However, few data are available concerning the impact of CKD and anemia on clinical outcomes among AMI patients undergoing primary percutaneous coronary intervention (PCI) in Japan, 9,10) and in terms of CKD concomitant with anemia, only the recent report from Matsue and colleagues has examined the longterm prognostic impact of CKD/anemia combination after hospital discharge in Japanese AMI patients.…”