Impact of hemoglobin levels at admission on outcomes among elderly patients with acute coronary syndrome treated with low-dose Prasugrel or clopidogrel: A sub-study of the ELDERLY ACS 2 trial.

ABSTRACT

Hemoglobin (Hb) levels have emerged as a useful tool for risk stratification and the prediction of outcome after myocardial infarction. We aimed at evaluating the prognostic impact of this parameter among patients in advanced age, where the larger prevalence of anemia and the higher rate of comorbidities could directly impact on the cardiovascular risk. METHODS: All the patients in the ELDERLY-2 trial, were included in this analysis and stratified according to the values of hemoglobin at admission. The primary endpoint of this study was cardiovascular mortality within one year. The secondary endpoints were all-cause mortality, MI, Bleeding Academic Research Consortium (BARC) type 2-3 or 5 bleeding, any stroke, re-hospitalization for cardiovascular event or stent thrombosis (probable or definite) within 12 months after index admission. RESULTS: We included in our analysis 1364 patients, divided in quartiles of Hb values (<12.2; 12.2-13.39; 13.44-14.49; ≥ 4.5 g/dl). At a mean follow- up of 330.4 ± 99.9 days cardiovascular mortality was increased in patients with lower Hb (HR[95%CI] = 0.76 [0.59-0.97], p = 0.03). Results were no more significant after correction for baseline differences (adjusted HR[95%CI] = 1.22 [0.41-3.6], p = 0.16). Similar results were observed for overall mortality. At subgroup analysis, (according to Hb median values) a significant interaction was observed only with the type of antiplatelet therapy, but not with major high-risk subsets of patients. CONCLUSIONS: Among elderly patients with acute coronary syndrome managed invasively, lower hemoglobin at admission is associated with higher cardiovascular and all-cause mortality and major ischemic events, mainly explained by the higher risk profile.