The blood of young adults remains hyperviscous for at least 3 months after acute myocardial infarction (AMI), according to a 2003 study by Caimi et al. The haemorheological pattern, or blood flow properties, of young adults who recently experienced a heart attack was compared to that of healthy controls. The influence of heart attack risk factors and the extent of coronary artery disease on these blood flow parameters was evaluated. Blood viscosity at high and low shear rates, plasma and serum viscosity, and red blood cell aggregation was studied in 64 subjects aged less than 46 years old with a recent heart attack. The subjects were subdivided based on their heart attack risk factors [(tobacco smoking, hypertension, diabetes, hypercholesterolemia, and family history of coronary artery disease), and when compared with control subjects, it was found that these risk factors had a significant influence on blood flow properties (p < 0.001). Among the heart attack subjects, low shear blood viscosity was greater in those with 3 or more risk factors (p < 0.05) and more than one stenosed coronary vessel (p < 0.05).
The heart attack group as a whole showed an increase in blood viscosity, a significant increase in plasma and serum viscosity, and a significant decrease in whole-blood filtration (p < 0.001 for all). The subjects were re-examined after three months, and results showed that blood viscosity was not significantly different from that of the first evaluation. These results indicate that in young subjects there is a hyperviscosity syndrome that persists during subsequent months after a heart attack, which may unfavorably influence the long-term prognosis of heart attacks in young adults.
Caimi G, Hoffmann E, Montana M, Canino B, Dispensa F, Catania A, and Lo Presti R. Haemorheological pattern in young adults with acute myocardial infraction. Clinical Hemorheology and Microcirculation. 2003.