Association between red blood cell distribution width and the risk of future cardiovascular events

In patients with acute myocardial infarction (AMI), high red blood cell distribution width (RDW) seems to predict further cardiovascular events, although the mechanism and its possible relation with anaemia and inflammation remains uncertain. We determined in 119 AMI patients before hospital discharge RDW, along with haemoglobin, haematimetric indices and inflammatory parameters (fibrinogen, C-reactive protein, plasma viscosity, neutrophil count). In the follow-up period (21 ± 11 months), 30 patients (25%) developed a recurrent cardiovascular event. In the lineal regression analysis, MCH and neutrophil count were independent determinants for RDW (beta coefficient = -0.544 p < 0.001; beta coefficient: 0.279 p = 0.001, respectively). The logistic regression analysis showed that RDW >14% increases the risk of future events by 6 times; OR 6.19 IC 95% (2.1-18.5); even after adjusting for anaemia, mean corpuscular haemoglobin (MCH) <27 pg/L, fibrinogen >400 mg/dL and neutrophil count >5.7 (103/μL). Our results confirm that RDW, an available and inexpensive measurement reported in routine blood cell counts, seems to be an independent predictor for recurrent cardiovascular events in AMI patients. As we found no association of RDW with either anaemia or inflammatory parameters, the mechanism responsible for increased RDW deserves further research.