Type of Anemia, Chronic Non-cardiovascular Illnesses and Outcomes of Patients with ST-segment Elevation Myocardial Infarction

Background: Anemia worsens prognosis after ST-segment elevation myocardial infarction (STEMI). However, the mechanisms of such association have not been elucidated.

Aim: To assess impact of different types of anemia and of concomitant non-cardiovascular chronic illnesses on outcomes of patients with STEMI and baseline anemia.

Methods: Based on the mean corpuscular volume (MCV), anemia was stratified into microcytic (

Results: Of 1,390 patients with STEMI, 294 patients had baseline anemia (21.2%), of whom normocytic, microcytic and macrocytic anemia was present in 77.2%, 17.0% and 5.8% patients, respectively. Initial strategy in most patients was reperfusion therapy (229/294; 77.9%) including 217 patients (73.8%) triaged to urgent coronary angiography and primary PCI. In-hospital bleeding occurred in 25 (8.5%) of the study population without significant differences between the groups. At a mean follow-up of 5.5±3.5 years, 104 patients (35.4%) died. Mortality was the highest in patients with macrocytic anemia followed by patients with normocytic anemia and microcytic anemia (58.8%, 37.0% and 20.0%, respectively; p=0.009). Independent predictors of long-term mortality included older age (Hazard ratio [HR] per 10 years increase=1.44; p=0.001), lower baseline hemoglobin (HR per 1g/dL decrease=0.75; p=0.004), atrial fibrillation (HR 3.50, p<0.0001), chronic non-cardiovascular condition (HR 1.54, p=0.019) and lower eGFR (HR per 10 mL/min/1.73m² decrease=0.89, p=0.015). Performance of coronary angiography within index hospitalization was associated with lower long-term mortality (HR 0.38, p=0.001). MCV did not predict either in-hospital bleeding or mortality.

Conclusions: Chronic non-cardiovascular illnesses are highly prevalent among patients with STEMI and baseline anemia, and are strongly associated with long-term mortality. Type of anemia is not related to prognosis post STEMI.