Acute cardiorenal anemia syndrome among ST-elevation myocardial infarction patients treated by primary percutaneous intervention

Background Acute kidney injury (AKI) and anemia have been extensively studied in ST-elevation myocardial infarction (STEMI), yet the precise nature of their reciprocal relationship has not been elucidated in STEMI patients. Methods We performed a retrospective analysis of 2096 consecutive patients admitted for STEMI between January 2008 and December 2018 and treated with primary coronary intervention. Patients were stratified into four groups according to the presence of baseline anemia and occurrence of AKI: without anemia or AKI, baseline anemia without AKI, AKI without baseline anemia and acute cardiorenal anemia syndrome (CRAS), defined as the occurrence of AKI in patients with baseline anemia. Patients' medical records were reviewed for in-hospital complications, 30-day and long-Term mortality. Results The mean age was 61 ± 13 years and 1682 patients (80%) were men. Ten percent of patients had baseline anemia without AKI, 7% had AKI without baseline anemia and 3% were classified as CRAS. We found increments between the four groups for occurrence of new onset atrial fibrillation and heart failure rates, presence of a critical state, and both 30-day and long-Term mortality (P < 0.001 for all). Logistic regression models demonstrated that as compared to AKI alone, CRAS was associated with a higher risk for long-Term mortality (HR 10.49; 95% CI 6.5-17.1) as compared to anemia (HR 3.32, 95% CI 2.1-5.2) and AKI (HR 7.71, 95% CI 5.1-11.7) alone (P < 0.001 for all). Conclusions Among STEMI patients, the interaction between anemia and AKI is associated with worse short and long-Term outcomes and reflects the reciprocity of cardiac and renal exacerbations.