ABSTRACT
Anemia is an independent risk factor for adverse cardiovascular outcomes in patients with myocardial infarction [MI]. On the other hand, elevated Hct and Hgb level are associated with increased risk of MI. We sought to investigate whether increase or decrease of the hemoglobin level [Hgb] and the hematocrit [Hct] was an independent predictor for occurrence of acute coronary syndrome [ACS]. This retrospective case-control study included 594 MI patients, 596 unstable angina [UA] patients, and 590 controls who were hospitalized between 1994 and 2005. Patients were analyzed according to the baseline Hgb and Hct value. Prevalence of MI, based on Hgb and Hct in anemic patients was 17.9% and 14.0% and in patients with high level of normal range was 8.8% and 20.2%, respectively. Mean of Hgb and Hct concentration in patients with MI were [men: 14.79 +/- 1.94; women: 13.32 +/- 1.96] and [men: 44.90 +/- 5.63; women: 40.90 +/- 5.67], respectively. Mean differences of Hgb and Hct between MI patients, UA patients, and controls were significant only in men. A logistic regression between MI patients and controls showed that the odds ratio [OR] and 95%CI of MI for patients with low vs high Hgb and MCV were 0.215 [0.112-0.412] and 0.368 [0.243-0.558], respectively. The OR of MI for male vs female was 2.325 [1.749-3.090]. In MI and UA patients, anemia was an independent predictor of occurrence of ACS based on Hgb; while, based on Hct, both anemia and high Hct were predictors of occurrence of MI. Anemia was a predictor of occurrence of MI with age