CONGRESS ABSTRACT

Introduction: Little is known on long-term mortality influence of blood levels of hemoglobin (Hb) after acute coronary syndrome (ACS). Methods: To assess the association between low Hb levels during hospitalization with ACS and the very long-term global mortality risk, we enrolled 571 patients admitted with ACS to 3 Italian hospitals and discharged alive. Patients were followed prospectively for 26 years or until death. Continuous variables were used as tertiles. Categorical ones were used as proportion. Survival analysis was set using Cox regression models. Results: All except for three patients completed the follow-up, representing 7091 person-years. Patients' mean age was 66±12 years, 30% were females. Baseline blood Hb levels were 13.5±0.8 g/dL (14.0±1.6 and 12.6±1.5 in male and female, respectively, p<0.0001). During follow-up, 483 patients (85%) died (all cause mortality). The incidence rate was 68 per 1000 person-years (60 and 97 for males and females, respectively). At univariable analysis, baseline Hb did not result associated to outcome (HR: 0.9; 95% CI: 0.8-1.0; z=-1.8; p=0.07). Even after age and gender adjustment, Hb was not associated to outcome (age: HR: 3.0; 95% CI: 2.6-3.4; z=16.0; p<0.0001; female gender: HR: 1.0; 95% CI: 0.8-1.2; z=-0.1; p=0.95). When, in the Cox model, a formal interaction term was set, Hb showed a positive association (HR: 1.5; 95% CI: 1.1-2.2; z=2.6; p=0.01), and a negative interaction with age (HR: 0.8; 95% CI: 0.7-0.9; z=-2.6; p=0.01) for global mortality. Results kept very similar even in the fully adjusted model. Conclusions: This very long-term prospective study suggests that younger patients with low blood Hb levels during acute coronary syndrome have higher global mortality risk in the long-term than elderly patients. This observation is independent from gender and other main clinical characteristics of the patients. Keywords: acute coronary syndrome; hemoglobin; global mortality risk.